WorldWideScience

Sample records for reinforced resin matrix

  1. Damage analysis of fiber reinforced resin matrix composites irradiated by CW laser

    International Nuclear Information System (INIS)

    Wan Hong; Hu Kaiwei; Mu Jingyang; Bai Shuxin

    2008-01-01

    In this paper, the damage modes of the carbon fiber and the glass fiber reinforced epoxy or bakelite resin matrix composites irradiated by CW laser under different power densities were analyzed, and the changes of the microstructure and the tensile strength of the composites were also researched. When the resin matrix composites were radiated at a power density more than 0.1 kW/cm 2 , the matrix would be decomposed and the tensile properties of the radiated samples were lost over 30% while the carbon fiber hardly damaged and the glass fiber melted. When the power density of the laser was raised to 1 kW/cm 2 , the matrix burned violently and the carbon fiber cloth began to split with some carbon fiber being fractured, therefore, the fracture strength of the radiated sample lost over 80%. The higher the power density of radiation was, the more serious the damage of the sample was. It was also found that the difference of the matrixes had little effect on the damage extent of the composites. The influence of the radiation density on the temperature of the radiated surface of the carbon/resin composite was numerically calculated by ANSYS finite element software and the calculation results coincided with the damage mode of the radiated composites. (authors)

  2. Effect of γ irradiation on the properties of basalt fiber reinforced epoxy resin matrix composite

    International Nuclear Information System (INIS)

    Li, Ran; Gu, Yizhuo; Yang, Zhongjia; Li, Min; Wang, Shaokai; Zhang, Zuoguang

    2015-01-01

    Gamma-ray (γ-ray) irradiation is a crucial reason for the aging in materials used for nuclear industry. Due to high specific strength and stiffness, light weight and good corrosion resistance, fiber reinforced composites are regarded as an alternative of traditional materials used on nuclear facilities. In this study, basalt fiber (BF)/AG80 epoxy composite laminates were fabricated by autoclave process and treated with "6"0Co gamma irradiation dose up to 2.0 MGy. Irradiation induced polymer chain scission and oxidation of AG80 resin were detected from physical and chemical analysis. The experimental results show that the tensile and flexural performances of irradiated BF/AG80 composite maintain stable and have a low amplitude attenuation respectively, and the interlaminar shear strength has increased from irradiation dose of 0–1.5 MGy. Furthermore, the comparison between the studied BF composite and reported polymer and composite materials was done for evaluating the γ resistance property of BF composite. - Highlights: • The properties of basalt fiber reinforced epoxy resin matrix composite under "6"0Co γ irradiation up to 2.0 MGy were studied. • Basalt fiber can weaken the aging effects of γ irradiation on the resin matrix. • Tensile property of basalt fiber composite remains stable and flexural property has a low degree of attenuation. • Basalt fiber composite is an ideal candidate of structural material for nuclear industry.

  3. Effect of epoxy coatings on carbon fibers during manufacture of carbon fiber reinforced resin matrix composites

    International Nuclear Information System (INIS)

    Guo, Hui; Huang, Yudong; Liu, Li; Shi, Xiaohua

    2010-01-01

    The changes in oxygen and nitrogen during manufacture of the carbon fiber reinforced resin matrix composites were measured using the X-ray photoelectron spectroscopy method. The effects of the change in oxygen and nitrogen on the strength of the carbon fibers were investigated and the results revealed that the change of the tensile strength with increasing heat curing temperature was attributed to the change in the surface flaws of the carbon fibers because the carbon fibers are sensitive to the surface flaws. The effect of the surface energy that was calculated using Kaelble's method on the strength of the carbon fibers was investigated. Furthermore, the surface roughness of the carbon fibers was measured using atom force microscopy. The change trend of roughness was reverse to that of the strength, which was because of the brittle fracture of the carbon fibers.

  4. Optimal Design for Hybrid Ratio of Carbon/Basalt Hybrid Fiber Reinforced Resin Matrix Composites

    Directory of Open Access Journals (Sweden)

    XU Hong

    2017-08-01

    Full Text Available The optimum hybrid ratio range of carbon/basalt hybrid fiber reinforced resin composites was studied. Hybrid fiber composites with nine different hybrid ratios were prepared before tensile test.According to the structural features of plain weave, the unit cell's performance parameters were calculated. Finite element model was established by using SHELL181 in ANSYS. The simulated values of the sample stiffness in the model were approximately similar to the experimental ones. The stress nephogram shows that there is a critical hybrid ratio which divides the failure mechanism of HFRP into single failure state and multiple failure state. The tensile modulus, strength and limit tensile strain of HFRP with 45% resin are simulated by finite element method. The result shows that the tensile modulus of HFRP with 60% hybrid ratio increases by 93.4% compared with basalt fiber composites (BFRP, and the limit tensile strain increases by 11.3% compared with carbon fiber composites(CFRP.

  5. Effect of γ irradiation on the properties of basalt fiber reinforced epoxy resin matrix composite

    Science.gov (United States)

    Li, Ran; Gu, Yizhuo; Yang, Zhongjia; Li, Min; Wang, Shaokai; Zhang, Zuoguang

    2015-11-01

    Gamma-ray (γ-ray) irradiation is a crucial reason for the aging in materials used for nuclear industry. Due to high specific strength and stiffness, light weight and good corrosion resistance, fiber reinforced composites are regarded as an alternative of traditional materials used on nuclear facilities. In this study, basalt fiber (BF)/AG80 epoxy composite laminates were fabricated by autoclave process and treated with 60Co gamma irradiation dose up to 2.0 MGy. Irradiation induced polymer chain scission and oxidation of AG80 resin were detected from physical and chemical analysis. The experimental results show that the tensile and flexural performances of irradiated BF/AG80 composite maintain stable and have a low amplitude attenuation respectively, and the interlaminar shear strength has increased from irradiation dose of 0-1.5 MGy. Furthermore, the comparison between the studied BF composite and reported polymer and composite materials was done for evaluating the γ resistance property of BF composite.

  6. Low Cost Resin for Self-Healing High Temperature Fiber Reinforced Polymer Matrix Composites, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Over the past few decades, the manufacturing processes and our knowledge base for predicting the bulk mechanical response of fiber reinforced composite materials has...

  7. Low pressure process for continuous fiber reinforced polyamic acid resin matrix composite laminates

    Science.gov (United States)

    Druyun, Darleen A. (Inventor); Hou, Tan-Hung (Inventor); Kidder, Paul W. (Inventor); Reddy, Rakasi M. (Inventor); Baucom, Robert M. (Inventor)

    1994-01-01

    A low pressure processor was developed for preparing a well-consolidated polyimide composite laminate. Prepreg plies were formed from unidirectional fibers and a polyamic acid resin solution. Molding stops were placed at the sides of a matched metal die mold. The prepreg plies were cut shorter than the length of the mold in the in-plane lateral direction and were stacked between the molding stops to a height which was higher than the molding stops. The plies were then compressed to the height of the stops and heated to allow the volatiles to escape and to start the imidization reaction. After removing the stops from the mold, the heat was increased and 0 - 500 psi was applied to complete the imidization reaction. The heat and pressure were further increased to form a consolidated polyimide composite laminate.

  8. Mechanical and fracture properties of R-glass reinforced composites with pyrolysed polysiloxane resin as a matrix

    Czech Academy of Sciences Publication Activity Database

    Černý, Martin; Bednářová, D.; Glogar, Petr; Dusza, J.; Rudnayová, E.

    2005-01-01

    Roč. 290, - (2005), s. 344-347 ISSN 1013-9826. [International conference on fractography of advanced ceramics /2./. Stará Lesná, 03.10.2005-06.10.2005] R&D Projects: GA AV ČR(CZ) KSK2067107; GA ČR GA106/02/0177 Institutional research plan: CEZ:AV0Z30460519 Keywords : unidirectional composite * glass fiber reinforcement * pyrolysed polysiloxane resins Subject RIV: JH - Ceramics, Fire-Resistant Materials and Glass Impact factor: 0.224, year: 2005

  9. Cure Cycle Design Methodology for Fabricating Reactive Resin Matrix Fiber Reinforced Composites: A Protocol for Producing Void-free Quality Laminates

    Science.gov (United States)

    Hou, Tan-Hung

    2014-01-01

    For the fabrication of resin matrix fiber reinforced composite laminates, a workable cure cycle (i.e., temperature and pressure profiles as a function of processing time) is needed and is critical for achieving void-free laminate consolidation. Design of such a cure cycle is not trivial, especially when dealing with reactive matrix resins. An empirical "trial and error" approach has been used as common practice in the composite industry. Such an approach is not only costly, but also ineffective at establishing the optimal processing conditions for a specific resin/fiber composite system. In this report, a rational "processing science" based approach is established, and a universal cure cycle design protocol is proposed. Following this protocol, a workable and optimal cure cycle can be readily and rationally designed for most reactive resin systems in a cost effective way. This design protocol has been validated through experimental studies of several reactive polyimide composites for a wide spectrum of usage that has been documented in the previous publications.

  10. Fabrication and characterization of high impact hybrid matrix composites from thermoset resin and dyneema-glass fabric reinforcement

    Science.gov (United States)

    Patel, R. H.; Sharma, S.; Pansuriya, T.; Malgani, E. V.; Sevkani, V.

    2018-05-01

    Hybrid composites have been fabricated by hand lay-up technique with epoxy resin and diethylene tri amine as a hardener for high impact energy absorption with sandwich stacking of different reinforcements of dyneema and glass fabric. High impact grade composites are nowadays gaining a lot of importance in the field of high mechanical load bearing applications, ballistics and bulletproofing. The present work emphases on the fabrication and mechanical properties of the hybrid composites of cut resistant dyneema fabric along with glass fabric reinforced in the thermosetting resin. i.e. epoxy. The prime importance while fabricating such materials have been given to the processing along with selection of the raw materials. High impact resistive materials with low density and henceforth low weight have been manufactured and characterized by IZOD impact tester, UTM, Archimedes density meter and SEM. Throughout the work, satisfactory results have been obtained. Impact resistance was observed to be boosted three times as that of the reference sample of glass fabric and epoxy. The density of the hybrid composite is observed to be 25% as that of the reference sample.

  11. Ceramic matrix and resin matrix composites - A comparison

    Science.gov (United States)

    Hurwitz, Frances I.

    1987-01-01

    The underlying theory of continuous fiber reinforcement of ceramic matrix and resin matrix composites, their fabrication, microstructure, physical and mechanical properties are contrasted. The growing use of organometallic polymers as precursors to ceramic matrices is discussed as a means of providing low temperature processing capability without the fiber degradation encountered with more conventional ceramic processing techniques. Examples of ceramic matrix composites derived from particulate-filled, high char yield polymers and silsesquioxane precursors are provided.

  12. Ceramic matrix and resin matrix composites: A comparison

    Science.gov (United States)

    Hurwitz, Frances I.

    1987-01-01

    The underlying theory of continuous fiber reinforcement of ceramic matrix and resin matrix composites, their fabrication, microstructure, physical and mechanical properties are contrasted. The growing use of organometallic polymers as precursors to ceramic matrices is discussed as a means of providing low temperature processing capability without the fiber degradation encountered with more conventional ceramic processing techniques. Examples of ceramic matrix composites derived from particulate-filled, high char yield polymers and silsesquioxane precursors are provided.

  13. Fiber-reinforced Composite Resin Prosthesis to Restore Missing ...

    African Journals Online (AJOL)

    A fiber-reinforced composite inlay-onlay FPD was used for a single posterior tooth replacement in a patient refusing implant for psychological reasons. The FRC-FPD was made of pre-impregnated E-glass fibers (everStick, StickTeck, Turku, Finland) embedded in a resin matrix (Stick Resin, StickTeck, Turku, Finland).

  14. Long-Term Durability of Basalt Fiber-Reinforced Polymer (BFRP Sheets and the Epoxy Resin Matrix under a Wet–Dry Cyclic Condition in a Chloride-Containing Environment

    Directory of Open Access Journals (Sweden)

    Zhongyu Lu

    2017-11-01

    Full Text Available Basalt fiber-reinforced polymer (BFRP composites are receiving increasing attention as they represent a low-cost green source of raw materials. FRP composites have to face harsh environments, such as chloride ions in coastal marine environments or cold regions with salt deicing. The resistance of FRPs subjected to the above environments is critical for the safe design and application of BFRP composites. In the present paper, the long-term durability of BFRP sheets and the epoxy resin matrix in a wet–dry cyclic environment containing chloride ions was studied. The specimens of the BFRP sheet and epoxy resin matrix were exposed to alternative conditions of 8-h immersion in 3.5% NaCl solution at 40 °C and 16-h drying at 25 °C and 60% relative humidity (RH. The specimens were removed from the exposure chamber at the end of the 180th, 270th and 360th cycles of exposure and were analyzed for degradation with tensile tests, scanning electron microscopy (SEM and void volume fractions. It was found that the tensile modulus of the BFRP sheet increased by 3.4%, and the tensile strength and ultimate strain decreased by 45% and 65%, respectively, after the 360th cycle of exposure. For the epoxy resin matrix, the tensile strength, tensile modulus and ultimate strain decreased by 27.8%, 3.2% and 64.8% after the 360th cycle of exposure, respectively. The results indicated that the degradation of the BFRP sheet was dominated by the damage of the interface between the basalt fiber and epoxy resin matrix. In addition, salt precipitate accelerated the fiber–matrix interfacial debonding, and hydrolysis of the epoxy resin matrix resulted in many voids, which accelerated the degradation of the BFRP sheet.

  15. Characterization of selected LDEF polymer matrix resin composite materials

    Science.gov (United States)

    Young, Philip R.; Slemp, Wayne S.; Witte, William G., Jr.; Shen, James Y.

    1991-01-01

    The characterization of selected graphite fiber reinforced epoxy (934 and 5208) and polysulfone (P1700) matrix resin composite materials which received 5 years and 10 months of exposure to the LEO environment on the Long Duration Exposure Facility is reported. Resin loss and a decrease in mechanical performance as well as dramatic visual effects were observed. However, chemical characterization including infrared, thermal, and selected solution property measurements showed that the molecular structure of the polymeric matrix had not changed significantly in response to this exposure. The potential effect of a silicon-containing molecular contamination of these specimens is addressed.

  16. UV curing silicon-containing epoxy resin and its glass cloth reinforced composites

    International Nuclear Information System (INIS)

    Yang Guang; Tang Zhuo; Huang Pengcheng

    2007-01-01

    A UV-curable cationic silicon-containing epoxy resin formulation was developed. The gel conversion of the cured resin after 10-min UV irradiation reached 80% in the presence of 5% diaryliodonium salt photoinitiator and 5.5% polyol chain transfer agent by cationic ring-opening polymerization. The glass cloth-reinforced composites were fabricated with the silicon-containing epoxy resin using the wet lay-up technique and UV irradiation. The mechanical properties of the composites were evaluated. Compared with glass cloth reinforced bisphenol A epoxy resin matrix composites, the silicon-containing epoxy resin matrix composites possessed higher tensile strength and interlayer shear strength which was 158.5MPa and 9.9MPa respectively while other mechanical properties such as flexural property and tensile modulus were similar. (authors)

  17. Rheological characterization of addition polyimide matrix resins and prepregs

    Science.gov (United States)

    Maximovich, M. G.; Galeos, R. M.

    1984-01-01

    Although graphite-reinforced polyimide matrix composites offer outstanding specific strength and stiffness, together with high thermal oxidative stability, processing problems connected with their rheological behavior remain to be addressed. The present rheological studies on neat polyimide resin systems encountered outgassing during cure. A staging technique has been developed which can successfully handle polyimide samples, and novel methods were applied to generate rheological curves for graphite-reinforced prepregs. The commercial graphite/polyimide systems studied were PRM 15, LARC 160, and V378A.

  18. Characterization of Polyimide Matrix Resins and Prepregs

    Science.gov (United States)

    Maximovich, M. G.; Galeos, R. M.

    1985-01-01

    Graphite/polyimide composite materials are attractive candidates for a wide range of aerospace applications. They have many of the virtues of graphite/epoxies, i.e., high specific strengths and stiffness, and also outstanding thermal/oxidative stability. Yet they are not widely used in the aerospace industry due to problems of procesability. By their nature, modern addition polyimide (PI) resins and prepregs are more complex than epoxies; the key to processing lies in characterizing and understanding the materials. Chemical and rheological characterizations are carried out on several addition polyimide resins and graphite reinforced prepregs, including those based on PMR-15, LARC 160 (AP 22), LARC 160 (Curithane 103) and V378A. The use of a high range torque transducer with a Rheometrics mechanical spectrometer allows rheological data to be generated on prepreg materials as well as neat resins. The use of prepreg samples instead of neat resins eliminates the need for preimidization of the samples and the data correlates well with processing behavior found in the shop. Rheological characterization of the resins and prepregs finds significant differences not readily detected by conventional chemical characterization techniques.

  19. Thermal and mechanical behaviour of sub micron sized fly ash reinforced polyester resin composite

    Science.gov (United States)

    Nantha Kumar, P.; Rajadurai, A.; Muthuramalingam, T.

    2018-04-01

    The utilization of particles reinforced resin matrix composites is being increased owing to its lower density and high strength to weight ratio. In the present study, an attempt has been made to synthesize fly ash particles reinforced polyester resin composite for engine cowling application. The thermal stability and mechanical behaviours such as hardness and flexural strength of the composite with 2, 3 and 4 weight % of reinforcement is studied and analyzed. The thermo gravimetric analysis indicates that the higher addition of reinforcement increases the decomposition temperature due to its refractory nature. It is also observed that the hardness increases with higher filler addition owing to the resistance of FA particles towards penetration. The flexural strength is found to increase up to the addition of 3% of FA particles, whereas the polyester resin composite prepared with 4% FA particles addition is observed to have low flexural strength owing to agglomeration of particles.

  20. Processable polyimide adhesive and matrix composite resin

    Science.gov (United States)

    Pratt, J. Richard (Inventor); St.clair, Terry L. (Inventor); Progar, Donald J. (Inventor)

    1990-01-01

    A high temperature polyimide composition prepared by reacting 4,4'-isophthaloyldiphthalic anhydride with metaphenylenediamine is employed to prepare matrix resins, adhesives, films, coatings, moldings, and laminates, especially those showing enhanced flow with retention of mechanical and adhesive properties. It can be used in the aerospace industry, for example, in joining metals to metals or metals to composite structures. One area of application is in the manufacture of lighter and stronger aircraft and spacecraft structures.

  1. Synthesis of Y2O3-ZrO2-SiO2 composite coatings on carbon fiber reinforced resin matrix composite by an electro-plasma process

    Science.gov (United States)

    Zhang, Yuping; Lin, Xiang; Chen, Weiwei; Cheng, Huanwu; Wang, Lu

    2016-05-01

    In the present paper the Y2O3-ZrO2-SiO2 composite coating was successfully synthesized on carbon fiber reinforced resin matrix composite by an electro-plasma process. The deposition process, microstructures and oxidation resistance of the coatings with different SiO2 concentrations were systematically investigated. A relatively dense microstructure was observed for the Y2O3-ZrO2-SiO2 composite coating with the SiO2 concentration above 5 g/L. The coating exhibited very good oxidation resistance at 1273 K with the mass loss rate as low as ∼30 wt.%, compared to 100 wt.% of the substrate. The formation of the ceramic composites was discussed in detail based on the electrochemical mechanism and the deposition dynamics in order to explain the effect of the plasma discharge. We believe that the electro-plasma process will find wide applications in preparing ceramics and coatings in industries.

  2. Development of new and improved polymer matrix resin systems, phase 1

    Science.gov (United States)

    Hsu, M. S.

    1983-01-01

    Vinystilbazole (vinylstryrylpyridine) and vinylpolystyrulpyridine were prepared for the purpose of modifying bismaleimide composite resins. Cure studies of resins systems were investigated by differential scanning calorimetry. The vinylstyrylpyridine-modified bismaleimide composite resins were found to have lower cure and gel temperatures, and shorter cure times than the corresponding unmodified composite resins. The resin systems were reinforced with commercially avialable satin-weave carbon cloth. Prepregs were fabricated by solvent or hot melt techniques. Thermal stability, flammability, moisture absorption, and mechanical properties of the composites (such as flexural strength, modulus, tensile and short beam shear strength) were determined. Composite laminates showed substantial improvements in both processability and mechanical properties compared to he bismaleimide control systems. The vinylstyrylpyridine modified bismaleimide resins can be used as advanced matrix resins for graphite secondary structures where ease of processing, fireworthiness, and high temperature stability are required for aerospace applications.

  3. Influence of Coating with Some Natural Based Materials on the Erosion Wear Behavior of Glass Fiber Reinforced Epoxy Resin

    OpenAIRE

    Aseel Basim Abdul Hussein; Emad Saadi AL-Hassani; Reem Alaa Mohamed

    2015-01-01

    In the present study, composites were prepared by Hand lay-up molding. The composites constituents were epoxy resin as a matrix, 6% volume fractions of glass fibers (G.F) as reinforcement and 3%, 6% volume fractions of preparation natural material (Rice Husk Ash, Carrot Powder, and Sawdust) as filler. Studied the erosion wear behavior and coating by natural wastes (Rice Husk Ash) with epoxy resin after erosion. The results showed the non – reinforced epoxy have lower resistance erosion than n...

  4. Experimental Study on Fibre-reinforced Cementitious Matrix Confined Concrete Columns under Axial Compression

    Directory of Open Access Journals (Sweden)

    Lan Zeng

    2017-03-01

    Full Text Available Poor fire resistance of fibre-reinforced polymer (FRP restricts its further application in construction structures. In this paper, a novel fibre-reinforced cementitious matrix confined concrete column (FRCMCC using fireproof grout as the fibre matrix was developed, and experiments were conducted to establish its performance and analyse the mechanical properties under axial compression. The test results show that its failure mode was more moderate compared to the traditional fibre-reinforced resinous matrix confined concrete column (FRRMCC, and the concrete columns confined with multi-layer fibres and end reinforcement could provide both good strength and ductility.

  5. Properties of discontinuous S2-glass fiber-particulate-reinforced resin composites with two different fiber length distributions.

    Science.gov (United States)

    Huang, Qiting; Garoushi, Sufyan; Lin, Zhengmei; He, Jingwei; Qin, Wei; Liu, Fang; Vallittu, Pekka Kalevi; Lassila, Lippo Veli Juhana

    2017-10-01

    To investigate the reinforcing efficiency and light curing properties of discontinuous S2-glass fiber-particulate reinforced resin composite and to examine length distribution of discontinuous S2-glass fibers after a mixing process into resin composite. Experimental S2-glass fiber-particulate reinforced resin composites were prepared by mixing 10wt% of discontinuous S2-glass fibers, which had been manually cut into two different lengths (1.5 and 3.0mm), with various weight ratios of dimethacrylate based resin matrix and silaned BaAlSiO 2 filler particulates. The resin composite made with 25wt% of UDMA/SR833s resin system and 75wt% of silaned BaAlSiO 2 filler particulates was used as control composite which had similar composition as the commonly used resin composites. Flexural strength (FS), flexural modulus (FM) and work of fracture (WOF) were measured. Fractured specimens were observed by scanning electron microscopy. Double bond conversion (DC) and fiber length distribution were also studied. Reinforcement of resin composites with discontinuous S2-glass fibers can significantly increase the FS, FM and WOF of resin composites over the control. The fibers from the mixed resin composites showed great variation in final fiber length. The mean aspect ratio of experimental composites containing 62.5wt% of particulate fillers and 10wt% of 1.5 or 3.0mm cutting S2-glass fibers was 70 and 132, respectively. No difference was found in DC between resin composites containing S2-glass fibers with two different cutting lengths. Discontinuous S2-glass fibers can effectively reinforce the particulate-filled resin composite and thus may be potential to manufacture resin composites for high-stress bearing application. Copyright © 2017. Published by Elsevier Ltd.

  6. Preparation and characterisation of poly p-phenylene-2,6-benzobisoxazole fibre-reinforced resin matrix composite for endodontic post material: a preliminary study.

    Science.gov (United States)

    Hu, Chen; Wang, Feng; Yang, Huiyong; Ai, Jun; Wang, Linlin; Jing, Dongdong; Shao, Longquan; Zhou, Xingui

    2014-12-01

    Currently used fibre-reinforced composite (FRC) intracanal posts possess low flexural strength which usually causes post fracture when restoring teeth with extensive loss. To improve the flexural strength of FRC, we aimed to apply a high-performance fibre, poly p-phenylene-2, 6-benzobisoxazole (PBO), to FRCs to develop a new intracanal post material. To improve the interfacial adhesion strength, the PBO fibre was treated with coupling agent (Z-6040), argon plasma, or a combination of above two methods. The effects of the surface modifications on PBO fibre were characterised by determining the single fibre tensile strength and interfacial shear strength (IFSS). The mechanical properties of PBO FRCs were characterised by flexural strength and flexural modulus. The cytotoxicity of PBO FRC was evaluated by the MTT assay. Fibres treated with a combination of Z-6040 and argon plasma possessed a significantly higher IFSS than untreated fibres. Fibre treated with the combination of Z-6040-argon-plasma FRC had the best flexural strength (531.51 ± 26.43MPa) among all treated fibre FRCs and had sufficient flexural strength and appropriate flexural moduli to be used as intracanal post material. Furthermore, an in vitro cytotoxicity assay confirmed that PBO FRCs possessed an acceptable level of cytotoxicity. In summary, our study verified the feasibility of using PBO FRC composites as new intracanal post material. Although the mechanical property of PBO FRC still has room for improvement, our study provides a new avenue for intracanal post material development in the future. To our knowledge, this is the first study to verify the feasibility of using PBO FRC composites as new intracanal post material. Our study provided a new option for intracanal post material development. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. Impact fatigue behaviour of carbon fibre-reinforced vinylester resin

    Indian Academy of Sciences (India)

    Two types of unidirectional carbon fibre, one of high strength (DHMS) and another of medium strength (VLMS) reinforced vinylester resin composites have been examined for their impact fatigue behaviour over 104 impact cycles for the first time. The study was conducted using a pendulum type repeated impact apparatus ...

  8. Impact fatigue behaviour of carbon fibre-reinforced vinylester resin ...

    Indian Academy of Sciences (India)

    Unknown

    Abstract. Two types of unidirectional carbon fibre, one of high strength (DHMS) and another of medium strength (VLMS) reinforced vinylester resin composites have been examined for their impact fatigue behaviour over 104 impact cycles for the first time. The study was conducted using a pendulum type repeated impact.

  9. Fiber reinforced silicon-containing arylacetylene resin composites

    Directory of Open Access Journals (Sweden)

    2007-12-01

    Full Text Available A silicon-containing arylacetylene resin (SAR, a poly(dimethylsilyleneethynylene phenyleneethynylene (PMSEPE, was synthesized. The PMSEPE is a solid resin at ambient temperature with a softening temperature about 60°C and soluble in some solvents like tetrahydrofuran. The melt viscosity of the PMSEPE resin is less than 1 Pa•s. The resin could cure at the temperature of lower than 200°C. Fiber reinforced PMSEPE composites were prepared from prepregs which were made by the impregnation of fibers in PMSEPE resin solution. The composites exhibit good mechanical properties at room temperature and 250°C. The observation on fracture surfaces of the composites reinforced by glass fibers and carbon fibers demonstrates that the adhesion between the fibers and resin is good. The results from an oxyacetylene flame test show that the composites have good ablation performance and XRD analyses indicate that SiC forms in the residues during the ablation of the composites.

  10. Physicochemical properties of discontinuous S2-glass fiber reinforced resin composite.

    Science.gov (United States)

    Huang, Qiting; Qin, Wei; Garoushi, Sufyan; He, Jingwei; Lin, Zhengmei; Liu, Fang; Vallittu, Pekka K; Lassila, Lippo V J

    2018-01-30

    The objective of this study was to investigate several physicochemical properties of an experimental discontinuous S2-glass fiber-reinforced resin composite. The experimental composite was prepared by mixing 10 wt% of discontinuous S2-glass fibers with 27.5 wt% of resin matrix and 62.5 wt% of particulate fillers. Flexural strength (FS) and modulus (FM), fracture toughness (FT), work of fracture (WOF), double bond conversion (DC), Vickers hardness, volume shrinkage (VS) and fiber length distribution were determined. These were compared with two commercial resin composites. The experimental composite showed the highest FS, WOF and FT compared with two control composites. The DC of the experimental composite was comparable with controls. No significant difference was observed in VS between the three tested composites. The use of discontinuous glass fiber fillers with polymer matrix and particulate fillers yielded improved physical properties and substantial improvement was associated with the use of S2-glass fiber.

  11. Synthesis and Characterization of Pine Needles Reinforced RF Matrix Based Biocomposites

    Directory of Open Access Journals (Sweden)

    A. S. Singha

    2008-01-01

    Full Text Available Synthesis and characterization of pine needles reinforced thermosetting resin (Resorcinol-Formaldehyde which is most suitable as composite matrix has been reported. The polycondensation reaction between resorcinol and formaldehyde (RF in different molar ratios has been applied to the synthesis of RF polymer matrix. A thermosetting resin based composite, containing approximately 10, 20, 30 and 40% of natural fiber by weight, has been obtained by adding pine needles to the Resorcinol-Formaldehyde (RF resin. The mechanical properties of randomly oriented intimately mixed particle reinforced (Pine needles composites were determined. Effect of fiber loading in terms of weight % on mechanical properties such as tensile, compressive, and flexural and wear properties have also been evaluated. The reinforcing of the resin with Pine needles was accomplished in particle size of 200 micron by employing optimized resin. Present work reveals that mechanical properties of the RF resin increases to extensive extent when reinforced with Pine needles. Thermal (TGA/DTA and morphological studies (SEM of the resin, fiber and polymer composites thus synthesized have also been carried out.

  12. Piezoelectric ceramic-reinforced metal matrix composites

    OpenAIRE

    2004-01-01

    Composite materials comprising piezoelectric ceramic particulates dispersed in a metal matrix are capable of vibration damping. When the piezoelectric ceramic particulates are subjected to strain, such as the strain experienced during vibration of the material, they generate an electrical voltage that is converted into Joule heat in the surrounding metal matrix, thereby dissipating the vibrational energy. The piezoelectric ceramic particulates may also act as reinforcements to improve the mec...

  13. Spray pond piping made from fiberglass-reinforced thermosetting resin

    International Nuclear Information System (INIS)

    Anon.

    1979-01-01

    A method is presented for implementing requirements pertaining to the design, fabrication, and testing of fiberglass-reinforced thermosetting resin piping for spray pond applications. These requirements are given in 10 CFR Part 50, Section 50.55a and Apppendix A, Criterion 1. This guide applies to both light-water-cooled and gas-cooled reactors. Input has been provided by the Advisory Committee on Reactor Safeguards

  14. Mechanical and thermal properties of phthalonitrile resin reinforced with silicon carbide particles

    International Nuclear Information System (INIS)

    Derradji, Mehdi; Ramdani, Noureddine; Zhang, Tong; Wang, Jun; Feng, Tian-tian; Wang, Hui; Liu, Wen-bin

    2015-01-01

    Highlights: • SiC microparticles improve the mechanical properties of phthalonitrile resin. • Excellent thermal stability achieved by adding SiC particles in phthalonitrile resin. • Adding 20 wt.% of SiC microparticles increases the T g by 38 °C. • Silane coupling agent can enhance the adhesion and dispersion of particles/matrix. - Abstract: A new type of composite based on phthalonitrile resin reinforced with silicon carbide (SiC) microparticles was prepared. For various weight ratios ranging between 0% and 20%, the effect of the micro-SiC particles on the mechanical and thermal properties has been studied. Results from thermal analysis revealed that the starting decomposition temperature and the residual weight were significantly improved upon adding the reinforcing phase. At the maximum micro-SiC loading, dynamic mechanical analysis (DMA) showed an important enhancement in both the storage modulus and glass transition temperature (T g ), reaching 3.1 GPa and 338 °C, respectively. The flexural strength and modulus as well as the microhardness were significantly enhanced by adding the microfillers. Tensile test revealed enhancements in the composites toughness upon adding the microparticles. Polarization optical microscope (POM) and scanning electron microscope (SEM) analysis confirmed that mechanical and thermal properties improvements are essentially attributed to the good dispersion and adhesion between the particles and the resin

  15. Ferroelastic ceramic-reinforced metal matrix composites

    OpenAIRE

    2006-01-01

    Composite materials comprising ferroelastic ceramic particulates dispersed in a metal matrix are capable of vibration damping. When the ferroelastic ceramic particulates are subjected to stress, such as the cyclic stress experienced during vibration of the material, internal stresses in the ceramic cause the material to deform via twinning, domain rotation or domain motion thereby dissipating the vibrational energy. The ferroelastic ceramic particulates may also act as reinforcements to impro...

  16. Annealing effects of carbon fiber-reinforced epoxy resin composites irradiated by electron beams

    International Nuclear Information System (INIS)

    Udagawa, Akira; Sasuga, Tuneo; Ito, Hiroshi; Hagiwara, Miyuki

    1987-01-01

    Carbon cloth-reinforced epoxy resin composites were irradiated with 2 MeV electrons at room temperature and then annealed in air for 2 h at temperatures up to 180 deg C. A considerable decrease in the three-point bending strength occurred when the irradiated composites were annealed in the temperature range of 115 - 135 deg C which is below the glass transition temperature T g of the matrix resin, while the bending strength remained unchanged up to 180 deg C for the unirradiated composites. In the dynamic viscoelastic spectra of the irradiated matrix, a new relaxation appeared at the temperature extending from 50 deg C to just below the matrix T g and disappeared on annealing for 2 h at 135 deg C. Annealing also decreased the concentration of free radicals existing stably in the irradiated matrix at room temperature. After annealing, a large amount of clacks and voids were observed in the fractography of the composites by scanning electron microscopy. These results indicate: (1) Annealing brings about rearrangement of the radiation-induced molecular chain scission in the matrix; (2) The bending strength of the irradiated composites decreased owing to the increased brittleness of the matrix by annealing. (author)

  17. Synthesis of wrinkled mesoporous silica and its reinforcing effect for dental resin composites.

    Science.gov (United States)

    Wang, Ruili; Habib, Eric; Zhu, X X

    2017-10-01

    The aim of this work is to explore the reinforcing effect of wrinkled mesoporous silica (WMS), which should allow micromechanical resin matrix/filler interlocking in dental resin composites, and to investigate the effect of silica morphology, loading, and compositions on their mechanical properties. WMS (average diameter of 496nm) was prepared through the self-assembly method and characterized by the use of the electron microscopy, dynamic light scattering, and the N 2 adsorption-desorption measurements. The mechanical properties of resin composites containing silanized WMS and nonporous smaller silica were evaluated with a universal mechanical testing machine. Field-emission scanning electron microscopy was used to study the fracture morphology of dental composites. Resin composites including silanized silica particles (average diameter of 507nm) served as the control group. Higher filler loading of silanized WMS substantially improved the mechanical properties of the neat resin matrix, over the composites loaded with regular silanized silica particles similar in size. The impregnation of smaller secondary silica particles with diameters of 90 and 190nm, denoted respectively as Si90 and Si190, increased the filler loading of the bimodal WMS filler (WMS-Si90 or WMS-Si190) to 60wt%, and the corresponding composites exhibited better mechanical properties than the control fillers made with regular silica particles. Among all composites, the optimal WMS-Si190- filled composite (mass ratio WMS:Si190=10:90, total filler loading 60wt%) exhibited the best mechanical performance including flexural strength, flexural modulus, compressive strength and Vickers microhardness. The incorporation of WMS and its mixed bimodal fillers with smaller silica particles led to the design and formulation of dental resin composites with superior mechanical properties. Copyright © 2017 The Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  18. Porous structure analysis of radioactive spent resin cementation matrix

    International Nuclear Information System (INIS)

    Zhou Yaozhong; Yun Guichun

    2004-01-01

    According to a cement product microstructure, a radioactive spent resin cementation matrix has the properties of porous matters. The distributing of the pore size and the pore microstructure stability are closely related to many crucial macro properties, including strength and permeability of the matrixes. By using a new computer-controlled Hg pressure test, a experiment methods of the matrix micro-properties was studied. By using porous structure analyses, it was found that the experimental method is useful for the future cementation research. In this test, it was also found that ASC cement matrixes of spent resin have superior microstructure to the OPC's. They have better pore size distribution, more stable structure and higher ability to hold the Hg in the matrixes than OPC's, and these properties are the important factors that make ASC cement matrixes have more stable macro-structure and lower leaching of nuclides. (authors)

  19. Aluminum matrix composites reinforced with alumina nanoparticles

    CERN Document Server

    Casati, Riccardo

    2016-01-01

    This book describes the latest efforts to develop aluminum nanocomposites with enhanced damping and mechanical properties and good workability. The nanocomposites exhibited high strength, improved damping behavior and good ductility, making them suitable for use as wires. Since the production of metal matrix nanocomposites by conventional melting processes is considered extremely problematic (because of the poor wettability of the nanoparticles), different powder metallurgy routes were investigated, including high-energy ball milling and unconventional compaction methods. Special attention was paid to the structural characterization at the micro- and nanoscale, as uniform nanoparticle dispersion in metal matrix is of prime importance. The aluminum nanocomposites displayed an ultrafine microstructure reinforced with alumina nanoparticles produced in situ or added ex situ. The physical, mechanical and functional characteristics of the materials produced were evaluated using different mechanical tests and micros...

  20. Seating load parameters impact on dental ceramic reinforcement conferred by cementation with resin-cements.

    LENUS (Irish Health Repository)

    Addison, Owen

    2010-09-01

    Cementation of all-ceramic restorations with resin-cements has been demonstrated to reduce the incidence of fracture in service. The aim was to investigate the influence of loading force and loading duration applied during cementation on the reinforcement conferred by a resin-cement on a leucite reinforced glass-ceramic.

  1. Microhardness of resin composite materials light-cured through fiber reinforced composite.

    NARCIS (Netherlands)

    Fennis, W.M.M.; Ray, N.J.; Creugers, N.H.J.; Kreulen, C.M.

    2009-01-01

    OBJECTIVES: To compare polymerization efficiency of resin composite basing materials when light-cured through resin composite and fiber reinforced composite (FRC) by testing microhardness. METHODS: Simulated indirect restorations were prepared by application of resin composite (Clearfil AP-X) or FRC

  2. Matrix resin effects in composite delamination - Mode I fracture aspects

    Science.gov (United States)

    Hunston, Donald L.; Moulton, Richard J.; Johnston, Norman J.; Bascom, Willard D.

    1987-01-01

    A number of thermoset, toughened thermoset, and thermoplastic resin matrix systems were characterized for Mode I critical strain energy release rates, and their composites were tested for interlaminar critical strain energy release rates using the double cantilever beam method. A clear correlation is found between the two sets of data. With brittle resins, the interlaminar critical strain energy release rates are somewhat larger than the neat resin values due to a full transfer of the neat resin toughness to the composite and toughening mechanisms associated with crack growth. With tougher matrices, the higher critical strain energy release rates are only partially transferred to the composites, presumably because the fibers restrict the crack-tip deformation zones.

  3. The correlation of low-velocity impact resistance of graphite-fiber-reinforced composites with matrix properties

    Science.gov (United States)

    Bowles, Kenneth J.

    1988-01-01

    Summarized are basic studies that were conducted to correlate the impact resistance of graphite-fiber-reinforced composites with polymer matrix properties. Three crosslinked epoxy resins and a linear polysulfone were selected as composite matrices. As a group, these resins possess a significantly large range of mechanical properties. The mechanical properties of the resins and their respective composites were measured. Neat resin specimens and unidirectional and crossply composite specimens were impact tested with an instrumented dropweight tester. Impact resistances of the specimens were assesseed on the basis of loading capability, energy absorption, and extent of damage.

  4. Effects of LDEF flight exposure on selected polymer matrix resin composite materials

    Science.gov (United States)

    Slemp, Wayne S.; Young, Philip R.; Witte, William G., Jr.; Shen, James Y.

    1992-01-01

    The characterization of selected graphite fiber reinforced epoxy (934 and 5208) and polysulfone (P1700) matrix resin composites materials which received over five years and nine months of exposure to the low earth orbit (LEO) environment in experiment AO134 on the Long Duration Exposure Facility is reported. The changes in mechanical properties of ultimate tensile strength and tensile modulus for exposed flight specimens are compared to the three sets of control specimens. Marked changes in surface appearance are discussed, and resin loss is reported. The chemical characterization including infrared, thermal, and selected solution property measurements showed that the molecular structure of the polymetric matrix had not changed significantly in response to this exposure.

  5. Aluminium/iron reinforced polyfurfuryl alcohol resin as advanced biocomposites

    Directory of Open Access Journals (Sweden)

    Rakesh Kumar

    2016-07-01

    Full Text Available Aluminium and iron are widely used in construction sectors for the preparation of advanced composites with epoxy resins as matrices. In recent times, there are several reports on the polymerization of polyfufuryl alcohol (PFA a thermoset bioresins from furfuryl alcohol (FA. FA is obtained from waste of sugarcane bagasse. In this work, first the possibility of curing PFA from FA in the presence of aluminium or iron has been explored. Absorbance results from colorimeter/spectrophotometerindicated that the curing of FA to PFA in presence of aluminium started easily while in presence of iron the curing of FA to PFA could not start. Based on the above results, aluminium wire reinforced composites were successfully prepared with three different weight fractions (0.13, 0.09 and 0.07 of aluminium wire. The mechanical properties of these composites were determined theoretically and reported.

  6. Puncture-Healing Thermoplastic Resin Carbon-Fiber-Reinforced Composites

    Science.gov (United States)

    Gordon, Keith L. (Inventor); Siochi, Emilie J. (Inventor); Grimsley, Brian W. (Inventor); Cano, Roberto J. (Inventor); Czabaj, Michael W. (Inventor)

    2015-01-01

    A composite comprising a combination of a self-healing polymer matrix and a carbon fiber reinforcement is described. In one embodiment, the matrix is a polybutadiene graft copolymer matrix, such as polybutadiene graft copolymer comprising poly(butadiene)-graft-poly(methyl acrylate-co-acrylonitrile). A method of fabricating the composite is also described, comprising the steps of manufacturing a pre-impregnated unidirectional carbon fiber preform by wetting a plurality of carbon fibers with a solution, the solution comprising a self-healing polymer and a solvent, and curing the preform. A method of repairing a structure made from the composite of the invention is described. A novel prepreg material used to manufacture the composite of the invention is described.

  7. Preparation and characterization of silane-modified SiO2 particles reinforced resin composites with fluorinated acrylate polymer.

    Science.gov (United States)

    Liu, Xue; Wang, Zengyao; Zhao, Chengji; Bu, Wenhuan; Na, Hui

    2018-04-01

    A series of fluorinated dental resin composites were prepared with two kinds of SiO 2 particles. Bis-GMA (bisphenol A-glycerolate dimethacrylate)/4-TF-PQEA (fluorinated acrylate monomer)/TEGDMA (triethylene glycol dimethacrylate) (40/30/30, wt/wt/wt) was introduced as resin matrix. SiO 2 nanopartices (30nm) and SiO 2 microparticles (0.3µm) were silanized with 3-methacryloxypropyl trimethoxysilane (γ-MPS) and used as fillers. After mixing the resin matrix with 0%, 10%, 20%, 30% SiO 2 nanopartices and 0%, 10%, 20%, 30%, 40%, 50% SiO 2 microparticles, respectively, the fluorinated resin composites were obtained. Properties including double bond conversion (DC), polymerization shrinkage (PS), water sorption (W p ), water solubility (W y ), mechanical properties and cytotoxicity were investigated in comparison with those of neat resin system. The results showed that, filler particles could improve the overall performance of resin composites, particularly in improving mechanical properties and reducing PS of composites along with the addition of filler loading. Compared to resin composites containing SiO 2 microparticles, SiO 2 nanoparticles resin composites had higher DC, higher mechanical properties, lower PS and lower W p under the same filler content. Especially, 50% SiO 2 microparticles reinforced resins exhibited the best flexural strength (104.04 ± 7.40MPa), flexural modulus (5.62 ± 0.16GPa), vickers microhardness (37.34 ± 1.13 HV), compressive strength (301.54 ± 5.66MPa) and the lowest polymerization (3.42 ± 0.22%). Copyright © 2018 Elsevier Ltd. All rights reserved.

  8. Tensile Properties of Unsaturated Polyester and Epoxy Resin Reinforced with Recycled Carbon-Fiber-Reinforced Plastic

    Science.gov (United States)

    Okayasu, Mitsuhiro; Kondo, Yuta

    2018-06-01

    To better understand the mechanical properties of recycled carbon-fiber-reinforced plastic (rCFRP), CFRP crushed into small pieces was mixed randomly in different proportions (0-30 wt%) with two different resins: unsaturated polyester and epoxy resin. Two different sizes of crushed CFRP were used: 0.1 mm × 0.007 mm (milled CFRP) and 30 mm × 2 mm (chopped CFRP). The tensile strength of rCFRP was found to depend on both the proportion and the size of the CFRP pieces. It increased with increasing proportion of chopped CFRP, but decreased with increasing proportion of milled CFRP. There was no clear dependence of the tensile strength on the resin that was used. A low fracture strain was found for rCFRP samples made with chopped CFRP, in contrast to those made with milled CFRP. The fracture strain was found to increase with increasing content of milled CFRP up to 20 wt%, at which point, coalescence of existing microvoids occurred. However, there was a reduction in fracture strain for rCFRP with 30 wt% of milled CFRP, owing to the formation of defects (blow holes). Overall, the fracture strain was higher for rCFRPs based on epoxy resin than for those based on unsaturated polyester with the same CFRP content, because of the high ductility of the epoxy resin. The different tensile properties reflected different failure characteristics, with the use of chopped CFRP leading to a complicated rough fracture surface and with milled CFRP causing ductile failure through the presence of tiny dimple-like fractures. However, for a high content of milled CFRP (30 wt%), large blow holes were observed, leading to low ductility.

  9. Mechanical properties and fire retardancy of bidirectional reinforced composite based on biodegradable starch resin and basalt fibres

    Directory of Open Access Journals (Sweden)

    2008-11-01

    Full Text Available Environmental problems caused by extensive use of polymeric materials arise mainly due to lack of landfill space and depletion of finite natural resources of fossil raw materials, such as petroleum or natural gas. The substitution of synthetic petroleum-based resins with natural biodegradable resins appears to be one appropriate measure to remedy the above-mentioned situation. This study presents the development of a composite that uses environmentally degradable starch-based resin as matrix and basalt fibre plain fabric as reinforcement. Prepreg sheets were manufactured by means of a modified doctor blade system and a hot power press. The sheets were used to manufacture bidirectional-reinforced specimens with fibre volume contents ranging from 33 to 61%. Specimens were tested for tensile and flexural strength, and exhibited values of up to 373 and 122 MPa, respectively. Through application of silane coupling agents to the reinforcement fibres, the flexural composite properties were subsequently improved by as much as 38%. Finally, in order to enhance the fire retardancy and hence the applicability of the composite, fire retardants were applied to the resin, and their effectiveness was tested by means of flame rating (according to UL 94 and thermogravimetric analysis (TGA, respectively.

  10. Modeling the curing process of thermosetting resin matrix composites

    Science.gov (United States)

    Loos, A. C.

    1986-01-01

    A model is presented for simulating the curing process of a thermosetting resin matrix composite. The model relates the cure temperature, the cure pressure, and the properties of the prepreg to the thermal, chemical, and rheological processes occurring in the composite during cure. The results calculated with the computer code developed on the basis of the model were compared with the experimental data obtained from autoclave-curved composite laminates. Good agreement between the two sets of results was obtained.

  11. Fundamental studies of low velocity impact resistance of graphite fiber reinforced polymer matrix composites

    International Nuclear Information System (INIS)

    Bowles, K.J.

    1985-01-01

    A study was conducted to relate the impact resistance of graphite fiber reinforced composites with matrix properties through gaining an understanding of the basic mechanics involved in the deformation and fracture process, and the effect of the polymer matrix structure on these mechanisms. It was found that the resin matrix structure influences the composite impact resistance in at least two ways. The integration of flexibilizers into the polymer chain structure tends to reduce the T/sub G/ and the mechanical properties of the polymer. The reduction in the mechanical properties of the matrix does not enhance the composite impact resistance because it allows matrix controlled failure to initiate impact damage. Linear polymers, which contain no active groups for cross-linking, do not toughen composites because the fiber-matrix interfacial bond is not of sufficient strength to prevent interfacial failure from occurring. Toughness must be built into the basic polymer backbone and cross-linking structure

  12. Structural Foaming at the Nano-, Micro-, and Macro-Scales of Continuous Carbon Fiber Reinforced Polymer Matrix Composites

    Science.gov (United States)

    2012-10-29

    structural porosity at MNM scales could be introduced into the matrix, the carbon fiber reinforcement, and during prepreg lamination processing, without...areas, including fibers. Furthermore, investigate prepreg thickness and resin content effects on the thermomechanical performance of laminated ...Accomplishment 4) 5 Develop constitutive models for nano- foamed and micro- foamed PMC systems from single ply prepreg to multilayer laminated

  13. Nanoscale Reinforced, Polymer Derived Ceramic Matrix Coatings

    Energy Technology Data Exchange (ETDEWEB)

    Rajendra Bordia

    2009-07-31

    The goal of this project was to explore and develop a novel class of nanoscale reinforced ceramic coatings for high temperature (600-1000 C) corrosion protection of metallic components in a coal-fired environment. It was focused on developing coatings that are easy to process and low cost. The approach was to use high-yield preceramic polymers loaded with nano-size fillers. The complex interplay of the particles in the polymer, their role in controlling shrinkage and phase evolution during thermal treatment, resulting densification and microstructural evolution, mechanical properties and effectiveness as corrosion protection coatings were investigated. Fe-and Ni-based alloys currently used in coal-fired environments do not possess the requisite corrosion and oxidation resistance for next generation of advanced power systems. One example of this is the power plants that use ultra supercritical steam as the working fluid. The increase in thermal efficiency of the plant and decrease in pollutant emissions are only possible by changing the properties of steam from supercritical to ultra supercritical. However, the conditions, 650 C and 34.5 MPa, are too severe and result in higher rate of corrosion due to higher metal temperatures. Coating the metallic components with ceramics that are resistant to corrosion, oxidation and erosion, is an economical and immediate solution to this problem. Good high temperature corrosion protection ceramic coatings for metallic structures must have a set of properties that are difficult to achieve using established processing techniques. The required properties include ease of coating complex shapes, low processing temperatures, thermal expansion match with metallic structures and good mechanical and chemical properties. Nanoscale reinforced composite coatings in which the matrix is derived from preceramic polymers have the potential to meet these requirements. The research was focused on developing suitable material systems and

  14. Development study of concrete reinforcement made of aramid fiber-reinforced plastic rods with high radiation resistance. 1. Epoxy resin compounds with a handling at room temperature impregnation

    International Nuclear Information System (INIS)

    Udagawa, Akira; Seguchi, Tadao; Moriya, Toshio; Matsubara, Sumiyuki; Hongou, Yoshihiko

    1999-03-01

    Aramid fiber-reinforced plastic (ArFRP) rods were developed in order to avoid from conduction current and/or magnetization of the metallic reinforcement using concrete constructions. For the polymer matrix, new epoxy resin compounds consist of tetraglycidyl diaminodiphenylmethane (30%), diglycidyl ether of bisphenol-A (60%), styrene oxide (10%) and aromatic diamine as a hardner were found to be the best formulation, and which were easily impregnated to the aramid fiber braiding yarn at room temperature. The ArFRP rods has a high radiation resistance, and the tensile strength was maintained to 98% (1.45 GPa) after irradiation dose of 100 MGy (absorbed energy MJ/kg), which is available for the reinforcement of concrete construction for the house of fusion reactor with super conducting magnets. (author)

  15. [Effect of amount of silane coupling agent on flexural strength of dental composite resins reinforced with aluminium borate whisker].

    Science.gov (United States)

    Zhu, Ming-yi; Zhang, Xiu-yin

    2015-06-01

    To evaluate the effect of amount of silane coupling agent on flexural strength of dental composite resins reinforced with aluminium borate whisker (ABW). ABW was surface-treated with 0%, 1%, 2%, 3% and 4% silan coupling agent (γ-MPS), and mixed with resin matrix to synthesize 5 groups of composite resins. After heat-cured at 120 degrees centigrade for 1 h, specimens were tested in three-point flexure to measure strength according to ISO-4049. One specimen was selected randomly from each group and observed under scanning electron microscope (SEM). The data was analyzed with SAS 9.2 software package. The flexural strength (117.93±11.9 Mpa) of the group treated with 2% silane coupling agent was the highest, and significantly different from that of the other 4 groups (α=0.01). The amount of silane coupling agent has impact on the flexural strength of dental composite resins reinforced with whiskers; The flexual strength will be reduced whenever the amount is higher or lower than the threshold. Supported by Research Fund of Science and Technology Committee of Shanghai Municipality (08DZ2271100).

  16. Microhardness of dual-polymerizing resin cements and foundation composite resins for luting fiber-reinforced posts.

    Science.gov (United States)

    Yoshida, Keiichi; Meng, Xiangfeng

    2014-06-01

    The optimal luting material for fiber-reinforced posts to ensure the longevity of foundation restorations remains undetermined. The purpose of this study was to evaluate the suitability of 3 dual-polymerizing resin cements and 2 dual-polymerizing foundation composite resins for luting fiber-reinforced posts by assessing their Knoop hardness number. Five specimens of dual-polymerizing resin cements (SA Cement Automix, G-Cem LincAce, and Panavia F2.0) and 5 specimens of dual-polymerizing foundation composite resins (Clearfil DC Core Plus and Unifil Core EM) were polymerized from the top by irradiation for 40 seconds. Knoop hardness numbers were measured at depths of 0.5, 2.0, 4.0, 6.0, 8.0, and 10.0 mm at 0.5 hours and 7 days after irradiation. Data were statistically analyzed by repeated measures ANOVA, 1-way ANOVA, and the Tukey compromise post hoc test (α=.05). At both times after irradiation, the 5 resins materials showed the highest Knoop hardness numbers at the 0.5-mm depth. At 7 days after irradiation, the Knoop hardness numbers of the resin materials did not differ significantly between the 8.0-mm and 10.0-mm depths (P>.05). For all materials, the Knoop hardness numbers at 7 days after irradiation were significantly higher than those at 0.5 hours after irradiation at all depths (Presin materials were found to decrease in the following order: DC Core Plus, Unifil Core EM, Panavia F2.0, SA Cement Automix, and G-Cem LincAce (Pcomposite resins were higher than those of the 3 dual-polymerizing resin cements, notable differences were seen among the 5 materials at all depths and at both times after irradiation. Copyright © 2014 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

  17. Fracture resistance of Kevlar-reinforced poly(methyl methacrylate) resin: a preliminary study.

    Science.gov (United States)

    Berrong, J M; Weed, R M; Young, J M

    1990-01-01

    The reinforcing effect of Kevlar fibers incorporated in processed poly(methyl methacrylate) resin samples was studied using 0% (controls), 0.5%, 1%, and 2% by weight of the added fibers. The samples were subjected to impact testing to determine fracture resistance, and sample groups were statistically compared using an ANOVA. Each reinforced sample had significantly greater fracture resistance (P less than 0.05) than the control, and no difference was found either within or between control groups. The use of reinforcing Kevlar fibers appears to enhance the fracture resistance of acrylic resin denture base materials.

  18. Imidazolium Ionic Liquid Modified Graphene Oxide: As a Reinforcing Filler and Catalyst in Epoxy Resin

    Directory of Open Access Journals (Sweden)

    Qing Lyu

    2017-09-01

    Full Text Available Surface modification of graphene oxide (GO is one of the most important issues to produce high performance GO/epoxy composites. In this paper, the imidazole ionic liquid (IMD-Si was introduced onto the surface of GO sheets by a cheap and simple method, to prepare a reinforcing filler, as well as a catalyst in epoxy resin. The interlayer spacing of GO sheets was obviously increased by the intercalation of IMD-Si, which strongly facilitated the dispersibility of graphene oxide in organic solvents and epoxy matrix. The addition of 0.4 wt % imidazolium ionic liquid modified graphene oxide (IMD-Si@GO, yielded a 12% increase in flexural strength (141.3 MPa, a 26% increase in flexural modulus (4.69 GPa, and a 52% increase in impact strength (18.7 kJ/m2, compared to the neat epoxy. Additionally the IMD-Si@GO sheets could catalyze the curing reaction of epoxy resin-anhydride system significantly. Moreover, the improved thermal conductivities and thermal stabilities of epoxy composites filled with IMD-Si@GO were also demonstrated.

  19. Mechanical Property Analysis on Sandwich Structured Hybrid Composite Made from Natural Fibre, Glass Fibre and Ceramic Fibre Wool Reinforced with Epoxy Resin

    Science.gov (United States)

    Bharat, K. R.; Abhishek, S.; Palanikumar, K.

    2017-06-01

    Natural fibre composites find wide range of applications and usage in the automobile and manufacturing industries. They find lack in desired properties, which are required for present applications. In current scenario, many developments in composite materials involve the synthesis of Hybrid composite materials to overcome some of the lacking properties. In this present investigation, two sandwich structured hybrid composite materials have been made by reinforcing Aloe Vera-Ceramic Fibre Wool-Glass fibre with Epoxy resin matrix and Sisal fibre-Ceramic Fibre Wool-Glass fibre with Epoxy resin matrix and its mechanical properties such as Tensile, Flexural and Impact are tested and analyzed. The test results from the two samples are compared and the results show that sisal fibre reinforced hybrid composite has better mechanical properties than aloe vera reinforced hybrid composite.

  20. Evaluation of olibanum and its resin as rate controlling matrix for controlled release of diclofenac

    OpenAIRE

    Chowdary KPR; Mohapatra P; Murali Krishna M

    2006-01-01

    Olibanum and its resin and carbohydrate fractions were evaluated as rate controlling matrix materials in tablets for controlled release of diclofenac. Diclofenac matrix tablets were formulated employing olibanum and its resin and carbohydrate fractions in different concentrations and the tablets were evaluated for various tablet characters including drug release kinetics and mechanism. Olibanum and its resin component exhibited excellent retarding effect on drug release from the matrix tablet...

  1. Thermo-mechanical characterization of siliconized E-glass fiber/hematite particles reinforced epoxy resin hybrid composite

    Energy Technology Data Exchange (ETDEWEB)

    Arun Prakash, V.R., E-mail: vinprakash101@gmail.com; Rajadurai, A., E-mail: rajadurai@annauniv.edu.in

    2016-10-30

    Highlights: • Particles dimension have reduced using Ball milling process. • Importance of surface modification was explored. • Surface modification has been done to improve adhesion of fiber/particles with epoxy. • Mechanical properties has been increased by adding modified fiber and particles. • Thermal properties have been increased. - Abstract: In this present work hybrid polymer (epoxy) matrix composite has been strengthened with surface modified E-glass fiber and iron(III) oxide particles with varying size. The particle sizes of 200 nm and <100 nm has been prepared by high energy ball milling and sol-gel methods respectively. To enhance better dispersion of particles and improve adhesion of fibers and fillers with epoxy matrix surface modification process has been done on both fiber and filler by an amino functional silane 3-Aminopropyltrimethoxysilane (APTMS). Crystalline and functional groups of siliconized iron(III) oxide particles were characterized by XRD and FTIR spectroscopy analysis. Fixed quantity of surface treated 15 vol% E-glass fiber was laid along with 0.5 and 1.0 vol% of iron(III) oxide particles into the matrix to fabricate hybrid composites. The composites were cured by an aliphatic hardener Triethylenetetramine (TETA). Effectiveness of surface modified particles and fibers addition into the resin matrix were revealed by mechanical testing like tensile testing, flexural testing, impact testing, inter laminar shear strength and hardness. Thermal behavior of composites was evaluated by TGA, DSC and thermal conductivity (Lee’s disc). The scanning electron microscopy was employed to found shape and size of iron(III) oxide particles adhesion quality of fiber with epoxy matrix. Good dispersion of fillers in matrix was achieved with surface modifier APTMS. Tensile, flexural, impact and inter laminar shear strength of composites was improved by reinforcing surface modified fiber and filler. Thermal stability of epoxy resin was improved

  2. Behaviour of E-glass fibre reinforced vinylester resin composites ...

    Indian Academy of Sciences (India)

    Unknown

    Central Glass and Ceramic Research Institute, Kolkata 700 032, India. Abstract. ... Impact fatigue; static fatigue; residual stress; E-glass fibre; vinylester resin. 1. ... The present work ..... American Society for Testing and Materials) 497 p. 311.

  3. Towards reinforcement solutions for urban fibre/fabric waste using bio-based biodegradable resins.

    Science.gov (United States)

    Agrawal, Pramod; Hermes, Alina; Bapeer, Solaf; Luiken, Anton; Bouwhuis, Gerrit; Brinks, Ger

    2017-10-01

    The main research question is how to systematically define and characterize urban textile waste and how to effectively utilise it to produce reinforcement(s) with selected bio-based biodegradable resin(s). Several composite samples have been produced utilising predominantly natural and predominantly synthetic fibres by combining loose fibres with PLA, nonwoven fabric with PLA, woven fabric with PLA, two-layer composite & four-layer composite samples. Physio-chemical characterisations according to the established standards have been conducted. The present work is a step toward the circular economy and closing the loop in textile value chain.

  4. Compressive behavior of wire reinforced bulk metallic glass matrix composites

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Seung-Yub [Department of Materials Science, M/C 138-78, California Institute of Technology, Pasadena, CA 91125 (United States); Clausen, Bjorn [Lujan Neutron Science Center, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Uestuendag, Ersan [Department of Materials Science and Engineering, Iowa State University, Ames, IA 50011 (United States)]. E-mail: ustundag@iastate.edu; Choi-Yim, Haein [Department of Materials Science, M/C 138-78, California Institute of Technology, Pasadena, CA 91125 (United States); Aydiner, C. Can [Department of Materials Science and Engineering, Iowa State University, Ames, IA 50011 (United States); Bourke, Mark A.M. [Materials Science and Technology Division, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)

    2005-06-15

    Bulk metallic glasses (BMGs) possess a unique set of mechanical properties that make them attractive structural materials. However, when loaded without constraint, BMGs fracture catastrophically due to formation of macroscopic shear bands and this behavior reduces their reliability. To address this issue, BMG matrix composites have been developed. In this investigation, neutron diffraction was used during uniaxial compressive loading to measure the internal strains in the second phases of various BMG composites reinforced with Ta, Mo, or stainless steel wires. The diffraction data were then employed to develop a finite element model that deduced the in situ constitutive behavior of each phase. It was found that the reinforcements yielded first and started transferring load to the matrix, which remained elastic during the whole experiment. While the present composites exhibited enhanced ductility, largely due to their ductile reinforcements, they yielded at applied stresses lower than those found in W reinforced composites.

  5. Graphene-Reinforced Metal and Polymer Matrix Composites

    Science.gov (United States)

    Kasar, Ashish K.; Xiong, Guoping; Menezes, Pradeep L.

    2018-06-01

    Composites have tremendous applicability due to their excellent capabilities. The performance of composites mainly depends on the reinforcing material applied. Graphene is successful as an efficient reinforcing material due to its versatile as well as superior properties. Even at very low content, graphene can dramatically improve the properties of polymer and metal matrix composites. This article reviews the fabrication followed by mechanical and tribological properties of metal and polymer matrix composites filled with different kinds of graphene, including single-layer, multilayer, and functionalized graphene. Results reported to date in literature indicate that functionalized graphene or graphene oxide-polymer composites are promising materials offering significantly improved strength and frictional properties. A similar trend of improved properties has been observed in case of graphene-metal matrix composites. However, achieving higher graphene loading with uniform dispersion in metal matrix composites remains a challenge. Although graphene-reinforced composites face some challenges, such as understanding the graphene-matrix interaction or fabrication techniques, graphene-reinforced polymer and metal matrix composites have great potential for application in various fields due to their outstanding properties.

  6. Vertically aligned TiO2 nanorods-woven carbon fiber for reinforcement of both mechanical and anti-wear properties in resin composite

    Science.gov (United States)

    Fei, Jie; Zhang, Chao; Luo, Dan; Cui, Yali; Li, Hejun; Lu, Zhaoqing; Huang, Jianfeng

    2018-03-01

    A series of TiO2 nanorods were successfully grown on woven carbon fiber by hydrothermal method to reinforce the resin composite. The TiO2 nanorods improved the mechanical interlocking among woven carbon fibers and resin matrix, resulting in better fibers/resin interfacial bonding. Compared with desized-woven carbon fiber, the uniform TiO2 nanorods array resulted in an improvement of 84.3% and 73.9% in the tensile and flexural strength of the composite. However, the disorderly TiO2 nanorods on woven carbon fiber leaded to an insignificant promotion of the mechanical strength. The enhanced performance of well-proportioned TiO2 nanorods-woven carbon fiber was also reflected in the nearly 56% decrease of wear rate, comparing to traditional woven carbon fiber reinforced composite.

  7. Double Vacuum Bag Process for Resin Matrix Composite Manufacturing

    Science.gov (United States)

    Hou, Tan-Hung (Inventor); Jensen, Brian J. (Inventor)

    2007-01-01

    A double vacuum bag molding assembly with improved void management and laminate net shape control which provides a double vacuum enviromnent for use in fabricating composites from prepregs containing air and/or volatiles such as reactive resin matrix composites or composites from solvent containing prepregs with non-reactive resins matrices. By using two vacuum environments during the curing process, a vacuum can be drawn during a B-stage of a two-step cycle without placing the composite under significant relative pressure. During the final cure stage, a significant pressure can be applied by releasing the vacuum in one of the two environments. Inner and outer bags are useful for creating the two vacuum environments with a perforated tool intermediate the two. The composite is placed intermediate a tool plate and a caul plate in the first environment with the inner bag and tool plate defining the first environment. The second environment is characterized by the outer bag which is placed over the inner bag and the tool plate.

  8. Mechanical properties of aluminium matrix composites reinforced with intermetallics

    International Nuclear Information System (INIS)

    Torres, B.; Garcia-Escorial, A.; Ibanez, J.; Lieblich, M.

    2001-01-01

    In this work 2124 aluminium matrix composites reinforced with Ni 3 Al, NiAl, MoSi 2 and Cr 3 Si intermetallic powder particles have been investigated. For comparison purposes, un reinforced 2124 and reinforced with SiC have also been studied. In all cases, the same powder metallurgy route was used, i. e. the 2124 alloy was obtained by rapid solidification and the intermetallic particles by self-propagating high-temperature synthesis (SHS). The matrix and the intermetallics were mechanically blended, cold compacted and finally hot extruded. Tensile tests were carried out in T1 and T4 treatments. Results indicate that mechanical properties depend strongly on the tendency to form new phases at the matrix-intermetallic interface during processing and/or further thermal treatments. The materials which present better properties are those that present less reaction between matrix and intermetallic reinforcement, i. e. MoSi 2 and SiC reinforced composites. (Author) 9 refs

  9. 21 CFR 177.2355 - Mineral reinforced nylon resins.

    Science.gov (United States)

    2010-04-01

    ... (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: POLYMERS Substances for Use Only... resins may contain up to 0.2 percent by weight of titanium dioxide as an optional adjuvant substance. (c...-contact surface tested. (d) In accordance with good manufacturing practice, finished articles containing...

  10. Metal Matrix Composites Reinforced by Nano-Particles—A Review

    Directory of Open Access Journals (Sweden)

    Riccardo Casati

    2014-03-01

    Full Text Available Metal matrix composites reinforced by nano-particles are very promising materials, suitable for a large number of applications. These composites consist of a metal matrix filled with nano-particles featuring physical and mechanical properties very different from those of the matrix. The nano-particles can improve the base material in terms of wear resistance, damping properties and mechanical strength. Different kinds of metals, predominantly Al, Mg and Cu, have been employed for the production of composites reinforced by nano-ceramic particles such as carbides, nitrides, oxides as well as carbon nanotubes. The main issue of concern for the synthesis of these materials consists in the low wettability of the reinforcement phase by the molten metal, which does not allow the synthesis by conventional casting methods. Several alternative routes have been presented in literature for the production of nano-composites. This work is aimed at reviewing the most important manufacturing techniques used for the synthesis of bulk metal matrix nanocomposites. Moreover, the strengthening mechanisms responsible for the improvement of mechanical properties of nano-reinforced metal matrix composites have been reviewed and the main potential applications of this new class of materials are envisaged.

  11. Effect of ultraviolet light irradiation period on bond strengths between fiber-reinforced composite post and core build-up composite resin.

    Science.gov (United States)

    Asakawa, Yuya; Takahashi, Hidekazu; Iwasaki, Naohiko; Kobayashi, Masahiro

    2014-01-01

    The aim of the present study was to characterize the effects of the ultraviolet light (UV) irradiation period on the bond strength of fiber-reinforced composite (FRC) posts to core build-up resin. Three types of FRC posts were prepared using polymethyl methacrylate, urethane dimethacrylate, and epoxy resin. The surfaces of these posts were treated using UV irradiation at a distance of 15 mm for 0 to 600 s. The pull-out bond strength was measured and analyzed with the Dunnett's comparison test (α=0.05). The bond strengths of the post surfaces without irradiation were 6.9 to 7.4 MPa; those after irradiation were 4.2 to 26.1 MPa. The bond strengths significantly increased after 15 to 120-s irradiation. UV irradiation on the FRC posts improved the bond strengths between the FRC posts and core build-up resin regardless of the type of matrix resin.

  12. MICROWAVE INDUCED DEGRADATION OF GLASS FIBER REINFORCED POLYESTER FOR FIBER AND RESIN RECOVERY

    DEFF Research Database (Denmark)

    Ucar, Hülya; Nielsen, Rudi Pankratz; Søgaard, Erik Gydesen

    A solvolysis process to depolymerize the resin in glass fiber reinforced composites and recover the glass fibers has been investigated using microwave induced irradiation. The depolymerization was carried out in HNO3 with concentrations in the range of 1M-7M and in KOH with concentrations ranging...

  13. Effect of the surface roughness on interfacial properties of carbon fibers reinforced epoxy resin composites

    International Nuclear Information System (INIS)

    Song Wei; Gu Aijuan; Liang Guozheng; Yuan Li

    2011-01-01

    The effect of the surface roughness on interfacial properties of carbon fibers (CFs) reinforced epoxy (EP) resin composite is studied. Aqueous ammonia was applied to modify the surfaces of CFs. The morphologies and chemical compositions of original CFs and treated CFs (a-CFs) were characterized by Atomic Force Microscopy (AFM), and X-ray Photoelectron Spectroscopy (XPS). Compared with the smooth surface of original CF, the surface of a-CF has bigger roughness; moreover, the roughness increases with the increase of the treating time. On the other hand, no obvious change in chemical composition takes place, indicating that the treating mechanism of CFs by aqueous ammonia is to physically change the morphologies rather than chemical compositions. In order to investigate the effect of surface roughness on the interfacial properties of CF/EP composites, the wettability and Interfacial Shear Strength (IFSS) were measured. Results show that with the increase of the roughness, the wettabilities of CFs against both water and ethylene glycol improves; in addition, the IFSS value of composites also increases. These attractive phenomena prove that the surface roughness of CFs can effectively overcome the poor interfacial adhesions between CFs and organic matrix, and thus make it possible to fabricate advanced composites based on CFs.

  14. Weather ability studies of phenolic resin coated woods and glass fiber reinforced laminates

    International Nuclear Information System (INIS)

    Munir, A.; Hussain, R.; Rizvi, M.H.; Ahmed, F.

    1997-01-01

    Phenolic resins have made a major breakthrough in the field of high technology in 80's. These are now active participants of h igh tech' areas ranging from electronics, computers, communication, outer space, aerospace, advanced materials, bio materials and technology. A phenol - formaldehyde (1:1.5) resin having resin content of 70% synthesized in the laboratory has been applied for wood coating and reinforcing glass fiber. The weatherability and solvent resistance of these items have been studied and results discussed keeping in view the envisaged application for structural materials and chemical equipment. The toxic materials released during contact with solvents for chemical applications and during degradation general have been monitored. The results are discussed with reference to environmental pollution due to these resins and their composites under different conditions. (authors)

  15. Solventless LARC-160 Polyimide Matrix Resin. [applied for use in aerospace engineering

    Science.gov (United States)

    Stclair, T. L.; Jewell, R. A.

    1978-01-01

    The addition polyimide, LARC-160, which was originally synthesized from low cost liquid monomers as a laminating resin in ethanol, was prepared as a solventless, high viscosity, neat liquid resin. The resin was processed by hot-melt coating techniques into graphite prepreg with excellent tack and drape. Comparable data on graphite reinforced laminates made from solvent-coated and various hot-melt coated prepreg were generated. LARC-160, because of its liquid nature, can be easily autoclave processed to produce low void laminates. Liquid chromatographic fingerprints indicate good reaction control on resin scale ups. Minor changes in monomer ratios were also made to improve the thermal aging performance of graphite laminates.

  16. Load transfer in short fibre reinforced metal matrix composites

    International Nuclear Information System (INIS)

    Garces, Gerardo; Bruno, Giovanni; Wanner, Alexander

    2007-01-01

    The internal load transfer and the deformation behaviour of aluminium-matrix composites reinforced with 2D-random alumina (Saffil) short fibres was studied for different loading modes. The evolution of stress in the metallic matrix was measured by neutron diffraction during in situ uniaxial deformation tests. Tensile and compressive tests were performed with loading axis parallel or perpendicular to the 2D-reinforcement plane. The fibre stresses were computed based on force equilibrium considerations. The results are discussed in light of a model recently established by the co-authors for composites with visco-plastic matrix behaviour and extended to the case of plastic deformation in the present study. Based on that model, the evolution of internal stresses and the macroscopic stress-strain were simulated. Comparison between the experimental and computational results shows a qualitative agreement in all relevant aspects

  17. Interfacial adhesion improvement in carbon fiber/carbon nanotube reinforced hybrid composites by the application of a reactive hybrid resin initiated by gamma irradiation

    Science.gov (United States)

    Szebényi, G.; Faragó, D.; Lámfalusi, Cs.; Göbl, R.

    2018-04-01

    Interfacial adhesion is a key factor in composite materials. The effective co-working of the reinforcing materials and matrix is essential for the proper load transfer between them, and to achieve the desired reinforcing effect. In case of nanocomposites, especially carbon nanotube (CNT) reinforced nanocomposites the adhesion between the CNTs and the polymer matrix is poor. To improve the interfacial adhesion and exploit the reinforcing effect of these nanoparticles a two step curable epoxy (EP)/vinylester (VE) hybrid resin system was developed where the EP is cured using hardener in the first step, during the composite production, and in the second step the curing of the VE is initiated by gamma irradiation, which also activates the reinforcing materials and the cured matrix component. A total of six carbon fiber reinforced composite systems were compared with neat epoxy and EP/VE hybrid matrices with and without chemical initiator and MWCNT nano-reinforcement. The effect of gamma irradiation was investigated at four absorbed dose levels. According to our three point bending and interlaminar shear test results the adhesion has improved between all constituents of the composite system. It was demonstrated that gamma irradiation has beneficial effect on the static mechanical, especially interlaminar properties of both micro- and nanocomposites in terms of modulus, strength and interlaminar shear strength.

  18. Experimental Investigation and Taguchi Optimisation of Drilling Properties on Teak Wood Reinforced Epoxy Resin

    Science.gov (United States)

    Lilly Mercy, J.; Shaqir Tanvir, Mohamed; Swaroopkanth, K.

    2017-05-01

    The drilling properties of teak reinforced epoxy resin composite are explored in this work. The thrust force and temperature during the drilling process was found and optimised. Nine holes were drilled in accordance with L9 orthogonal array on Medium Density Fibre board and Teak wood reinforced epoxy composite board and the thrust force and temperature induced during drilling is measured. Drilling experiments were conducted using CNC Vertical drilling machine and the thrust force was measured using dynamometer and temperature using infra-red thermometer. The experiments were conducted with varying levels of spindle speed and feed rate and optimised using Taguchi optimisation. It was observed that higher thrust and temperature were observed while drilling teak wood composite due to the high mechanical strength of teak wood. The hard and brittle properties of the resin seemed to be more pronounced in the composite. The experimental results were optimised to find the best combination of input parameters for reduced thrust and temperature. When speed increases, thrust force decreases and temperature increases. When feed increases, thrust force increases and temperature decreases. Experimental findings encouragesto use teak wood reinforced epoxy resin as a substitute for the traditionally used Medium Density Fibre Board. The percentage of mixing of teak dust can be increased with various resin combinations to arrive at the best suitable combination for obtaining optimal mechanical properties.

  19. Flexural properties of polyethylene, glass and carbon fiber-reinforced resin composites for prosthetic frameworks.

    Science.gov (United States)

    Maruo, Yukinori; Nishigawa, Goro; Irie, Masao; Yoshihara, Kumiko; Minagi, Shogo

    2015-01-01

    High flexural properties are needed for fixed partial denture or implant prosthesis to resist susceptibility to failures caused by occlusal overload. The aim of this investigation was to clarify the effects of four different kinds of fibers on the flexural properties of fiber-reinforced composites. Polyethylene fiber, glass fiber and two types of carbon fibers were used for reinforcement. Seven groups of specimens, 2 × 2 × 25 mm, were prepared (n = 10 per group). Four groups of resin composite specimens were reinforced with polyethylene, glass or one type of carbon fiber. The remaining three groups served as controls, with each group comprising one brand of resin composite without any fiber. After 24-h water storage in 37°C distilled water, the flexural properties of each specimen were examined with static three-point flexural test at a crosshead speed of 0.5 mm/min. Compared to the control without any fiber, glass and carbon fibers significantly increased the flexural strength (p glass fiber (p glass fibers (p > 0.05). Fibers could, therefore, improve the flexural properties of resin composite and carbon fibers in longitudinal form yielded the better effects for reinforcement.

  20. [Acrylic resin reinforcement with metallic and nonmetallic inserts].

    Science.gov (United States)

    Preoteasa, Elena; Murariu, Cătălina Măgureanu; Ionescu, Ecaterina; Preoteasa, Cristina Teodora

    2007-01-01

    In the current use of acrylic resin for removable dentures and orthodontic treatments we are frequently facing the fact of base fracture. The repairing of this, determine most of the time, discomfort of the patient, by excluding the prosthetic device, affecting the treatment, loosing patient's time, doctor's time, implying the dental laboratory and extra expenses. The causes of fractures are many, from clinical cases with some specific anatomic and functional particularities, or parafunctional, to the incorrect designing, manufacturing or wearing of the prosthetic part, being connected with the materials characteristics. The consequences and costs of these fractures are leading to unsatisfying results in some of the clinical cases, in presence of parafunctions like bruxism or clenching and specifically for the new types of prosthetic rehabilitation, on natural teeth or implants.

  1. Multi-Scale CNT-Based Reinforcing Polymer Matrix Composites for Lightweight Structures

    Science.gov (United States)

    Eberly, Daniel; Ou, Runqing; Karcz, Adam; Skandan, Ganesh; Mather, Patrick; Rodriguez, Erika

    2013-01-01

    additional weight savings. More robust structures capable of withstanding micrometeoroid and space debris impacts will be possible with the enhanced mechanical properties imparted by the aligned CNTs incorporated into the fiber composite structure, as well as the potential for improved electrical and thermal properties. The materials fabrication approach developed in the present effort is a platform for customer applications where additional reinforcement is required or would be beneficial, especially in FRC structures and component parts. Depending upon the specific customer application, the NRM could be tailored to the specific matrix resin and desired property enhancement.

  2. Effect of resin system on the mechanical properties and water absorption of kenaf fibre reinforced laminates

    International Nuclear Information System (INIS)

    Rassmann, S.; Paskaramoorthy, R.; Reid, R.G.

    2011-01-01

    The objective of this study is to compare the mechanical and water absorption properties of kenaf (Hibiscus cannabinus L.) fibre reinforced laminates made of three different resin systems. The use of different resin systems is considered so that potentially complex and expensive fibre treatments are avoided. The resin systems used include a polyester, a vinyl ester and an epoxy. Laminates of 15%, 22.5% and 30% fibre volume fraction were manufactured by resin transfer moulding. The laminates were tested for strength and modulus under tensile and flexural loading. Additionally, tests were carried out on laminates to determine the impact energy, impact strength and water absorption. The results revealed that properties were affected in markedly different ways by the resin system and the fibre volume fraction. Polyester laminates showed good modulus and impact properties, epoxy laminates displayed good strength values and vinyl ester laminates exhibited good water absorption characteristics. Scanning electron microscope studies show that epoxy laminates fail by fibre fracture, polyester laminates by fibre pull-out and vinyl ester laminates by a combination of the two. A comparison between kenaf and glass laminates revealed that the specific tensile and flexural moduli of both laminates are comparable at the volume fraction of 15%. However, glass laminates have much better specific properties than the kenaf laminates at high fibre volume fractions for all three resins used.

  3. Cement matrix for immobilisation of spent anionic resins in borate form arising from nuclear power plants

    International Nuclear Information System (INIS)

    Sathi Sasidharan, N.; Deshingkar, D.S.; Wattal, P.K.

    2005-11-01

    In water cooled reactors boron is added as boric acid to control nuclear reactor power levels. The boric acid concentration in coolant/moderator water, is controlled by using strongly basic anionic resins in borate (H 2 BO 3 - ) form. The spent anionic resins in borate form contain 131 Iodine, 99 Technitium and 137 Cesium activities. Direct immobilisation of anionic resins in borate form in Ordinary Portland Cement (OPC) and Slag Cement was investigated using vermiculite, bentonite, calcium oxide and silica as admixtures. The cumulative fraction of 137 Cesium leached and 137 Cesium leach rate for slag cement matrix were 0.029 and 0.00064 g.cm 2 .d -1 respectively for 95 days of leaching. The volume reduction factor achieved by direct immobilisation of anionic resins in borate form was 0.48. Immobilisation of pyrolysis residues from these resins in OPC matrix was also studied. Leaching of matrix blocks was carried out for 180 days in DM water to optimise the matrix formulation. The cumulative fraction of 137 Cesium leached and 137 Cesium leach rate were 0.076 and 0.00054 respectively for 180 days leaching. The volume reduction factor achieved by immobilisation of pyrolysis residues was 2.4. OPC is non compatible to cationic resins loaded with alkali in absence of specific admixtures. Hence cationic resins loaded with alkali and anionic resins in borate form can not be immobilised together. (author)

  4. Matrix-reinforcement reactivity in P/M titanium matrix composites

    International Nuclear Information System (INIS)

    Amigo, V.; Romero, F.; Salvador, M. D.; Busquets, D.

    2007-01-01

    The high reactivity of titanium and the facility of the same one to form intermetallics makes difficult obtaining composites with this material and brings the need in any case of covering the principal fibres used as reinforcement. To obtain composites of titanium reinforced with ceramic particles ins proposed in this paper, for this reason it turns out to be fundamental to evaluate the reactivity between the matrix and reinforcement. Both titanium nitride and carbide (TiN and TiC) are investigated as materials of low reactivity whereas titanium silicide (TiSi 2 ) is also studied as materials of major reactivity, already stated by the scientific community. This reactivity will be analysed by means of scanning electron microscopy (SEM) there being obtained distribution maps of the elements that allow to establish the possible influence of the sintering temperature and time. Hereby the matrix-reinforcement interactions are optimized to obtain suitable mechanical properties. (Author) 39 refs

  5. Morphology and contact angle studies of poly(styrene-co-acrylonitrile modified epoxy resin blends and their glass fibre reinforced composites

    Directory of Open Access Journals (Sweden)

    2007-06-01

    Full Text Available In this study, the surface characteristics of blends and composites of epoxy resin were investigated. Poly(styrene-co-acylonitrile (SAN was used to modify diglycedyl ether of bisphenol-A (DGEBA type epoxy resin cured with diamino diphenyl sulfone (DDS and the modified epoxy resin was used as the matrix for fibre reinforced composites (FRP’s. E-glass fibre was used as the fibre reinforcement. The scanning electron micrographs of the fractured surfaces of the blends and composites were analyzed. Morphological analysis revealed different morphologies such as dispersed, cocontinuous and phase-inverted structures for the blends. Contact angle studies were carried out using water and methylene iodide at room temperature. The solid surface energy was calculated using harmonic mean equations. Blending of epoxy resin increases its contact angle. The surface free energy, work of adhesion, interfacial free energy, spreading coefficient and Girifalco-Good’s interaction parameter were changed significantly in the case of blends and composites. The incorporation of thermoplastic and glass fibre reduces the wetting and hydrophilicity of epoxy resin.

  6. Silver matrix composites reinforced with galvanically silvered particles

    OpenAIRE

    J. Śleziona; J. Wieczorek,

    2007-01-01

    Purpose: The paper presents the possibility of the application of metalic layers drifted with the use of the galvanic methods on the ceramic particles surface. The application of the layers was aimed at obtaining the rewetting of the reinforcing particles with the liquid silver in the course of the producing of silver matrix composites with the use of mechanical stirring method. To enable introducing of the iron powder and glass carbon powder to liquid silver the solution of covering the powd...

  7. Obtaining nanofibers from sisal to reinforce nanocomposites biodegradable matrixes

    International Nuclear Information System (INIS)

    Oliveira, Francieli B. de; Teixeira, Eliangela de M.; Marconcini, Jose M.; Mattoso, Luiz H.C.; Teodoro, Kelcilene B.R.

    2009-01-01

    Cellulose nanofibers have been extracted by acid hydrolysis from sisal fibers. They are seen a good source material due to availability and low cost. The nanofibers was evaluated by thermal degradation behavior using thermogravimetry (TG), crystallinity by X-ray diffraction and morphological structure was investigated by atomic force microscopy (AFM) experiments. The resulting nanofibers was shown high crystallinity and a network of rodlike cellulose elements. The nanofibers will be incorporated as reinforcement in a biodegradable matrix and evaluated. (author)

  8. Fracture Resistance Evaluation of Fibre Reinforced Brittle Matrix Composites

    Czech Academy of Sciences Publication Activity Database

    Dlouhý, Ivo; Chlup, Zdeněk

    2005-01-01

    Roč. 290, - (2005), s. 167-174 ISSN 1013-9826. [Fractography of Advanced Ceramic s /2./. Stará Lesná, 03.10.2004-06.10.2004] R&D Projects: GA AV ČR(CZ) IAA2041003; GA ČR(CZ) GA101/02/0683 Keywords : fibre-reinforced ceramic s * glass matrix composites * chevron notch Subject RIV: JL - Materials Fatigue, Friction Mechanics Impact factor: 0.224, year: 2005

  9. Ceramic fiber reinforced glass-ceramic matrix composite

    Science.gov (United States)

    Bansal, Narottam P. (Inventor)

    1993-01-01

    A slurry of BSAS glass powders is cast into tapes which are cut to predetermined sizes. Mats of continuous chemical vapor deposition (CVD)-SiC fibers are alternately stacked with these matrix tapes. This tape-mat stack is warm-pressed to produce a 'green' composite which is heated to burn out organic constituents. The remaining interim material is then hot-pressed to form a BSAS glass-ceramic fiber-reinforced composite.

  10. Mechanical characterization and structural analysis of recycled fiber-reinforced-polymer resin-transfer-molded beams

    Science.gov (United States)

    Tan, Eugene Wie Loon

    1999-09-01

    The present investigation was focussed on the mechanical characterization and structural analysis of resin-transfer-molded beams containing recycled fiber-reinforced polymers. The beams were structurally reinforced with continuous unidirectional glass fibers. The reinforcing filler materials consisted entirely of recycled fiber-reinforced polymer wastes (trim and overspray). The principal resin was a 100-percent dicyclo-pentadiene unsaturated polyester specially formulated with very low viscosity for resin transfer molding. Variations of the resin transfer molding technique were employed to produce specimens for material characterization. The basic materials that constituted the structural beams, continuous-glass-fiber-reinforced, recycled-trim-filled and recycled-overspray-filled unsaturated polyesters, were fully characterized in axial and transverse compression and tension, and inplane and interlaminar shear, to ascertain their strengths, ultimate strains, elastic moduli and Poisson's ratios. Experimentally determined mechanical properties of the recycled-trim-filled and recycled-overspray-filled materials from the present investigation were superior to those of unsaturated polyester polymer concretes and Portland cement concretes. Mechanical testing and finite element analyses of flexure (1 x 1 x 20 in) and beam (2 x 4 x 40 in) specimens were conducted. These structurally-reinforced specimens were tested and analyzed in four-point, third-point flexure to determine their ultimate loads, maximum fiber stresses and mid-span deflections. The experimentally determined load capacities of these specimens were compared to those of equivalent steel-reinforced Portland cement concrete beams computed using reinforced concrete theory. Mechanics of materials beam theory was utilized to predict the ultimate loads and mid-span deflections of the flexure and beam specimens. However, these predictions proved to be severely inadequate. Finite element (fracture propagation

  11. EFFECT OF HARDENER ON MECHANICAL PROPERTIES OF CARBON FIBRE REINFORCED PHENOLIC RESIN COMPOSITES

    Directory of Open Access Journals (Sweden)

    S. SULAIMAN

    2008-04-01

    Full Text Available In this paper the effect of hardener on mechanical properties of carbon reinforced phenolic resin composites is investigated. Carbon fibre is one of the most useful reinforcement materials in composites, its major use being the manufacture of components in the aerospace, automotive, and leisure industries. In this study, carbon fibres are hot pressed with phenolic resin with various percentages of carbon fibre and hardener contents that range from 5-15%. Composites with 15% hardener content show an increase in flexural strength, tensile strength and hardness. The ultimate tensile strength (UTS, flexural strength and hardness for 15% hardener are 411.9 MPa, 51.7 MPa and 85.4 HRR respectively.

  12. In vitro comparative evaluation of the effect of two different fiber reinforcements on the fracture toughness of provisional restorative resins

    Directory of Open Access Journals (Sweden)

    Vaibhav D Kamble

    2012-01-01

    Clinical Implications: On the basis of this in--vitro study, the use of Glass and Polyethylene fibers tested may be an effective way to reinforce resins used to fabricate fixed provisional restorations.

  13. Chemical recycling of carbon fibers reinforced epoxy resin composites in oxygen in supercritical water

    International Nuclear Information System (INIS)

    Bai, Yongping; Wang, Zhi; Feng, Liqun

    2010-01-01

    The carbon fibers in carbon fibers reinforced epoxy resin composites were recovered in oxygen in supercritical water at 30 ± 1 MPa and 440 ± 10 o C. The microstructure of the recovered carbon fibers was observed using scanning electron microscopy (SEM) and atom force microscopy (AFM). The results revealed that the clean carbon fibers were recovered and had higher tensile strength relative to the virgin carbon fibers when the decomposition rate was above 85 wt.%, although the recovered carbon fibers have clean surface, the epoxy resin on the surface of the recovered carbon fibers was readily observed. As the decomposition rate increased to above 96 wt.%, no epoxy resin was observed on the surface of the carbon fibers and the oxidation of the recovered carbon fibers was readily measured by X-ray photoelectron spectroscopy (XPS) analysis. The carbon fibers were ideally recovered and have original strength when the decomposition rates were between 94 and 97 wt.%. This study clearly showed the oxygen in supercritical water is a promising way for recycling the carbon fibers in carbon fibers reinforced resin composites.

  14. The Effect of an Active Diluent on the Properties of Epoxy Resin and Unidirectional Carbon-Fiber-Reinforced Plastics

    Science.gov (United States)

    Solodilov, V. I.; Gorbatkina, Y. A.; Kuperman, A. M.

    2003-11-01

    The influence of an active diluent on the properties of an epoxy matrix and carbon-fiber-reinforced plastics (CFRP) is investigated. The physicomechanical properties of an ED-20 epoxy resin modified with diglycidyl ether of diethylene glycol (DEG-1), the adhesion strength at the epoxy matrix-steel wire interface, and the mechanical properties of unidirectional CFRP are determined. The concentration of DEG-1 was varied from 0 to 50 wt.%. The properties of the matrix, the interface, and the composites are compared. It is stated that the matrix strength affects the strength of unidirectional CFRP in bending and not their strength in tension, compression, and shear. The latter fact seems somewhat unexpected. The interlaminar fracture toughness of the composites investigated correlates with the ultimate elongation of the binder. A comparison between the concentration dependences of adhesion strength and the strength of CFRP shows that the matrices utilized provide such a high interfacial strength that the strength of CFRP no longer depends on the adhesion of its constituents.

  15. Natural tooth pontic with splinting of periodontally weakened teeth using fiber-reinforced composite resin

    Directory of Open Access Journals (Sweden)

    Gauri Srinidhi

    2014-01-01

    Full Text Available Replacement of missing anterior teeth due to periodontal reasons is challenging due to the poor support of abutment teeth. This prevents the use of fixed partial dentures (FPDs. Fiber-reinforced splinting provides a viable alternative to the dentist while choosing a treatment plan in replacing missing anterior teeth in periodontally compromised patients as opposed to conventional modalities like FPDs or removable partial dentures. Replacing missing teeth using either patient′s own tooth or a denture tooth as pontic can be done by splinting adjacent teeth with fiber reinforced composite. The splinting has an additional advantage of stabilizing adjacent mobile teeth. This case report details the case selection, procedure with follow-up of a case where the natural extracted tooth of the patient was used as pontic to replace a missing anterior tooth. The splinting was done with fiber reinforced composite resin. Fiber-reinforced composite resin splinting of patient′s extracted natural tooth is economical, fast, and easy to use chairside technique with the added benefit of periodontal stabilization.

  16. Effects of alumina nanoparticles on dynamic impact responses of carbon fiber reinforced epoxy matrix nanocomposites

    OpenAIRE

    Halil B. Kaybal; Hasan Ulus; Okan Demir; Ömer S. Şahin; Ahmet Avcı

    2018-01-01

    The influence of alumina (Al2O3) nanoparticles addition upon low-velocity impact behaviors of carbon fiber (CF) reinforced laminated epoxy nanocomposites have been investigated. For this purpose, different amounts of Al2O3 nanoparticles ranging from 1 to 5 wt% were added to the epoxy resin in order to observe the effect of nanoparticle loadings. CF reinforced epoxy based laminated nanocomposites were produced using Vacuum Assisted Resin Infusion Method (VARIM). The low velocity impact (LVI) t...

  17. Reinforcement of a PMMA resin for fixed interim prostheses with nanodiamonds.

    Science.gov (United States)

    Protopapa, Popi; Kontonasaki, Eleana; Bikiaris, Dimitrios; Paraskevopoulos, Konstantinos M; Koidis, Petros

    2011-01-01

    The aim of this study was to investigate the possible reinforcement of Nanodiamonds (ND) in a PMMA resin for fixed interim restorations. The fracture toughness (K(Ic)), impact strength and the dynamic thermomechanical properties (T(g), E´, E´´, tanδ) of a series of PMMA-ND nanocomposites with different amounts of ND were evaluated. The fracture toughness increased as the ND percentage increased up to 0.38% wt but a greater amount of ND induced a decrease in K(Ic). Impact strength and Young's modulus were also increased by increasing nanoparticles content, indicating the reinforcing effect of ND. Dynamic mechanical properties were also affected. By increasing the ND content an increase of storage modulus was recorded, while glass transition was shifted at higher temperatures. Under the limitations of this study, it can be suggested that reinforcing PMMA with ND nanoparticles -especially at low concentrations- may increase the overall performance of fixed interim prostheses.

  18. Discontinuously reinforced intermetallic matrix composites via XD synthesis. [exothermal dispersion

    Science.gov (United States)

    Kumar, K. S.; Whittenberger, J. D.

    1992-01-01

    A review is given of recent results obtained for discontinuously reinforced intermetallic matrix composites produced using the XD process. Intermetallic matrices investigated include NiAl, multiphase NiAl + Ni2AlTi, CoAl, near-gamma titanium aluminides, and Ll2 trialuminides containing minor amounts of second phase. Such mechanical properties as low and high temperature strength, compressive and tensile creep, elastic modulus, ambient ductility, and fracture toughness are discussed as functions of reinforcement size, shape, and volume fraction. Microstructures before and after deformation are examined and correlated with measured properties. An observation of interest in many of the systems examined is 'dispersion weakening' at high temperatures and high strain rates. This behavior is not specific to the XD process; rather similar observations have been reported in other discontinuous composites. Proposed mechanisms for this behavior are presented.

  19. Behavior study of spend ion exchange resins immobilized in pyrolyzed polymer matrix

    International Nuclear Information System (INIS)

    Ramos, P.B; Fuentes, N.O; Luca, V.

    2012-01-01

    The pyrolysis of spent ion exchange resins contained in epoxy resins represents an attractive alternative to cementation as a confining method. In this sense, a significant reduction of volume can be achieved, as well as avoiding the dispersion of the exhausted ion exchange resin by the means of an epoxy resin used as a matrix, while potentially limiting the release of highly radioactive long life isotopes such us Cs-137, Sr-90 and Co-60 among others. Three types of monoliths were made: (i) epoxy resin, (ii) epoxy resin with carbon and (iii) a binder of epoxy resin and clay. In every case, the monolith contained the ion exchange resin. They were prepared by the mixing of resin pearl loaded with epoxy cations and a subsequent pyrolysis process with a temperature increase ratio of 2 o C /min reaching maximum values in the range between 200 o C - 800 o C, remaining in it for 1 hour. Monoliths obtained for each final temperature had been characterized to obtain data corresponding to the mass loss, volume reduction and lixiviation, as well as mechanical and microstructural properties (author)

  20. Leaching studies on ion exchange resins immobilized in bitumen matrix

    International Nuclear Information System (INIS)

    Grosche Filho, C.E.; Chandra, U.; Villalobos, J.P.

    1986-01-01

    Many samples of bitumen mixed with ion exchange resin labelled with 134 Cs were prepared to study radionuclide leaching from bitumen waste forms. The resins used in tests were nuclear grade mixed cationic/aniocic bead resins. Different bitumen types were assayed: two distilled and two oxidized bitumens. Leached fractions were collected accordingly to the recommendation of ISO method, with complete exchange of leachant after each sampling. The volume collected for analysis was one liter. Marinelli beckers were used to improve counting efficiency in a Ge(Li) detector. The diffusion coefficients for samples prepared with distilled and oxidized bitumens were obtained. Mathematical models of transport phenomena applied to cylindrical geometry was employed to fit experimental data aiming to explain leaching mechanism and predict the long time behavior of immobilized radionuclides. (M.C.K.) [pt

  1. [Three-point bending moment of two types of resin for temporary bridges after reinforcement with glass fibers].

    Science.gov (United States)

    Didia, E E; Akon, A B; Thiam, A; Djeredou, K B

    2010-03-01

    One of the concerns of the dental surgeon in the realization of any operational act is the durability of this one. The mechanical resistance of the provisional prostheses contributes in a large part to the durability of those. The resins in general, have weak mechanical properties. The purpose of this study is to evaluate the resistance in inflection of temporary bridges reinforced with glass fibre. To remedy the weak mechanical properties of resins, we thought in this study, to reinforce them with glass fibres. For this purpose, we realized with two different resins, four groups of temporary bridges of 3 elements, including two groups reinforced fibreglass and the others not. Tests of inflection 3 points have been made on these bridges and resistance to fracture was analysed. The statistical tests showed a significant difference in four groups with better resistance for the reinforced bridges.

  2. Carbide-reinforced metal matrix composite by direct metal deposition

    Science.gov (United States)

    Novichenko, D.; Thivillon, L.; Bertrand, Ph.; Smurov, I.

    Direct metal deposition (DMD) is an automated 3D laser cladding technology with co-axial powder injection for industrial applications. The actual objective is to demonstrate the possibility to produce metal matrix composite objects in a single-step process. Powders of Fe-based alloy (16NCD13) and titanium carbide (TiC) are premixed before cladding. Volume content of the carbide-reinforced phase is varied. Relationships between the main laser cladding parameters and the geometry of the built-up objects (single track, 2D coating) are discussed. On the base of parametric study, a laser cladding process map for the deposition of individual tracks was established. Microstructure and composition of the laser-fabricated metal matrix composite objects are examined. Two different types of structures: (a) with the presence of undissolved and (b) precipitated titanium carbides are observed. Mechanism of formation of diverse precipitated titanium carbides is studied.

  3. Restorasi Resin Komposit dengan Pasak Fiber Reinforced Composite untuk Perbaikan Gigi Insisivus Sentralis Maksila Pasca Trauma

    Directory of Open Access Journals (Sweden)

    Mella Synthya Dewi

    2011-06-01

    Full Text Available Latar belakang. Trauma pada gigi dapat menyebabkan injuri pulpa dengan atau tanpa kerusakan mahkota atau akar. Pulpektomi menjadi pilihan perawatan pada fraktur mahkota yang membutuhkan restorasi kompleks. Gigi pasca perawatan saluran akar biasanya telah kehilangan struktur jaringan keras yang cukup banyak sehingga membutuhkan retensi intrakanal berupa pasak untuk mendukung restorasi akhir. Pasak Fiber Reinforced Composite (FRG memiliki flexure dan fatigue strength yang lebih besar, modulus elastisitas yang mendekati dentin, kemampuan untuk membentuk monoblok (kompleks akar-pasak dalam saluran akar, dan meningkatkan estetik jika dibandingkan dengan pasak logam. Resin komposit memiliki warna dan translusensi yang menyerupai dentin dan email sehingga mampu menghasilkan estetik yang baik pada gigi anterior. Tujuan. Melaporkan restorasi resin komposit dengan pasak FRG untuk memperbaiki gigi insisivus sentralis maksila yang mengalami fraktur mahkota kompleks pasca trauma. Kasus dan penanganan. Perempuan 20 tahun, gigi insisivus sentralis kanan dan kiri maksila mengalami Fraktur Ellis klas III akibat kecelakaan. Gigi 11 pulpitis ireversibel dan gigi 21 nekrosis pulpa. Kedua gigi malposisi. Dilakukan pulpektomi atau perawatan saluran akar multi kunjungan. Resin komposit dengan pasak FRG customized digunakan sebagai restorasi akhir. Kesimpulan. Restorasi resin komposit dengan pasak FRG customized memberikan hasil yang memuaskan secara estetik dan fungsional untuk merestorasi gigi insisivus sentralis pasca trauma dan perawatan saluran akar.

  4. Effect of Home Bleaching on Microleakage of Fiber-reinforced and Particle-filled Composite Resins

    Directory of Open Access Journals (Sweden)

    Farahnaz Sharafeddin

    2013-12-01

    Full Text Available Background and aims. Bleaching may exert some negative effects on existing composite resin restorations. The aim of this study was to evaluate the effect of home bleaching on microleakage of fiber-reinforced and particle-filled composite resins. Materials and methods. Ninety class V cavities (1.5×2×3 mm were prepared on the buccal surfaces of 90 bovine teeth. The teeth were randomly divided into 6 groups (n=15 and restored as follows: Groups 1 and 2 with Z100, groups 3 and 4 with Z250, and groups 5 and 6 with Nulite F composite resins. All the specimens were thermocycled. Groups 1, 3 and 5 were selected as control groups (without bleaching and the experimental groups 2, 4 and 6 were bleached with 22% carbamide peroxide gel. All the samples were immersed in 2% basic fuchsin dye for 24 hours and then sectioned longitudinally. Dye penetration was evaluated under a stereomicroscope (×25, at both the gingival and incisal margins. Data were analyzed using Kruskal-Wallis, Mann-Whitney and Wilcoxon tests (α=0.05. Results. Statistical analyses revealed that bleaching gel increased microleakage only at gingival margins with Z250 (P=0.007. Moreover, the control groups showed a statistically significant difference in microleakage at their gingival margins. Nulite F had the maximum microleakage while Z250 showed the minimum (P=0.006. Conclusion. Microleakage of home-bleached restorations might be related to the type of composite resin used.

  5. Experimental resin cements containing bioactive fillers reduce matrix metalloproteinase-mediated dentin collagen degradation.

    Science.gov (United States)

    Osorio, Raquel; Yamauti, Monica; Sauro, Salvatore; Watson, Thimoty F; Toledano, Manuel

    2012-09-01

    Collagen dentin matrix may represent a suitable scaffold to be remineralized in the presence of bioactive materials. The purpose of this study was to determine if experimental resin cements containing bioactive fillers may modulate matrix metalloproteinase-mediated collagen degradation of etched dentin. Human dentin beams demineralized using 10% phosphoric acid or 0.5 mol/L EDTA were infiltrated with the following experimental resins: (1) unfilled resin, (2) resin with Bioglass 45S5 particles (Sylc; OSspray Ltd, London, UK), and (3) resin with β-tricalcium phosphate-modified calcium silicate cement (HCAT-β) particles. The filler/resin ratio was 40/60 wt%. The specimens were stored in artificial saliva, and the determination of C-terminal telopeptide (ICTP) was performed by radioimmunoassay after 24 hours, 1 week, and 4 weeks. Scanning electron microscopic analysis of dentin surfaces after 4 weeks of storage was also executed. Collagen degradation was prominent both in phosphoric acid and EDTA-treated dentin. Resin infiltration strongly reduced the MMP activity in demineralized dentin. Resin-containing Bioglass 45S5 particles exerted higher and more stable protection of collagen at all tested dentin states and time points. HCAT-β induced collagen protection from MMPs only in EDTA-treated specimens. Dentin remineralization was achieved when dentin was infiltrated with the resin cements containing bioactive fillers. MMP degradation of dentin collagen is strongly reduced in resin-infiltrated dentin. The inclusion of Bioglass 45S5 particles exerted an additional protection of collagen during dentin remineralization. Copyright © 2012 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  6. Leaching studies on ion exchange resins immobilized in bitument matrix

    International Nuclear Information System (INIS)

    Grosche Filho, C.E.; Chandra, U.; Villalobos, J.P.

    1987-01-01

    To study radionuclide leaching from bitumen waste forms, many samples of bitumen mixed with ion-exchange resin labelled with 134 Cs were prepared. The resins used in the tests were nuclear grade mixed cationic/anionic bead resins. Different bittumen types were assayed: two destilled and to oxidized bitumens. Laboratory to scale samples, with surface/volume ratio (S/V) = 1, were molded to 5 cm diameter and 10 cm height. The composition of the mixtures were: 30, 40, 50 and 60% by weight of dried resin with bitumen. The leachant was deionized water with a leachant volume to sample surface rario of about 8 cm. Leached fractions were collected according to the recommendation of ISO method, with complete exchange of leachant beckers after each sampling. The volume collected for analysis was one liter. Marinelli were used for counting in a Ge(Li) detector. Up to now, results of 250 days have been accumulated. Samples prepared with distilled bitumen have shown a diffusion coefficient of the order of 10 -14 cm 2 /sec and those prepared with oxidized bitumen yielded a diffusion coefficient of the order of 10 -12 cm 2 /sec. Mathematical models of transport phenomena applied to cylindrical geometry were employed to fit experimental data. (Author) [pt

  7. Effect of Different Liners on Fracture Resistance of Premolars Restored with Conventional and Short Fiber-Reinforced Composite Resins.

    Science.gov (United States)

    Shafiei, Fereshteh; Doozandeh, Maryam; Ghaffaripour, Dordaneh

    2018-01-11

    To see whether applying four different liners under short fiber-reinforced composite (SFRC), everX Posterior, compared to conventional composite resin, Z250, affected their strengthening property in premolar MOD cavities. Mesio-occluso-distal (MOD) cavities were prepared in 120 sound maxillary premolars divided into 10 groups (n = 12) in terms of two composite resin types and 4 liners or no liner. For each composite resin, in 5 groups no liner, resin-modified glass ionomer (RMGI), conventional flowable composite (COFL), self-adhesive flowable composite resin (SAFL), and self-adhesive resin cement (SARC) were applied prior to restoring incrementally. After water storage and thermocycling, static fracture resistance was tested. Data (in Newtons) were analyzed using two-way ANOVA (α = 0.05). Fracture resistance was significantly affected by composite resin type (p = 0.02), but not by the liner (p > 0.05). The interaction of the two factors was not statistically significant (p > 0.05). SFRC exhibited higher fracture strength (1470 ± 200 N) compared to conventional composite resin (1350 ± 290), irrespective of the application of liners. Application of SARC and SAFL liners led to a higher number of restorable fractures for both composite resins. The four liners can be used without interfering with the higher efficacy of SFRC, compared to conventional composite resins, to improve the fracture strength of premolar MOD cavities. © 2018 by the American College of Prosthodontists.

  8. Assessment of Tensile Bond Strength of Fiber-Reinforced Composite Resin to Enamel Using Two Types of Resin Cements and Three Surface Treatment Methods

    Directory of Open Access Journals (Sweden)

    Tahereh Ghaffari

    2015-10-01

    Full Text Available Background: Resin-bonded bridgework with a metal framework is one of the most conservative ways to replace a tooth with intact abutments. Visibility of metal substructure and debonding are the complications of these bridgeworks. Today, with the introduction of fiber-reinforced composite resins, it is possible to overcome these complications. The aim of this study was to evaluate the bond strength of fiber-reinforced composite resin materials (FRC to enamel. Methods: Seventy-two labial cross-sections were prepared from intact extracted teeth. Seventy-two rectangular samples of cured Vectris were prepared and their thickness was increased by adding Targis. The samples were divided into 3 groups for three different surface treatments: sandblasting, etching with 9% hydrofluoric acid, and roughening with a round tapered diamond bur. Each group was then divided into two subgroups for bonding to etched enamel by Enforce and Variolink II resin cements. Instron universal testing machine was used to apply a tensile force. The fracture force was recorded and the mode of failure was identified under a reflective microscope. Results: There were no significant differences in bond strength between the three surface treatment groups (P=0.53. The mean bond strength of Variolink II cement was greater than that of Enforce (P=0.04. There was no relationship between the failure modes (cohesive and adhesive and the two cement types. There was some association between surface treatment and failure mode. There were adhesive failures in sandblasted and diamond-roughened groups and the cohesive failure was dominant in the etched group. Conclusion: It is recommended that restorations made of fiber-reinforced composite resin be cemented with VariolinkII and surface-treated by hydrofluoric acid.   Keywords: Tensile bond strength; surface treatment methods; fiber-reinforced composite resin

  9. Dual-nanoparticulate-reinforced aluminum matrix composite materials

    International Nuclear Information System (INIS)

    Kwon, Hansang; Cho, Seungchan; Kawasaki, Akira; Leparoux, Marc

    2012-01-01

    Aluminum (Al) matrix composite materials reinforced with carbon nanotubes (CNT) and silicon carbide nanoparticles (nano-SiC) were fabricated by mechanical ball milling, followed by hot-pressing. Nano-SiC was used as an active mixing agent for dispersing the CNTs in the Al powder. The hardness of the produced composites was dramatically increased, up to eight times higher than bulk pure Al, by increasing the amount of nano-SiC particles. A small quantity of aluminum carbide (Al 4 C 3 ) was observed by TEM analysis and quantified using x-ray diffraction. The composite with the highest hardness values contained some nanosized Al 4 C 3 . Along with the CNT and the nano-SiC, Al 4 C 3 also seemed to play a role in the enhanced hardness of the composites. The high energy milling process seems to lead to a homogeneous dispersion of the high aspect ratio CNTs, and of the nearly spherical nano-SiC particles in the Al matrix. This powder metallurgical approach could also be applied to other nanoreinforced composites, such as ceramics or complex matrix materials. (paper)

  10. Mechanical Properties of Natural Jute Fabric/Jute Mat Fiber Reinforced Polymer Matrix Hybrid Composites

    Directory of Open Access Journals (Sweden)

    Elsayed A. Elbadry

    2012-01-01

    Full Text Available Recycled needle punched jute fiber mats as a first natural fiber reinforcement system and these jute mats used as a core needle punched with recycled jute fabric cloths as skin layers as a second natural fiber reinforcement system were used for unsaturated polyester matrix composites via modifying the hand lay-up technique with resin preimpregnation into the jute fiber in vacuum. The effect of skin jute fabric on the tensile and bending properties of jute mat composites was investigated for different fiber weight contents. Moreover, the notch sensitivity of these composites was also compared by using the characteristic distance do calculated by Finite Element Method (FEM. The results showed that the tensile and flexural properties of jute mat composites increased by increasing the fiber weight content and by adding the jute fabric as skin layers. On the other hand, by adding the skins, the characteristic distance decreased and, therefore, the notch sensitivity of the composites increased. The fracture behavior investigated by SEM showed that extensive fiber pull-out mechanism was revealed at the tension side of jute mat composites under the bending load and by adding the jute cloth, the failure mode of jute mat was changed to fiber bridge mechanism.

  11. Effect of reinforcement with resin composite on fracture strength of structurally compromised roots.

    Science.gov (United States)

    Fukui, Yuji; Komada, Wataru; Yoshida, Keiichi; Otake, Shiho; Okada, Daizo; Miura, Hiroyuki

    2009-09-01

    This study was aimed at evaluating the fracture resistance of structurally compromised roots restored with four different post and core systems. Thirty-two bovine roots were uniformly shaped to simulate human mandibular premolar roots. The roots were divided into four groups based on the type of restoration: cemented cast post and core (Group MC), resin composite build-up (Group CR), resin composite and prefabricated glass fiber post build-up (Group FRC), and thick-layer dual-cured resin composite-reinforced small-diameter tapered cast post and core (Group CRM). After a static loading test, the failure mode and fracture resistance were recorded. Group CRM (719.38+/-196.73 N) exhibited a significantly high fracture resistance compared with the other groups (Group MC: 429.56+/-82.43 N; Group CR: 349.56+/-66.21 N; Group FRC: 398.94+/-112.71 N; pCRM exhibited better mechanical properties for structurally compromised roots with no ferrules, although all types of restorations showed non-restorable fracture modes.

  12. Environmentally Compliant Vinyl Ester Resin (VER) Composite Matrix Resin Derived from Renewable Resources

    Science.gov (United States)

    2011-11-01

    polycar- bonate and polyacrylate thermoplastic resins. Annual production of phenol in the United States (Dow) exceeds 650 million pounds with virtually...second method reacted glycidol with methyl methacrylate in the presence of 2, 4- dimethyl-6-tert.butyl phenol and potassium cyanide [24]. The mixture...presence of DCC and the second reacted glycidol with methyl methacrylate in the presence of potassium cyanide and 2, 4-dimethyl-6-tert.butyl phenol

  13. Creep Forming of Carbon-Reinforced Ceramic-Matrix Composites

    Science.gov (United States)

    Vaughn, Wallace L.; Scotti, Stephan J.; Ashe, Melissa P.; Connolly, Liz

    2007-01-01

    A set of lecture slides describes an investigation of creep forming as a means of imparting desired curvatures to initially flat stock plates of carbon-reinforced ceramic-matrix composite (C-CMC) materials. The investigation is apparently part of a continuing effort to develop improved means of applying small CCMC repair patches to reinforced carbon-carbon leading edges of aerospace vehicles (e.g., space shuttles) prior to re-entry into the atmosphere of the Earth. According to one of the slides, creep forming would be an intermediate step in a process that would yield a fully densified, finished C-CMC part having a desired size and shape (the other steps would include preliminary machining, finish machining, densification by chemical vapor infiltration, and final coating). The investigation included experiments in which C-CMC disks were creep-formed by heating them to unspecified high temperatures for time intervals of the order of 1 hour while they were clamped into single- and double-curvature graphite molds. The creep-formed disks were coated with an oxidation- protection material, then subjected to arc-jet tests, in which the disks exhibited no deterioration after exposure to high-temperature test conditions lasting 490 seconds.

  14. Novel matrix resins for composites for aircraft primary structures, phase 1

    Science.gov (United States)

    Woo, Edmund P.; Puckett, P. M.; Maynard, S.; Bishop, M. T.; Bruza, K. J.; Godschalx, J. P.; Mullins, M. J.

    1992-01-01

    The objective of the contract is the development of matrix resins with improved processability and properties for composites for primarily aircraft structures. To this end, several resins/systems were identified for subsonic and supersonic applications. For subsonic aircraft, a series of epoxy resins suitable for RTM and powder prepreg was shown to give composites with about 40 ksi compressive strength after impact (CAI) and 200 F/wet mechanical performance. For supersonic applications, a thermoplastic toughened cyanate prepreg system has demonstrated excellent resistance to heat aging at 360 F for 4000 hours, 40 ksi CAI and useful mechanical properties at greater than or equal to 310 F. An AB-BCB-maleimide resin was identified as a leading candidate for the HSCT. Composite panels fabricated by RTM show CAI of approximately 50 ksi, 350 F/wet performance and excellent retention of mechanical properties after aging at 400 F for 4000 hours.

  15. Near-Infrared Spectroscopic Method for Monitoring Water Content in Epoxy Resins and Fiber-Reinforced Composites

    Directory of Open Access Journals (Sweden)

    Andrey E. Krauklis

    2018-04-01

    Full Text Available Monitoring water content and predicting the water-induced drop in strength of fiber-reinforced composites are of great importance for the oil and gas and marine industries. Fourier transform infrared (FTIR spectroscopic methods are broadly available and often used for process and quality control in industrial applications. A benefit of using such spectroscopic methods over the conventional gravimetric analysis is the possibility to deduce the mass of an absolutely dry material and subsequently the true water content, which is an important indicator of water content-dependent properties. The objective of this study is to develop an efficient and detailed method for estimating the water content in epoxy resins and fiber-reinforced composites. In this study, Fourier transform near-infrared (FT-NIR spectroscopy was applied to measure the water content of amine-epoxy neat resin. The method was developed and successfully extended to glass fiber-reinforced composite materials. Based on extensive measurements of neat resin and composite samples of varying water content and thickness, regression was performed, and the quantitative absorbance dependence on water content in the material was established. The mass of an absolutely dry resin was identified, and the true water content was obtained. The method was related to the Beer–Lambert law and explained in such terms. A detailed spectroscopic method for measuring water content in resins and fiber-reinforced composites was developed and described.

  16. Near-Infrared Spectroscopic Method for Monitoring Water Content in Epoxy Resins and Fiber-Reinforced Composites.

    Science.gov (United States)

    Krauklis, Andrey E; Gagani, Abedin I; Echtermeyer, Andreas T

    2018-04-11

    Monitoring water content and predicting the water-induced drop in strength of fiber-reinforced composites are of great importance for the oil and gas and marine industries. Fourier transform infrared (FTIR) spectroscopic methods are broadly available and often used for process and quality control in industrial applications. A benefit of using such spectroscopic methods over the conventional gravimetric analysis is the possibility to deduce the mass of an absolutely dry material and subsequently the true water content, which is an important indicator of water content-dependent properties. The objective of this study is to develop an efficient and detailed method for estimating the water content in epoxy resins and fiber-reinforced composites. In this study, Fourier transform near-infrared (FT-NIR) spectroscopy was applied to measure the water content of amine-epoxy neat resin. The method was developed and successfully extended to glass fiber-reinforced composite materials. Based on extensive measurements of neat resin and composite samples of varying water content and thickness, regression was performed, and the quantitative absorbance dependence on water content in the material was established. The mass of an absolutely dry resin was identified, and the true water content was obtained. The method was related to the Beer-Lambert law and explained in such terms. A detailed spectroscopic method for measuring water content in resins and fiber-reinforced composites was developed and described.

  17. Development of high radiation-resistant glass fiber reinforced plastics with cyanate-based resin for superconducting magnet systems

    Energy Technology Data Exchange (ETDEWEB)

    Idesaki, Akira, E-mail: idesaki.akira@qst.go.jp [Quantum Beam Science Directorate, Japan Atomic Energy Agency, Watanuki 1233, Takasaki, Gunma 370-1292 (Japan); Nakamoto, Tatsushi [Cryogenic Science Center, High Energy Accelerator Research Organization (KEK), 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan); Yoshida, Makoto [Institute of Particle and Nuclear Studies, High Energy Accelerator Research Organization (KEK), 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan); Shimada, Akihiko [Quantum Beam Science Directorate, Japan Atomic Energy Agency, Watanuki 1233, Takasaki, Gunma 370-1292 (Japan); Iio, Masami; Sasaki, Kenichi; Sugano, Michinaka [Cryogenic Science Center, High Energy Accelerator Research Organization (KEK), 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan); Makida, Yasuhiro [Institute of Particle and Nuclear Studies, High Energy Accelerator Research Organization (KEK), 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan); Ogitsu, Toru [Cryogenic Science Center, High Energy Accelerator Research Organization (KEK), 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan)

    2016-11-15

    Highlights: • GFRPs for superconducting magnet systems were developed. • Cyanate-based resins were used for GFRPs as matrices. • Radiation resistance was evaluated based on gas evolution and mechanical properties. • GFRP with bismaleimide-triazine resin exhibited excellent radiation resistance. - Abstract: Glass fiber reinforced plastics (GFRPs) with cyanate ester resin/epoxy resin, bismaleimide resin/epoxy resin, and bismaleimide-triazine resin as matrices were developed for the superconducting magnet systems used in high intensity accelerators. The radiation resistance of these GFRPs was evaluated based on their gas evolution and changes in their mechanical properties after gamma-ray irradiation with dose of 100 MGy in vacuum at ambient temperature. After irradiation, a small amount of gas was evolved from all of the GFRPs, and a slight decrease in mechanical properties was observed compared with the conventional epoxy resin-GFRP, G10. Among the GFRPs, the smallest amount of gas (6 × 10{sup −5} mol/g) was evolved from the GFRP with the bismaleimide-triazine resin, which also retained more than 88% of its flexural strength after 100 MGy irradiation; this GFRP is thus considered the most promising material for superconducting magnet systems.

  18. Simulating Resin Infusion through Textile Reinforcement Materials for the Manufacture of Complex Composite Structures

    Directory of Open Access Journals (Sweden)

    Robert S. Pierce

    2017-10-01

    Full Text Available Increasing demand for weight reduction and greater fuel efficiency continues to spur the use of composite materials in commercial aircraft structures. Subsequently, as composite aerostructures become larger and more complex, traditional autoclave manufacturing methods are becoming prohibitively expensive. This has prompted renewed interest in out-of-autoclave processing techniques in which resins are introduced into a reinforcing preform. However, the success of these resin infusion methods is highly dependent upon operator skill and experience, particularly in the development of new manufacturing strategies for complex parts. Process modeling, as a predictive computational tool, aims to address the issues of reliability and waste that result from traditional trial-and-error approaches. Basic modeling attempts, many of which are still used in industry, generally focus on simulating fluid flow through an isotropic porous reinforcement material. However, recent efforts are beginning to account for the multiscale and multidisciplinary complexity of woven materials, in simulations that can provide greater fidelity. In particular, new multi-physics process models are able to better predict the infusion behavior through textiles by considering the effect of fabric deformation on permeability and porosity properties within the reinforcing material. In addition to reviewing previous research related to process modeling and the current state of the art, this paper highlights the recent validation of a multi-physics process model against the experimental infusion of a complex double dome component. By accounting for deformation-dependent flow behavior, the multi-physics process model was able to predict realistic flow behavior, demonstrating considerable improvement over basic isotropic permeability models.

  19. Evaluation of the Compressive Strength of Cement-Spent Resins Matrix Mixed with Bio char

    International Nuclear Information System (INIS)

    Zalina Laili; Muhamad Samudi Yasir; Zalina Laili; Mohd Abdul Wahab; Nur Azna Mahmud; Nurfazlina Zainal Abidin

    2015-01-01

    The evaluation of compressive strength of cement-spent resins matrix mixed with bio char was investigated. In this study, bio char with different percentage (5 %, 8 %, 11 % 14 % and 18 %) was used as alternative admixture material for cement solidification of spent resins. Some properties of the physical and chemical of spent resins and bio char were also investigated. The performance of cemented spent resins with the addition of bio char was evaluated based on their compressive strength and the water resistance test. The compressive strength was evaluated at three different curing periods of 7, 14 and 28 days, while 4 weeks of immersion in distilled water was chosen for water resistance test. The result indicated that the compressive strength at 7, 14 and 28 days of curing periods were above the minimum criterion for example > 3.45 MPa of acceptable level for cemented waste form. Statistical analysis showed that there was no significant relationship between the compressive strength of the specimen and the percentage of bio char content. Result from the water resistance test showed that only one specimen that contained of 5 % of bio char failed the water resistance test due to the high of spent resins/ bio char ratio. The compressive strength of cement solidified spent resins was found increased after the water resistance test indicating further hydration occurred after immersed in water. The results of this study also suggest that the specimen with 8 %, 11 %, 14 % and 18 % of bio char content were resistance in water and suitable for the leaching study of radionuclides from cement-bio char-spent resins matrix. (author)

  20. Microtensile bond strength of a resin cement to glass infiltrated zirconia-reinforced ceramic: The effect of surface conditioning

    NARCIS (Netherlands)

    Amaral, R.; Ozcan, M.; Bottino, M.A.; Valandro, L.F.

    2006-01-01

    Objectives. This study evaluated the effect of three surface conditioning methods on the microtensile bond strength of resin cement to a glass-infiltrated zirconia-reinforced alumina-based core ceramic. Methods. Thirty blocks (5 x 5 x 4 mm) of In-Ceram Zirconia ceramics (In-Ceram Zirconia-INC-ZR,

  1. Microtensile bond strength of a resin cement to glass infiltrated zirconia-reinforced ceramic : The effect of surface conditioning

    NARCIS (Netherlands)

    Amaral, R; Ozcan, M; Bottino, MA; Valandro, LF

    Objectives. This study evaluated the effect of three surface conditioning methods on the microtensile bond strength of resin cement to a glass-infiltrated zirconia-reinforced alumina-based core ceramic. Methods. Thirty blocks (5 x 5 x 4 mm) of In-Ceram Zirconia ceramics (In-Ceram Zirconia-INC-ZR,

  2. Reinforcement of a PMMA resin for interim fixed prostheses with silica nanoparticles.

    Science.gov (United States)

    Topouzi, Marianthi; Kontonasaki, Eleana; Bikiaris, Dimitrios; Papadopoulou, Lambrini; Paraskevopoulos, Konstantinos M; Koidis, Petros

    2017-05-01

    Fractures in long span provisional/interim restorations are a common complication. Adequate fracture toughness is necessary to resist occlusal forces and crack propagation, so these restorations should be constructed with materials of improved mechanical properties. The aim of this study was to investigate the possible reinforcement of neat silica nanoparticles and trietoxyvinylsilane-modified silica nanoparticles in a PMMA resin for fixed interim restorations. Composite PMMA-Silica nanoparticles powders were mixed with PMMA liquid and compact bar shaped specimens were fabricated according to the British standard BS EN ISO 127337:2005. The single-edge notched method was used to evaluate fracture toughness (three-point bending test), while the dynamic thermomechanical properties (Storage Modulus, Loss Modulus, tanδ) of a series of nanocomposites with different amounts of nanoparticles (0.25%, 0.50%, 0.75%, 1% w.t.) were evaluated. Statistical analysis was performed and the statistically significant level was set to pPMMA resins used in fixed provisional restorations. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Discontinuously reinforced titanium matrix composites for fusion applications

    International Nuclear Information System (INIS)

    Castro, V.; Leguey, T.; Monge, M.A.; Munoz, A.; Pareja, R.; Victoria, M.

    2002-01-01

    We have reinforced α-Ti with different contents of TiC particles using the in situ technique and conventional casting. Compositional and microstructural characterization of the TiC/Ti composite material was made by XRD and SEM-EDS. Tensile tests at RT, 723 and 973 K have been performed on samples heat treated at 1000 K for 30 min which were prepared from cold rolled material. The effect of the content, size and morphology of the TiC particles on the tensile properties has been investigated. The results indicate that the expected improvement in the mechanical characteristics of TiC/Ti composites is inhibited by the detrimental presence of coarse dendritic particles of TiC. The premature failure of these composites at RT is due to cracking of the coarse TiC particles. Local softening due to inhomogeneous plastic deformation of the Ti matrix appears to contribute to the tensile failure of the TiC/Ti composites deformed at 723 and 973 K.

  4. Discontinuously reinforced titanium matrix composites for fusion applications

    Energy Technology Data Exchange (ETDEWEB)

    Castro, V. E-mail: mvcastro@fis.uc3m.es; Leguey, T.; Monge, M.A.; Munoz, A.; Pareja, R.; Victoria, M

    2002-12-01

    We have reinforced {alpha}-Ti with different contents of TiC particles using the in situ technique and conventional casting. Compositional and microstructural characterization of the TiC/Ti composite material was made by XRD and SEM-EDS. Tensile tests at RT, 723 and 973 K have been performed on samples heat treated at 1000 K for 30 min which were prepared from cold rolled material. The effect of the content, size and morphology of the TiC particles on the tensile properties has been investigated. The results indicate that the expected improvement in the mechanical characteristics of TiC/Ti composites is inhibited by the detrimental presence of coarse dendritic particles of TiC. The premature failure of these composites at RT is due to cracking of the coarse TiC particles. Local softening due to inhomogeneous plastic deformation of the Ti matrix appears to contribute to the tensile failure of the TiC/Ti composites deformed at 723 and 973 K.

  5. Milling of Nanoparticles Reinforced Al-Based Metal Matrix Composites

    Directory of Open Access Journals (Sweden)

    Alokesh Pramanik

    2018-03-01

    Full Text Available This study investigated the face milling of nanoparticles reinforced Al-based metal matrix composites (nano-MMCs using a single insert milling tool. The effects of feed and speed on machined surfaces in terms of surface roughness, surface profile, surface appearance, chip surface, chip ratio, machining forces, and force signals were analyzed. It was found that surface roughness of machined surfaces increased with the increase of feed up to the speed of 60 mm/min. However, at the higher speed (100–140 mm/min, the variation of surface roughness was minor with the increase of feed. The machined surfaces contained the marks of cutting tools, lobes of material flow in layers, pits and craters. The chip ratio increased with the increase of feed at all speeds. The top chip surfaces were full of wrinkles in all cases, though the bottom surfaces carried the evidence of friction, adhesion, and deformed material layers. The effect of feed on machining forces was evident at all speeds. The machining speed was found not to affect machining forces noticeably at a lower feed, but those decreased with the increase of speed for the high feed scenario.

  6. The study on compatibility of polymer matrix resins with liquid oxygen

    International Nuclear Information System (INIS)

    Wang Ge; Li Xiaodong; Yan Rui; Xing Suli

    2006-01-01

    Liquid oxygen (LOX) polymer composite tank is very important in the development of next generation of launch vehicles. To study LOX compatible polymeric matrix resins, three kinds of epoxy resins were studied. LOX impact test was used to evaluate polymers' compatibility with LOX. Thermogravimetric analysis was used to analyze polymers' oxidation. It seemed that polymers with better anti-oxidation properties, characterized by lower oxidation weight gain, lower weight loss and lower flash point, behaved better LOX compatibility. Fourier transform infrared attenuated total reflection spectroscopy confirmed the chemical reactions during the LOX impact process on the surface of polymers were similar to the oxidation reaction in gaseous oxygen (GOX) at high temperatures, which indicated the chemical mechanism of LOX compatibility of polymers was just oxidation reaction. In this way, two new epoxy resins with desirable LOX compatibility were acquired by modification

  7. High temperature resin matrix composites for aerospace structures

    Science.gov (United States)

    Davis, J. G., Jr.

    1980-01-01

    Accomplishments and the outlook for graphite-polyimide composite structures are briefly outlined. Laminates, skin-stiffened and honeycomb sandwich panels, chopped fiber moldings, and structural components were fabricated with Celion/LARC-160 and Celion/PMR-15 composite materials. Interlaminar shear and flexure strength data obtained on as-fabricated specimens and specimens that were exposed for 125 hours at 589 K indicate that epoxy sized and polyimide sized Celion graphite fibers exhibit essentially the same behavior in a PMR-15 matrix composite. Analyses and tests of graphite-polyimide compression and shear panels indicate that utilization in moderately loaded applications offers the potential for achieving a 30 to 50 percent reduction in structural mass compared to conventional aluminum panels. Data on effects of moisture, temperature, thermal cycling, and shuttle fluids on mechanical properties indicate that both LARC-160 and PMR-15 are suitable matrix materials for a graphite-polyimide aft body flap. No technical road blocks to building a graphite-polyimide composite aft body flap are identified.

  8. FT-Raman spectroscopy study of organic matrix degradation in nanofilled resin composite.

    Science.gov (United States)

    Soares, Luís Eduardo Silva; Nahórny, Sídnei; Martin, Airton Abrahão

    2013-04-01

    This in vitro study evaluated the effect of light curing unit (LCU) type, mouthwashes, and soft drink on chemical degradation of a nanofilled resin composite. Samples (80) were divided into eight groups: halogen LCU, HS--saliva (control); HPT--Pepsi Twist®; HLC--Listerine®; HCP--Colgate Plax®; LED LCU, LS--saliva (control); LPT--Pepsi Twist®; LLC--Listerine®; LCP--Colgate Plax®. The degree of conversion analysis and the measure of the peak area at 2,930 cm-1 (organic matrix) of resin composite were done by Fourier-transform Raman spectroscopy (baseline, after 7 and 14 days). The data were subjected to multifactor analysis of variance (ANOVA) at a 95% confidence followed by Tukey's HSD post-hoc test. The DC ranged from 58.0% (Halogen) to 59.3% (LED) without significance. Differences in the peak area between LCUs were found after 7 days of storage in S and PT. A marked increase in the peak intensity of HLC and LLC groups was found. The soft-start light-activation may influence the chemical degradation of organic matrix in resin composite. Ethanol contained in Listerine® Cool Mint mouthwash had the most significant degradation effect. Raman spectroscopy is shown to be a useful tool to investigate resin composite degradation.

  9. Influence of tool pin in friction stir welding on activated carbon reinforced aluminium metal matrix composite

    Science.gov (United States)

    DijuSamuel, G.; Raja Dhas, J. Edwin

    2017-10-01

    This paper focus on impact of tool pin in friction stir welding on activated carbon reinforced aluminium metal matrix composite. For fabrication of metal matrix composite AA6061 is used as matrix and activated carbon is used as reinforcement and it is casted using modified stir casting technique. After casting metal matrix composite has undergone various microstructure tests like SEM,EDAX and XRD. FSW is carried out in this metal matrix composite by choosing various tool pin profile like square,round,Threaded round, hexagon and taper. The quality of welded plates is measured in terms of ultimate tensile strength and hardness.

  10. Application of ceramic short fiber reinforced Al alloy matrix composite on piston for internal combustion engines

    Directory of Open Access Journals (Sweden)

    Wu Shenqing

    2010-11-01

    Full Text Available The preparation and properties of ceramic short fiber reinforced Al-Si alloy matrix composite and it’s application on the piston for internal combustion engines are presented. Alumina or aluminosilicate fibers reinforced Al-Si alloy matrix composite has more excellent synthetical properties at elevated temperature than the matrix alloys. A partially reinforced Al-Si alloy matrix composite piston produced by squeeze casting technique has a firm interface between reinforced and unreinforced areas, low reject rate and good technical tolerance. As a new kind of piston material, it has been used for mass production of about 400,000 pieces of automobile engines piston. China has become one of a few countries in which aluminum alloy matrix composite materials have been used in automobile industry and attained industrialization.

  11. Obtention and dynamical mechanical behavior of polymer matrix carbon fire reinforced composites

    International Nuclear Information System (INIS)

    Da Silva, Nelson Marques

    2001-01-01

    Polymer matrix composites reinforced with carbon fibres have been extensively used in the nuclear, aeronautics, automotive and leisure industry. This is due to their superior performance when compared to conventional materials in terms of specific strength and specific modulus (3 to 4 times higher than that of mild steels). However, these materials are anisotropic, requiring characterisation for each process and particular application. In the present work, the evaluation of epoxy resin reinforced with unidirectional and continuous carbon fibres was carried out. The composites materials were obtained by filament winding, with three different cure cycles, with two types of carbon fibres (6000 and 12000 filaments per strand) and with fibres volumetric fraction around 60 %. The evaluation of the composites was undertaken using following techniques: scanning electron microscopy (SEM); dynamic mechanical analysis (DMA); thermogravimetric analysis (TGA), and differential scanning calorimeter (DSC). These techniques allowed the evaluation and comparison of storage modulus, internal energy dissipation, glass transition region and glass transition temperature - Tg, cure cycling. Besides, void volumetric fraction was measured. The results indicate that the DMA is a good alternative technique to DSC and TGA. It provides an indication of the quality of the produced composite, both thermal and mechanical. The technique can assist the quality control of composite components by measuring mechanical and thermal properties - modulus and Tg. The DMA technique was sensitive to cure cycling evaluation. Regarding the obtained composites, the results showed the need for the development of specific cure cycle for each application, establishing a compromise between properties such as storage modulus and internal energy dissipation, and involved costs. The results demonstrated differences between the storage modulus and internal energy dissipation for the two types of used fibres. (author)

  12. Ultra-low Temperature Curable Conductive Silver Adhesive with different Resin Matrix

    Science.gov (United States)

    Zhou, Xingli; Wang, Likun; Liao, Qingwei; Yan, Chao; Li, Xing; Qin, Lei

    2018-03-01

    The ultra-low temperature curable conductive silver adhesive with curing temperature less than 100 °C needed urgently for the surface conductive treatment of piezoelectric composite material due to the low thermal resistance of composite material and low adhesion strength of adhesive. An ultra-low temperature curable conductive adhesive with high adhesion strength was obtained for the applications of piezoelectric composite material. The microstructure, conductive properties and adhesive properties with different resin matrix were investigated. The conductive adhesive with AG-80 as the resin matrix has the shorter curing time (20min), lower curing temperature (90°C) and higher adhesion strength (7.6MPa). The resistivity of AG-80 sample has the lower value (2.13 × 10-4Ω·cm) than the 618 sample (4.44 × 10-4Ω·cm).

  13. A study on the damping capacity of BaTiO3-reinforced Al-matrix ...

    Indian Academy of Sciences (India)

    the results showed that the damping capacity of Al-matrix composites can increase greatly [3–5]. Therefore, reinforcing. Al alloy matrix with higher damping particles could be an efficient way to obtain Al-matrix composites with both high strength and high damping capacity. Ferroelectric and piezoelectric ceramics can exhibit ...

  14. Tempering Behavior of TiC-Reinforced SKD11 Steel Matrix Composite

    Science.gov (United States)

    Hwang, Ji-In; Kim, Seong Hoon; Heo, Yoon-Uk; Kim, Dae Ha; Hwang, Keum-Cheol; Suh, Dong-Woo

    2018-03-01

    TiC-reinforced SKD11 steel matrix composite, fabricated by a pressure infiltration casting, undergoes monotonic decrease in hardness as tempering temperature increases. Element mappings by TEM-EDS and thermodynamic calculation indicate that remarkable redistribution of V between the reinforcement and the steel matrix occurs by partial dissolution and re-precipitation of MC carbides upon casting process. The absence of secondary hardening is led by the enrichment of V in the reinforcement that reduces the V content in the steel matrix; this reduction in V content makes the precipitation of fine VC sluggish during the tempering.

  15. Reinforcing styrene butadiene rubber with lignin-novolac epoxy resin networks

    Directory of Open Access Journals (Sweden)

    P. Yu

    2015-01-01

    Full Text Available In this study, lignin-novolac epoxy resin networks were fabricated in the styrene butadiene rubber (SBR matrix by combination of latex compounding and melt mixing. Firstly, SBR/lignin compounds were co-coagulated by SBR latex and lignin aqueous solution. Then the novolac epoxy resin (F51 was added in the SBR/lignin compounds by melt compounding method. F51 was directly cured by lignin via the ring-opening reaction of epoxy groups of F51 and OH groups (or COOH groups of lignin during the curing process of rubber compounds, as was particularly evident from Fourier transform infrared spectroscopy (FTIR studies and maximum torque of the curing analysis. The existence of lignin-F51 networks were also detected by scanning electron microscope (SEM and dynamic mechanical analysis (DMA. The structure of the SBR/lignin/F51 was also characterized by rubber process analyzer (RPA, thermogravimetric analysis (TGA and determination of crosslinking density. Due to rigid lignin-F51 networks achieved in SBR/lignin/F51 composites, it was found that the hardness, modulus, tear strength, crosslinking density, the temperature of 5 and 10% weight-loss were significantly enhanced with the loading of F51.

  16. Mechanical and electrical properties of a polyester resin reinforced with clay-based fillers

    Energy Technology Data Exchange (ETDEWEB)

    Buncianu, Dorel; Jadaneant, Mihai [UPT Timisoara, Timisoara (Romania); Tessier-Doyen, Nicolas; Absi, Joseph [Centre Européen de la Céramique, Limoges Cedex (France); Courreges, Fabien [Laboratoire XLIM, 123, Limoges Cedex (France)

    2017-03-15

    In this study, composite polymer-based materials were fabricated, in which a significant proportion of polyester resin was substituted by low-cost and environmentally-friendly clay-based raw materials. The main objective is to improve mechanical properties while maintaining a reasonable electrical insulating behavior. A homogenized distribution of fillers within the matrix compatible with the processing parameters was obtained up to a maximum added fraction of 20 vol%. Mechanical characterization using uniaxial traction tests and Charpy impact pendulum machine showed that stress-to-rupture can be enhanced of approximately 25 %. In addition, fracture energy was doubled for the best formulation. Dielectric constant was decreased and loss factor was slightly increased when electrical resistivity remained almost constant. In general, the composite materials with metakaolin fillers exhibited higher mechanical properties and greater electrical insulating behavior. Microstructural observation showed the presence of decohesive agglomerates of particles at the interface with the matrix. The mechanical properties were found to be more sensitive than electrical properties to the homogeneity of filler dispersion in the matrix.

  17. Wear Characterization of Aluminium/Basalt Fiber Reinforced Metal Matrix Composites - A Novel Material

    Directory of Open Access Journals (Sweden)

    P. Amuthakkannan

    2017-06-01

    Full Text Available Aluminum alloy based metal matrix composite participate have a wider applications in wear resistance applications. Attempt made in current study is that, basalt fiber reinforced aluminum metal matrix composite have been prepared using stir casting method. Different weight percentage of basalt fiber reinforced with Al (6061 metal matrix composites are used to study the wear resistance of the composites. For wear study, percentage of reinforcement, normal load and sliding velocity are the considered as important parameters. To study the effect of basalt fiber reinforcement on the dry sliding wear of Al6061 alloy composites the Pin On wear tester is used. Initially hardness of the composites was tested, it was found that increasing reinforcement in the composite hardness value of the composites also increased. Based on the Grey relation analysis (GRA the effects of wear resistance of the composites were studied.

  18. Effect of surface modification on carbon fiber and its reinforced phenolic matrix composite

    Energy Technology Data Exchange (ETDEWEB)

    Yuan Hua [Key Laboratory for Liquid phase chemical oxidation Evolution and Processing of Materials (Ministry of Education), Shandong University, Jinan 250061 (China); Carbon Fibre Engineering Research Center, Faculty of Materials Science, Shandong University, Jinan 250061 (China); Wang Chengguo, E-mail: sduwangchg@gmail.com [Carbon Fibre Engineering Research Center, Faculty of Materials Science, Shandong University, Jinan 250061 (China); Zhang Shan; Lin Xue [Carbon Fibre Engineering Research Center, Faculty of Materials Science, Shandong University, Jinan 250061 (China)

    2012-10-15

    Highlights: Black-Right-Pointing-Pointer We used very simple and effective modification method to treat PAN-based carbon fiber by liquid oxidation and coupling agent. Black-Right-Pointing-Pointer Carbon fiber surface functional groups were analyzed by LRS and XPS. Black-Right-Pointing-Pointer Proper treatment of carbon fiber can prove an effective way to increase composite's performance. Black-Right-Pointing-Pointer Carbon fiber surface modifications by oxidation and APS could strengthen fiber activity and enlarge surface area as well as its roughness. - Abstract: In this work, polyacrylonitrile (PAN)-based carbon fiber were chemically modified with H{sub 2}SO{sub 4}, KClO{sub 3} and silane coupling agent ({gamma}-aminopropyltriethoxysilane, APS), and carbon fiber reinforced phenolic matrix composites were prepared. The structural and surface characteristics of the carbon fiber were investigated by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), laser Raman scattering (LRS) and Fourier transform infrared spectroscopy (FTIR). Single fiber mechanical properties, specific surface area, composite impact properties and interfacial shear strength (ILSS) were researched to indicate the effects of surface modification on fibers and the interaction between modified fiber surface and phenolic matrix. The results showed that carbon fiber surface modification by oxidation and APS can strengthen fiber surface chemical activity and enlarge the fiber surface area as well as its roughness. When carbon fiber (CF) is oxidized treatment, the oxygen content as well as the O/C ratio will be obviously increased. Oxygen functional groups increase with oxidation time increasing. Carbon fiber treated with APS will make C-O-R content increase and O-C=O content decrease due to surface reaction. Proper treatment of carbon fiber with acid and silane coupling agent prove an effective way to increase the interfacial adhesion and improve the mechanical and outdoor

  19. Effect of surface modification on carbon fiber and its reinforced phenolic matrix composite

    International Nuclear Information System (INIS)

    Yuan Hua; Wang Chengguo; Zhang Shan; Lin Xue

    2012-01-01

    Highlights: ► We used very simple and effective modification method to treat PAN-based carbon fiber by liquid oxidation and coupling agent. ► Carbon fiber surface functional groups were analyzed by LRS and XPS. ► Proper treatment of carbon fiber can prove an effective way to increase composite's performance. ► Carbon fiber surface modifications by oxidation and APS could strengthen fiber activity and enlarge surface area as well as its roughness. - Abstract: In this work, polyacrylonitrile (PAN)-based carbon fiber were chemically modified with H 2 SO 4 , KClO 3 and silane coupling agent (γ-aminopropyltriethoxysilane, APS), and carbon fiber reinforced phenolic matrix composites were prepared. The structural and surface characteristics of the carbon fiber were investigated by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), laser Raman scattering (LRS) and Fourier transform infrared spectroscopy (FTIR). Single fiber mechanical properties, specific surface area, composite impact properties and interfacial shear strength (ILSS) were researched to indicate the effects of surface modification on fibers and the interaction between modified fiber surface and phenolic matrix. The results showed that carbon fiber surface modification by oxidation and APS can strengthen fiber surface chemical activity and enlarge the fiber surface area as well as its roughness. When carbon fiber (CF) is oxidized treatment, the oxygen content as well as the O/C ratio will be obviously increased. Oxygen functional groups increase with oxidation time increasing. Carbon fiber treated with APS will make C-O-R content increase and O-C=O content decrease due to surface reaction. Proper treatment of carbon fiber with acid and silane coupling agent prove an effective way to increase the interfacial adhesion and improve the mechanical and outdoor performance of the resulting fiber/resin composites.

  20. The study of mechanical properties of pineapple leaf fibre reinforced tapioca based bioplastic resin composite

    Directory of Open Access Journals (Sweden)

    Mathivanan D.

    2016-01-01

    Full Text Available Natural fibre reinforced composite has brought the material engineering to a high new level of research. Natural fibres are compatible with matrices like polypropylene and can be used as reinforcement material to reduce the composition of plastic in a material. Natural fibres such as kenaf, pineapple leaf, and coir already found its importance in reducing the dependence of petroleum based products. However the biodegradability of the product at the end of the intended lifespan is still questionable. This has led many researches to look for a suitable replacement for synthetic fibres and achieve better adhesion between fibre and matrix. In this study, fiber and matrix which are hydrophilic in nature was used and the mixture was extruded and hot compressed to acquire better mechanical properties. The specimens were fabricated and tested according to ASTM D638. The 30% composition illustrates the best average modulus value among other composition and from this result it can be concluded that the increase of PALF fibre in TBR composite increases the modulus strength of the composite.

  1. A Review on Artificial Aging Behaviors of Fiber Reinforced Polymer-matrix Composites

    OpenAIRE

    Meng Jiangyan; Wang Yunying

    2016-01-01

    As is known, factors in climate environment such as hygrothermal effect and UV may have a negative effect on the mechanical properties of fiber reinforced polymer-matrix composites, resulting in their strength and stiffness degraded. In this review, we summarize all the recent studies on the artificial climate aging, hygrothermal aging, and thermal-oxidation aging of fiber reinforced polymer-matrix composites, as well as their artificial accelerated aging and natural aging. In addition, studi...

  2. Friction Stir Processing of Copper-Coated SiC Particulate-Reinforced Aluminum Matrix Composite

    Directory of Open Access Journals (Sweden)

    Chih-Wei Huang

    2018-04-01

    Full Text Available In the present work, we proposed a novel friction stir processing (FSP to produce a locally reinforced aluminum matrix composite (AMC by stirring copper-coated SiC particulate reinforcement into Al6061 alloy matrix. Electroless-plating process was applied to deposit the copper surface coating on the SiC particulate reinforcement for the purpose of improving the interfacial adhesion between SiC particles and Al matrix. The core-shell SiC structure provides a layer for the atomic diffusion between aluminum and copper to enhance the cohesion between reinforcing particles and matrix on one hand, the dispersion of fine copper in the Al matrix during FSP provides further dispersive strengthening and solid solution strengthening, on the other hand. Hardness distribution and tensile results across the stir zone validated the novel concept in improving the mechanical properties of AMC that was realized via FSP. Optical microscope (OM and Transmission Electron Microscopy (TEM investigations were conducted to investigate the microstructure. Energy dispersive spectrometer (EDS, electron probe micro-analyzer (EPMA, and X-ray diffraction (XRD were explored to analyze the atomic inter-diffusion and the formation of intermetallic at interface. The possible strengthening mechanisms of the AMC containing Cu-coated SiC particulate reinforcement were interpreted. The concept of strengthening developed in this work may open a new way of fabricating of particulate reinforced metal matrix composites.

  3. The influence of FRCs reinforcement on marginal adaptation of CAD/CAM composite resin endocrowns after simulated fatigue loading.

    Science.gov (United States)

    Rocca, Giovanni Tommaso; Saratti, Carlo Massimo; Poncet, Antoine; Feilzer, Albert J; Krejci, Ivo

    2016-05-01

    To evaluate the marginal adaptation of endodontically treated molars restored with CAD/CAM composite resin endocrowns either with or without reinforcement by fibre reinforced composites (FRCs), used in different configurations. 32 human endodontically treated molars were cut 2 mm over the CEJ. Two interproximal boxes were created with the margins located 1 mm below the CEJ (distal box) and 1 mm over the CEJ (mesial box). All specimens were divided in four groups (n = 8). The pulp chamber was filled with: group 1 (control), hybrid resin composite (G-aenial Posterior, GC); group 2, as group 1 but covered by 3 meshes of E-glass fibres (EverStick NET, Stick Tech); group 3, FRC resin (EverX Posterior, GC); group 4, as group 3 but covered by 3 meshes of E-glass fibres. The crowns of all teeth were restored with CAD/CAM composite resin endocrowns (LAVA Ultimate, 3M). All specimens were thermo-mechanically loaded in a computer-controlled chewing machine (600,000 cycles, 1.6 Hz, 49 N and simultaneously 1500 thermo-cycles, 60 s, 5-55 °C). Marginal analysis before and after the loading was carried out on epoxy replicas by SEM at 200× magnification. For all the groups, the percentage values of perfect marginal adaptation after loading were always significantly lower than before loading (p marginal adaptation before and after loading was not significantly different between the experimental groups (p > 0.05). Within the limitations of this in vitro study, the use of FRCs to reinforce the pulp chamber of devitalized molars restored with CAD/CAM composite resin restorations did not significantly influenced their marginal quality.

  4. NaF-loaded core-shell PAN-PMMA nanofibers as reinforcements for Bis-GMA/TEGDMA restorative resins.

    Science.gov (United States)

    Cheng, Liyuan; Zhou, Xuegang; Zhong, Hong; Deng, Xuliang; Cai, Qing; Yang, Xiaoping

    2014-01-01

    A kind of core-shell nanofibers containing sodium fluoride (NaF) was produced and used as reinforcing materials for dimethacrylate-based dental restorative resins in this study. The core-shell nanofibers were prepared by coaxial-electrospinning with polyacrylonitrile (PAN) and poly(methyl methacrylate) (PMMA) solutions as core and shell fluids, respectively. The produced PAN-PMMA nanofibers varied in fiber diameter and the thickness of PMMA shell depending on electrospinning parameters. NaF-loaded nanofibers were obtained by incorporating NaF nanocrystals into the core fluid at two loadings (0.8 or 1.0wt.%). Embedment of NaF nanocrystals into the PAN core did not damage the core-shell structure. The addition of PAN-PMMA nanofibers into Bis-GMA/TEGDMA clearly showed the reinforcement due to the good interfacial adhesion between fibers and resin. The flexural strength (Fs) and flexural modulus (Ey) of the composites decreased slightly as the thickness of PMMA shell increasing. Sustained fluoride releases with minor initial burst release were achieved from NaF-loaded core-shell nanofibers and the corresponding composites, which was quite different from the case of embedding NaF nanocrystals into the dental resin directly. The study demonstrated that NaF-loaded PAN-PMMA core-shell nanofibers were not only able to improve the mechanical properties of restorative resin, but also able to provide sustained fluoride release to help in preventing secondary caries. © 2013.

  5. Mechanical Properties of Abutments: Resin-Bonded Glass Fiber-Reinforced Versus Titanium.

    Science.gov (United States)

    Bassi, Mirko Andreasi; Bedini, Rosells; Pecci, Raffaela; Ioppolo, Pietro; Laritano, Dorina; Carinci, Francesco

    2016-01-01

    The clinical success and longevity of endosseous implants, after their prosthetic finalization, mainly depends on mechanical factors. Excessive mechanical stress has been shown to cause initial bone loss around implants in the presence of a rigid implant-prosthetic connection. The implant abutments are manufactured with high elastic modulus materials such as titanium, steel, precious alloys, or esthetic ceramics. These materials do not absorb any type of shock from the chewing loads or ensure protection of the bone-implant interface, especially when the esthetic restorative material is ceramic rather than composite resin. The mechanical resistance to cyclical load was evaluated in a tooth-colored fiber-reinforced abutment prototype (TCFRA) and compared to that of a similarly shaped titanium abutment (TA). Eight TCFRAs and eight TAs were adhesively cemented on as many titanium implants. The swinging the two types of abutments showed during the application of sinusoidal load was also analyzed. In the TA group, fracture and deformation occurred in 12.5% of samples, while debonding occurred in 62.5%. In the TCFRA group, only debonding was present, in 37.5% of samples. In comparison to the TAs, the TCFRAs exhibited greater swinging during the application of sinusoidal load. In the TA group extrusion prevailed, whereas in the TCFRA group intrusion was more frequent. TCFRA demonstrated a greater elasticity than did TAs to the flexural load, absorbing part of the transversal load applied on the fixture during the chewing function and thus reducing the stress on the bone-implant interface.

  6. Mechanical properties of resin glass fiber-reinforced abutment in comparison to titanium abutment

    Science.gov (United States)

    Andreasi Bassi, Mirko; Bedini, Rossella; Pecci, Raffella; Ioppolo, Pietro; Lauritano, Dorina; Carinci, Francesco

    2015-01-01

    Purpose: So far, definitive implant abutments have been performed with high elastic modulus materials, which prevented any type of shock absorption of the chewing loads and as a consequence, the protection of the bone-fixture interface. This is particularly the case when the esthetic restorative material chosen is ceramic rather than composite resin. The adoption of an anisotropic abutment, characterized by an elastic deformability, could allow decreasing the impulse of chewing forces transmitted to the crestal bone. Materials and Methods: According to research protocol, the mechanical resistance to cyclical load was evaluated in a tooth-colored fiber-reinforced abutment (TCFRA) prototype and compared to that of a titanium abutment (TA), thus eight TCFRAs and eight TAs were adhesively cemented on as many titanium implants. The swinging that the two types of abutments showed during the application of sinusoidal load was also analyzed. Results: In the TA group, both fracture and deformation occurred in 12.5% of samples while debonding 62.5%. In the TCFRA group, only debonding was present in 37.5% of samples. In comparison to the TAs, the TCFRAs exhibited a greater swinging during the application of sinusoidal load. In the TA group, the extrusion prevailed, whereas in the TCFRA group, the intrusion was more frequent. Conclusion: The greater elasticity of TCFRA to the flexural load allows absorbing part of the transversal load applied on the fixture during the chewing function, thus reducing the stress on the bone-implant interface. PMID:26229266

  7. Polarization Behavior of Squeeze Cast Al2O3 Fiber Reinforced Aluminum Matrix Composites

    International Nuclear Information System (INIS)

    Ham, S. H.; Kang, Y. C.; Cho, K. M.; Park, I. M.

    1992-01-01

    Electrochemical polarization behavior of squeeze cast Al 2 O 3 short fiber reinforced Al alloy matrix composites was investigated for the basic understanding of the corrosion properties of the composites. The composites were fabricated with variations of fiber volume fraction and matrix alloys. It was found that the reinforced composites are more susceptible to corrosion attack than the unreinforced matrix alloys in general. Corrosion resistance shows decreasing tendency with increasing Al 2 O 3 fiber volume fraction in AC8A matrix. Effect of the matrix alloys revealed that the AC8A Al matrix composite is less susceptible to corrosion attack than the 2024 and 7075 Al matrix composites. Effect of plastic deformation on electrochemical polarization behavior of the squeeze cast Al/Al 2 O 3 composites was examined after extrusion of AC8A-10v/o Al 2 O 3 . Result shows that corrosion resistance is deteriorated after plastic deformation

  8. Composite resin reinforced with pre-tensioned fibers: a three-dimensional finite element study on stress distribution.

    Science.gov (United States)

    Jie, Lin; Shinya, Akikazu; Lassila, Lippo V J; Vallittu, Pekka K

    2013-01-01

    Pre-tensioned construction material is utilized in engineering applications of high strength demands. The purpose of this study was to evaluate the effect of the pre-tensioning fibers of fiber-reinforced composite (FRC) using three-dimensional finite element (FE) analysis. The 3D FE models of particulate composite resin (CR), FRC and composite resin reinforced with pre-tensioned fibers (PRE-T-FRC) were constructed. The uniaxial three-point bending test was simulated using FE analysis to calculate the principal stress distribution. In the FRC and PRE-T-FRC, stresses were higher than CR, and they were located in the fiber. However, the maximum principal stress value at the composite of PRE-T-FRC was lower than the FRC and CR. Composite resin reinforced with pre-tensioned fibers was advantageous for stress distribution and lowering the stress at the composite itself. Experimental studies on physical properties of pre-tensioned FRC are encouraged to be conducted.

  9. Characterisation of Microstructure of We43 Magnesium Matrix Composites Reinforced with Carbon Fibres

    Directory of Open Access Journals (Sweden)

    Gryc A.

    2016-06-01

    Full Text Available In the paper the microstructures of WE43 matrix composites reinforced with carbon fibres have been characterised. The influence of reinforcement type and T6 heat treatment (a solution treatment at 525°C for 8 h, a hot water quench and a subsequent ageing treatment at 250°C for 16 h on microstructure have been evaluated. The light microscope and scanning electron microscope investigations have been carried out. No significant differences in samples reinforced with non-coated textiles have been reported. The substantial changes in sample reinforced with nickel-coated textile have been observed. The segregation of alloying elements to the matrix-reinforcement layer has been identified. The T6 heat treatment caused the appearance of disperse precipitates of β phase, but the process cannot be considered as satisfactory (irregular distribution, low volume fraction, relatively large size.

  10. Ceramic fiber-reinforced monoclinic celsian phase glass-ceramic matrix composite material

    Science.gov (United States)

    Bansal, Narottam P. (Inventor); Dicarlo, James A. (Inventor)

    1994-01-01

    A hyridopolysilazane-derived ceramic fiber reinforced monoclinic celsian phase barium aluminum silicate glass-ceramic matrix composite material is prepared by ball-milling an aqueous slurry of BAS glass powder and fine monoclinic celsian seeds. The fibers improve the mechanical strength and fracture toughness and with the matrix provide superior dielectric properties.

  11. Development and optimization of manufacture process for heat resistant fibre reinforced ceramic matrix composites

    Czech Academy of Sciences Publication Activity Database

    Glogar, Petr; Hron, P.; Burian, M.; Balík, Karel; Černý, Martin; Sucharda, Zbyněk; Vymazalová, Z.; Červencl, J.; Pivoňka, M.

    -, č. 14 (2005), 25-32 ISSN 1214-9691 R&D Projects: GA ČR(CZ) GA106/02/0177 Institutional research plan: CEZ:AV0Z30460519 Keywords : polysiloxane resin * pyrolysis * ceramic matrix composite Subject RIV: JI - Composite Materials

  12. Effect of Reinforcement Using Stainless Steel Mesh, Glass Fibers, and Polyethylene on the Impact Strength of Heat Cure Denture Base Resin - An In Vitro Study.

    Science.gov (United States)

    Murthy, H B Mallikarjuna; Shaik, Sharaz; Sachdeva, Harleen; Khare, Sumit; Haralur, Satheesh B; Roopa, K T

    2015-06-01

    The impact strength of denture base resin is of great concern and many approaches have been made to strengthen acrylic resin dentures. The objective of this study was to compare the impact strength of the denture base resin with and without reinforcement and to evaluate the impact strength of denture base resin when reinforced with stainless steel mesh, glass fiber, and polyethylene fibers in the woven form. The specimens (maxillary denture bases) were fabricated using a standard polyvinylsiloxane mold with conventional heat cured polymethyl methacrylate resin. The specimens were divided into four groups (n = 10). Group I specimens or control group were not reinforced. Group II specimens were reinforced with stainless steel mesh and Group III and Group IV specimens were reinforced with three percent by weight of glass fibers and polyethylene fibers in weave form respectively. All the specimens were immersed in water for 1-week before testing. The impact strength was measured with falling weight impact testing machine. One-way analysis of variance and Tukey's post-hoc test were used for statistical analysis. Highest impact strength values were exhibited by the specimens reinforced with polyethylene fibers followed by glass fibers, stainless steel mesh, and control group. Reinforcement of maxillary complete dentures showed a significant increase in impact strength when compared to unreinforced dentures. Polyethylene fibers exhibit better impact strength followed by glass fibers and stainless steel mesh. By using pre-impregnated glass and polyethylene fibers in woven form (prepregs) the impact strength of the denture bases can be increased effectively.

  13. The effect of joint surface contours and glass fiber reinforcement on the transverse strength of repaired acrylic resin: An in vitro study

    Directory of Open Access Journals (Sweden)

    Nayana Anasane

    2013-01-01

    Full Text Available Background : Denture fracture is an unresolved problem in complete denture prosthodontics. However, the repaired denture often experiences a refracture at the repaired site due to poor transverse strength. Hence, this study was conducted to evaluate the effect of joint surface contours and glass fiber reinforcement on the transverse strength of repaired acrylic resins. Materials and Methods: A total of 135 specimens of heat polymerized polymethyl methacrylate resin of dimensions 64 × 10 × 2.5 mm were fabricated. Fifteen intact specimens served as the control and 120 test specimens were divided into four groups (30 specimens each, depending upon the joint surface contour (butt, bevel, rabbet and round, with two subgroups based on type of the repair. Half of the specimens were repaired with plain repair resin and the other half with glass fibers reinforced repair resin. Transverse strength of the specimens was determined using three-point bending test. The results were analyzed using one-way ANOVA and Tukey post-hoc test (α= 0.05. Results: Transverse strength values for all repaired groups were significantly lower than those for the control group ( P < 0.001 (88.77 MPa, with exception of round surface design repaired with glass fiber reinforced repair resin (89.92 MPa which was significantly superior to the other joint surface contours ( P < 0.001. Glass fiber reinforced resin significantly improved the repaired denture base resins as compared to the plain repair resin ( P < 0.001. Conclusion: Specimens repaired with glass fiber reinforced resin and round surface design exhibited highest transverse strength; hence, it can be advocated for repair of denture base resins.

  14. Fracture Toughness of Carbon Nanotube-Reinforced Metal- and Ceramic-Matrix Composites

    International Nuclear Information System (INIS)

    Chen, Y.L.; Liu, B.; Hwang, K.C.; Chen, Y.L.; Huang, Y.

    2011-01-01

    Hierarchical analysis of the fracture toughness enhancement of carbon nanotube- (CNT-) reinforced hard matrix composites is carried out on the basis of shear-lag theory and fracture mechanics. It is found that stronger CNT/matrix interfaces cannot definitely lead to the better fracture toughness of these composites, and the optimal interfacial chemical bond density is that making the failure mode just in the transition from CNT pull-out to CNT break. For hard matrix composites, the fracture toughness of composites with weak interfaces can be improved effectively by increasing the CNT length. However, for soft matrix composite, the fracture toughness improvement due to the reinforcing CNTs quickly becomes saturated with an increase in CNT length. The proposed theoretical model is also applicable to short fiber-reinforced composites.

  15. Fracture Toughness of Carbon Nanotube-Reinforced Metal- and Ceramic-Matrix Composites

    Directory of Open Access Journals (Sweden)

    Y. L. Chen

    2011-01-01

    Full Text Available Hierarchical analysis of the fracture toughness enhancement of carbon nanotube- (CNT- reinforced hard matrix composites is carried out on the basis of shear-lag theory and facture mechanics. It is found that stronger CNT/matrix interfaces cannot definitely lead to the better fracture toughness of these composites, and the optimal interfacial chemical bond density is that making the failure mode just in the transition from CNT pull-out to CNT break. For hard matrix composites, the fracture toughness of composites with weak interfaces can be improved effectively by increasing the CNT length. However, for soft matrix composite, the fracture toughness improvement due to the reinforcing CNTs quickly becomes saturated with an increase in CNT length. The proposed theoretical model is also applicable to short fiber-reinforced composites.

  16. An experimental study of mechanical behavior of natural fiber reinforced polymer matrix composites

    Science.gov (United States)

    Ratna, Sanatan; Misra, Sheelam

    2018-05-01

    Fibre-reinforced polymer composites have played a dominant role for a long time in a variety of applications for their high specific strength and modulus. The fibre which serves as a reinforcement in reinforced plastics may be synthetic or natural. Past studies show that only synthetic fibres such as glass, carbon etc., have been used in fibre reinforced plastics. Although glass and other synthetic fibre-reinforced plastics possess high specific strength, their fields of application are very limited because of their inherent higher cost of production. In this connection, an investigation has been carried out to make use of horse hair, an animal fibre abundantly available in India. Animal fibres are not only strong and lightweight but also relatively very cheaper than mineral fibre. The present work describes the development and characterization of a new set of animal fiber based polymer composites consisting of horse hair as reinforcement and epoxy resin. The newly developed composites are characterized with respect to their mechanical characteristics. Experiments are carried out to study the effect of fibre length on mechanical behavior of these epoxy based polymer composites. Composite made form horse hair can be used as a potential reinforcing material for many structural and non-structural applications. This work can be further extended to study other aspects of such composites like effect of fiber content, loading pattern, fibre treatment on mechanical behavior of horse hair based polymer horse hair.

  17. Synthesis and characterisation of epoxy resins reinforced with carbon nanotubes and nanofibers.

    Science.gov (United States)

    Prolongo, S G; Gude, M R; Ureña, A

    2009-10-01

    Epoxy nanocomposites were fabricated using two kinds of nanofiller, amino-functionalized multi-walled carbon nanotubes (CNTs) and non-treated long carbon nanofibers (CNFs). The non-cured mixtures were analysed through viscosity measurements. The effect of the nanoreinforcement on the curing process was determined by differential scanning calorimetry. Finally, the characterisation of cured nanocomposites was carried out studying their thermo-mechanical and electrical behaviour. At room temperature, the addition of CNTs causes a viscosity increase of epoxy monomer much more marked than the introduction of CNFs due to their higher specific area. It was probed that in that case exists chemical reaction between amino-functionalized CNTs and the oxirane rings of epoxy monomer. The presence of nanoreinforcement induces a decrease of curing reaction rate and modifies the epoxy conversion reached. The glass transition temperature of the nanocomposites decreases with the contents of CNTs and CNFs added, which could be related to plasticization phenomena of the nanoreinforcements. The storage modulus of epoxy resin significantly increases with the addition of CNTs and CNFs. This augment is higher with amino-functionalized CNTs due, between other reasons, to the stronger interaction with the epoxy matrix. The electrical conductivity is greatly increased with the addition of CNTs and CNFs. In fact, the percolation threshold is lower than 0.25 wt% due to the high aspect ratio of the used nanoreinforcements.

  18. Review on preparation techniques of particle reinforced metal matrix composites

    Directory of Open Access Journals (Sweden)

    HAO Bin

    2006-02-01

    Full Text Available This paper reviews the investigation status of the techniques for preparation of metal matrix composites and the research outcomes achieved recently. The mechanisms, characteristics, application ranges and levels of development of these preparation techniques are analyzed. The advantages and the disadvantages of each technique are synthetically evaluated. Lastly, the future directions of research and the prospects for the preparation techniques of metal matrix composites are forecasted.

  19. Magnetic properties of Fe-oxide and (Fe, Co) oxide nanoparticles synthesized in polystyrene resin matrix

    Science.gov (United States)

    Rodak, D.; Kroll, E.; Tsoi, G. M.; Vaishnava, P. P.; Naik, R.; Wenger, L. E.; Suryanarayanan, R.; Naik, V. M.; Boolchand, P.

    2003-03-01

    Magnetic nanoparticles have potential applications ranging from drug delivery and imaging in the medical field to sensing and memory storage in technology. The preparation, structure, and physical properties of iron oxide-based nanoparticles synthesized by ion exchange in a polystyrene resin matrix have been investigated. Employing a synthesis method developed originally by Ziolo, et. al^1, nanoparticles were prepared in a sulfonated divinyl benzene polystyrene resin matrix using various aqueous solutions of (1) FeCl_2, (2) FeCl_3, (3) FeCl2 : 2FeCl3 , (4) 9FeCl2 : CoCl_2, and (5) 4FeCl2 : CoCl_2. Powder x-ray diffraction measurements were used to identify the phases present while transmission electron microscopy was used for particle size distribution determinations. SQUID magnetization measurements (field-cooled and zero-field-cooled) and Fe^57 Mössbauer effect measurements indicate the presence of ferromagnetic iron oxide phases and a superparamagnetic behavior with blocking temperatures (T_B) varying from 50 K to room temperature. Nanoparticles synthesized using a stoichiometric mixture of FeCl2 and FeCl3 exhibit the lowest TB and smallest particle size distribution. The Mössbauer effect measurements have also been used to identify the iron oxides phases present and their relative amounts in the nanoparticles ^1R.F. Ziolo, et al., Science 207, 219 (1992). *Permanent address: Kettering University, Flint, MI 48504

  20. Preparation of Ti-aluminide reinforced in situ aluminium matrix composites by reactive hot pressing

    International Nuclear Information System (INIS)

    Roy, D.; Ghosh, S.; Basumallick, A.; Basu, B.

    2007-01-01

    Aluminium based metal matrix composites reinforced with in situ Ti-aluminide and alumina particles were prepared by reactive hot pressing a powder mix of aluminium and nanosized TiO 2 powders. The reinforcements were formed in situ by exothermal reaction between the TiO 2 nano crystalline powder and aluminium. The thermal characteristics of the in situ reaction were studied with the aid of Differential scanning calorimetry (DSC). X-ray diffraction (XRD), Energy dispersive spectroscopy (EDS) and Scanning electron microscopy (SEM) techniques were employed to study the microstructural architecture of the composites as a function of hot pressing temperature and volume percent reinforcement. Microhardness measurements on the as prepared in situ aluminium matrix composites exhibit significant increase in hardness with increase in hot pressing temperature and volume fraction of reinforcement

  1. Pre design processing of waste of ex-resin without materials matrix from nuclear power plant type PWR 1000 MW

    International Nuclear Information System (INIS)

    Cerdas Tarigan

    2010-01-01

    Have been done pre design processing of waste ex-resin without capacities matrix materials from nuclear power plant type PWR 1000 MW During the time radioactive waste of ex-resin processed to use process of immobilization use matrix materials like mixture cement and epoxy resin and then conditioning. This process is not effective and efficient because end result volume of end product bigger than volume early operation system and maintenance of its installation more difficult. To overcome this created a design of technology processing of waste of ex- resin without matrix materials through process of strainer, drying and conditioning represent technological innovation newly processing of radioactive waste of ex-resin. Besides this process more effective and efficient, volume of end product waste much more small from volume early and operation system and maintenance of its easier installation. Pre design is expected to be used as a basis to make conceptual of pre design installation of strainer, drying and conditioning for the processing of waste of ex-resin from nuclear power plant type PWR 1000 MW. (author)

  2. [Influence of retainer design on fixation strength of resin-bonded glass fiber reinforced composite fixed cantilever dentures].

    Science.gov (United States)

    Petrikas, O A; Voroshilin, Iu G; Petrikas, I V

    2013-01-01

    Fiber-reinforced composite (FRC) fixed partial dentures (FPD) have become an accepted part of the restorative dentist's armamentarium. The aim of this study was to evaluate in vitro the influence of retainer design on the strength of two-unit cantilever resin-bonded glass FRC-FPDs. Four retainer designs were tested: a dual wing, a dual wing + horizontal groove, a dual wing + occlusal rest and a step-box. Of each design on 7 human mandibular molars, FRC-FPDs of a premolar size were produced. The FRC framework was made of resin Revolution (Kerr) impregnated glass fibers (GlasSpan, GlasSpan) and veneered with hybrid resin composite (Charisma, Kulzer). Revolution (Kerr) was used as resin luting cement. FRC-FPDs were loaded to failure in a universal testing machine. T (Student's)-test was used to evaluate the data. The four designs were analyzed with finite element analysis (FEA) to reveal the stress distribution within the tooth/restoration complex. Significantly lower fracture strengths were observed with inlay-retained FPDs (step-box: 172±11 N) compared to wing-retained FPDs (poptimal design for replacement of a single premolar by means of a two-unit cantilever FRC-FPDs.

  3. Effect of sintering temperatures on titanium matrix composites reinforced by ceramic particles

    Energy Technology Data Exchange (ETDEWEB)

    Romero, F.; Amigo, V.; Busquets, D.; Klyatskina, E. [Mechanical and Materials Engineering Department. Polytechnical University of Valencia, Valencia (Spain)

    2005-07-01

    Titanium and titanium composites have a potential use in aerospace and biotechnology industries, and nowadays in others like sports and fashion ones. In this work composite materials, based on titanium matrix reinforced with ceramic particles, have been developed. PM route is used to obtain compact and sintered samples. TiN and TiAl powders, are milled with Ti powder in different volumetric percentages in a ball mill. These mixtures are pressed in a uniaxial press and sintered in a vacuum furnace at different temperatures between 1180 to 1220 deg. C. Porosity of samples is analysed, before and after the sintering process, by Archimedes technique and by image analysis. Mechanical properties and the reinforcement particles influence in the titanium matrix are studied by flexion test in green and sintered states, and by hardness and microhardness tests. Complimentarily, a microstructural analysis is carried out by optical and electron microscopy, and the reactivity between the reinforce particles and titanium matrix are studied. (authors)

  4. The influence of matrix composition and reinforcement type on the properties of polysialate composites

    Science.gov (United States)

    Hammell, James A.

    There is a critical need for the development of materials for eliminating fire as a cause of death in aircraft accidents. Currently available composites that use organic matrices not only deteriorate at temperatures above 300°C but also emit toxic fumes. The results presented in this dissertation focus on the development of an inorganic matrix that does not burn or emit toxic fumes. The matrix, known as polysialate, can withstand temperatures in excess of 1000°C. The matrix behaves like a ceramic, but does not need high curing temperatures, so it can be processed like many common organic matrices. The major parameters evaluated in this dissertation are: (i) Influence of reinforcement type, (ii) Matrix formulation for both wet-dry durability and high temperature resistance, (iii) Influence of processing variables such as moisture reduction and storage, (iv) Tensile strain capacity of modified matrices and matrices reinforced with ceramic microfibers and discrete carbon fibers, and (v) analytical modeling of mechanical properties. For the reinforcement type; carbon, glass, and stainless steel wire fabrics were investigated. Carbon fabrics with 1, 3, 12, and 50k tows were used. A matrix chemical formulation that can withstand wetting and drying was developed. This formulation was tested at high temperatures to ascertain its stability above 400°C. On the topic of processing, shelf life of prepregged fabric layers and efficient moisture removal methods were studied. An analytical model based on layered reinforcement was developed for analyzing flexural specimens. It is shown that the new inorganic matrix can withstand wetting and drying, and also high temperature. The layered reinforcement concept provides accurate prediction of strength and stiffness for composites reinforced with 1k and 3k tows. The prepregged fabric layers can be stored for 14 days at -15°C without losing strength.

  5. Effect of Fiber Poisson Contraction on Matrix Multicracking Evolution of Fiber-Reinforced Ceramic-Matrix Composites

    Science.gov (United States)

    Longbiao, Li

    2015-12-01

    An analytical methodology has been developed to investigate the effect of fiber Poisson contraction on matrix multicracking evolution of fiber-reinforced ceramic-matrix composites (CMCs). The modified shear-lag model incorporated with the Coulomb friction law is adopted to solve the stress distribution in the interface slip region and intact region of the damaged composite. The critical matrix strain energy criterion which presupposes the existence of an ultimate or critical strain energy limit beyond which the matrix fails has been adopted to describe matrix multicracking of CMCs. As more energy is placed into the composite, matrix fractures and the interface debonding occurs to dissipate the extra energy. The interface debonded length under the process of matrix multicracking is obtained by treating the interface debonding as a particular crack propagation problem along the fiber/matrix interface. The effects of the interfacial frictional coefficient, fiber Poisson ratio, fiber volume fraction, interface debonded energy and cycle number on the interface debonding and matrix multicracking evolution have been analyzed. The theoretical results are compared with experimental data of unidirectional SiC/CAS, SiC/CAS-II and SiC/Borosilicate composites.

  6. Nanofiber reinforcement of a geopolymer matrix for improved composite materials mechanical performance

    Science.gov (United States)

    Rahman, AKM Samsur

    Geopolymers have the potential to cross the process performance gap between polymer matrix and ceramic matrix composites (CMC), enabling high temperature capable composites that are manufactured at relatively low temperatures. Unfortunately, the inherently low toughness of these geopolymers limits the performance of the resulting fiber reinforced geopolymer matrix composites. Toughness improvements in composites can be addressed through the adjustments in the fiber/matrix interfacial strength and through the improvements in the inherent toughness of the constituent materials. This study investigates the potential to improve the inherent toughness of the geopolymer matrix material through the addition of nanofillers, by considering physical dimensions, mechanical properties, reinforcing capability and interfacial bond strength effects. A process optimization study was first undertaken to develop the ability to produce consistent, neat geopolymer samples, a critical precursor to producing nano-filled geopolymer for toughness evaluation. After that, single edge notched bend beam fracture toughness and un-notched beam flexural strength were evaluated for silicon carbide, alumina and carbon nanofillers reinforced geopolymer samples treated at various temperatures in reactive and inert environments. Toughness results of silicon carbide and carbon nanofillers reinforced geopolymers suggested that with the improved baseline properties, high aspect ratio nanofillers with high interfacial bond strength are the most capable in further improving the toughness of geopolymers. Among the high aspect ratio nanofillers i.e. nanofibers, 2vol% silicon carbide whicker (SCW) showed the highest improvement in fracture toughness and flexural strength of ~164% & ~185%, respectively. After heat treatment at 650 °C, SCW reinforcement was found to be effective, with little reduction in the performance, while the performance of alumina nanofiber (ANF) reinforced geopolymer significantly

  7. Carbon fibre reinforced copper matrix composites: processing routes and properties

    Energy Technology Data Exchange (ETDEWEB)

    Le Petitcorps, Y. [Bordeaux-1 Univ., 33 - Pessac (France). ICMCB; Poueylaud, J.M. [Bordeaux-1 Univ., 33 - Pessac (France). ICMCB; Albingre, L. [Bordeaux-1 Univ., 33 - Pessac (France). ICMCB; Berdeu, B. [L`Electrolyse, 33 - Latresne (France); Lobstein, P. [L`Electrolyse, 33 - Latresne (France); Silvain, J.F. [Bordeaux-1 Univ., 33 - Pessac (France). ICMCB

    1997-06-01

    Copper matrix composites are of interest for applications in the electronic field which requires materials with high thermal conductivity properties. The use of carbon fibres can (1) decrease the density and the coefficient of thermal expansion of the material and (2) increase the stiffness and strength to rupture of the resulting composite. In order to produce cheap materials, chemical plating and uniaxial hot pressing processing routes were chosen. 1D-C{sub (P55Thornel)} / Cu prepregs were hot pressed in an argon atmosphere at 750 C during 30 min. The volume fraction of the fibres within the composite was in the range of 10-35%. Physical (density and thermal expansion coefficient) and thermal conductivity properties of the composite were in good agreement with the predictions. However this material exhibits very poor mechanical properties (Young`s modulus and tensile strength). Scanning electron microscopy (SEM) observations of the surfaces of ruptures have shown that (1) a very weak bonding between the graphite fibres and the copper matrix was formed and (2) the rupture of the composite was initiated in the matrix at the copper grain boundaries. In order to overcome these two difficulties, the carbon fibres were pre-coated with a thin layer (100 nm) of cobalt. The aim of the cobalt was to react with the carbon to form carbide compounds and as a consequence to increase the bonding between the metal and the fibre. The tensile properties ({sigma}{sub c}{sup R} and E{sub c}) of this composite were then increased by 50% in comparison with the former material; however the strain to rupture was still too weak ({epsilon}{sub c}{sup R} = 0.5%). In order to explain the role of each constituents, X-ray profiles and TEM analyses were done at the fibre/matrix interface and at the grain boundaries. Some modifications of the chemical plating steps were done to improve the purity of the copper. (orig.)

  8. Metallic-fibre-reinforced ceramic-matrix composite

    International Nuclear Information System (INIS)

    Prevost, F.; Schnedecker, G.; Boncoeur, M.

    1994-01-01

    A refractory metal wire cloth is embedded in an oxide ceramic matrix, using a plasma spraying technology, in order to elaborate composite plates. When mechanically tested, the composite fails with a pseudo-ductile fracture mode whereas the ceramic alone is originally brittle. It exhibits a higher fracture strength, and remains in the form of a single piece even when straining is important. No further heat treatment is needed after the original processing to reach these characteristics. (authors). 2 figs., 2 refs

  9. Optimization and characterization of woven kevlar reinforced epoxy matrix composite materials

    International Nuclear Information System (INIS)

    Imran, A.; Aslam, S.

    2007-01-01

    Composite materials are actually well established materials that have demonstrated their promising advantages among the light weight structural materials used for aerospace and advanced applications. An effort is now being made to develop and characterize the Kevlar Epoxy Composite Materials by changing the vol. fraction of Kevlar in epoxy matrix. The optimum characteristics were observed with 37% fiber with resin by applying hand-lay-up process. The composites produced were subjected to mechanical testing to evaluate the mechanical characteristics. (author)

  10. Effect of reinforcement on the cutting forces while machining metal matrix composites–An experimental approach

    Directory of Open Access Journals (Sweden)

    Ch. Shoba

    2015-12-01

    Full Text Available Hybrid metal matrix composites are of great interest for researchers in recent years, because of their attractive superior properties over traditional materials and single reinforced composites. The machinabilty of hybrid composites becomes vital for manufacturing industries. The need to study the influence of process parameters on the cutting forces in turning such hybrid composite under dry environment is essentially required. In the present study, the influence of machining parameters, e.g. cutting speed, feed and depth of cut on the cutting force components, namely feed force (Ff, cutting force (Fc, and radial force (Fd has been investigated. Investigations were performed on 0, 2, 4, 6 and 8 wt% Silicon carbide (SiC and rice husk ash (RHA reinforced composite specimens. A comparison was made between the reinforced and unreinforced composites. The results proved that all the cutting force components decrease with the increase in the weight percentage of the reinforcement: this was probably due to the dislocation densities generated from the thermal mismatch between the reinforcement and the matrix. Experimental evidence also showed that built-up edge (BUE is formed during machining of low percentage reinforced composites at high speed and high depth of cut. The formation of BUE was captured by SEM, therefore confirming the result. The decrease of cutting force components with lower cutting speed and higher feed and depth of cut was also highlighted. The related mechanisms are explained and presented.

  11. Fracture and fatigue considerations in the development of ductile-phase reinforced intermetallic-matrix composites

    International Nuclear Information System (INIS)

    Venkateswara Rao, K.T.; Ritchie, R.O.

    1994-01-01

    The salient microstructural factors influencing fracture and fatigue-crack growth resistance of ductile-particle reinforced intermetallic-matrix composites at ambient temperature are reviewed through examples from the Nb/MoSi 2 , TiNb/TiAl, Nb/TiAl and Nb/Nb 3 Al systems; specific emphasis is placed on properties and morphology of the reinforcement and its interfacial properties with the matrix. It is shown that composites must be fabricated with a high aspect ratio ductile-reinforcement morphology in order to promote crack-particle interception and resultant crack bridging for improved fracture and fatigue properties. Concurrently, however, the ductile phases have contrasting effects on crack growth under monotonic vs. cyclic loading suggesting that composite microstructures tailored for optimal toughness may not necessarily yield optimal fatigue resistance. Perspectives for the future development of damage-tolerant intermetallic-composite microstructures are discussed

  12. Overall mechanical properties of fiber-reinforced metal matrix composites for fusion applications

    International Nuclear Information System (INIS)

    You, J.H.; Bolt, H.

    2002-01-01

    The high-temperature strength and creep properties are among the crucial criteria for the structural materials of plasma facing components (PFC) of fusion reactors, as they will be subjected to severe thermal stresses. The fiber-reinforced metal matrix composites are a potential heat sink material for the PFC application, since the combination of different material properties can lead to versatile performances. In this article, the overall mechanical properties of two model composites based on theoretical predictions are presented. The matrix materials considered were a precipitation hardened CuCrZr alloy and reduced activation martensitic steel 'Eurofer'. Continuous SiC fibers were used for the reinforcement. The results demonstrate that yield stress, ultimate tensile strength, work hardening rate and creep resistance could be extensively improved by the fiber reinforcement up to fiber content of 40 vol.%. The influence of the residual stresses on the plastic behavior of the composites is also discussed

  13. Behaviour of Aluminosilicate Inorganic Matrix Sial During and After Solidification of Radioactive Sludge And Radioactive Spent Resins and Their Mixtures

    International Nuclear Information System (INIS)

    Lichvar, P.; Rozloznik, M.; Sekely, S.

    2013-01-01

    SIAL matrix is the product of inorganic compounds by polycondensation. The inorganic SIAL matrix was subject of study from the atomic level to the level of technological application. Infrared spectroscopy measurement and X-ray analysis confirmed that SIAL matrix is mostly formed by amorphous phase. This satisfies the required criteria for disposal of immobilized radioactive waste of appropriate properties into surface repository (Slovak and Czech Republic). First of all, leaching of radioactive nuclide Cs-137 and compressive strength of the final product were found. Various remotely operated devices have been designed, manufactured and successfully used for the radioactive sludge and sludge/resins mixture solidification at the Nuclear power plant (NPP) A-1, V-2 in Jaslovske Bohunice, at Mochovce NPP (Slovak Republic), at Dukovany NPP and at Temelin NPP (Czech Republic). The SIAL matrix was approved for waste package for sludge/resins mixture by the Slovak and Czech Nuclear Regulatory Authorities. (author)

  14. Behaviour of Aluminosilicate Inorganic Matrix Sial During and After Solidification of Radioactive Sludge And Radioactive Spent Resins and Their Mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Lichvar, P.; Rozloznik, M.; Sekely, S. [Amec Nuclear Slovakia, 919 31 Jaslovske Bohunice (Slovakia)

    2013-09-15

    SIAL matrix is the product of inorganic compounds by polycondensation. The inorganic SIAL matrix was subject of study from the atomic level to the level of technological application. Infrared spectroscopy measurement and X-ray analysis confirmed that SIAL matrix is mostly formed by amorphous phase. This satisfies the required criteria for disposal of immobilized radioactive waste of appropriate properties into surface repository (Slovak and Czech Republic). First of all, leaching of radioactive nuclide Cs-137 and compressive strength of the final product were found. Various remotely operated devices have been designed, manufactured and successfully used for the radioactive sludge and sludge/resins mixture solidification at the Nuclear power plant (NPP) A-1, V-2 in Jaslovske Bohunice, at Mochovce NPP (Slovak Republic), at Dukovany NPP and at Temelin NPP (Czech Republic). The SIAL matrix was approved for waste package for sludge/resins mixture by the Slovak and Czech Nuclear Regulatory Authorities. (author)

  15. Research and Development Progress of National Key Laboratory of Advanced Composites on Advanced Aeronautical Resin Matrix Composites

    Directory of Open Access Journals (Sweden)

    LI Bintai

    2016-06-01

    Full Text Available Applications and research progress in advanced aeronautical resin matrix composites by National Key Laboratory of Advanced Composites (LAC were summarized. A novel interlaminar toughening technology employing ultra-thin TP non-woven fabric was developed in LAC, which significantly improved the compression after impact (CAI performances of composite laminates.Newly designed multilayer sandwich stealth composite structures exhibited a good broadband radar absorbing properties at 1-18 GHz.There were remarkable developments in high toughness and high temperature resin matrix composites, covering major composite processing technologies such as prepreg-autoclave procedure, liquid composite molding and automation manufacture, etc. Finally, numerical simulation and optimization methods were deliberately utilized in the study of composites curing behavior, resin flow and curing deformation. A composite material database was also established.In conclusion, LAC has been a great support for the development of aeronautical equipment, playing such roles as innovation leading, system dominating, foundation supporting and application ensuring of aerocomposites.

  16. Mechanical performance optimization of neutron shielding material based on short carbon fiber reinforced B4C/epoxy resin

    International Nuclear Information System (INIS)

    Wang Peng; Tang Xiaobin; Chen Feida; Chen Da

    2013-01-01

    To satisfy engineering requirements for mechanics performance of neutron shielding material, short carbon fiber was used to reinforce the traditional containing B 4 C neutron shielding material and effects of fiber content, length and surface treatment to mechanics performance of material was discussed. Based on Americium-Beryllium neutron source, material's neutron shielding performance was tested. The result of experiment prove that tensile strength of material which the quality ratio of resin and fiber is 5:1 is comparatively excellent for 10wt% B 4 C of carbon fiber reinforced epoxy resin. The tensile properties of material change little with the fiber length ranged from 3-10 mm The treatment of fiber surface with silane coupling agent KH-550 can increase the tensile properties of materials by 20% compared with the untreated of that. A result of shielding experiment that the novel neutron shielding material can satisfy the neutron shielding requirements can be obtained by comparing with B 4 C/polypropylene materials. The material has good mechanical properties and wide application prospect. (authors)

  17. Flexural Behavior of RC Slabs Strengthened in Flexure with Basalt Fabric-Reinforced Cementitious Matrix

    Directory of Open Access Journals (Sweden)

    Sugyu Lee

    2018-01-01

    Full Text Available This paper presents both experimental and analytical research results for predicting the flexural capacity of reinforced concrete (RC slabs strengthened in flexure with basalt fabric-reinforced cementitious matrix (FRCM. A total of 13 specimens were fabricated to evaluate the flexural behavior of RC slabs strengthened with basalt FRCM composite and were tested under four-point loading. The fiber type, tensile reinforcement ratio, and the number of fabric layers were chosen as experimental variables. The maximum load of FRCM-strengthened specimens increased from 11.2% to 98.2% relative to the reference specimens. The energy ratio and ductility of the FRCM-strengthened specimens decreased with the higher amount of fabric and tensile reinforcement. The effective stress level of FRCM fabric can be accurately predicted by a bond strength of ACI 549 and Jung’s model.

  18. Research Progress on Carbon Nanotubes Reinforced Cu-matrix Composites

    Directory of Open Access Journals (Sweden)

    TAO Jing-mei

    2017-04-01

    Full Text Available The critical issues of CNTs/Cu composites were reviewed. The preparation techniques of the composites were classified, and the research progress on powder metallurgic methods, electrochemical methods and other methods was summarized, with an emphasis on the relationship between preparation methods and properties. The interfacial characteristic of the CNTs/Cu composites was analyzed, and the research progress and existing problems of mechanical properties, electrical properties, thermal properties and wear and friction properties of the composites were also summarized. It was pointed out that the key to increase the comprehensive properties of the composites is to obtain the homogeneous distribution of CNTs and good interfacial bonding between CNTs and the Cu matrix by improving the preparation methods.

  19. NewIn-situ synthesis method of magnesium matrix composites reinforced with TiC particulates

    Directory of Open Access Journals (Sweden)

    Zhang Xiuqing

    2006-12-01

    Full Text Available Magnesium matrix composites reinforced with TiC particulates was prepared using a new in-situ synthesis method of remelting and dilution technique. And measurements were performed on the composites. The results of x ray diffraction (XRD analysis confirmed that TiC particulates were synthesized during the sintering process, and they retained in magnesium matrix composites after the remelting and dilution processing. From the microstructure characterization and electron probe microanalysis (EPMA, we could see that fine TiC particulates distributed uniformly in the matrix material.

  20. Interfacial reaction in cast WC particulate reinforced titanium metal matrix composites coating produced by laser processing

    Science.gov (United States)

    Liu, Dejian; Hu, Peipei; Min, Guoqing

    2015-06-01

    Laser injection of ceramic particle was conducted to produce particulate reinforced metal matrix composites (MMCs) coating on Ti-6Al-4V alloy. Cast WC particle (WCp) was used as injection reinforcement to avoid excessive release of carbon atoms into the melt pool. The interfaces and boundaries between WC and Ti matrix were investigated by electron microscopy study. Compared with single crystal WCp, cast WCp was an appropriate solution to control the reaction products (TiC) in the matrix and the total amount of reaction products was significantly reduced. Irregular-shape reaction layers were formed around cast WCp. The reaction layers consist of a W2C layer and a mixed layer of W and TiC. Such reaction layers are effective in load transfer under an external load.

  1. The effect of reinforcement percentages on properties of copper matrix composites reinforced with TiC particles

    Energy Technology Data Exchange (ETDEWEB)

    Bagheri, GH.A., E-mail: Gh.a.bagheri65@gmail.com

    2016-08-15

    In this research, copper matrix composites reinforced with different amounts of titanium carbide particles were produced by mechanical milling and in-situ formation of reinforcements. Morphology and size of milled powders were inspected by scanning electron microscopy (SEM) several times during milling process. Changes in lattice parameter, crystallite size, lattice strain, dislocation density and Gibbs free energy changes (due to increasing in dislocation densities and grain boundaries) in different samples (with different TiC particles contents) were studied by X-Ray Diffraction technique with Cu-kα radiation and using Nelson–Riley method and Williamson–Hall equation. Microstructure of samples after sintering was investigated by FESEM. Finally, densitometry, hardness, determination of electrical resistance and pin on disk wear test were performed and effect of reinforcement percentages on the physical and mechanical properties of composites was studied. Results show incredible improvement in mechanical properties with increasing in TiC value, even though, electrical conductivity dropped off considerably. - Highlights: • Microstructures, mechanical and physical properties of composites have been studied. • Stored Gibbs free energy of dislocations and grain boundaries has been calculated. • Gibbs free energy increased with increasing in titanium percent. • Higher TiC percentage led to better mechanical and unfavorable physical properties.

  2. Interactions between tungsten carbide (WC) particulates and metal matrix in WC-reinforced composites

    International Nuclear Information System (INIS)

    Lou, D.; Hellman, J.; Luhulima, D.; Liimatainen, J.; Lindroos, V.K.

    2003-01-01

    A variety of experimental techniques have been used to investigate the interactions between tungsten carbide (WC-Co 88/12) particulates and the matrix in some new wear resistant cobalt-based superalloy and steel matrix composites produced by hot isostatic pressing. The results show that the chemical composition of the matrix has a strong influence on the interface reaction between WC and matrix and the structural stability of the WC particulates in the composite. Some characteristics of the interaction between matrix and reinforcement are explained by the calculation of diffusion kinetics. The three-body abrasion wear resistance of the composites has been examined based on the ASTM G65-91 standard procedure. The wear behavior of the best composites of this study shows great potential for wear protection applications

  3. Jordanian silica sand and cement as a reinforcement material for polystyrene matrix composites

    International Nuclear Information System (INIS)

    Jalham, S. I.

    1999-01-01

    The behaviour of polystyrene matrix composites with different percentages of Jordaanian Silica Sand as a Reinforcement Materials (0, 5, 25, 50, and 75 wt%) and different mean grain sizes of sand particles (60, 75, 85, and 300μ m) and with cement as a boning materials in the amount fo 1/6 wt% of the wt% of silica sand were manufactured and tested under compression loading in the Industrial Engineering Department as the Uninersity of Jordan as a part of large study on local materials. The main conclusions of this investigation are: a long-term, durable structure of the polystyrene composite reinforced by silica sand and cement was achieved by mixing the constituents with water; the higher the volume fraction of the reinforcement, the higher the volume fraction of reinforcement, the higher the strength while for 75% of reinforcement, the strength dropped to an amount less than that of the matrix; the higher the grain size, the higher the strength; longitudinal brittle fracture was observed for the composites, and a homogeneous distribution of the sand particles helped in increasing the strength of the composite by playing an important role in distributing the applied load. (author). 11 refs., 6 tabs, 2 figs

  4. Fabrication of BN Nanosheet Reinforced ZrO{sub 2} Composite Pellets for Inert Matrix Fuel

    Energy Technology Data Exchange (ETDEWEB)

    Shukeir, Malik; Umer, Malik; Lee, Bin; Ryu, Ho Jin [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of)

    2014-10-15

    Plutonium also can be resulted from the dismantlement of nuclear weapons. This will result in the increase of the stockpile of plutonium. For that purpose many organizations are focusing their R-D work on the concept of Inert Matrix Fuel IMF, where a U-free matrix is used to eliminate the U-Pu conversion. R-D work was standardized around Zirconiabased IMF as a result of many screening and ranking studies performed on various candidates. Regardless of its outstanding radiation resistance, chemical stability and its high melting point, it has a very low thermal conductivity, which could be detrimental for the fuel matrix especially in case of accidents. A reinforcement phase could be used for the enhancement of the thermomechanical properties. Among many possible reinforcements, 2D structured nanosheets have emerged as an excellent candidate to enhance the thermal properties and mechanical properties simultaneously. In this approach Boron Nitride Nanosheets BNNS are used for that purpose. BNNS have a very low density, very high thermal conductivity, very high mechanical properties and high neutron absorption cross-section for Boron which is used frequently as a burnable poison. They have properties similar to graphene but they exhibit superior thermal stability in the oxide structure. Despite all the studies on other reinforcements, BNNS reinforced ZrO{sub 2} has not yet been reported. In this study, pure ZrO{sub 2} and partially stabilized Zirconia PSZ (using Yttria) ceramics are mixed with different volume fractions of BNNS.

  5. Steady-shear rheological properties of graphene-reinforced epoxy resin for manufacturing of aerospace composite films

    Science.gov (United States)

    Clausi, Marialaura; Santonicola, M. Gabriella; Laurenzi, Susanna

    2016-05-01

    The aim of this work is to analyze the steady-shear rheological behavior and the absolute viscosity of epoxy matrix reinforced with graphene nanoplatelets (xGnP) before cure. Three different grades of xGnP (grades C, M and H) were dispersed homogenously at different weight percentages (wt%) into the epoxy matrix, ranging from 0.5 to 5 wt%. It is found that nanocomposite fluids with xGnP-C exhibit a Newtonian behavior at shear rate in the range 0.1-100 s-1, conversely, nanocomposite fluids with xGnP of grade M and H exhibit a shear-thinning behavior with the increase of nanoplatelet loading. Results from this analysis indicate how the steady shear rheological properties of the nano-reinforced polymer fluids depend on the geometrical characteristics of the graphene nanoplatelets.

  6. Fracture Resistance of Endodontically Treated Teeth Restored with 2 Different Fiber-reinforced Composite and 2 Conventional Composite Resin Core Buildup Materials: An In Vitro Study.

    Science.gov (United States)

    Eapen, Ashly Mary; Amirtharaj, L Vijay; Sanjeev, Kavitha; Mahalaxmi, Sekar

    2017-09-01

    The purpose of this in vitro study was to comparatively evaluate the fracture resistance of endodontically treated teeth restored with 2 fiber-reinforced composite resins and 2 conventional composite resin core buildup materials. Sixty noncarious unrestored human maxillary premolars were collected, endodontically treated (except group 1, negative control), and randomly divided into 5 groups (n = 10). Group 2 was the positive control. The remaining 40 prepared teeth were restored with various direct core buildup materials as follows: group 3 teeth were restored with dual-cure composite resin, group 4 with posterior composite resin, group 5 with fiber-reinforced composite resin, and group 6 with short fiber-reinforced composite resin. Fracture strength testing was performed using a universal testing machine. The results were statistically analyzed by 1-way analysis of variance and the post hoc Tukey test. Fracture patterns for each sample were also examined under a light microscope to determine the level of fractures. The mean fracture resistance values (in newtons) were obtained as group 1 > group 6 > group 4 > group 3 > group 5 > group 2. Group 6 showed the highest mean fracture resistance value, which was significantly higher than the other experimental groups, and all the fractures occurred at the level of enamel. Within the limitations of this study, a short fiber-reinforced composite can be used as a direct core buildup material that can effectively resist heavy occlusal forces against fracture and may reinforce the remaining tooth structure in endodontically treated teeth. Copyright © 2017 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  7. Physico-Chemical Studies Involving Incorporation of Radioactive and Industrial Waste In Cement-Epoxy Resin Matrix

    International Nuclear Information System (INIS)

    Sayed, M.S.; Hafez, N.

    1999-01-01

    Cement and epoxy resin as chemical additives are proposed to incorporate different types of wastes. The study was extended to prepare different mixtures of cement and epoxy resin in presence of some toxic ions. The studied ions were Cd II, Ni II, Cu II, Fe III, Ce IV, 154+152 Eu, phenol and toluene. The physical, mechanical and leaching properties of the mixtures were studied. The thermal analysis and infrared spectra were also investigated. It was observed that all the studied properties of the epoxy modified cement as a disposal matrix was improved

  8. Resin Systems and Chemistry-Degradation Mechanisms and Durability in Long-Term Durability of Polymeric Matrix Composites. Chapter 1

    Science.gov (United States)

    Hinkley, Jeffrey A.; Connell, John W.

    2012-01-01

    In choosing a polymer-matrix composite material for a particular application, a number of factors need to be weighed. Among these are mechanical requirements, fabrication method (e.g. press-molding, resin infusion, filament winding, tape layup), and use conditions. Primary among the environmental exposures encountered in aerospace structures are moisture and elevated temperatures, but certain applications may require resistance to other fluids and solvents, alkaline agents, thermal cycling, radiation, or rapid, localized heating (for example, lightning strike). In this chapter, the main classes of polymer resin systems found in aerospace composites will be discussed. Within each class, their responses to environmental factors and the associated degradation mechanisms will be reviewed.

  9. Production of NbC reinforced aluminum matrix composites by mechanical alloying

    International Nuclear Information System (INIS)

    Silva, Marina Judice; Cardoso, Katia Regina; Travessa, Dilermando Nagle

    2014-01-01

    Aluminum and their alloys are key materials for the automotive and aerospace industries. The dispersion of hard ceramic particles in the Al soft matrix produces lightweight composites with interesting properties, as environmental resistance, high specific strength and stiffness, high thermal and electrical conductivity, and good wear resistance, encouraging their technological use. Powder metallurgy techniques like mechanical alloying (MA) are very attractive to design metal matrix composites, as they are able to achieve a homogeneous distribution of well dispersed particles inside the metal matrix. In this work, pure aluminum has been reinforced with particles of Niobium carbide (NbC), an extremely hard and stable refractory ceramic. NbC is frequently used as a grain growth inhibitor in micro-alloyed steel due to their low solubility in austenite. In the present work, NbC is expected to act as a reinforcing phase by its fine dispersion into the aluminum matrix, produced by MA. Composite powders produced after different milling times (up to 50h), with 10 and 20% (volume) of NbC were characterized by diffraction laser particle size analysis, scanning electron microscopy (SEM) and by X-ray diffraction (DRX), in order to establish a relationship between the milling time and the characteristics of the powder produced, as size and morphology, crystallite size and reinforcement distribution. This characterization is important in defining the MA process for production of composites for further consolidation by hot extrusion process. (author)

  10. Niobium Carbide-Reinforced Al Matrix Composites Produced by High-Energy Ball Milling

    Science.gov (United States)

    Travessa, Dilermando Nagle; Silva, Marina Judice; Cardoso, Kátia Regina

    2017-06-01

    Aluminum and its alloys are key materials for the transportation industry as they contribute to the development of lightweight structures. The dispersion of hard ceramic particles in the Al soft matrix can lead to a substantial strengthening effect, resulting in composite materials exhibiting interesting mechanical properties and inspiring their technological use in sectors like the automotive and aerospace industries. Powder metallurgy techniques are attractive to design metal matrix composites, achieving a homogeneous distribution of the reinforcement into the metal matrix. In this work, pure aluminum has been reinforced with particles of niobium carbide (NbC), an extremely hard and stable refractory ceramic. Its use as a reinforcing phase in metal matrix composites has not been deeply explored. Composite powders produced after different milling times, with 10 and 20 vol pct of NbC were produced by high-energy ball milling and characterized by scanning electron microscopy and by X-ray diffraction to establish a relationship between the milling time and size, morphology, and distribution of the particles in the composite powder. Subsequently, an Al/10 pct NbC composite powder was hot extruded into cylindrical bars. The strength of the obtained composite bars is comparable to the commercial high-strength, aeronautical-grade aluminum alloys.

  11. Corn gluten meal as a biodegradable matrix material in wood fibre reinforced composites

    International Nuclear Information System (INIS)

    Beg, M.D.H.; Pickering, K.L.; Weal, S.J.

    2005-01-01

    This study was undertaken to investigate corn gluten meal (CGM) as a biodegradable matrix material for wood fibre reinforced composites. CGM was used alone, as well as hybridized with polypropylene, and reinforced with radiata pine (Pinus Radiata) fibre using a twin-screw extruder followed by injection moulding. Tensile testing, scanning electron microscopy and differential scanning calorimetry were carried out to assess the composites. For composites from CGM and wood fibres, extrusion was carried out with the aid of the following plasticizers: octanoic acid, glycerol, polyethylene glycol and water. Windows of processability for the different plasticizers were obtained for all plasticizers. These were found to lie between 20 and 50 wt.% of plasticizer with a maximum of approximately 20% wood fibre reinforcement. The best mechanical properties were obtained with a matrix containing 10 wt.% octanoic acid and 30 wt.% water, which gave a tensile strength and Young's modulus of 18.7 MPa and 4 GPa, respectively. Hybrid matrix composites were compounded with a maleated polypropylene coupling agent and benzoyl peroxide as a cross-linking agent. The highest tensile strength and Young's modulus obtained from hybrid matrix composites were 36.9 MPa and 5.8 GPa with 50 wt.% fibre

  12. Corn gluten meal as a biodegradable matrix material in wood fibre reinforced composites

    Energy Technology Data Exchange (ETDEWEB)

    Beg, M.D.H. [Department of Materials and Process Engineering, University of Waikato, Private Bag 3105, Hamilton (New Zealand); Pickering, K.L. [Department of Materials and Process Engineering, University of Waikato, Private Bag 3105, Hamilton (New Zealand)]. E-mail: klp@waikato.ac.nz; Weal, S.J. [Department of Materials and Process Engineering, University of Waikato, Private Bag 3105, Hamilton (New Zealand)

    2005-12-05

    This study was undertaken to investigate corn gluten meal (CGM) as a biodegradable matrix material for wood fibre reinforced composites. CGM was used alone, as well as hybridized with polypropylene, and reinforced with radiata pine (Pinus Radiata) fibre using a twin-screw extruder followed by injection moulding. Tensile testing, scanning electron microscopy and differential scanning calorimetry were carried out to assess the composites. For composites from CGM and wood fibres, extrusion was carried out with the aid of the following plasticizers: octanoic acid, glycerol, polyethylene glycol and water. Windows of processability for the different plasticizers were obtained for all plasticizers. These were found to lie between 20 and 50 wt.% of plasticizer with a maximum of approximately 20% wood fibre reinforcement. The best mechanical properties were obtained with a matrix containing 10 wt.% octanoic acid and 30 wt.% water, which gave a tensile strength and Young's modulus of 18.7 MPa and 4 GPa, respectively. Hybrid matrix composites were compounded with a maleated polypropylene coupling agent and benzoyl peroxide as a cross-linking agent. The highest tensile strength and Young's modulus obtained from hybrid matrix composites were 36.9 MPa and 5.8 GPa with 50 wt.% fibre.

  13. Production of NbC reinforced aluminum matrix composites by mechanical alloying

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Marina Judice; Cardoso, Katia Regina; Travessa, Dilermando Nagle, E-mail: dilermando.travessa@unifesp.br [Universidade Federal de Sao Paulo (UNIFESP), Sao Jose dos Campos, SP (Brazil). Instituto de Ciencia e Tecnologia

    2014-07-01

    Aluminum and their alloys are key materials for the automotive and aerospace industries. The dispersion of hard ceramic particles in the Al soft matrix produces lightweight composites with interesting properties, as environmental resistance, high specific strength and stiffness, high thermal and electrical conductivity, and good wear resistance, encouraging their technological use. Powder metallurgy techniques like mechanical alloying (MA) are very attractive to design metal matrix composites, as they are able to achieve a homogeneous distribution of well dispersed particles inside the metal matrix. In this work, pure aluminum has been reinforced with particles of Niobium carbide (NbC), an extremely hard and stable refractory ceramic. NbC is frequently used as a grain growth inhibitor in micro-alloyed steel due to their low solubility in austenite. In the present work, NbC is expected to act as a reinforcing phase by its fine dispersion into the aluminum matrix, produced by MA. Composite powders produced after different milling times (up to 50h), with 10 and 20% (volume) of NbC were characterized by diffraction laser particle size analysis, scanning electron microscopy (SEM) and by X-ray diffraction (DRX), in order to establish a relationship between the milling time and the characteristics of the powder produced, as size and morphology, crystallite size and reinforcement distribution. This characterization is important in defining the MA process for production of composites for further consolidation by hot extrusion process. (author)

  14. Flexural properties and impact strength of denture base resins reinforced with micronized glass flakes

    Directory of Open Access Journals (Sweden)

    Ronak H Choksi

    2016-01-01

    Conclusion: Flexural strength of unmodified PMMA denture base resin decreases with increase in the concentration of glass flakes. Impact strength does not show any significant change at 5% concentration of glass flakes and impact strength significantly reduces with the addition of glass flakes in 10% and 20%.

  15. Thermal oxidation induced degradation of carbon fiber reinforced composites and carbon nanotube sheet enhanced fiber/matrix interface for high temperature aerospace structural applications

    Science.gov (United States)

    Haque, Mohammad Hamidul

    Recent increase in the use of carbon fiber reinforced polymer matrix composite, especially for high temperature applications in aerospace primary and secondary structures along with wind energy and automotive industries, have generated new challenges to predict its failure mechanisms and service life. This dissertation reports the experimental study of a unidirectional carbon fiber reinforced bismaleimide (BMI) composites (CFRC), an excellent candidate for high temperature aerospace components, undergoing thermal oxidation at 260 °C in air for over 3000 hours. The key focus of the work is to investigate the mechanical properties of the carbon fiber BMI composite subjected to thermal aging in three key aspects - first, studying its bulk flexural properties (in macro scale), second, characterizing the crack propagation along the fiber direction, representing the interfacial bonding strength between fiber and matrix (in micro scale), and third, introducing nano-structured materials to modify the interface (in nano scale) between the carbon fiber and BMI resin and mechanical characterization to study its influence on mitigating the aging effect. Under the first category, weight loss and flexural properties have been monitored as the oxidation propagates through the fiber/matrix interface. Dynamic mechanical analysis and micro-computed tomography analysis have been performed to analyze the aging effects. In the second category, the long-term effects of thermal oxidation on the delamination (between the composite plies) and debonding (between fiber and matrix) type fracture toughness have been characterized by preparing two distinct types of double cantilever beam specimens. Digital image correlation has been used to determine the deformation field and strain distribution around the crack propagation path. Finally the resin system and the fiber/matrix interface have been modified using nanomaterials to mitigate the degradations caused by oxidation. Nanoclay modified

  16. Failure behavior / characteristics of fabric reinforced polymer matrix composite and aluminum6061 on dynamic tensile loading

    International Nuclear Information System (INIS)

    Bang, Hyejin; Cho, Chongdu

    2017-01-01

    Composite materials are composed of multiple types of materials as reinforcement and matrix. Among them, CFRP (Carbon fiber reinforced polymer) is widely used materials in automotive and defense industry. Carbon fibers are used as a reinforcement, of which Young's modulus is in a prepreg form. In automotive industry, especially, high strain rate test is needed to measure dynamic properties, used in dynamic analysis like high inertia included simulation as a car crash. In this paper, a SHTB (Split Hopkinson tensile bar) machine is employed for estimating stress-strain curve under dynamic load condition on aluminum 6061 and CFRP. The strain rate range is about from 100 /s to 1000 /s and the number of prepreg layers of composite specimen is total eight plies which are stacked symmetrically to structure CFRP. As a result, stress / strain point data are obtained and used for simulation into stacked composites.

  17. Failure behavior / characteristics of fabric reinforced polymer matrix composite and aluminum6061 on dynamic tensile loading

    Energy Technology Data Exchange (ETDEWEB)

    Bang, Hyejin; Cho, Chongdu [Inha University, Incheon (Korea, Republic of)

    2017-08-15

    Composite materials are composed of multiple types of materials as reinforcement and matrix. Among them, CFRP (Carbon fiber reinforced polymer) is widely used materials in automotive and defense industry. Carbon fibers are used as a reinforcement, of which Young's modulus is in a prepreg form. In automotive industry, especially, high strain rate test is needed to measure dynamic properties, used in dynamic analysis like high inertia included simulation as a car crash. In this paper, a SHTB (Split Hopkinson tensile bar) machine is employed for estimating stress-strain curve under dynamic load condition on aluminum 6061 and CFRP. The strain rate range is about from 100 /s to 1000 /s and the number of prepreg layers of composite specimen is total eight plies which are stacked symmetrically to structure CFRP. As a result, stress / strain point data are obtained and used for simulation into stacked composites.

  18. Design of strong wooden box coated with fiberglass reinforced resin for shipping and burial of contaminated glove boxes. Final report

    International Nuclear Information System (INIS)

    1982-01-01

    The project scope of work included the complete decontamination and decommissioning (D and D) of the Westinghouse ARD Fuel Laboratories at the Cheswick Site in the shortest possible time. This has been accomplished in the following four phases: (1) preparation of documents and necessary paperwork; packaging and shipping of all special nuclear materials in an acceptable form to a reprocessing agency; (2) decontamination of all facilities, glove boxes and equipment; loading of generated waste into bins, barrels and strong wooden boxes; (3) shipping of al bins, barrels and boxes containing waste to the designated burial site; removal of all utility services from the laboratories; and (4) final survey of remaining facilities and certification for nonrestricted use; preparation of final report. This attachment contains design of strong wooden box coated with fiberglass reinforced resin for shipping and burial of contaminated glove boxes

  19. Microstructure Characteristics of Fe-Matrix Composites Reinforced by In-Situ Carbide Particulates

    Science.gov (United States)

    Huang, Xiaodong; Song, Yanpei

    2017-10-01

    Carbide particulates reinforced iron-matrix composites were prepared by in-situ synthesis reaction between Ti, V and C on liquid alloys surface. The microstructure of the composite was characterized by SEM, TEM and OM. The results showed that the main phases were α-Fe, carbide particulate; besides, there were small amounts of γ-Fe and graphite (G) in the composite. The carbides were TiVC2 and VC in the shape of short bar and graininess. The matrix consisted of martensite and small amounts of retained austenite.

  20. The Particle Shape of WC Governing the Fracture Mechanism of Particle Reinforced Iron Matrix Composites.

    Science.gov (United States)

    Li, Zulai; Wang, Pengfei; Shan, Quan; Jiang, Yehua; Wei, He; Tan, Jun

    2018-06-11

    In this work, tungsten carbide particles (WC p , spherical and irregular particles)-reinforced iron matrix composites were manufactured utilizing a liquid sintering technique. The mechanical properties and the fracture mechanism of WC p /iron matrix composites were investigated theoretically and experimentally. The crack schematic diagram and fracture simulation diagram of WC p /iron matrix composites were summarized, indicating that the micro-crack was initiated both from the interface for spherical and irregular WC p /iron matrix composites. However, irregular WC p had a tendency to form spherical WC p . The micro-cracks then expanded to a wide macro-crack at the interface, leading to a final failure of the composites. In comparison with the spherical WC p , the irregular WC p were prone to break due to the stress concentration resulting in being prone to generating brittle cracking. The study on the fracture mechanisms of WC p /iron matrix composites might provide a theoretical guidance for the design and engineering application of particle reinforced composites.

  1. Repair of Impact-Damaged Prestressed Bridge Girders Using Strand Splices and Fabric Reinforced Cementitious Matrix

    OpenAIRE

    Jones, Mark Stevens

    2017-01-01

    This thesis investigates the repair of impact-damaged prestressed concrete bridge girders with strand splices and fabric-reinforced cementitious matrix systems, specifically for repair of structural damage to the underside of an overpass bridge girder due to an overheight vehicle collision. Collision damage to bridges can range from minor to catastrophic, potentially requiring repair or replacement of a bridge girder. This thesis investigates the performance of two different types of repair...

  2. Optimization of the rheological properties of epoxy resins for glass and carbon reinforced plastics

    Science.gov (United States)

    Phyo Maung, Pyi; Malysheva, G.; Romanova, I.

    2016-10-01

    Vacuum assisted resin transfer moulding (VARTM) offers advantages such as simplicity, low cost of consumables, and the ability to carry out the impregnation process and curing without using expensive equipment and tooling. In the VARTM process, rheological properties of resin have a critical impact on the impregnation and curing process. In this article, the experimental results of viscosity are presented, including the glass transition temperature, and the tensile and bending strength of the epoxy binders with the amine hardener, which depend on the quantity of its active solvent composition. The active solvent used is diethylene glycol. It shows that for an increase in the content of the active solvent, a reduction in the viscosity and a reduction of the glass transition temperature and strength occurs. The optimum composition of the binder is selected by using the Pareto optimization criteria and the Cayley - Smorodinskaya method. By using the epoxy binder, the active solvent should not exceed 10-15% by weight. This approach helps to optimize the amount of active solvent added to the epoxy resins for the criterion of viscosity, strength, and heat resistance.

  3. Effect of disaccharide, gamma radiation and temperature on the physico-mechanical properties of jute fabrics reinforced unsaturated polyester resin-based composite

    Science.gov (United States)

    Sahadat Hossain, Md.; Chowdhury, A. M. Sarwaruddin; Khan, Ruhul A.

    2017-06-01

    The jute fabrics reinforced unsaturated polyester resin (jute/UPR)-based composites were prepared successfully by the hand-lay-up technique. The percentage of jute fabrics was kept constant at 40% fiber (by weight). The disaccharide percentage was also kept constant at 2% (by weight), but at this percentage the mechanical properties were lower than the untreated composites. Gamma radiation dose was varied at 0, 2.5, 5 and 7.5 kGy for jute/UPR-based composites. At 5.0 kGy gamma dose highest TS, TM and Eb were obtained. The jute/UPR-based composites were treated under 30°C, 50°C and -18°C for the measurement of mechanical properties. At low temperature (-18°C), the highest mechanical properties were observed. The water uptake properties were measured for disaccharide-treated and disaccharide-untreated composites up to 10 days, but no water was absorbed by the composites. The soil degradation test was carried out under 12 inch soil containing at least 25% water, but no significant decrease was observed for untreated and sucrose-treated composites. For the functional group analysis, FT-IR was carried out. For the fiber matrix adhesion analysis, the scanning electron microscopic image was taken.

  4. Microstructure and Mechanical Properties of Graphene-Reinforced Titanium Matrix/Nano-Hydroxyapatite Nanocomposites.

    Science.gov (United States)

    Li, Feng; Jiang, Xiaosong; Shao, Zhenyi; Zhu, Degui; Zhu, Minhao

    2018-04-16

    Biomaterial composites made of titanium and hydroxyapatite (HA) powder are among the most important biomedicalmaterials due to their good mechanical properties and biocompatibility. In this work, graphene-reinforced titanium matrix/nano-hydroxyapatite nanocomposites were prepared by vacuum hot-pressing sintering. The microstructure and mechanical properties of graphene-reinforced titanium matrix/nano-hydroxyapatite nanocomposites with different graphene content were systematically investigated. Microstructures of the nanocomposites were examined by X-ray diffraction (XRD), back scattered electron imaging (BSE), scanning electron microscope (SEM) equipped with energy dispersive spectrometer (EDS), electron probe microanalyzer (EPMA), and transmission electron microscope (TEM). The mechanical properties were determined from microhardness, shear strength, and compressive strength. Results showed that during the high-temperature sintering process, complex chemical reactions occurred, resulting in new phases of nucleation such as Ca₃(PO₄)₂, Ti x P y , and Ti₃O.The new phases, which easily dropped off under the action of external force, could hinder the densification of sintering and increase the brittleness of the nanocomposites. Results demonstrated that graphene had an impact on the microstructure and mechanical properties of the nanocomposites. Based on the mechanical properties and microstructure of the nanocomposites, the strengthening and fracture mechanisms of the graphene-reinforced titanium matrix/nano-hydroxyapatite nanocomposites with different graphene content were analyzed.

  5. Microstructure and Mechanical Properties of Graphene-Reinforced Titanium Matrix/Nano-Hydroxyapatite Nanocomposites

    Directory of Open Access Journals (Sweden)

    Feng Li

    2018-04-01

    Full Text Available Biomaterial composites made of titanium and hydroxyapatite (HA powder are among the most important biomedicalmaterials due to their good mechanical properties and biocompatibility. In this work, graphene-reinforced titanium matrix/nano-hydroxyapatite nanocomposites were prepared by vacuum hot-pressing sintering. The microstructure and mechanical properties of graphene-reinforced titanium matrix/nano-hydroxyapatite nanocomposites with different graphene content were systematically investigated. Microstructures of the nanocomposites were examined by X-ray diffraction (XRD, back scattered electron imaging (BSE, scanning electron microscope (SEM equipped with energy dispersive spectrometer (EDS, electron probe microanalyzer (EPMA, and transmission electron microscope (TEM. The mechanical properties were determined from microhardness, shear strength, and compressive strength. Results showed that during the high-temperature sintering process, complex chemical reactions occurred, resulting in new phases of nucleation such as Ca3(PO42, TixPy, and Ti3O.The new phases, which easily dropped off under the action of external force, could hinder the densification of sintering and increase the brittleness of the nanocomposites. Results demonstrated that graphene had an impact on the microstructure and mechanical properties of the nanocomposites. Based on the mechanical properties and microstructure of the nanocomposites, the strengthening and fracture mechanisms of the graphene-reinforced titanium matrix/nano-hydroxyapatite nanocomposites with different graphene content were analyzed.

  6. ECAP – New consolidation method for production of aluminium matrix composites with ceramic reinforcement

    Directory of Open Access Journals (Sweden)

    Mateja Šnajdar Musa

    2013-06-01

    Full Text Available Aluminium based metal matrix composites are rapidly developing group of materials due to their unique combination of properties that include low weight, elevated strength, improved wear and corrosion resistance and relatively good ductility. This combination of properties is a result of mixing two groups of materials with rather different properties with aluminium as ductile matrix and different oxides and carbides added as reinforcement. Al2O3, SiC and ZrO2 are the most popular choices of reinforcement material. One of the most common methods for producing this type of metal matrix composites is powder metallurgy since it has many variations and also is relatively low-cost method. Many different techniques of compacting aluminium and ceramic powders have been previously investigated. Among those techniques equal channel angular pressing (ECAP stands out due to its beneficial influence on the main problem that arises during powder compaction and that is a non-uniform distribution of reinforcement particles. This paper gives an overview on ECAP method principles, advantages and produced powder composite properties.

  7. Full incorporation of Strattice™ Reconstructive Tissue Matrix in a reinforced hiatal hernia repair: a case report

    Directory of Open Access Journals (Sweden)

    Freedman Bruce E

    2012-08-01

    Full Text Available Abstract Introduction A non-cross-linked porcine acellular dermal matrix was used to reinforce an esophageal hiatal hernia repair. A second surgery was required 11 months later to repair a slipped Nissen; this allowed for examination of the hiatal hernia repair and showed the graft to be well vascularized and fully incorporated. Case presentation A 71-year-old Caucasian woman presented with substernal burning and significant dysphagia. An upper gastrointestinal series revealed a type III complex paraesophageal hiatal hernia. She underwent laparoscopic surgery to repair a hiatal hernia that was reinforced with a xenograft (Strattice™ Reconstructive Tissue Matrix, LifeCell, Branchburg, NJ, USA along with a Nissen fundoplication. A second surgery was required to repair a slipped Nissen; this allowed for examination of the hiatal repair and graft incorporation 11 months after the initial surgery. Conclusion In this case, a porcine acellular dermal matrix was an effective tool to reinforce the crural hiatal hernia repair. The placement of the mesh and method of fixation are believed to be crucial to the success of the graft. It was found to be well vascularized 11 months after the original placement with no signs of erosion, stricture, or infection. Further studies and long-term follow-up are required to support the findings of this case report.

  8. Degree of conversion and cross-link density within a resin-matrix composite.

    Science.gov (United States)

    Al-Zain, Afnan O; Eckert, George J; Lukic, Henry; Megremis, Spiro J; Platt, Jeffrey A

    2018-05-01

    The aims of this study were to profile light radiated from two light-curing units (LCUs) and evaluate profile relationship to polymerization patterns within a resin-matrix composite (RMC). Beam profiles of one multiple emission peak light-emitting-diode and one quartz-tungsten-halogen curing-unit were measured using a beam profiler/spectrometer system. A camera-based profiler and an integrating sphere/spectrometer assembly were used to evaluate each LCU beam. Polymerization patterns within a nano-hybrid RMC were investigated using a mapping approach by assessing the degree of conversion utilizing micro-Raman spectroscopy and indirectly estimating cross-link-density by repeated microhardness testing before and after exposure to ethanol (%KH reduction, n = 3). The irradiance received on the top and bottom specimen surfaces from both LCUs was measured using a MARC-RC system. The investigated beam profile area from both LCUs was non-uniform and yielded localized discrepancies in DC (55.7-74.9%) and %KH reduction (26.7-54.1%). The LCU irradiance received at the bottom of the specimens was ∼10% of the top value. This study demonstrated that LCU beam profiles were non-uniform in the area explored. Localized differences in DC and %KH reduction existed throughout the RMC specimens but did not follow a specific pattern. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 1496-1504, 2018. © 2017 Wiley Periodicals, Inc.

  9. Polymer matrix of fiber-reinforced composites: Changes in the semi-interpenetrating polymer network during the shelf life.

    Science.gov (United States)

    Khan, Aftab A; Al-Kheraif, Abdulaziz A; Al-Shehri, Abdullah M; Säilynoja, Eija; Vallittu, Pekka K

    2018-02-01

    This laboratory study was aimed to characterize semi-interpenetrating polymer network (semi-IPN) of fiber-reinforced composite (FRC) prepregs that had been stored for up to two years before curing. Resin impregnated prepregs of everStick C&B (StickTech-GC, Turku, Finland) glass FRC were stored at 4°C for various lengths of time, i.e., two-weeks, 6-months and 2-years. Five samples from each time group were prepared with a light initiated free radical polymerization method, which were embedded to its long axis in self-curing acrylic. The nanoindentation readings on the top surface toward the core of the sample were made for five test groups, which were named as "stage 1-5". To evaluate the nanohardness and modulus of elasticity of the polymer matrix, a total of 4 slices (100µm each) were cut from stage 1 to stage 5. Differences in nanohardness values were evaluated with analysis of variance (ANOVA), and regression model was used to develop contributing effect of the material's different stages to the total variability in the nanomechanical properties. Additional chemical and thermal characterization of the polymer matrix structure of FRC was carried out. It was hypothesized that time of storage may have an influence on the semi-IPN polymer structure of the cured FRC. The two-way ANOVA test revealed that the storage time had no significant effect on the nanohardness of FRC (p = 0.374). However, a highly significant difference in nanohardness values was observed between the different stages of FRC (Pprepregs might be due to phase-segregation of components of semi-IPN structure of FRC prepregs before their use. This may have an influence to the surface bonding properties of the cured FRC. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Resin Composites Reinforced by Nanoscaled Fibers or Tubes for Dental Regeneration

    Science.gov (United States)

    Li, Xiaoming; Liu, Wei; Sun, Lianwen; Aifantis, Katerina E.; Yu, Bo; Fan, Yubo; Cui, Fuzhai; Watari, Fumio

    2014-01-01

    It has been stated clearly that nanofillers could make an enhancement on the mechanical performances of dental composites. In order to address current shortage of traditional dental composites, fillers in forms of nanofibers or nanotubes are broadly regarded as ideal candidates to greatly increase mechanical performances of dental composites with low content of fillers. In this review, the efforts using nanofibers and nanotubes to reinforce mechanical performances of dental composites, including polymeric nanofibers, metallic nanofibers or nanotubes, and inorganic nanofibers or nanotubes, as well as their researches related, are demonstrated in sequence. The first purpose of current paper was to confirm the enhancement of nanofibers or nanotubes' reinforcement on the mechanical performances of dental restorative composite. The second purpose was to make a general description about the reinforcement mechanism of nanofibers and nanotubes, especially, the impact of formation of interphase boundary interaction and nanofibers themselves on the advanced mechanical behaviors of the dental composites. By means of the formation of interface interaction and poststretching nanofibers, reinforced effect of dental composites by sorts of nanofibers/nanotubes has been successfully obtained. PMID:24982894

  11. Mechanical characterization of SiC particulate & E-glass fiber reinforced Al 3003 hybrid metal matrix composites

    Science.gov (United States)

    Narayana, K. S. Lakshmi; Shivanand, H. K.

    2018-04-01

    Metal matrix composites constitute a class of low cost high quality materials which offer high performance for various industrial applications. The orientation of this research is towards the study of mechanical properties of as cast silicon carbide (SiC) particulates and Short E-Glass fibers reinforced Aluminum matrix composites (AMCs). The Hybrid metal matrix composite is developed by reinforcing SiC particulates of 100 microns and short E-Glass fibers of 2-3 mm length with Al 3003 in different compositions. The vortex method of stir casting was employed, in which the reinforcements were introduced into the vortex created by the molten metal by means of mechanical stirrer. The mechanical properties of the prepared metal matrix composites were analyzed. From the studies it was noticed that an improvement in mechanical properties of the reinforced alloys compared to unreinforced alloys.

  12. Correlation of microstructure and compressive properties of amorphous matrix composites reinforced with tungsten continuous fibers or porous foams

    International Nuclear Information System (INIS)

    Son, Chang-Young; Lee, Sang-Bok; Lee, Sang-Kwan; Kim, Choongnyun Paul; Lee, Sunghak

    2010-01-01

    Zr-based amorphous alloy matrix composites reinforced with tungsten continuous fibers or porous foams were fabricated without pores or defects by liquid pressing process, and their microstructures and compressive properties were investigated. About 65-70 vol.% of tungsten reinforcements were homogeneously distributed inside the amorphous matrix. The compressive test results indicated that the tungsten-reinforced composites showed considerable plastic strain as the compressive load was sustained by fibers or foams. Particularly in the tungsten porous foam-reinforced composite, the compressive stress continued to increase according to the work hardening after the yielding, thereby leading to the maximum strength of 2764 MPa and the plastic strain of 39.4%. This dramatic increase in strength and ductility was attributed to the simultaneous and homogeneous deformation at tungsten foams and amorphous matrix since tungsten foams did not show anisotropy and tungsten/matrix interfaces were excellent.

  13. Graphene-Reinforced Aluminum Matrix Composites: A Review of Synthesis Methods and Properties

    Science.gov (United States)

    Chen, Fei; Gupta, Nikhil; Behera, Rakesh K.; Rohatgi, Pradeep K.

    2018-06-01

    Graphene-reinforced aluminum (Gr-Al) matrix nanocomposites (NCs) have attracted strong interest from both research and industry in high-performance weight-sensitive applications. Due to the vastly different bonding characteristics of the Al matrix (metallic) and graphene (in-plane covalent + inter-plane van der Waals), the graphene phase has a general tendency to agglomerate and phase separate in the metal matrix, which is detrimental for the mechanical and chemical properties of the composite. Thus, synthesis of Gr-Al NCs is extremely challenging. This review summarizes the different methods available to synthesize Gr-Al NCs and the resulting properties achieved in these NCs. Understanding the effect of processing parameters on the realized properties opens up the possibility of tailoring the synthesis methods to achieve the desired properties for a given application.

  14. Graphene-Reinforced Aluminum Matrix Composites: A Review of Synthesis Methods and Properties

    Science.gov (United States)

    Chen, Fei; Gupta, Nikhil; Behera, Rakesh K.; Rohatgi, Pradeep K.

    2018-03-01

    Graphene-reinforced aluminum (Gr-Al) matrix nanocomposites (NCs) have attracted strong interest from both research and industry in high-performance weight-sensitive applications. Due to the vastly different bonding characteristics of the Al matrix (metallic) and graphene (in-plane covalent + inter-plane van der Waals), the graphene phase has a general tendency to agglomerate and phase separate in the metal matrix, which is detrimental for the mechanical and chemical properties of the composite. Thus, synthesis of Gr-Al NCs is extremely challenging. This review summarizes the different methods available to synthesize Gr-Al NCs and the resulting properties achieved in these NCs. Understanding the effect of processing parameters on the realized properties opens up the possibility of tailoring the synthesis methods to achieve the desired properties for a given application.

  15. Stereological observations of platelet-reinforced mullite- and zirconia-matrix composites

    International Nuclear Information System (INIS)

    Cherian, I.K.; Kriven, W.M.; Lehigh, M.D.; Nettleship, I.

    1996-01-01

    Recently, the effect of solid inclusions on the sintering of ceramic powders has been explained in terms of a back-stress that opposes densification. Several analyses have been proposed to describe this problem. However, little quantitative information exists concerning the effect of reinforcement on microstructural evolution. This study compares the microstructural development of zirconia and mullite matrices in the presence of alumina platelets. The effect of platelet loading on density is similar for both composites. Quantitative stereological examinations reveal that the average grain size and pore size are finer for the zirconia-matrix composite. The platelet loading does not have any noticeable effect on the average grain size of the matrix in either composite. However, the average pore size increases as the volume fraction of platelets increases for both materials. Contiguity measurements have detected some aggregation of platelets in the zirconia-matrix composite

  16. The effect of joint surface contours and glass fiber reinforcement on the transverse strength of repaired acrylic resin: An in vitro study.

    Science.gov (United States)

    Anasane, Nayana; Ahirrao, Yogesh; Chitnis, Deepa; Meshram, Suresh

    2013-03-01

    Denture fracture is an unresolved problem in complete denture prosthodontics. However, the repaired denture often experiences a refracture at the repaired site due to poor transverse strength. Hence, this study was conducted to evaluate the effect of joint surface contours and glass fiber reinforcement on the transverse strength of repaired acrylic resins. A total of 135 specimens of heat polymerized polymethyl methacrylate resin of dimensions 64 × 10 × 2.5 mm were fabricated. Fifteen intact specimens served as the control and 120 test specimens were divided into four groups (30 specimens each), depending upon the joint surface contour (butt, bevel, rabbet and round), with two subgroups based on type of the repair. Half of the specimens were repaired with plain repair resin and the other half with glass fibers reinforced repair resin. Transverse strength of the specimens was determined using three-point bending test. The results were analyzed using one-way ANOVA and Tukey post-hoc test (α= 0.05). Transverse strength values for all repaired groups were significantly lower than those for the control group (P transverse strength; hence, it can be advocated for repair of denture base resins.

  17. Microstructure and Strengthening Mechanisms of Carbon Nanotube Reinforced Magnesium Matrix Composites Fabricated by Accumulative Roll Bonding

    International Nuclear Information System (INIS)

    Yoo, Seong Jin; Kim, Woo Jin

    2014-01-01

    A combination of accumulative roll bonding (ARB) and high-energy ball milling was used to fabricate carbon nano tube (CNT)-reinforced Mg composites in sheet form. CNT-Al composite powders synthesized using the high-energy ball-milling process, were coated on the surface of Mg sheets using either spraying or dipping methods. The coated sheets were stacked and then subjected to ARB. Formation of CNT-intermetallic compounds through inter-diffusion between Al and Mg, fragmentation of the CNTintermetallic compounds, and their dispersion into the matrix by plastic flow; as well as dissolution of the intermetallic compound particles into the matrix while leaving CNTs in the matrix, occurred in sequence during the ARB process. This eventually resulted in the uniform distribution of nano-sized CNT particles in the Mg matrix. As the thickness of the Mg sheet and of the coating layer of Al-CNT powder on the surface of the Mg sheet were similar, the dispersion of CNTs into the Mg matrix occurred more uniformly and the strengthening effect of adding CNTs was greater. The strengthening gained by adding CNTs was attributed to Orowan strengthening and dislocation-density increase due to a thermal mismatch between the matrix and the CNTs.

  18. The effect of the matrix superplastic deformation on interface reaction in fiber-reinforced composites

    International Nuclear Information System (INIS)

    Astanin, V.V.; Imayeva, L.A.

    1995-01-01

    It is known that superplastic deformation affects the processes o solid phases bonding. In particular, the effect of a character of matrix flow upon nucleation and growth of the reaction products at the fiber/matrix interface should be expected during consolidation of the fiber-reinforced composites under superplastic conditions. The matrix material flow in thin clearance (about 20μm) between strengthening fibers is a special feature of composite consolidation. In previous papers, it was shown that the character of the flow in thin specimens, when the specimen thickness is equal to several grain sizes, is very different from that in thick specimens. In this manner the question of the effect of the deformation on the fiber/matrix interface formation is complicated and one should consider the peculiarities of matrix deformation during the composite fabrication and the effect of localization of the deformation on the fiber/matrix interface reaction. In this paper, the authors shall focus on these two problems

  19. Production and Characterization of WC-Reinforced Co-Based Superalloy Matrix Composites

    Science.gov (United States)

    Özgün, Özgür; Dinler, İlyas

    2018-05-01

    Cobalt-based superalloy matrix composite materials were produced through the powder metallurgy technique using element powders at high purity and nano-sized wolfram carbide (WC) reinforcement in this study. An alloy that had the same chemical composition as the Stellite 6 alloy but not containing carbon was selected as the matrix alloy. The powder mixtures obtained as a result of mixing WC reinforcing member and element powders at the determined ratio were shaped by applying 300 MPa of pressure. The green components were sintered under argon atmosphere at 1240 °C for 120 minutes. The densities of the sintered components were determined by the Archimedes' principle. Microstructural characterization was performed via X-ray diffraction analysis, scanning electron microscope examinations, and energy-dispersive spectrometry. Hardness measurements and tensile tests were performed for determining mechanical characteristics. The relative density values of the sintered components increased by increasing the WC reinforcement ratio and they could almost reach the theoretical density. It was determined from the microstructural examinations that the composite materials consisted of fine and equiaxed grains and coarse carbides demonstrating a homogeneous dispersion along the microstructure at the grain boundaries. As it was the case in the density values, the hardness and strength values of the composites increased by increasing the WC ratio.

  20. Microstructure and hardness of WC-Co particle reinforced iron matrix surface composite

    Directory of Open Access Journals (Sweden)

    Zhang Peng

    2013-11-01

    Full Text Available In this study, a high Cr cast iron surface composite material reinforced with WC-Co particles 2-6 mm in size was prepared using a pressureless sand mold infiltration casting technique. The composition, microstructure and hardness were determined by means of energy dispersive spectrometry (EDS, electron probe microanalysis (EPMA, scanning electron microscope (SEM and Rockwell hardness measurements. It is determined that the obtained composite layer is about 15 mm thick with a WC-Co particle volumetric fraction of ~38%. During solidification, interface reaction takes place between WC-Co particles and high chromium cast iron. Melting and dissolving of prefabricated particles are also found, suggesting that local Co melting and diffusion play an important role in promoting interface metallurgical bonding. The composite layer is composed of ferrite and a series of carbides, such as (Cr, W, Fe23C6, WC, W2C, M6C and M12C. The inhomogeneous hardness in the obtained composite material shows a gradient decrease from the particle reinforced metal matrix composite layer to the matrix layer. The maximum hardness of 86.3 HRA (69.5 HRC is obtained on the particle reinforced surface, strongly indicating that the composite can be used as wear resistant material.

  1. A Brief Research Review for Improvement Methods the Wettability between Ceramic Reinforcement Particulate and Aluminium Matrix Composites

    Science.gov (United States)

    Razzaq, Alaa Mohammed; Majid, Dayang Laila Abang Abdul; Ishak, M. R.; B, Uday M.

    2017-05-01

    The development of new methods for addition fine ceramic powders to Al aluminium alloy melts, which would lead to more uniform distribution and effective incorporation of the reinforcement particles into the aluminium matrix alloy. Recently the materials engineering research has moved to composite materials from monolithic, adapting to the global need for lightweight, low cost, quality, and high performance advanced materials. Among the different methods, stir casting is one of the simplest ways of making aluminium matrix composites. However, it suffers from poor distribution and combination of the reinforcement ceramic particles in the metal matrix. These problems become significantly effect to reduce reinforcement size, more agglomeration and tendency with less wettability for the ceramic particles in the melt process. Many researchers have carried out different studies on the wettability between the metal matrix and dispersion phase, which includes added wettability agents, fluxes, preheating the reinforcement particles, coating the reinforcement particles, and use composting techniques. The enhancement of wettability of ceramic particles by the molten matrix alloy and the reinforcement particles distribution improvement in the solidified matrix is the main objective for many studies that will be discussed in this paper.

  2. Shear Bond Strength of Resin Buttons to Lithium Disilicate and Leucite Reinforced Feldspathic Restorations

    Science.gov (United States)

    2016-05-01

    utilizing enamel bonding procedures. These fixed orthodontic appliances are the gold standard in orthodontic treatment and can be used to correct... enamel of teeth. When this same procedure needs to be done on a restorative material such as lithium disilicate, or leucite reinforced feldspathic...toughness from its crystal size and orientation which causes cracks to deflect instead of propagate. The second material being tested, IPS Empress

  3. Fracture resistance of class IV fiber-reinforced composite resin restorations: An in vitro study

    Directory of Open Access Journals (Sweden)

    P S Praveen Kumar

    2017-01-01

    Full Text Available Objectives: The aim of this study was to evaluate fracture resistance of incisal edge fractures (Class IV restored with a Glass Fiber-reinforced Composite (FRC. Materials and Methods: Twenty-four extracted sound maxillary central incisors were randomly divided into two groups. Group I (control contained untreated teeth. Samples in experimental groups II were prepared by cutting the incisal (one-third part of the crown horizontally and was subjected to enamel preparations, then restored with a Glass FRC. Fracture resistance was evaluated as Newton's for samples tested in a Hounsfield universal testing machine. Failure modes were examined microscopically. Results: Mean peak failure load (Newton's observed in Glass Fiber-reinforced Nanocomposite was 863.50 ± 76.12. The experimental group showed similar types of failure modes with the majority occurring as cohesive and mixed type. 58% of the teeth in Glass FRC group fractured below the cementoenamel junction. Conclusion: Using Fiber reinforced composite substructure under conventional composites in Class IV restorations, the fracture resistance of the restored incisal edge could be increased.

  4. RC beams shear-strengthened with fabric-reinforced-cementitious-matrix (FRCM) composite

    Science.gov (United States)

    Loreto, Giovanni; Babaeidarabad, Saman; Leardini, Lorenzo; Nanni, Antonio

    2015-12-01

    The interest in retrofit/rehabilitation of existing concrete structures has increased due to degradation and/or introduction of more stringent design requirements. Among the externally-bonded strengthening systems fiber-reinforced polymers is the most widely known technology. Despite its effectiveness as a material system, the presence of an organic binder has some drawbacks that could be addressed by using in its place a cementitious binder as in fabric-reinforced cementitious matrix (FRCM) systems. The purpose of this paper is to evaluate the behavior of reinforced concrete (RC) beams strengthened in shear with U-wraps made of FRCM. An extensive experimental program was undertaken in order to understand and characterize this composite when used as a strengthening system. The laboratory results demonstrate the technical viability of FRCM for shear strengthening of RC beams. Based on the experimental and analytical results, FRCM increases shear strength but not proportionally to the number of fabric plies installed. On the other hand, FRCM failure modes are related with a high consistency to the amount of external reinforcement applied. Design considerations based on the algorithms proposed by ACI guidelines are also provided.

  5. Enhanced impact properties of cementitious composites reinforced with pultruded flax/polymeric matrix fabric

    Directory of Open Access Journals (Sweden)

    Magdi El-Messiry

    2017-09-01

    Full Text Available Fiber reinforced concrete (FRC has become increasingly applied in civil engineering in the last decades. Natural fiber fabric reinforced cement composites are considered to prevent damage resulting from an impact loading on the cementite plate. Flax woven fabric that has a high energy absorption capability was chosen. To increase the interfacial shear properties, the fabric was pultruded with different matrix properties that affect the strength and toughness of the pultruded fabric. In this study, three fabric structures are used to increase the anchoring of the cement in the fabric. The compressive strength and the impact energy were measured. The results revealed that pultruded fabric reinforced cement composite (PFRC absorbs much more impact energy. PFRC under impact loading has more micro cracks, while plain cement specimen shows brittle failure. The compressive test results of PFRC indicate that flax fiber fabric polymer enhanced compressive strength remarkably. Fiber reinforcement is a very effective in improving the impact resistance of PFRC. The study defines the influence factors that control the energy dissipation of the composite, which are the hardness of the polymer and the fabric cover factor. Significant correlation between impact energy and compressive strength was proved.

  6. Recent advances in understanding the reinforcing ability and mechanism of carbon nanotubes in ceramic matrix composites

    International Nuclear Information System (INIS)

    Estili, Mehdi; Sakka, Yoshio

    2014-01-01

    Since the discovery of carbon nanotubes (CNTs), commonly referred to as ultimate reinforcement, the main purpose for fabricating CNT–ceramic matrix composites has been mainly to improve the fracture toughness and strength of the ceramic matrix materials. However, there have been many studies reporting marginal improvements or even the degradation of mechanical properties. On the other hand, those studies claiming noticeable toughening measured using indentation, which is an indirect/unreliable characterization method, have not demonstrated the responsible mechanisms applicable to the nanoscale, flexible CNTs; instead, those studies proposed those classical methods applicable to microscale fiber/whisker reinforced ceramics without showing any convincing evidence of load transfer to the CNTs. Therefore, the ability of CNTs to directly improve the macroscopic mechanical properties of structural ceramics has been strongly questioned and debated in the last ten years. In order to properly discuss the reinforcing ability (and possible mechanisms) of CNTs in a ceramic host material, there are three fundamental questions to our knowledge at both the nanoscale and macroscale levels that need to be addressed: (1) does the intrinsic load-bearing ability of CNTs change when embedded in a ceramic host matrix?; (2) when there is an intimate atomic-level interface without any chemical reaction with the matrix, could one expect any load transfer to the CNTs along with effective load bearing by them during crack propagation?; and (3) considering their nanometer-scale dimensions, flexibility and radial softness, are the CNTs able to improve the mechanical properties of the host ceramic matrix at the macroscale when individually, intimately and uniformly dispersed? If so, how? Also, what is the effect of CNT concentration in such a defect-free composite system? Here, we briefly review the recent studies addressing the above fundamental questions. In particular, we discuss the new

  7. Recent advances in understanding the reinforcing ability and mechanism of carbon nanotubes in ceramic matrix composites.

    Science.gov (United States)

    Estili, Mehdi; Sakka, Yoshio

    2014-12-01

    Since the discovery of carbon nanotubes (CNTs), commonly referred to as ultimate reinforcement, the main purpose for fabricating CNT-ceramic matrix composites has been mainly to improve the fracture toughness and strength of the ceramic matrix materials. However, there have been many studies reporting marginal improvements or even the degradation of mechanical properties. On the other hand, those studies claiming noticeable toughening measured using indentation, which is an indirect/unreliable characterization method, have not demonstrated the responsible mechanisms applicable to the nanoscale, flexible CNTs; instead, those studies proposed those classical methods applicable to microscale fiber/whisker reinforced ceramics without showing any convincing evidence of load transfer to the CNTs. Therefore, the ability of CNTs to directly improve the macroscopic mechanical properties of structural ceramics has been strongly questioned and debated in the last ten years. In order to properly discuss the reinforcing ability (and possible mechanisms) of CNTs in a ceramic host material, there are three fundamental questions to our knowledge at both the nanoscale and macroscale levels that need to be addressed: (1) does the intrinsic load-bearing ability of CNTs change when embedded in a ceramic host matrix?; (2) when there is an intimate atomic-level interface without any chemical reaction with the matrix, could one expect any load transfer to the CNTs along with effective load bearing by them during crack propagation?; and (3) considering their nanometer-scale dimensions, flexibility and radial softness, are the CNTs able to improve the mechanical properties of the host ceramic matrix at the macroscale when individually, intimately and uniformly dispersed? If so, how? Also, what is the effect of CNT concentration in such a defect-free composite system? Here, we briefly review the recent studies addressing the above fundamental questions. In particular, we discuss the new

  8. Recent advances in understanding the reinforcing ability and mechanism of carbon nanotubes in ceramic matrix composites

    Science.gov (United States)

    Estili, Mehdi; Sakka, Yoshio

    2014-01-01

    Since the discovery of carbon nanotubes (CNTs), commonly referred to as ultimate reinforcement, the main purpose for fabricating CNT–ceramic matrix composites has been mainly to improve the fracture toughness and strength of the ceramic matrix materials. However, there have been many studies reporting marginal improvements or even the degradation of mechanical properties. On the other hand, those studies claiming noticeable toughening measured using indentation, which is an indirect/unreliable characterization method, have not demonstrated the responsible mechanisms applicable to the nanoscale, flexible CNTs; instead, those studies proposed those classical methods applicable to microscale fiber/whisker reinforced ceramics without showing any convincing evidence of load transfer to the CNTs. Therefore, the ability of CNTs to directly improve the macroscopic mechanical properties of structural ceramics has been strongly questioned and debated in the last ten years. In order to properly discuss the reinforcing ability (and possible mechanisms) of CNTs in a ceramic host material, there are three fundamental questions to our knowledge at both the nanoscale and macroscale levels that need to be addressed: (1) does the intrinsic load-bearing ability of CNTs change when embedded in a ceramic host matrix?; (2) when there is an intimate atomic-level interface without any chemical reaction with the matrix, could one expect any load transfer to the CNTs along with effective load bearing by them during crack propagation?; and (3) considering their nanometer-scale dimensions, flexibility and radial softness, are the CNTs able to improve the mechanical properties of the host ceramic matrix at the macroscale when individually, intimately and uniformly dispersed? If so, how? Also, what is the effect of CNT concentration in such a defect-free composite system? Here, we briefly review the recent studies addressing the above fundamental questions. In particular, we discuss the new

  9. A biomimetic approach to enhancing interfacial interactions: polydopamine-coated clay as reinforcement for epoxy resin.

    Science.gov (United States)

    Yang, Liping; Phua, Si Lei; Teo, Jun Kai Herman; Toh, Cher Ling; Lau, Soo Khim; Ma, Jan; Lu, Xuehong

    2011-08-01

    A facile biomimetic method was developed to enhance the interfacial interaction in polymer-layered silicate nanocomposites. By mimicking mussel adhesive proteins, a monolayer of polydopamine was constructed on clay surface by a controllable coating method. The modified clay (D-clay) was incorporated into an epoxy resin, it is found that the strong interfacial interactions brought by the polydopamine benefits not only the dispersion of the D-clay in the epoxy but also the effective interfacial stress transfer, leading to greatly improved thermomechanical properties at very low inorganic loadings. Rheological and infrared spectroscopic studies show that the interfacial interactions between the D-clay and epoxy are dominated by the hydrogen bonds between the catechol-enriched polydopamine and the epoxy.

  10. Effects of ultraviolet and electron radiations on graphite-reinforced polysulfone and epoxy resins

    International Nuclear Information System (INIS)

    Giori, C.; Yamauchi, T.

    1984-01-01

    Degradation mechanisms have been investigated for graphite/polysulfone and graphite/epoxy laminates exposed to ultraviolet and high-energy electron radiations in vacuum up to 960 equivalent sun hours and 10 9 rads, respectively. Based on GC and combined GC/MS analysis of volatile by-products evolved during irradiation, several free radical mechanisms of composite degradation have been identified. All the composite materials evaluated have shown high electron radiation stability and relatively low ultraviolet stability as indicated by low G values and high quantum yields for gas formation. Mechanical property measurements of irradiated samples did not reveal significant changes, with the possible exception of UV exposed polysulfone laminates. Hydrogen and methane have been identified as the main byproducts of irradiation, along with unexpectedly high levels of CO and CO 2 . Initial G values for methane relative to hydrogen formation are higher in the presence of isopropylidene linkages, which occur in bisphenol-A resins

  11. Short and long carbon fibre reinforced Cu-matrix composites: microstructural results and structural origin of properties

    International Nuclear Information System (INIS)

    Buchgraber, W.

    1997-01-01

    Carbon fibre reinforced copper matrix composites possess properties of copper, i.e. excellent thermal and electrical conductivities, and properties of carbon fibre, i.e. a small thermal expansion coefficient. Since the desirable properties of the composite can be obtained by selecting the amount, type and orientation of the carbon fibres, it is considered to be suitable for use as electric and electronic materials. This lecture focuses on two-dimensional isotropic carbon fibre reinforced copper matrix composites with long or short carbon fibres. Short carbon fibre reinforced copper matrix composites have been produced by hot-pressing of copper coated short carbon fibres. During hot-pressing, the carbon fibres take on a preferred orientation in a plane perpendicular to the hot pressing direction. Within this plane the fibre orientation is random. Long carbon fibre reinforced copper matrix composites have been made by hot pressing of monolayers consisting of copper coated long carbon fibres. Different orientations of the monolayers will be compared. Both the physical and mechanical properties of the discussed composites are strongly influenced not only by the properties of its individual constituents, but also by the microstructure and properties of the fibre matrix interface. The problem of poor wettability of the carbon fibre by the copper matrix will be discussed. The microstructure of several types of carbon fibre reinforced copper matrix composites will be discussed. Their thermophysical properties will be compared with microstructural results. (author)

  12. Micromechanical performance of interfacial transition zone in fiber-reinforced cement matrix

    Science.gov (United States)

    Zacharda, V.; Němeček, J.; Štemberk, P.

    2017-09-01

    The paper investigates microstructure, chemical composition and micromechanical behavior of an interfacial transition zone (ITZ) in steel fiber reinforced cement matrix. For this goal, a combination of scanning electron microscopy (SEM), nanoindentation and elastic homogenization theory are used. The investigated sample of cement paste with dispersed reinforcement consists of cement CEM I 42,5R and a steel fiber TriTreg 50 mm. The microscopy revealed smaller portion of clinkers and larger porosity in the ITZ. Nanoindentation delivered decreased elastic modulus in comparison with cement bulk (67%) and the width of ITZ (∼ 40 μm). The measured properties served as input parameters for a simple two-scale model for elastic properties of the composite. Although, no major influence of ITZ properties on the composite elastic behavior was found, the findings about the ITZ reduced properties and its size can serve as input to other microstructural fracture based models.

  13. Investigation of Selective Laser Melting Surface Alloyed Aluminium Metal Matrix Dispersive Reinforced Layers

    Science.gov (United States)

    Kamburov, V. V.; Dimitrova, R. B.; Kandeva, M. K.; Sofronov, Y. P.

    2018-01-01

    The aim of the paper is to investigate the improvement of mechanical properties and in particular wear resistance of laser surface alloyed dispersive reinforced thin layers produced by selective laser melting (SLM) technology. The wear resistance investigation of aluminium matrix composite layers in the conditions of dry friction surface with abrasive particles and nanoindentation tests were carried out. The process parameters (as scan speed) and their impact on the wear resistant layers have been evaluated. The alloyed layers containing metalized SiC particles were studied by Optical and Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray microanalysis (EDX). The obtained experimental results of the laser alloyed thin layers show significant development of their wear resistance and nanohardness due to the incorporated reinforced phase of electroless nickel coated SiC particles.

  14. Parametric study for graphene reinforced aluminum matrix composites production using Box Behnken design

    Science.gov (United States)

    Dasari, Bhagya Lakshmi; Nouri, Jamshid M.; Brabazon, Dermot; Naher, Sumsun

    2017-10-01

    The production of graphene reinforced aluminum matrix composite through powder metallurgical route requires optimization of process parameters to obtain better performance characteristics. One of the advanced method available for statistical analysis of parameters is Response Surface Methodology (RSM). The statistical analysis was carried out with three parameters, weight percentage of graphene reinforcement Wg (0.05%, 0.1% and 0.2%), stirring time ST(1h, 2h and 3h) and compaction pressure Pc(16T, 17T and 19T) while sintering temperature T kept constant. The performance of the Box Behnken design was analyzed and optimized using Design Expert software for the effective production of composites. From the results obtained from the analysis, the best set of parameters were considered for the future production of composites.

  15. Microstructure and wear characteristics on Al alloy matrix composite reinforced with Ni perform

    Energy Technology Data Exchange (ETDEWEB)

    Park, Won Jo; Park, Cheol Hong; Kim, Hyung Jin; Huh, Sun Chul [Gyeongsang National University, Tongyeong, (Korea, Republic of)

    2012-06-15

    Al based composite reinforced with Nickel is used for diesel engine piston, because the thermal properties, strength and corrosion resistant are for better than Al alloy alone. For processing, the intermetallic compounds of Ni and Al improves wear resistance due to its high hardness. Existing process methods for MMC (metal matrix composite) using preform were manufactured under high-pressure. However, this causes deformation of the preform or weaknesses in the completed MMC. Low-pressure infiltration can prevent these problems, and there is an advantage of cost reduction in of production with small-scale of production equipment. In this study, the microstructure and wear characteristics of Al-based composite with Ni preform as reinforcement with low-pressure infiltration was analyzed.

  16. Wear Resistance of TiC Reinforced Cast Steel Matrix Composite

    Directory of Open Access Journals (Sweden)

    Sobula S.

    2017-03-01

    Full Text Available Wear resistance of TiC-cast steel metal matrix composite has been investigated. Composites were obtained with SHSB method known as SHS synthesis during casting. It has been shown the differences in wear between composite and base cast steel. The Miller slurry machine test were used to determine wear loss of the specimens. The slurry was composed of SiC and water. The worn surface of specimens after test, were studied by SEM. Experimental observation has shown that surface of composite zone is not homogenous and consist the matrix lakes. Microscopic observations revealed the long grooves with SiC particles indented in the base alloy area, and spalling pits in the composite area. Due to the presence of TiC carbides on composite layer, specimens with TiC reinforced cast steel exhibited higher abrasion resistance. The wear of TiC reinforced cast steel mechanism was initially by wearing of soft matrix and in second stage by polishing and spalling of TiC. Summary weight loss after 16hr test was 0,14÷0,23 g for composite specimens and 0,90 g for base steel.

  17. Mechanical properties of Nextel trademark 312 fiber-reinforced SiC matrix composites

    International Nuclear Information System (INIS)

    Vaidyanathan, K.R.; Sankar, J.; Kelkar, A.D.; Weaver, B.

    1995-01-01

    Vapor phase synthesis is emerging as a method for the preparation of near final-shape, ceramic matrix composites for advanced structural applications. Oxide fiber-reinforced silicon carbide matrix composites are currently being developed for these applications. The mechanical properties of Nextel trademark 312 fiber reinforced SiC matrix composites fabricated employing the forced-flow, thermal gradient chemical vapor infiltration process (FCVI) were evaluated at room temperature in pure tension. The composites were fabricated with a 0.15 μm pyrolytic carbon interface layer for improving the toughness of the composite system. Because of the available FCVI apparatus, only short length specimens (7--8 cm) could be fabricated. Room temperature tensile strengths were measured and compared to room temperature flexure strength results for the composite. Excellent toughness and composite behavior was obtained for the composite system. Fractography as well as possible factors responsible for the differences in tensile and flexural strengths for the composite system is presented in this paper

  18. Al-matrix composite materials reinforced by Al-Cu-Fe particles

    International Nuclear Information System (INIS)

    Bonneville, J; Laplanche, G; Joulain, A; Gauthier-Brunet, V; Dubois, S

    2010-01-01

    Al-matrix material composites were produced using hot isostatic pressing technique, starting with pure Al and icosahedral (i) Al-Cu-Fe powders. Depending on the processing temperature, the final reinforcement particles are either still of the initial i-phase or transformed into the tetragonal ω-Al0 0.70 Cu 0.20 Fe 0.10 crystalline phase. Compression tests performed in the temperature range 293K - 823K on the two types of composite, i.e. Al/i and Al/ω, indicate that the flow stress of both composites is strongly temperature dependent and exhibit distinct regimes with increasing temperature. Differences exist between the two composites, in particular in yield stress values. In the low temperature regime (T ≤ 570K), the yield stress of the Al/ω composite is nearly 75% higher than that of the Al/i composite, while for T > 570K both composites exhibit similar yield stress values. The results are interpreted in terms of load transfer contribution between the matrix and the reinforcement particles and elementary dislocation mechanisms in the Al matrix.

  19. Matrix density effects on the mechanical properties of SiC fiber-reinforced silicon nitride matrix properties

    Science.gov (United States)

    Bhatt, Ramakrishna T.; Kiser, Lames D.

    1990-01-01

    The room temperature mechanical properties were measured for SiC fiber reinforced reaction-bonded silicon nitride composites (SiC/RBSN) of different densities. The composites consisted of approx. 30 vol percent uniaxially aligned 142 micron diameter SiC fibers (Textron SCS-6) in a reaction-bonded Si3N4 matrix. The composite density was varied by changing the consolidation pressure during RBSN processing and by hot isostatically pressing the SiC/RBSN composites. Results indicate that as the consolidation pressure was increased from 27 to 138 MPa, the average pore size of the nitrided composites decreased from 0.04 to 0.02 microns and the composite density increased from 2.07 to 2.45 gm/cc. Nonetheless, these improvements resulted in only small increases in the first matrix cracking stress, primary elastic modulus, and ultimate tensile strength values of the composites. In contrast, HIP consolidation of SiC/RBSN resulted in a fully dense material whose first matrix cracking stress and elastic modulus were approx. 15 and 50 percent higher, respectively, and ultimate tensile strength values were approx. 40 percent lower than those for unHIPed SiC/RBSN composites. The modulus behavior for all specimens can be explained by simple rule-of-mixture theory. Also, the loss in ultimate strength for the HIPed composites appears to be related to a degradation in fiber strength at the HIP temperature. However, the density effect on matrix fracture strength was much less than would be expected based on typical monolithic Si3N4 behavior, suggesting that composite theory is indeed operating. Possible practical implications of these observations are discussed.

  20. Mechanical properties study of particles reinforced aluminum matrix composites by micro-indentation experiments

    Directory of Open Access Journals (Sweden)

    Yuan Zhanwei

    2014-04-01

    Full Text Available By using instrumental micro-indentation technique, the microhardness and Young’s modulus of SiC particles reinforced aluminum matrix composites were investigated with micro-compression-tester (MCT. The micro-indentation experiments were performed with different maximum loads, and with three loading speeds of 2.231, 4.462 and 19.368 mN/s respectively. During the investigation, matrix, particle and interface were tested by micro-indentation experiments. The results exhibit that the variations of Young’s modulus and microhardness at particle, matrix and interface were highly dependent on the loading conditions (maximum load and loading speed and the locations of indentation. Micro-indentation hardness experiments of matrix show the indentation size effects, i.e. the indentation hardness decreased with the indentation depth increasing. During the analysis, the effect of loading conditions on Young’s modulus and microhardness were explained. Besides, the elastic–plastic properties of matrix were analyzed. The validity of calculated results was identified by finite element simulation. And the simulation results had been preliminarily analyzed from statistical aspect.

  1. Microstructural analysis and mechanical characterization of aluminum matrix nanocomposites reinforced with uncoated and Cu-coated alumina particles

    Energy Technology Data Exchange (ETDEWEB)

    Beygi, H., E-mail: hossein.beygi@stu-mail.um.ac.ir; Sajjadi, S.A.; Zebarjad, S.M.

    2014-06-01

    Aluminum matrix composites used in the aerospace, military and automotive industries are typically fabricated by a stir casting method. However, when nanoparticles are used for reinforcement, fabrication of composite materials by this method leads to the formation of a large number of structural defects. In this study, copper coating of alumina reinforcement particles is investigated as a technique for improving the structure of Al-Al{sub 2}O{sub 3} composites. Microstructural investigations by optical microscopy (OM), scanning electron microscopy (SEM) equipped with energy dispersion spectroscopy (EDS) and transmission electron microscopy (TEM) showed that the alumina particles were coated uniformly with copper shells. Copper coating of the reinforcing particles significantly increased their wettability in the molten aluminum alloy, strengthened the matrix-particle interfaces and improved the distribution of reinforcing particles within the matrix. Due to these microstructural improvements, the hardness, compressive strength, yield stress, tensile strength and elongation of the composites were enhanced by copper coating of the alumina particles.

  2. Microstructure and Mechanical Behavior of Microwave Sintered Cu50Ti50 Amorphous Alloy Reinforced Al Metal Matrix Composites

    Science.gov (United States)

    Reddy, M. Penchal; Ubaid, F.; Shakoor, R. A.; Mohamed, A. M. A.

    2018-06-01

    In the present work, Al metal matrix composites reinforced with Cu-based (Cu50Ti50) amorphous alloy particles synthesized by ball milling followed by a microwave sintering process were studied. The amorphous powders of Cu50Ti50 produced by ball milling were used to reinforce the aluminum matrix. They were examined by x-ray diffraction (XRD), scanning electron microscopy (SEM), microhardness and compression testing. The analysis of XRD patterns of the samples containing 5 vol.%, 10 vol.% and 15 vol.% Cu50Ti50 indicates the presence of Al and Cu50Ti50 peaks. SEM images of the sintered composites show the uniform distribution of reinforced particles within the matrix. Mechanical properties of the composites were found to increase with an increasing volume fraction of Cu50Ti50 reinforcement particles. The hardness and compressive strength were enhanced to 89 Hv and 449 MPa, respectively, for the Al-15 vol.% Cu50Ti50 composites.

  3. Microstructural analysis and mechanical characterization of aluminum matrix nanocomposites reinforced with uncoated and Cu-coated alumina particles

    International Nuclear Information System (INIS)

    Beygi, H.; Sajjadi, S.A.; Zebarjad, S.M.

    2014-01-01

    Aluminum matrix composites used in the aerospace, military and automotive industries are typically fabricated by a stir casting method. However, when nanoparticles are used for reinforcement, fabrication of composite materials by this method leads to the formation of a large number of structural defects. In this study, copper coating of alumina reinforcement particles is investigated as a technique for improving the structure of Al-Al 2 O 3 composites. Microstructural investigations by optical microscopy (OM), scanning electron microscopy (SEM) equipped with energy dispersion spectroscopy (EDS) and transmission electron microscopy (TEM) showed that the alumina particles were coated uniformly with copper shells. Copper coating of the reinforcing particles significantly increased their wettability in the molten aluminum alloy, strengthened the matrix-particle interfaces and improved the distribution of reinforcing particles within the matrix. Due to these microstructural improvements, the hardness, compressive strength, yield stress, tensile strength and elongation of the composites were enhanced by copper coating of the alumina particles

  4. Short and long term behaviour of externally bonded fibre reinforced polymer laminates with bio-based resins for flexural strengthening of concrete beams

    Science.gov (United States)

    McSwiggan, Ciaran

    The use of bio-based resins in composites for construction is emerging as a way to reduce of embodied energy produced by a structural system. In this study, two types of bio-based resins were explored: an epoxidized pine oil resin blend (EP) and a furfuryl alcohol resin (FA) derived from corn cobs and sugar cane. Nine large-scale reinforced concrete beams strengthened using externally bonded carbon and glass fibre reinforced bio-based polymer (CFRP and GFRP) sheets were tested. The EP resin resulted in a comparable bond strength to conventional epoxy (E) when used in wet layup, with a 7% higher strength for CFRP. The FA resin, on the other hand, resulted in a very weak bond, likely due to concrete alkalinity affecting curing. However, when FA resin was used to produce prefabricated cured CFRP plates which were then bonded to concrete using conventional epoxy paste, it showed an excellent bond strength. The beams achieved an increase in peak load ranging from 18-54% and a 9-46% increase in yielding load, depending on the number of FRP layers and type of fibres and resin. Additionally, 137 concrete prisms with a mid-span half-depth saw cut were used to test CFRP bond durability, and 195 CFRP coupons were used to examine tensile strength durability. Specimens were conditioned in a 3.5% saline solution at 23, 40 or 50°C, for up to 240 days. Reductions in bond strength did not exceed 15%. Bond failure of EP was adhesive with traces of cement paste on CFRP, whereas that of FA was cohesive with a thicker layer of concrete on CFRP, suggesting that the bond between FA and epoxy paste is excellent. EP tension coupons had similar strength and modulus to E resin, whereas FA coupons had a 9% lower strength and 14% higher modulus. After 240 days of exposure, maximum reductions in tensile strength were 8, 19 and 10% for EP, FA and E resins, respectively. Analysis of Variance (ANOVA) was also performed to assess the significance of the reductions observed. High degrees of

  5. Micro structural analysis of nanocomposite of metallic matrix of aluminum reinforced by 2% of NTC

    International Nuclear Information System (INIS)

    Dias, Fabio Saldanha; LavaredaCarlos Romulo; Mendes, Luiz Fernando; Queiroz, Jennyson Luz

    2016-01-01

    The study of based on aluminum materials has a high importance level, mainly when is intense wanted in automobile and aerospace industry to transform in light and high perform parts. Aluminum has low specific weight and easiness to join with other materials and these qualities can supply excellent properties and lots of technological applications. Components based on aluminum represents good examples to develop optimized micro structures during the fabrication process that can be basic on properties mechanical performance. As a result this work analyses the micro structure's composites with metallic matrix reinforced by 2% of Multi-Walled Carbon Nanotubes manufactured by aluminum splinters mixed to CNT (author)

  6. A comparative study to check fracture strength of provisional fixed partial dentures made of autopolymerizing polymethylmethacrylate resin reinforced with different materials: An in vitro study.

    Science.gov (United States)

    Gupt, Parikshit; Nagpal, Archana; Samra, Rupandeep Kaur; Verma, Ramit; Kaur, Jasjeet; Abrol, Surbhi

    2017-01-01

    The purpose of the study was to evaluate the fracture strength of provisional fixed partial dentures made of autopolymerizing polymethylmethacrylate (PMMA) resin using different types of reinforcement materials to determine the best among them. Fifty samples were made (10 samples for each group) with autopolymerizing PMMA resin using reinforcement materials (stainless steel wire: looped and unlooped and glass fiber: loose and unidirectional) as 3-unit posterior bridge. The test specimens were divided into five groups depending on the reinforcing material as Group I, II, III, IV, and V; Group I: PMMA unreinforced (control group), Group II: PMMA reinforced with stainless steel wire (straight ends), Group III: PMMA reinforced with stainless steel wire (looped ends), Group IV: PMMA reinforced with unidirectional glass fibers, and Group V: PMMA reinforced with randomly distributed glass fibers. Universal testing machine was used to evaluate and compare the fracture strength of samples. Comparison of mean ultimate force and ultimate stress was done employing one-way analysis of variance and Tukey's post hoc tests. The highest and lowest mean ultimate force and mean ultimate stress were of Group IV and I, respectively. Tukey's post hoc honestly significant difference multiple comparison for mean ultimate force and stress shows the increase in strength to be statistically significant ( P 0.05). Unidirectional glass fibers showed the maximum strength, which was comparable to mean values of both stainless steel wire groups. Low cost and easy technique of using stainless steel wire make it the material of choice over the unidirectional glass fiber for reinforcement in nonesthetic areas where high strength is required.

  7. Cashew nut shell liquid resin used as matrix for compound materials

    International Nuclear Information System (INIS)

    Abreu, Hamilton Ferreira Gomes de; Nogueira, Ricardo Emilio Ferreira Quevedo

    1996-01-01

    Cashew nut shell liquid resin a by product of cashew processing industry is a naturally occurring phenol of low cost and are used in Brazil as fuel in the industrial production of cashew nut or as a structural material when associated with coconut fiber or rice shell. A high measured Tg points to noble applications. This paper presents some properties of LCC resin and concludes that it has good perspectives as a composite matrice to work at elevated temperatures. (author)

  8. Vacuum brazing of high volume fraction SiC particles reinforced aluminum matrix composites

    Science.gov (United States)

    Cheng, Dongfeng; Niu, Jitai; Gao, Zeng; Wang, Peng

    2015-03-01

    This experiment chooses A356 aluminum matrix composites containing 55% SiC particle reinforcing phase as the parent metal and Al-Si-Cu-Zn-Ni alloy metal as the filler metal. The brazing process is carried out in vacuum brazing furnace at the temperature of 550°C and 560°C for 3 min, respectively. The interfacial microstructures and fracture surfaces are investigated by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and energy spectrum analysis (EDS). The result shows that adequacy of element diffusion are superior when brazing at 560°C, because of higher activity and liquidity. Dislocations and twins are observed at the interface between filler and composite due to the different expansion coefficient of the aluminum alloy matrix and SiC particles. The fracture analysis shows that the brittle fracture mainly located at interface of filler and composites.

  9. AlN nanoparticle-reinforced nanocrystalline Al matrix composites: Fabrication and mechanical properties

    International Nuclear Information System (INIS)

    Liu, Y.Q.; Cong, H.T.; Wang, W.; Sun, C.H.; Cheng, H.M.

    2009-01-01

    To improve the specific strength and stiffness of Al-based composites, AlN/Al nanoparticles were in-situ synthesized by arc plasma evaporation of Al in nitrogen atmosphere and consolidated by hot-pressing to fabricate AlN nanoparticle-reinforced nanocrystalline Al composites (0-39 vol.% AlN). Microstructure characterization shows that AlN nanoparticles homogeneously distribute in the matrix of Al nanocrystalline, which forms atomically bonded interfaces of AlN/Al. The hardness and the elastic modulus of the nanocomposite have been improved dramatically, up to 3.48 GPa and 142 GPa, respectively. Such improvement is believed to result from the grain refinement strengthening and the interface strengthening (load transfer) between the Al matrix and AlN nanoparticles

  10. Dry Sliding Friction and Wear Studies of Fly Ash Reinforced AA-6351 Metal Matrix Composites

    Directory of Open Access Journals (Sweden)

    M. Uthayakumar

    2013-01-01

    Full Text Available Fly ash particles are potentially used in metal matrix composites due to their low cost, low density, and availability in large quantities as waste by-products in thermal power plants. This study describes multifactor-based experiments that were applied to research and investigation on dry sliding wear system of stir-cast aluminum alloy 6351 with 5, 10, and 15 wt.% fly ash reinforced metal matrix composites (MMCs. The effects of parameters such as load, sliding speed, and percentage of fly ash on the sliding wear, specific wear rate, and friction coefficient were analyzed using Grey relational analysis on a pin-on-disc machine. Analysis of variance (ANOVA was also employed to investigate which design parameters significantly affect the wear behavior of the composite. The results showed that the applied load exerted the greatest effect on the dry sliding wear followed by the sliding velocity.

  11. Development and characterization of woven kevlar reinforced epoxy matrix composite materials

    International Nuclear Information System (INIS)

    Imran, A.; Alam, S.; Irfan, S.; Iftikhar, F.; Raza, M.A.

    2006-01-01

    Composite materials are actually well established materials that have demonstrated their promising advantages among the light weight structural materials used for aerospace and advanced applications. A great effort is now being made to develop and characterize the Kevlar Epoxy Composite Materials by changing the % age composition of curing agent in epoxy matrix. In order to study the phenomenon; how the change in composition of curing agent effect the composite material and which optimum composition can give the optimum properties of the material, when Kevlar reinforced to Epoxy Matrix by Hand Lay-up process. It was ensured that factors which can .affect the experiment remained the same for each experiment. The composite produced were subjected to mechanical tests to analyze the performance, to optimize the material. (author)

  12. Obtainment of silica nanofiber and its preliminary investigation and its effects as reinforcement in polymeric matrix

    International Nuclear Information System (INIS)

    Teixeira, R.S.; Oliveira, G.L.; Silva, F.D.C.; Teofilo, E. T.; Farias, R.C.; Menezes, R.R.

    2016-01-01

    Silica is widely used as fillers in polymers, and may confer flame retardant characteristics and improve mechanical properties. their use usually occurs as spherical nanoparticles or short fibers of. Studies using this reinforce in the form of nanofibers are promising. This analysis proposes to obtain silica nanofibers by blowspinning method in solution (SBS), and investigate its application in polymeric matrix. To synthesize the silica nanofibers it was used a precursor solution that has been subjected to SBS process and calcined for forming the silica layer. The DR-X indicated the obtainment of amorphous silica phase and SEM showed the the fibers are at the nanometer scale. Silica nanofibers were incorporated into filmogenic solution Polyamide 6. Preliminary results showed no improvement in mechanical properties. Future stages propose to verify that the surface chemical modification of silica nanofibers enables interaction charge / matrix. (author)

  13. Enhancement of interfacial properties of basalt fiber reinforced nylon 6 matrix composites with silane coupling agents

    Directory of Open Access Journals (Sweden)

    2010-10-01

    Full Text Available In this work solution surface treatment was applied for producing basalt fiber reinforced PA6 matrix composites. Beyond scanning electron microscopy, static and dynamic mechanical tests, dynamic mechanical analysis of composites was used for qualifying the interfacial adhesion in a wide temperature range. The loss factor peak height of loss factor is particularly important, because it is in close relationship with the mobility of polymer molecular chain segments and side groups, hence it correlates with the number and strength of primary or secondary bondings established between the matrix and the basalt fibers. It was proven, that the interfacial adhesion between basalt fibers and polyamide can be largely improved by the application of silane coupling agents in the entire usage temperature range of composites. The presence of coupling agents on the surface of basalt fibers was proven by Fourier transform infrared spectroscopy. The best results were obtained by 3-glycidoxypropyltrimethoxysilane coupling agent.

  14. Radiation resistance of the carbon fiber reinforced composite material with PEEK as the matrix resin

    International Nuclear Information System (INIS)

    Sasuga, Tsuneo; Seguchi, Tadao; Sakai, Hideo; Nakakura, Toshiyuki; Masutani, Masahiro.

    1987-01-01

    In the fast breeder reactor etc. the structural materials are exposed to various environment, i.e., repeated high and low temperature, stress, etc. Irradiation effect (electron radiation) in the mechanical characteristic at low and high temperature has been studied in the PEEK-CF, polyarylether · ether · ketone - carbon fiber composite. Following are the results. (1) Radiation resistance of PEEK-CF is higher than that of PEEK-PES-CF, PEEK - polyethersulfone surface treated CF composite. In PEEK-PES-CF, PES is deteriorated by irradiation so the adhesive power lowers. (2) In the unirradiated PEEK-CF, its mechanical characteristic decreases beyond 140 deg C. With increase of the radiation dose, however, the characteristic rises. (3) Mechanical characteristic of PEEK-CF thus little drops by the heat treatment after the irradiation. (Mori, K.)

  15. Flexible Bionanocomposites from Epoxidized Hemp Seed Oil Thermosetting Resin Reinforced with Halloysite Nanotubes.

    Science.gov (United States)

    Shuttleworth, Peter S; Díez-Pascual, Ana M; Marco, Carlos; Ellis, Gary

    2017-03-23

    Hemp seed (Cannabis sativa L.) oil comprises a variety of beneficial unsaturated triglycerides with well-documented nutritional and health benefits. However, it can become rancid over a relatively short time period, leading to increased industrial costs and waste of a valuable product. The development of sustainable polymers is presented as a strategy, where both the presence of unsaturation and peroxide content could be effectively used to alleviate both the waste and financial burden. After the reaction with peroxyacetic acid, the incorporation of halloysite nanotubes (HNTs), and the subsequent thermal curing, without the need for organic solvents or interfacial modifiers, flexible transparent materials with a low glass-transition temperature were developed. The improvement in the thermal stability and both the static and dynamic mechanical properties of the bionanocomposites were significantly enhanced with the well-dispersed HNT filler. At an optimum concentration of 0.5 wt % HNTs, a simultaneous increase in stiffness, strength, ductility, and toughness was observed in comparison to the unfilled cured resin. These sustainable food-waste-derived bionanocomposites may provide an interesting alternative to petroleum-based materials, particularly for low-load-bearing applications, such as packaging.

  16. Structural and thermophysical properties characterization of continuously reinforced cast Al matrix composite

    Directory of Open Access Journals (Sweden)

    Brian Gordon

    2010-11-01

    Full Text Available In this work the process of manufacturing a continuously reinforced cast Al matrix composite and its properties are presented. The described technology permits obtaining a structural material of competitive properties compared to either heat treatable aluminum alloys or polymer composites for several types of applications. The examined thermophysical properties and structural characterization, including material anisotropy, coupled with the results of previous measurements of the mechanical properties of both Al2O3 reinforcing filaments and metallic prepregs have proven the high quality of this material and the possibility of its operation under special loading modes and environmental conditions. Microscopic examinations (LM, SEM were carried out to reveal the range of morphological homogeneity of the microstructure, the anisotropy of the filament band distribution, and simultaneously the adhesive behavior of the metal/fiber interface. The 3D morphology of the chosen microstructure components was revealed by computed tomography. The obtained results indicate that special properties of the examined prepreg materials have been strongly influenced, on the one hand, by the geometry of its internal microstructure, i.e. spatial distribution and volume fraction of the Al2O3 reinforcing filaments and, on the other hand, by a very good compatibility obtained between the individual metal prepreg components.

  17. Influence of thermal residual stress on behaviour of metal matrix composites reinforced with particles

    Science.gov (United States)

    Guzmán, R. E.; Hernández Arroyo, E.

    2016-02-01

    The properties of a metallic matrix composites materials (MMC's) reinforced with particles can be affected by different events occurring within the material in a manufacturing process. The existence of residual stresses resulting from the manufacturing process of these materials (MMC's) can markedly differentiate the curves obtained in tensile tests obtained from compression tests. One of the themes developed in this work is the influence of residual stresses on the mechanical behaviour of these materials. The objective of this research work presented is numerically estimate the thermal residual stresses using a unit cell model for the Mg ZC71 alloy reinforced with SiC particles with volume fraction of 12% (hot-forging technology). The MMC's microstructure is represented as a three dimensional prismatic cube-shaped with a cylindrical reinforcing particle located in the centre of the prism. These cell models are widely used in predicting stress/strain behaviour of MMC's materials, in this analysis the uniaxial stress/strain response of the composite can be obtained through the calculation using the commercial finite-element code.

  18. Magnetic properties of γ-Fe2O3 nanoparticles incorporated in a polystyrene resin matrix

    Science.gov (United States)

    Vaishnava, P. P.; Senaratne, U.; Buc, E. C.; Naik, R.; Naik, V. M.; Tsoi, G. M.; Wenger, L. E.

    2007-07-01

    γ-Fe2O3 magnetic nanoparticles ranging in average diameter from 3to10nm were synthesized into a polystyrene resin matrix by an ion-exchange method and characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), Mössbauer spectroscopy, and SQUID magnetometry. The average particle size as determined from XRD and TEM was found to be strongly dependent upon the initial Fe valence state of the starting chloride salt(s) and on the number of steps that the salt introduction and ion-exchange process were repeated. Regardless of the initial Fe valence state and processing conditions, Mössbauer spectroscopy confirmed that the Fe in the resulting nanoparticles existed only as Fe(III) ions and that γ-Fe2O3 was the only phase present. The values of the saturation magnetization at 5K were found to be dependent upon the processing conditions and ranged from 203to333emu/cm3 , which are significantly smaller than the bulk value (408emu/cm3) for γ-Fe2O3 . As expected, the nanoparticles exhibited superparamagnetic behavior with the magnetic moments becoming frozen with decreasing temperature as evidenced by the appearance of a six-line splitting in the Mössbauer spectra, a bifurcation in the zero-field-cooled (ZFC) and field-cooled (FC) magnetizations, and an opening in the MV -vs- H hysteresis curves. The values of magnetic anisotropy constant (1.2-2.1×106ergs/cm3) determined from the differences between the ZFC and FC magnetizations were found to be higher than the bulk value (1.1×105ergs/cm3) for γ-Fe2O3 , and are probably due to surface effects. Likewise, the nanoparticle size distributions as deduced from the blocking temperature distribution function f(TB) based on fits to the difference in the ZFC and FC magnetization curves as well as from fits of the MV -vs- H curves in the superparamagnetic regime with a Langevin function indicate fairly broad distributions of particle sizes with the particle sizes being comparable to those deduced from XRD

  19. Non-isothermal curing kinetics and physical properties of MMT-reinforced unsaturated polyester (UP) resins

    Energy Technology Data Exchange (ETDEWEB)

    Vargas, María A., E-mail: angelesvh@yahoo.com [Tecnológico de Estudios Superiores de Ecatepec, Av. Tecnológico S/N, Valle de Anáhuac, 55210 Ecatepec de Morelos (Mexico); Vázquez, H. [Universidad Autónoma Metropolitana-Iztapalapa, Departamento de Física, Av. San Rafael Atlixco 186, col. Vicentina, Mexico, D.F. 09340 (Mexico); Guthausen, G. [KIT, Pro2NMR at MVM and IBG, Karlsruhe (Germany)

    2015-07-10

    Highlights: • Non-isothermal DSC analysis results have shown that the addition of MMT to a UP resin produces a delay in the cure reaction. • The shape of experimental heat-flow DSC curves showed two exothermic peaks for all the samples at different heating rates. • The overall kinetic analysis was performed by isoconversional methods. • It was found that the dependence of the activation energy (E{sub a}) on degree of reaction (α) is complex. - Abstract: Cure behavior of unsaturated polyester (UP)/montmorillonite (MMT)/methyl ethyl ketone peroxide (MEKP)/cobalt octoate intercalated nanocomposites with various MMT loadings was investigated by dynamic differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and transmission electron microscopy (TEM). UP/MMT nanocomposites were prepared by sequential mixing. Non-isothermal DSC curves were obtained by applying heating rates ranging from 5 to 20 °C/min. They presented two exothermic peaks, which should correspond to two independent cure reactions. The effective activation energy E{sub a}, was determined by applying both the Kissinger’s and Starink’s methods. The results showed slightly higher activation energy for nanocomposites, except for UP/10-MMT. It was found that the dependence of E{sub a} on α is complex. All the systems in this study fitted Sesták–Berggren (SB) model in overall reaction controlled kinetics and the corresponding model parameters, n, m, A were obtained, but it was insufficient in depicting the complex reaction kinetics. Transmission electron microscopy data support the formation of a partially delaminated nanocomposite material. UP and nanocomposites showed similar behavior on thermal stability.

  20. Process for the manufacture of seamless metal-clad fiber-reinforced organic matrix composite structures

    Science.gov (United States)

    Bluck, Raymond M. (Inventor); Bush, Harold G. (Inventor); Johnson, Robert R. (Inventor)

    1991-01-01

    A process for producing seamless metal-clad composite structures includes providing a hollow, metallic inner member and an outer sleeve to surround the inner member and define an inner space therebetween. A plurality of continuous reinforcing fibers is attached to the distal end of the outside diameter of the inner member, and the inner member is then introduced, distal end first, into one end of the outer sleeve. The inner member is then moved, distal end first, into the outer sleeve until the inner member is completely enveloped by the outer sleeve. A liquid matrix material is then injected into the space containing the reinforcing fibers between the inner member and the outer sleeve. Next a pressurized heat transfer medium is passed through the inner member to cure the liquid matrix material. Finally, the wall thickness of both the inner member and the outer sleeve are reduced to desired dimensions by chemical etching, which adjusts the thermal expansion coefficient of the metal-clad composite structure to a desired value.

  1. Processing and Material Characterization of Continuous Basalt Fiber Reinforced Ceramic Matrix Composites Using Polymer Derived Ceramics.

    Science.gov (United States)

    Cox, Sarah B.

    2014-01-01

    The need for high performance vehicles in the aerospace industry requires materials which can withstand high loads and high temperatures. New developments in launch pads and infrastructure must also be made to handle this intense environment with lightweight, reusable, structural materials. By using more functional materials, better performance can be seen in the launch environment, and launch vehicle designs which have not been previously used can be considered. The development of high temperature structural composite materials has been very limited due to the high cost of the materials and the processing needed. Polymer matrix composites can be used for temperatures up to 260C. Ceramics can take much higher temperatures, but they are difficult to produce and form in bulk volumes. Polymer Derived Ceramics (PDCs) begin as a polymer matrix, allowing a shape to be formed and cured and then to be pyrolized in order to obtain a ceramic with the associated thermal and mechanical properties. The use of basalt in structural and high temperature applications has been under development for over 50 years, yet there has been little published research on the incorporation of basalt fibers as a reinforcement in the composites. In this study, continuous basalt fiber reinforced PDCs have been fabricated and tested for the applicability of this composite system as a high temperature structural composite material. The oxyacetylene torch testing and three point bend testing have been performed on test panels and the test results are presented.

  2. Effects of heat treatment on mechanical properties and microstructure of tungsten fi ber reinforced grey cast iron matrix composites

    Directory of Open Access Journals (Sweden)

    Peng jianHong

    2009-11-01

    Full Text Available In this study, grey cast iron matrix composites reinforced by different volume fractions of tungsten fibers (Vr = 0.95 %, 1.90 %, 2.85 %, 3.80 % were investigated in as-cast and under the heat treatment temperatures of 1,000℃ and 1,100℃. The microstructure and mechanical properties of the composites were analyzed and tested by means of SEM, micro-hardness tester and three-point bend testing. The results show that with increasing of the volume fraction of tungsten fibers, the composites reinforced by the tungsten fiber have higher fl exural strength and modulus than that of cast iron without reinforcement, and the fl exural strength increases with the increasing of heat treatment temperatures. Due to diffusion reaction between matrix and reinforcing phases, the process of heat treatment, the number of graphite fl akes in the matrix seemingly becomes lower; and some hard carbide particles are formed around the residual tungsten fi bers. Not only does the hardness of both matrix and reinforcement change tremendously, but also the region of reinforcement is also extended from the original 0.11 mm to 0.19 mm in radius.

  3. Synthesis and characterization of ZA-27 alloy matrix composites reinforced with zinc oxide nanoparticles

    Directory of Open Access Journals (Sweden)

    B.O. Fatile

    2017-06-01

    Full Text Available An investigation has been carried out on the synthesis and characterization of ZA-27 alloy composites reinforced with zinc oxide nanoparticles. This was aimed at developing high performance ZA-27 matrix nanocomposite with low density. The particle size and morphology of the zinc oxide (ZnO nanoparticles were investigated by Transmission Electron Microscope (TEM and the elemental composition was obtained from Energy Dispersive Spectroscopy (EDS attached to TEM and X-ray fluorescence spectroscopy (XRF. ZA-27 nanocomposite samples were developed using 0, 1, 2, 3, 4 and 5 wt% of ZnO nanoparticles by double steps stir casting technique. Mechanical properties and Microstructural examination were used to characterize the composite samples produced. The results show that hardness and ultimate tensile strength of the composite samples increased progressively with increase in weight percentage of ZnO nanoparticles. Increase in Ultimate tensile strength (UTS of 10.2%, 21.1%, 22.3%, 35.5%, 33.4% and increase in hardness value of 8.2%, 14.8%, 21.7%, 27.9%, 27.1% were observed for nanocomposites reinforced with 1 wt%, 2 wt%, 3 wt%, 4 wt%, and 5 wt% ZnO nanoparticles respectively in comparison with unreinforced alloy. It was generally observed that composite sample containing 4 wt% of reinforcement has the highest tensile strength and hardness values. However, the fracture toughness and percent elongation of the composites samples slightly decreased with increase in ZnO nanoparticles content. Results obtained from the Microstructural examination using optical microscope and Scanning Electron Microscope (SEM show that the nanoparticles were well dispersed in the ZA-27 alloy matrix.

  4. Aluminium EN AW-2124 alloy matrix composites reinforced with Ti(C,N), BN and Al2O3 particles

    International Nuclear Information System (INIS)

    Dobrzanski, L.A.; Wlodarczyk, A.; Adamiak, M.

    2003-01-01

    Investigation results of the aluminium alloy EN AW-2124 matrix composite materials with particles of the powders Ti(C,N), BN and Al 2 O 3 (15 wt.%) are presented in the paper. In order to obtain uniform distribution of reinforcement particles in aluminium alloy matrix powders of composite components have been milled in the rotary ball-bearing pulverizer. The composites have been pressed in laboratory vertical press at room temperature under the pressure of 500 kN. Obtained die samplings have been heated to the temperature 520-550 o C and extruded. Bars of diameter 8 mm have been received as a final product. Metallographic examination of the composites materials' structure shows non-uniform distribution of reinforced powders in the aluminium alloy matrix banding of reinforcements particles corresponds to the extrusion direction. Particles of reinforcement distribution in aluminium alloy matrix is irregular, some agglomerations of powder of aluminium oxide and porosity of different size have been noticed. Investigations of hardness and ultimate compressive strength show that the particles of reinforcement improve mechanical properties of composite materials. Investigations of compressive strength, carried out at room temperature, enable to compare mechanical properties of matrix and composite. (author)

  5. The effect of processing on autohesive strength development in thermoplastic resins and composites

    Science.gov (United States)

    Howes, Jeremy C.; Loos, Alfred C.; Hinkley, Jeffrey A.

    1989-01-01

    In the present investigation of processing effects on the autohesive bond strength of neat polysulfone resin and graphite-reinforced polysulfone-matrix composites measured resin bond strength development in precracked compact tension specimens 'healed' by heating over a contact period at a given temperature. The critical strain energy release rate of refractured composite specimens did not exhibit the strong time or temperature dependence of the neat resin tests; only 80-90 percent of the undamaged fracture energy is recoverable.

  6. The mechanical properties of magnesium matrix composites reinforced with 10 wt.% W14Al86 alloy particles

    International Nuclear Information System (INIS)

    Tang, H.G.; Ma, X.F.; Zhao, W.; Cai, S.G.; Zhao, B.; Qiao, Z.H.

    2007-01-01

    The Mg-based metal matrix composite reinforced by 10 wt.% W 14 Al 86 alloy particles has been prepared by mechanical alloying and press-forming process. X-ray diffraction studies confirm the formation of the composite. Microstructure characterization of the samples reveals the uniform distribution of fine W 14 Al 86 alloy. Mechanical properties characterization revealed that the reinforcement of W 14 Al 86 alloy lead to a significant increase in hardness and tensile strength of Mg and AZ91

  7. Effects of electron beam irradiation on mechanical properties at low and high temperature of fiber reinforced composites using PEEK as matrix material

    International Nuclear Information System (INIS)

    Sasuga, Tsuneo; Seguchi, Tadao; Sakai, Hideo; Odajima, Toshikazu; Nakakura, Toshiyuki; Masutani, Masahiro.

    1987-11-01

    Carbon fiber reinforced composite (PEEK-CF) using polyarylether-ether-ketone (PEEK) as a matrix material was prepared and the electron beam radiation effects on the mechanical properties at low and high temperature and the effects of annealing after irradiation were studied. Cooling down to 77 K, the flexural strength of PEEK-CF increased to about 20 % than that at room temperature. The data of flexural strength for the irradiated specimens showed some scattering, but the strength and modulus at 77 K were changed scarcely up to 120 MGy. The flexural strength and modulus in the unirradiated specimen decreased with increasing of measurement temperature, and the strength at 140 deg C, which is the just below temperature of the glass transition of PEEK, was to 70 % of the value at room temperature. For the irradiated specimens, the strength and modulus increased with dose and the values at 140 deg C for the specimen irradiated with 120 MGy were nearly the same with the unirradiated specimen measured at room temperature. The improvement of mechanical properties at high temperature by irradiation was supported by a viscoelastic measurement in which the glass transition shifted to the higher temperature by the radiation-induced crosslinking. A glass fiber reinforced PEEK composite (PEEK-GF) was prepared and its irradiation effects by electron beam was studied. Unirradiated PEEK-GF showed the same performance with that for GFRP of epoxide resin as matrix material, but by irradiation the flexual strength and modulus decreased with dose. It was revealed that this composite was destroyed by delamination because inter laminar shear strength (ILSS) decreased with dose and analysis of the profile of S-S curve showed typical delamination. Fractoglaphy by electron microscopy supported the delamination which is caused by the lowering of adhesion on interface between the fiber and matrix with increase of dose. (author)

  8. Chemical and microstructural changes at high temperature in tungsten wire reinforced metal-matrix composite materials

    International Nuclear Information System (INIS)

    Eaton, H.C.; Norden, H.

    1985-01-01

    Tungsten wire reinforced metal-matrix composites have been developed as a gas turbine blade material. Initially it was thought desirable to employ nickel or iron based superalloys as the matrix material due to their demonstrated reliability in applications where a high degree of dimensional stability, and thermal and mechanical fatigue resistance are required. It has been found, however, that deleterious fiber/matrix interactions occur in these systems under in-service conditions. These interactions seriously degrade the mechanical properties, and there is an effective lowering of the recrystallization temperature of the tungsten to the degree that grain structure changes can take place at unusually low temperatures. The present communication reports a study of the early stages of these interactions. Several microscopic and analytical techniques are used: TEM, SIMS, FIM, and the field ion atom probe. The nickel/tungsten interaction is thought to involve solute atom transport along grain boundaries. The grain boundary chemistry after short exposures to nickel at 1100 0 C is determined. In this manner the precursor interaction mechanisms are observed. These observations suggest that the strong nickel/tungsten grain boundary interactions do not involve the formation of distinct alloy phases, but instead involve rapid diffusion of essentially unalloyed nickel along the grain boundaries

  9. Macro-mechanical material model for fiber reinforced metal matrix composites

    CERN Document Server

    Banks-Sills, L

    1999-01-01

    The stress-strain behavior of a metal matrix composite reinforced with unidirectional, continuous and periodic fibers is investigated. Three-dimensional micro-mechanical analyses of a unit cell by means of the finite element method $9 and homogenization-localization are carried out. These calculations allow the determination of material behavior of the in-plane, as well as the fiber directions. The fibers are assumed to be elastic and the matrix elasto-plastic. $9 The matrix material is governed by a von Mises yield surface, isotropic hardening and an associated flow rule. With the aid of these analyses, the foundation to a macro-mechanical material model is presented which is employed to $9 consider an elementary problem. The model includes an anisotropic yield surface with isotropic hardening and an associated flow rule. A beam in bending containing square fibers under plane strain conditions is analyzed by means of $9 the model. Two cases are considered: one in which the fibers are symmetric with respect t...

  10. Biphenyl liquid crystalline epoxy resin as a low-shrinkage resin-based dental restorative nanocomposite.

    Science.gov (United States)

    Hsu, Sheng-Hao; Chen, Rung-Shu; Chang, Yuan-Ling; Chen, Min-Huey; Cheng, Kuo-Chung; Su, Wei-Fang

    2012-11-01

    Low-shrinkage resin-based photocurable liquid crystalline epoxy nanocomposite has been investigated with regard to its application as a dental restoration material. The nanocomposite consists of an organic matrix and an inorganic reinforcing filler. The organic matrix is made of liquid crystalline biphenyl epoxy resin (BP), an epoxy resin consisting of cyclohexylmethyl-3,4-epoxycyclohexanecarboxylate (ECH), the photoinitiator 4-octylphenyl phenyliodonium hexafluoroantimonate and the photosensitizer champhorquinone. The inorganic filler is silica nanoparticles (∼70-100 nm). The nanoparticles were modified by an epoxy silane of γ-glycidoxypropyltrimethoxysilane to be compatible with the organic matrix and to chemically bond with the organic matrix after photo curing. By incorporating the BP liquid crystalline (LC) epoxy resin into conventional ECH epoxy resin, the nanocomposite has improved hardness, flexural modulus, water absorption and coefficient of thermal expansion. Although the incorporation of silica filler may dilute the reinforcing effect of crystalline BP, a high silica filler content (∼42 vol.%) was found to increase the physical and chemical properties of the nanocomposite due to the formation of unique microstructures. The microstructure of nanoparticle embedded layers was observed in the nanocomposite using scanning and transmission electron microscopy. This unique microstructure indicates that the crystalline BP and nanoparticles support each other and result in outstanding mechanical properties. The crystalline BP in the LC epoxy resin-based nanocomposite was partially melted during exothermic photopolymerization, and the resin expanded via an order-to-disorder transition. Thus, the post-gelation shrinkage of the LC epoxy resin-based nanocomposite is greatly reduced, ∼50.6% less than in commercialized methacrylate resin-based composites. This LC epoxy nanocomposite demonstrates good physical and chemical properties and good biocompatibility

  11. New high-temperature flame-resistant resin matrix for RP/C

    Science.gov (United States)

    Kourtides, D. A.

    1981-01-01

    The processing parameters of graphite composites utilizing graphite fabric and epoxy or other advanced thermoset and thermoplastic resins as matrices are discussed. The evaluated properties include anaerobic char yield, limiting oxygen index, smoke evolution, moisture absorption, and high-temperature mechanical properties. It is shown that graphite composites having the highest char yield exhibit optimum fire-resistant properties.

  12. Insight into the Effects of Reinforcement Shape on Achieving Continuous Martensite Transformation in Phase Transforming Matrix Composites

    Science.gov (United States)

    Zhang, Xudong; Ren, Junqiang; Wang, Xiaofei; Zong, Hongxiang; Cui, Lishan; Ding, Xiangdong

    2017-12-01

    A continuous martensite transformation is indispensable for achieving large linear superelasticity and low modulus in phase transforming metal-based composites. However, determining how to accurately condition the residual martensite in a shape memory alloy matrix though the reinforcement shape to achieve continuous martensite transformation has been a challenge. Here, we take the finite element method to perform a comparative study of the effects of nanoinclusion shape on the interaction and martensite phase transformation in this new composite. Two typical samples are compared: one reinforced by metallic nanowires and the other by nanoparticles. We find that the residual martensite within the shape memory alloy matrix after a pretreatment can be tailored by the reinforcement shape. In particular, our results show that the shape memory alloy matrix can retain enough residual martensite phases to achieve continuous martensite transformation in the subsequent loading when the aspect ratio of nanoreinforcement is larger than 20. In contrast, the composites reinforced with spherical or low aspect ratio reinforcement show a typical nonlinear superelasticity as a result of a low stress transfer-induced discontinuous martensite transformation within the shape memory alloy matrix.

  13. Swelling behavior of ion exchange resins incorporated in tri-calcium silicate cement matrix: I. Chemical analysis

    International Nuclear Information System (INIS)

    Neji, M.; Bary, B.; Le Bescop, P.; Burlion, N.

    2015-01-01

    This paper presents the first part of a theoretical and experimental work aiming at modeling the chemo-mechanical behavior of composites made up of ion exchange resins (IER) solidified in a tri-calcium silicate cement paste (C_3S). Because of ion exchange processes, the volume change of the IER may cause internal pressures leading to the degradation of the material. In this study, a predictive modeling is developed for describing the chemical behavior of such material. It is based on thermodynamic equilibria to determine the evolution of the ion exchange processes, and the potential precipitation of portlandite in the composite. In parallel, a phenomenological study has been set up to understand chemical phenomena related to the swelling mechanisms. The model created has been finally implemented in a finite elements software; the simulation of a laboratory test has been performed and the results compared to experimental data. - Highlights: • Ion exchange theory to model the swelling behavior of Ion exchange resin. • Experimental phenomenon analysis about Chemo-mechanical interaction between IER and cement paste matrix. • Chemo-Transport modeling on a composite material made with IER embedded into cement paste matrix.

  14. A simple stir casting technique for the preparation of in situ Fe-aluminides reinforced Al-matrix composites

    Directory of Open Access Journals (Sweden)

    Susanta K. Pradhan

    2016-09-01

    Full Text Available This article presents a simple stir casting technique for the development of Fe-aluminides particulate reinforced Al-matrix composites. It has been demonstrated that stirring of super-heated Al-melt by a mild steel plate followed by conventional casting and hot rolled results in uniform dispersion of in situ Al13Fe4 particles in the Al matrix; the amount of reinforcement is found to increase with increasing melt temperature. With reference to base alloy, the developed composite exhibits higher hardness and improved tensile strength without much loss of ductility; since, composite like base alloy undergoes ductile mode of fracture.

  15. Structure, mechanical and magnetic properties of Al4C3 reinforced nickel matrix nanocomposites

    Science.gov (United States)

    Chaudhari, Alok Kumar; Singh, Dhananjay Kumar; Singh, V. B.

    2018-05-01

    A new type of nanocomposite, Ni-Al4C3 was prepared using Al4C3 as reinforcement by cathodic co-deposition at different current densities (1.0 to 5.0 A dm‑2) from a nickel acetate-N-methyl formamide (non-aqueous) bath. Influence of current density and incorporation of Al4C3 particles in nickel matrix on the structure and properties of the composite coatings was investigated. Surface morphology and composition of the deposits were determined by SEM and EDAX. Crystallographic structure and orientation of the electrodeposited Ni-Al4C3 composite were studied by x-ray diffraction. Compared to nickel metal, these nanocomposites exhibited finer grains, higher microhardness, improved corrosion resistance and enhanced soft magnetic properties. Composite deposited at higher current densities (>2 A dm‑2) shows mild texturing along (200) plane. The effect of heat treatment on the microstructure, texture and microhardness of the nanocomposites was also investigated.

  16. Performance of Plain Woven Jute Fabric-Reinforced Polyester Matrix Composite in Multilayered Ballistic System

    Directory of Open Access Journals (Sweden)

    Sergio Neves Monteiro

    2018-02-01

    Full Text Available The ballistic performance of plain woven jute fabric-reinforced polyester matrix composites was investigated as the second layer in a multilayered armor system (MAS. Volume fractions of jute fabric, up to 30 vol %, were mixed with orthophthalic polyester to fabricate laminate composites. Ballistic tests were conducted using high velocity 7.62 mm ammunition. The depth of penetration caused by the bullet in a block of clay witness, simulating a human body, was used to evaluate the MAS ballistic performance according to the international standard. The fractured materials after tests were analyzed by scanning electron microscopy (SEM. The results indicated that jute fabric composites present a performance similar to that of the much stronger Kevlar™, which is an aramid fabric laminate, as MAS second layer with the same thickness. The mechanism of this similar ballistic behavior as well as the comparative advantages of the jute fabric composites over the Kevlar™ are discussed.

  17. HIGH TEMPERATURE EROSION WEAR OF CERMET PARTICLES REINFORCED SELF-FLUXING ALLOY MATRIX HVOF SPRAYED COATINGS

    Directory of Open Access Journals (Sweden)

    Andrei Surzhenkov

    2015-09-01

    Full Text Available In the present paper, the resistance of high velocity oxy-fuel (HVOF sprayed TiC-NiMo and Cr3C2-Ni cermet particles reinforced NiCrSiB self-fluxing alloy matrix coatings to high temperature erosion wear is studied. Microstructure of the coatings was examined by SEM, phase composition was determined by XRD. A four-channel centrifugal particle accelerator was applied to study the high temperature erosion wear of the coatings. The impact angles were 30 and 90 degrees, initial particle velocity was 50 m/s, temperature of the test - 650 degrees. Volume wear of the coatings was calculated and compared to the respective values of the reference materials. Wear mechanisms were studied by SEM.DOI: http://dx.doi.org/10.5755/j01.ms.21.3.7617

  18. Graphene-reinforced aluminum matrix composites prepared by spark plasma sintering

    Institute of Scientific and Technical Information of China (English)

    Wen-ming Tian; Song-mei Li; Bo Wang; Xin Chen; Jian-hua Liu; Mei Yu

    2016-01-01

    Graphene-reinforced 7055 aluminum alloy composites with different contents of graphene were prepared by spark plasma sinter-ing (SPS). The structure and mechanical properties of the composites were investigated. Testing results show that the hardness, compressive strength, and yield strength of the composites are improved with the addition of 1wt% graphene. A clean, strong interface is formed between the metal matrix and graphene via metallurgical bonding on atomic scale. Harmful aluminum carbide (Al4C3) is not formed during SPS processing. Further addition of graphene (above 1wt%) results in the deterioration in mechanical properties of the composites. The agglomeration of graphene plates is exacerbated with increasing graphene content, which is the main reason for this deterioration.

  19. Porosity characterization of fiber-reinforced ceramic matrix composite using synchrotron X-ray computed tomography

    International Nuclear Information System (INIS)

    Zou, C.; Li, B.; Zhang, C.; Wang, S.; Marrow, T.J.; Reinhard, C.

    2016-01-01

    The pore structure and porosity of a continuous fiber reinforced ceramic matrix composite has been characterized using high-resolution synchrotron X-ray computed tomography (XCT). Segmentation of the reconstructed tomograph images reveals different types of pores within the composite, the inter-fiber bundle open pores displaying a 'node-bond' geometry, and the intra-fiber bundle isolated micropores showing a piping shape. The 3D morphology of the pores is resolved and each pore is labeled. The quantitative filtering of the pores measures a total porosity 8.9% for the composite, amid which there is about 7.1∼ 9.3% closed micropores

  20. Microstructures and properties of ceramic particle-reinforced metal matrix composite layers produced by laser cladding

    Science.gov (United States)

    Zhang, Qingmao; He, Jingjiang; Liu, Wenjin; Zhong, Minlin

    2005-01-01

    Different weight ratio of titanium, zirconium, WC and Fe-based alloy powders were mixed, and cladded onto a medium carbon steel substrate using a 3kW continuous wave CO2 laser, aiming at producing Ceramic particles- reinforced metal matrix composites (MMCs) layers. The microstructures of the layers are typical hypoeutectic, and the major phases are Ni3Si2, TiSi2, Fe3C, FeNi, MC, Fe7Mo3, Fe3B, γ(residual austenite) and M(martensite). The microstructure morphologies of MMCs layers are dendrites/cells. The MC-type reinforcements are in situ synthesis Carbides which main compositions consist of transition elements Zr, Ti, W. The MC-type particles distributed within dendrite and interdendritic regions with different volume fractions for single and overlapping clad layers. The MMCs layers are dense and free of cracks with a good metallurgical bonding between the layer and substrate. The addition ratio of WC in the mixtures has the remarkable effect on the microhardness of clad layers.

  1. Anodization Mechanism on SiC Nanoparticle Reinforced Al Matrix Composites Produced by Power Metallurgy

    Directory of Open Access Journals (Sweden)

    Sonia C. Ferreira

    2014-12-01

    Full Text Available Specimens of aluminum-based composites reinforced by silicon carbide nanoparticles (Al/SiCnp produced by powder metallurgy (PM were anodized under voltage control in tartaric-sulfuric acid (TSA. In this work, the influence of the amount of SiCnp on the film growth during anodizing was investigated. The current density versus time response and the morphology of the porous alumina film formed at the composite surface are compared to those concerning a commercial aluminum alloy (AA1050 anodized under the same conditions. The processing method of the aluminum alloys influences the efficiency of the anodizing process, leading to a lower thicknesses for the unreinforced Al-PM alloy regarding the AA1050. The current density versus time response is strongly dependent on the amount of SiCnp. The current peaks and the steady-state current density recorded at each voltage step increases with the SiCnp volume fraction due to the oxidation of the SiCnp. The formation mechanism of the anodic film on Al/SiCnp composites is different from that occurring in AA1050, partly due the heterogeneous distribution of the reinforcement particles in the metallic matrix, but also to the entrapment of SiCnp in the anodic film.

  2. Anodization Mechanism on SiC Nanoparticle Reinforced Al Matrix Composites Produced by Power Metallurgy

    Science.gov (United States)

    Ferreira, Sonia C.; Conde, Ana; Arenas, María A.; Rocha, Luis A.; Velhinho, Alexandre

    2014-01-01

    Specimens of aluminum-based composites reinforced by silicon carbide nanoparticles (Al/SiCnp) produced by powder metallurgy (PM) were anodized under voltage control in tartaric-sulfuric acid (TSA). In this work, the influence of the amount of SiCnp on the film growth during anodizing was investigated. The current density versus time response and the morphology of the porous alumina film formed at the composite surface are compared to those concerning a commercial aluminum alloy (AA1050) anodized under the same conditions. The processing method of the aluminum alloys influences the efficiency of the anodizing process, leading to a lower thicknesses for the unreinforced Al-PM alloy regarding the AA1050. The current density versus time response is strongly dependent on the amount of SiCnp. The current peaks and the steady-state current density recorded at each voltage step increases with the SiCnp volume fraction due to the oxidation of the SiCnp. The formation mechanism of the anodic film on Al/SiCnp composites is different from that occurring in AA1050, partly due the heterogeneous distribution of the reinforcement particles in the metallic matrix, but also to the entrapment of SiCnp in the anodic film. PMID:28788295

  3. Anodization Mechanism on SiC Nanoparticle Reinforced Al Matrix Composites Produced by Power Metallurgy.

    Science.gov (United States)

    Ferreira, Sonia C; Conde, Ana; Arenas, María A; Rocha, Luis A; Velhinho, Alexandre

    2014-12-19

    Specimens of aluminum-based composites reinforced by silicon carbide nanoparticles (Al/SiC np ) produced by powder metallurgy (PM) were anodized under voltage control in tartaric-sulfuric acid (TSA). In this work, the influence of the amount of SiC np on the film growth during anodizing was investigated. The current density versus time response and the morphology of the porous alumina film formed at the composite surface are compared to those concerning a commercial aluminum alloy (AA1050) anodized under the same conditions. The processing method of the aluminum alloys influences the efficiency of the anodizing process, leading to a lower thicknesses for the unreinforced Al-PM alloy regarding the AA1050. The current density versus time response is strongly dependent on the amount of SiC np . The current peaks and the steady-state current density recorded at each voltage step increases with the SiC np volume fraction due to the oxidation of the SiC np . The formation mechanism of the anodic film on Al/SiC np composites is different from that occurring in AA1050, partly due the heterogeneous distribution of the reinforcement particles in the metallic matrix, but also to the entrapment of SiC np in the anodic film.

  4. Investigation of different carbon nanotube reinforcements for fabricating bulk AlMg5 matrix nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Kallip, Kaspar, E-mail: kaspar.kallip@empa.ch [Empa, Swiss Federal Laboratories for Material Science and Technology, Laboratory for Advanced Materials Processing, Feuerwerkerstrasse 39, CH-3602 Thun (Switzerland); Leparoux, Marc [Empa, Swiss Federal Laboratories for Material Science and Technology, Laboratory for Advanced Materials Processing, Feuerwerkerstrasse 39, CH-3602 Thun (Switzerland); AlOgab, Khaled A. [King Abdulaziz City for Science and Technology (KACST), National Centers for Advanced Materials, P O Box 6086, Riyadh, 11442 (Saudi Arabia); Clerc, Steve; Deguilhem, Guillaume [Empa, Swiss Federal Laboratories for Material Science and Technology, Laboratory for Advanced Materials Processing, Feuerwerkerstrasse 39, CH-3602 Thun (Switzerland); Arroyo, Yadira [Empa, Swiss Federal Laboratories for Material Science and Technology, Electron Microscopy Center, Ueberlandstrasse 129, CH-8600 Dübendorf (Switzerland); Kwon, Hansang [Empa, Swiss Federal Laboratories for Material Science and Technology, Laboratory for Advanced Materials Processing, Feuerwerkerstrasse 39, CH-3602 Thun (Switzerland); Pukyong National University, Department of Materials System Engineering, 365 Sinseon-ro, Busan 608-739 (Korea, Republic of)

    2015-10-15

    AlMg5-based metal matrix composites were successfully fabricated using high energy planetary ball-milling and hot pressing. The influence of 6 types of carbon nanotubes (CNTs) with different properties was investigated for reinforcement. Over 3 fold increase in hardness and ultimate tensile strength was achieved with maximum values of 200 HV{sub 20} and 720 MPa respectively by varying CNT content from 0.5 to 5 vol%. The state, the dispersion as well as the reactivity of the different CNTs were investigated by Raman spectroscopy, X-Ray diffraction and microscopy. The CNTs were considered to be dispersed homogeneously, but were shortened due to high energy milling. No significant differences in mechanical performances could be observed depending either on the nature or on the agglomeration initial state of the investigated CNTs. The milling time has to be however adjusted to the CNT content as higher concentrations require a longer milling time for achieving dispersion of the nano-reinforcement. - Highlights: • CNTs sustained the milling process and became homogeneously dispersed. • 3 times strengthening over unreinforced alloy achieved. • Flexible processing route for dispersing wide range of nanoparticulate materials.

  5. Recycling of Reinforced Plastics

    Science.gov (United States)

    Adams, R. D.; Collins, Andrew; Cooper, Duncan; Wingfield-Digby, Mark; Watts-Farmer, Archibald; Laurence, Anna; Patel, Kayur; Stevens, Mark; Watkins, Rhodri

    2014-02-01

    This work has shown is that it is possible to recycle continuous and short fibre reinforced thermosetting resins while keeping almost the whole of the original material, both fibres and matrix, within the recyclate. By splitting, crushing hot or cold, and hot forming, it is possible to create a recyclable material, which we designate a Remat, which can then be used to remanufacture other shapes, examples of plates and tubes being demonstrated. Not only can remanufacturing be done, but it has been shown that over 50 % of the original mechanical properties, such as the E modulus, tensile strength, and interlaminar shear strength, can be retained. Four different forms of composite were investigated, a random mat Glass Fibre Reinforced Plastic (GFRP) bathroom component and boat hull, woven glass and carbon fibre cloth impregnated with an epoxy resin, and unidirectional carbon fibre pre-preg. One of the main factors found to affect composite recyclability was the type of resin matrix used in the composite. Thermoset resins tested were shown to have a temperature range around the Glass Transition Temperature (Tg) where they exhibit ductile behaviour, hence aiding reforming of the material. The high-grade carbon fibre prepreg was found to be less easy to recycle than the woven of random fibre laminates. One method of remanufacturing was by heating the Remat to above its glass transition temperature, bending it to shape, and then cooling it. However, unless precautions are taken, the geometric form may revert. This does not happen with the crushed material.

  6. SYNTHESIS AND CHARACTERIZATION OF CANNABIS INDICA FIBER REINFORCED COMPOSITES

    Directory of Open Access Journals (Sweden)

    Amar Singh Singha

    2011-04-01

    Full Text Available This paper reports on the synthesis of Cannabis indica fiber-reinforced composites using Urea-Resorcinol-Formaldehyde (URF as a novel matrix through compression molding technique. The polycondensation between urea, resorcinol, and formaldehyde in different molar ratios was applied to the synthesis of the URF polymer matrix. A thermosetting matrix based composite, reinforced with lignocellulose from Cannabis indica with different fiber loadings 10, 20, 30, 40, and 50% by weight, was obtained. The mechanical properties of randomly oriented intimately mixed fiber particle reinforced composites were determined. Effects of fiber loadings on mechanical properties such as tensile, compressive, flexural strength, and wear resistance were evaluated. Results showed that mechanical properties of URF resin matrix increased considerably when reinforced with particles of Cannabis indica fiber. Thermal (TGA/DTA/DTG and morphological studies (SEM of the resin, fiber and polymer composite thus synthesized were carried out.

  7. Influence of retainer design on two-unit cantilever resin-bonded glass fiber reinforced composite fixed dental prostheses: an in vitro and finite element analysis study.

    Science.gov (United States)

    Keulemans, Filip; De Jager, Niek; Kleverlaan, Cornelis J; Feilzer, Albert J

    2008-10-01

    The aim of this study was to evaluate in vitro the influence of retainer design on the strength of two-unit cantilever resin-bonded glass fiber-reinforced composite (FRC) fixed dental prostheses (FDP). Four retainer designs were tested: a proximal box, a step-box, a dual wing, and a step-box-wing. Of each design on 8 human mandibular molars, FRC-FDPs of a premolar size were produced. The FRC framework was made of resin impregnated unidirectional glass fibers (Estenia C&B EG Fiber, Kuraray) and veneered with hybrid resin composite (Estenia C&B, Kuraray). Panavia F 2.0 (Kuraray) was used as resin luting cement. FRC-FDPs were loaded to failure in a universal testing machine. One-way ANOVA and Tukey's post-hoc test were used to evaluate the data. The four designs were analyzed with finite element analysis (FEA) to reveal the stress distribution within the tooth/restoration complex. Significantly lower fracture strengths were observed with inlay-retained FDPs (proximal box: 300 +/- 65 N; step-box: 309 +/- 37 N) compared to wing-retained FDPs (p optimal design for replacement of a single premolar by means of a two-unit cantilever FRC-FDPs.

  8. Polyester matrix composite reinforced by fiberglass: how far can have contact with oil; Composito de matriz poliester e reforco de fibra de vidro: ate onde pode ter contato com petroleo

    Energy Technology Data Exchange (ETDEWEB)

    Dantas, C.M.; Masieiro, F.R.S.; Felipe, R.C.T.S.; Felipe, R.N.B.; Medeiros, G.G. [Centro Federal de Educacao Tecnologica (CEFET), Natal, RN (Brazil)], e-mail: k1000_rn@hotmail.com

    2008-07-01

    The use of reinforced plastics (PR) in the petroleum industry is very incipient when compared to conventional materials such as steel, for example. PR are already being used in floorings and handrails, but still there is not studies about the behavior of these materials when they come into contact with oil. In this context, this work aims to obtain a composite using a matrix of polyester resin, and the fiberglass (E Glass) as material of reinforcement. After the obtention of the composite, proof bodies will be made for the determination of the mechanical properties related to the traction and bending. Some of these proof bodies will be immersed in oil for a period of 120 days. At the end of this period, they will be tested. Thus, the traction and bending of the proof bodies which was immersed will be compared to the other ones, seeking to verify the influence of this immersion on the mechanical properties of the material. (author)

  9. Development of quartz particulate reinforced AA6063 aluminum matrix composites via friction stir processing

    Directory of Open Access Journals (Sweden)

    S. Joyson Abraham

    2016-12-01

    Full Text Available Friction stir processing (FSP has been accepted as a potential method to produce aluminum matrix composites (AMCs without the drawbacks of liquid metallurgy methods. The present work focuses on the development of AMCs reinforced with quartz (SiO2 particles using FSP. Grooves with various dimensions were machined on AA6063 plates and compacted with quartz particles. A single pass FSP was carried out using a combination of optimized process parameters. The volume fraction of quartz particles in the AMCs was varied from 0 to 18 vol.% in steps of 6 vol.%. The developed AA6063/Quartz AMCs were characterized using optical, scanning and transmission electron microscopy. The quartz particles were distributed uniformly in the aluminum matrix irrespective of the location within the stir zone. The grains of the AA6063 were extensively refined by the combination of thermomechanical effect of FSP and the pinning effect of quartz particles. The dispersion of the quartz particles improved the microhardness and wear resistance of the AMCs. The role of quartz particles on the worn surface and wear debris is reported.

  10. Polyurethane elastomer as a matrix material for short carbon fiber reinforced thermoplastic composites

    Directory of Open Access Journals (Sweden)

    Ümit Tayfun

    2017-09-01

    Full Text Available Short carbon fibers (CF with different surface sized (epoxy (EP and polyurethane (PU were used as reinforcing agent in thermoplastic polyurethane (TPU based composites. Composites containing 5, 10, 15, and 20 weight % sized and desized CFs were prepared by using melt-mixing method. The surface characteristics of CFs were examined by energy dispersive X-ray spectroscopy (EDX and Fourier transform infrared spectroscopy (FTIR. Tensile testing, shore hardness test, dynamic mechanical analysis (DMA and melt flow index (MFI test were performed for determining final composite properties. The dispersion of CFs in TPU matrix was examined by scanning electron microscopy (SEM. Tensile strength, Youngs’ modulus and Shore hardness of TPU were enhanced by the addition of sized CFs. About two-fold improvement for tensile strength and ten-fold improvement for Youngs’ modulus were observed with the incorporation of 20 wt% EP-CF and PU-CF in TPU. The storage modulus of PU-CF containing composites was higher than those of TPU and other composites. No remarkable change was observed in MFI value of TPU after CF loadings. Processing conditions in this work was suitable for composite production. Sized CFs exhibited better dispersion with regard to desized CF due to the stronger adhesion of TPU matrix to fiber surface.

  11. Titanate nanotubes for reinforcement of a poly(ethylene oxide)/chitosan polymer matrix

    Science.gov (United States)

    Porras, R.; Bavykin, D. V.; Zekonyte, J.; Walsh, F. C.; Wood, R. J.

    2016-05-01

    Soft polyethylene oxide (PEO)/chitosan mixtures, reinforced with hard titanate nanotubes (TiNTs) by co-precipitation from aqueous solution, have been used to produce compact coatings by the ‘drop-cast’ method, using water soluble PEO polymer and stable, aqueous colloidal solutions of TiNTs. The effects of the nanotube concentration and their length on the hardness and modulus of the prepared composite have been studied using nanoindentation and nanoscratch techniques. The uniformity of TiNT dispersion within the polymer matrix has been studied using transmission electron microscopy (TEM). A remarkable increase in hardness and reduced Young’s modulus of the composites, compared to pure polymer blends, has been observed at a TiNT concentration of 25 wt %. The short (up to 30 min) ultrasound treatment of aqueous solutions containing polymers and a colloidal TiNT mixture prior to drop casting has resulted in some improvements in both hardness and reduced Young’s modulus of dry composite films, probably due to a better dispersion of ceramic nanotubes within the matrix. However, further (more than 1 h) treatment of the mixture with ultrasound resulted in a deterioration of the mechanical properties of the composite accompanied by a shortening of the nanotubes, as observed by the TEM.

  12. Effects of Interface Modification on Mechanical Behavior of Hi-Nicalon Fiber-Reinforced Celsian Matrix Composites

    Science.gov (United States)

    Bansal, Narottam P.; Eldridge, Jeffrey I.

    1997-01-01

    Unidirectional celsian matrix composites having approx. 42 volume percent of uncoated or BN/SiC-coated Hi-Nicalon fibers were tested in three-point bend at room temperature. The uncoated fiber-reinforced composites showed catastrophic failure with strength of 210 +/- 35 MPa and a flat fracture surface. In contrast, composites reinforced with BN/SiC-coated fibers exhibited graceful failure with extensive fiber pullout. Values of first matrix cracking stress and strain were 435 +/- 35 MPa and 0.27 +/- 0.01 %, respectively, with ultimate strength as high as 960 MPa. The elastic Young's modulus of the uncoated and BN/SiC-coated fiber-reinforced composites were measured as 184 q 4 GPa and 165 +/- 5 GPa, respectively. Fiber push-through tests and microscopic examination indicated no chemical reaction at the uncoated or coated fiber-matrix interface. The low strength of the uncoated fiber-reinforced composite is probably due to degradation of the fibers from mechanical surface damage during processing. Because both the coated and uncoated fiber reinforced composites exhibited weak interfaces, the beneficial effect of the BN-SiC dual layer is primarily the protection of fibers from mechanical damage during processing.

  13. Using Goals, Feedback, Reinforcement, and a Performance Matrix to Improve Customer Service in a Large Department Store

    Science.gov (United States)

    Eikenhout, Nelson; Austin, John

    2005-01-01

    This study employed an ABAC and multiple baseline design to evaluate the effects of (B) feedback and (C) a package of feedback, goalsetting, and reinforcement (supervisor praise and an area-wide celebration as managed through a performance matrix, on a total of 14 various customer service behaviors for a total of 115 employees at a large…

  14. Structure-property relations for silicon nitride matrix composites reinforced with pyrolytic carbon pre-coated Hi-Nicalon fibers

    NARCIS (Netherlands)

    Kooi, B.J.; Hosson, J.Th.M. De; Olivier, C.; Veyret, J.B.

    1999-01-01

    Si3N4 matrix composites reinforced with pyrolytic carbon pre-coated Hi-Nicalon (SiC) fibers, were studied using tensile testing and transmission electron microscopy. Three types of samples were evaluated all with a nominal coating thickness of 200 nm. The composites were densified by hot pressing at

  15. Effect of clustering on the mechanical properties of SiC particulate-reinforced aluminum alloy 2024 metal matrix composites

    International Nuclear Information System (INIS)

    Hong, Soon-Jik; Kim, Hong-Moule; Huh, Dae; Suryanarayana, C.; Chun, Byong Sun

    2003-01-01

    Al 2024-SiC metal matrix composite (MMC) powders produced by centrifugal atomization were hot extruded to investigate the effect of clustering on their mechanical properties. Fracture toughness and tension tests were conducted on specimens reinforced with different volume fractions of SiC. A model was proposed to suggest that the strength of the MMCs could be estimated from the load transfer model approach that takes into consideration the extent of clustering. This model has been successful in predicting the experimentally observed strength and fracture toughness values of the Al 2024-SiC MMCs. On the basis of experimental observations, it is suggested that the strength of particulate-reinforced MMCs may be calculated from the relation: σ y =σ m V m +σ r (V r -V c )-σ r V c , where σ and V represent the yield strength and volume fraction, respectively, and the subscripts m, r, and c represent the matrix, reinforcement, and clusters, respectively

  16. Effects of endodontic post surface treatment, dentin conditioning, and artificial aging on the retention of glass fiber-reinforced composite resin posts.

    Science.gov (United States)

    Albashaireh, Zakereyya S; Ghazal, Muhamad; Kern, Matthias

    2010-01-01

    Several post surface treatments with or without the application of a bonding agent have been recommended to improve the bond strength of resin cements to posts. A regimen that produces the maximum bond strength of glass fiber-reinforced composite resin posts has not been verified. The purpose of this study was to evaluate the influence of post surface conditioning methods and artificial aging on the retention and microleakage of adhesively luted glass fiber-reinforced composite resin posts. Seventy-two endodontically treated single-rooted teeth were prepared for glass fiber-reinforced composite resin posts. The posts were submitted to 3 different surface treatments (n=24), including no treatment, etching with phosphoric acid, and airborne-particle abrasion. Subgroups of the posts (n=8) were then allocated for 3 different experimental conditions: no artificial aging, no bonding agent; no artificial aging, bonding agent; or artificial aging, bonding agent. The posts were luted with resin cement (Calibra). Post retention was measured in tension at a crosshead speed of 2 mm/min. The posts assigned for microleakage investigation were placed in fuchsin dye for 72 hours. The dislodged posts and the post spaces were examined microscopically to evaluate the mode of failure and explore the microleakage. Data were analyzed by 2-way ANOVA followed by Tukey HSD test (alpha=.05). The mean (SD) retention values for test groups ranged from 269 (63.8) to 349 (52.2) N. The retention values of the airborne-particle-abrasion group were significantly higher than those of the acidic-treatment and no-treatment groups. The application of bonding agent on the post surface produced no significant influence on retention. The mean retention values after artificial aging were significantly higher than without artificial aging. Microscopic evaluation demonstrated that the failure mode was primarily mixed. Treating the surface of the posts with phosphoric acid for 15 seconds before cementation

  17. Characterization, optical properties and laser ablation behavior of epoxy resin coatings reinforced with high reflectivity ceramic particles

    Science.gov (United States)

    Li, Wenzhi; Kong, Jing; Wu, Taotao; Gao, Lihong; Ma, Zhuang; Liu, Yanbo; Wang, Fuchi; Wei, Chenghua; Wang, Lijun

    2018-04-01

    Thermal damage induced by high power energy, especially high power laser, significantly affects the lifetime and performance of equipment. High-reflectance coating/film has attracted considerable attention due to its good performance in the damage protection. Preparing a high-reflectance coating with high reaction endothermal enthalpy will effectively consume a large amount of incident energy and in turn protect the substrate from thermal damage. In this study, a low temperature process was used to prepare coatings onto substrate with complex shape and avoid thermal effect during molding. An advanced high reflection ceramic powder, La1‑xSrxTiO3+δ , was added in the epoxy adhesive matrix to improve the reflectivity of coating. The optical properties and laser ablation behaviors of coatings with different ceramic additive ratio of La1‑xSrxTiO3+δ and modified epoxy-La1‑xSrxTiO3+δ with ammonium polyphosphate coatings were investigated, respectively. We found that the reflectivity of coatings is extremely high due to mixed high-reflection La1‑xSrxTiO3+δ particles, up to 96% at 1070 nm, which can significantly improve the laser resistance. In addition, the ammonium polyphosphate modifies the residual carbon structure of epoxy resin from discontinuous fine particles structure to continuous and porous structure, which greatly enhances the thermal-insulation property of coating. Furthermore, the laser ablation threshold is improved obviously, which is from 800 W cm‑2 to 1000 W cm‑2.

  18. Magnetic Properties of Iron-Cobalt Oxide Nanocomposites Synthesized in Polystyrene Resin Matrix*

    Science.gov (United States)

    Vaishnava, P. P.; Senaratne, U.; Rodak, D.; Kroll, E.; Tsoi, G.; Naik, R.; Naik, V.; Wenger, L. E.; Tao, Qu; Boolchand, P.; Suryanarayanan, R.

    2004-03-01

    Magnetic nanoparticles have potential applications in memory devices and medical technology. Magnetic iron-cobalt oxide nanoparticles were prepared by in situ precipitation in an ion exchange resin using the method of Ziolo et al^1. The ion exchange resin, consisting of sulfonated divinyl benzene cross linked polystyrene, was exposed to different iron and cobalt salt solutions: a) 4FeCl2 + CoCl2 b) 9FeCl2 + CoCl2 c) 4FeCl3 + CoCl2 d) 9FeCl3 + CoCl_2. The ions bound to the resin are then oxidized with hydrogen peroxide in an alkaline media with mild heat. The resulting nanocomposites were characterized by X-ray diffraction (XRD), Transmission Electron Microscopy (TEM), Fe^57 Mossbauer Spectroscopy and SQUID magnetometry. It was found that the oxide composition, particle size distribution, magnetic properties including blocking temperature and the amount of superparamagnetic phases are strongly influenced by the stoichiometry of the starting FeCl_2, FeCl_3, and CoCl2 solutions. Three major phases CoFe_2O_4, Fe_3O4 and γ-Fe_2O3 have been identified. The nanocomposites prepared using Fe^2+ and Co^2+ contain larger nanoparticles (10 nm) than those prepared by Fe^3+ and Co^2+ (3 nm) . The details of the structural characterization by XRD and TEM measurements and magnetic characteristics will be presented. *Research supported by NSF grant DGE 980720 ^1Ziolo et al, Science, 257, 5067 (1992).

  19. Influence of differences in resin-matrix structure on ion-exchange adsorption of trace amounts of Ag(I), Co(II) and Cr(III)

    International Nuclear Information System (INIS)

    Matsuzuru, Hideo; Wadachi, Yoshiki

    1975-01-01

    The influence of differences in resin-matrix structure on the ion-exchange adsorption of trace amounts of Ag(I), Co(II) and Cr(III) was studied by using both macroreticular and gel-type resins. The results indicate that the rate-determining step of the exchange mechanism of these ions is film diffusion under conditions of finite volume and at an ionic strengh of 1x10 -4 . The diffusion coefficient decreases with increasing size of the hydrated ions - in the order Dsub(Ag)>Dsub(Co)>Dsub(Cr). It may be said that the faster rate of exchange in the macroreticular resin is due to the larger surface area and pore size of this resin. Also, in a column system - as opposed to batch operation, it is assumed that the rate-determining step of the exchange reaction is film diffusion. With both resins, the kinetic coefficient β decreases in the order: βsub(Ag)>βsub(Co)>βsub(Cr). For the same linear velocity, a higher β-value is obtained with the macroreticular than with the gel-type resin. Consequently, a higher separating efficiency may be expected from the macroreticular resin for concentrating and separating trace amounts of cations from aqueous solution. (auth.)

  20. Effect of silver-supported materials on the mechanical and antibacterial properties of reinforced acrylic resin composites

    International Nuclear Information System (INIS)

    Han, Zhihui; Zhu, Bangshang; Chen, Rongrong; Huang, Zhuoli; Zhu, Cailian; Zhang, Xiuyin

    2015-01-01

    Highlights: • The novel Novaron-nano-ZrO 2 –ABW/PMMA composites was synthesized. • Nano-ZrO 2 and ABWs could increase the mechanical behavior of this composites. • Novaron had synergistic effect to improve the composites mechanical property and the 4 wt% was the optimal proportion. • Novaron could improve the antibacterial properties through their direct contact with the bacteria. • The composites did not have an adverse affect on cell viability. - Abstract: The aim of this study was to investigate the effect of silver-supported material (Novaron (N)) in acrylic resin (poly(methyl methacrylate) (PMMA)) composites, which reinforced with zirconium dioxide nanoparticles (nano-ZrO 2 ) and aluminum borate whiskers (ABWs), on the mechanical behavior, antibacterial properties and cytotoxicity. Silanized ABWs (4 wt%) and nano-ZrO 2 (2 wt%) were mixed with PMMA powder to obtain nano-ZrO 2 –ABW/PMMA matrices. Various amounts of Novaron particles were incorporated into the matrices and the pure PMMA to test the flexural strength. In addition, Streptococcus mutans (S. mutans) and Canidia albicans (C. albicans) biofilms on the specimen surface and in the culture medium were investigated for metabolic activity and colony-forming units (CFUs). Extracts taken in the cell culture medium of the specimens were used to evaluate cell viability. Results showed that the silanized nano-ZrO 2 and ABWs could improve the flexural strength of composites compared with the pure PMMA. Novaron itself had no mechanical function for composites while it had synergistic effect when it mixed with silanized nano-ZrO 2 and ABWs. And when 4 wt% (N-4) Novaron mixed in nano-ZrO 2 –ABW/PMMA composites, flexural strength achieved an increase of 44%, getting the maximum value. For the antibacterial properties, the values of MTT and CFUs of S. mutans and C. albicans biofilms on the composites surface were greatly reduced (p < 0.05) with the higher proportion of Novaron, and no significant

  1. Magnetic properties of iron-oxide and (iron, cobalt)-oxide nanoparticles synthesized in polystyrene resin matrix

    International Nuclear Information System (INIS)

    Naik, R.; Kroll, E.; Rodak, D.; Tsoi, G.M.; McCullen, E.; Wenger, L.E.; Suryanarayanan, R.; Naik, V.M.; Vaishnava, P.P.; Tao, Qu; Boolchand, P.

    2004-01-01

    A sulfonated polystyrene resin matrix was ion exchanged with aqueous solutions of (1) FeCl 2 , (2) FeCl 3 , (3) 2FeCl 2 :FeCl 3 , (4) 9FeCl 2 :CoCl 2 , and (5) 4FeCl 2 :CoCl 2 to prepare magnetic nanoparticles of varying size. The samples were characterized by X-ray diffraction (XRD), 57 Fe Mossbauer spectroscopy, X-ray photoelectron spectroscopy (XPS), and transmission electron microscopy (TEM), and identify two major phases: γ-Fe 2 O 3 , CoFe 2 O 4 , and perhaps a minor Fe 3 O 4 phase. SQUID magnetometry measurements indicate superparamagnetic particles with blocking temperatures (T B ) ranging from 20 K to room temperature

  2. Magnetic properties of iron-oxide and (iron, cobalt)-oxide nanoparticles synthesized in polystyrene resin matrix

    Energy Technology Data Exchange (ETDEWEB)

    Naik, R. E-mail: naik@physics.wayne.edu; Kroll, E.; Rodak, D.; Tsoi, G.M.; McCullen, E.; Wenger, L.E.; Suryanarayanan, R.; Naik, V.M.; Vaishnava, P.P.; Tao, Qu; Boolchand, P

    2004-05-01

    A sulfonated polystyrene resin matrix was ion exchanged with aqueous solutions of (1) FeCl{sub 2}, (2) FeCl{sub 3}, (3) 2FeCl{sub 2}:FeCl{sub 3}, (4) 9FeCl{sub 2}:CoCl{sub 2}, and (5) 4FeCl{sub 2}:CoCl{sub 2} to prepare magnetic nanoparticles of varying size. The samples were characterized by X-ray diffraction (XRD), {sup 57}Fe Mossbauer spectroscopy, X-ray photoelectron spectroscopy (XPS), and transmission electron microscopy (TEM), and identify two major phases: {gamma}-Fe{sub 2}O{sub 3}, CoFe{sub 2}O{sub 4}, and perhaps a minor Fe{sub 3}O{sub 4} phase. SQUID magnetometry measurements indicate superparamagnetic particles with blocking temperatures (T{sub B}) ranging from 20 K to room temperature.

  3. Magnetic properties of iron-oxide and (iron, cobalt)-oxide nanoparticles synthesized in polystyrene resin matrix

    Science.gov (United States)

    Naik, R.; Kroll, E.; Rodak, D.; Tsoi, G. M.; McCullen, E.; Wenger, L. E.; Suryanarayanan, R.; Naik, V. M.; Vaishnava, P. P.; Tao, Qu; Boolchand, P.

    2004-05-01

    A sulfonated polystyrene resin matrix was ion exchanged with aqueous solutions of (1) FeCl2, (2) FeCl3, (3) 2FeCl2:FeCl3, (4) 9FeCl2:CoCl2, and (5) 4FeCl2:CoCl2 to prepare magnetic nanoparticles of varying size. The samples were characterized by X-ray diffraction (XRD), 57Fe Mossbauer spectroscopy, X-ray photoelectron spectroscopy (XPS), and transmission electron microscopy (TEM), and identify two major phases: γ-Fe2O3, CoFe2O4, and perhaps a minor Fe3O4 phase. SQUID magnetometry measurements indicate superparamagnetic particles with blocking temperatures (TB) ranging from 20K to room temperature.

  4. Modeling of the interaction between chemical and mechanical behavior of ion exchange resins encapsulated into a cement-based matrix

    International Nuclear Information System (INIS)

    Neji, Mejdi

    2014-01-01

    Ion exchange resins (IER) are widely used in the nuclear industry to purge non directly storable infected effluents. IER then become a solid waste which could be stored as any classical nuclear waste. One way of conditioning consists in embedding it into a cement paste matrix. This process raises some concerns regarding the cohesiveness of the composite. Once embedded, the IER might indeed interact with the cement paste which would lead, in some cases, to the swelling of the composite. This thesis has been set up to address this potential issue, with the aim to develop a numerical tool able to predict the mechanical behavior of this kind of material. This work only focuses on the long term behavior and more specifically on the potential degradations of the cement paste/IER composite due to cationic IER. (author)

  5. Influence of matrix metalloproteinase synthetic inhibitors on dentin microtensile bond strength of resin cements.

    Science.gov (United States)

    Stape, T H S; Menezes, M S; Barreto, B C F; Aguiar, F H B; Martins, L R; Quagliatto, P S

    2012-01-01

    This study evaluated the effect of dentin pretreatment with 2% chlorhexidine (CHX) or 24% ethylenediamine tetra-acetic acid gel (EDTA) on the dentin microtensile bond strength (μTBS) of resin cements. Composite blocks were luted to superficial noncarious human dentin (n=10) using two resin cements (RelyX ARC [ARC] and RelyX U100 [U100]) and three dentin pretreatments (without pretreatment-control, CHX, and EDTA). CHX was applied for 60 seconds on the acid-etched dentin in the ARC/CHX group, and for the same time on smear layer-covered dentin in the U100/CHX group. EDTA was applied for 45 seconds on smear-covered dentin in the U100/EDTA group, and it replaced phosphoric acid conditioning in the ARC/EDTA group for 60 seconds. After storage in water for 24 hours, specimens were prepared for microtensile bond strength testing. The results were submitted to two-way analysis of variance (ANOVA) followed by Tukey test. ARC produced significantly higher μTBS (pEDTA was used. For ARC, no pretreatment and CHX produced higher μTBS than EDTA. For U100, EDTA produced higher μTBS; no statistical difference occurred between CHX pretreatment and when no pretreatment was performed. While CHX did not affect immediate dentin bond strength of both cements, EDTA improved bond strength of U100, but it reduced dentin bond strength of ARC.

  6. Interlaminar shear strength of SiC matrix composites reinforced by continuous fibers at 900 °C in air

    International Nuclear Information System (INIS)

    Zhang, Chengyu; Gou, Jianjie; Qiao, Shengru; Wang, Xuanwei; Zhang, Jun

    2014-01-01

    Highlights: • The application of SiC fiber could improve ILSS of the SiC matrix composites. • The orientation of the warp fibers plays a critical role in determining ILSS of 2.5D-C/SiC. • The failure mechanisms of 2D composites involve matrix cracking, and interfacial debonding. - Abstract: To reveal the shear properties of SiC matrix composites, interlaminar shear strength (ILSS) of three kinds of silicon carbide matrix composites was investigated by compression of the double notched shear specimen (DNS) at 900 °C in air. The investigated composites included a woven plain carbon fiber reinforced silicon carbide composite (2D-C/SiC), a two-and-a-half-dimensional carbon fiber-reinforced silicon carbide composite (2.5D-C/SiC) and a woven plain silicon carbon fiber reinforced silicon carbide composite (2D-SiC/SiC). A scanning electron microscope was employed to observe the microstructure and fracture morphologies. It can be found that the fiber type and reinforcement architecture have significant impacts on the ILSS of the SiC matrix composites. Great anisotropy of ILSS can be found for 2.5D-C/SiC because of the different fracture resistance of the warp fibers. Larger ILSS can be obtained when the specimens was loaded along the weft direction. In addition, the SiC fibers could enhance the ILSS, compared with carbon fibers. The improvement is attributed to the higher oxidation resistance of SiC fibers and the similar thermal expansion coefficients between the matrix and the fibers

  7. Determining the fracture resistance of advanced SiC fiber reinforced SiC matrix composites

    International Nuclear Information System (INIS)

    Nozawa, T.; Katoh, Y.; Kishimoto, H.

    2007-01-01

    Full text of publication follows: One of the perceived advantages for highly-crystalline and stoichiometric silicon carbide (SiC) and SiC composites, e.g., advanced SiC fiber reinforced chemically-vapor-infiltrated (CVI) SiC matrix composites, is the retention of fast fracture properties after neutron irradiation at high-temperatures (∼1000 deg. C) to intermediate-doses (∼15 dpa). Accordingly, it has been clarified that the maximum allowable stress (or strain) limit seems unaffected in certain irradiation conditions. Meanwhile, understanding the mechanism of crack propagation from flaws, as potential weakest link to cause composite failure, is somehow lacking, despite that determining the strength criterion based on the fracture mechanics will eventually become important considering the nature of composites' fracture. This study aims to evaluate crack propagation behaviors of advanced SiC/SiC and to provide fundamentals on fracture resistance of the composites to define the strength limit for the practical component design. For those purposes, the effects of irreversible energies related to interfacial de-bonding, fiber bridging, and microcrack forming on the fracture resistance were evaluated. Two-dimensional SiC/SiC composites were fabricated by CVI or nano-infiltration and transient-eutectic-phase (NITE ) methods. Hi-Nicalon TM Type-S or Tyranno TM -SA fibers were used as reinforcements. In-plane mode-I fracture resistance was evaluated by the single edge notched bend technique. The key finding is the continuous Load increase with the crack growth for any types of advanced composites, while many studies specified the gradual load decrease for the conventional composites once the crack initiates. This high quasi-ductility appeared due primarily to high friction (>100 MPa) at the fiber/matrix interface using rough SiC fibers. The preliminary analysis based on the linear elastic fracture mechanics, which does not consider the effects of irreversible energy

  8. Dipole-Dipole Electron Excitation Energy Transfer in the System CdSe/ZnS Quantum Dot - Eosin in Butyral Resin Matrix

    Science.gov (United States)

    Myslitskaya, N. A.; Samusev, I. G.; Bryukhanov, V. V.

    2014-11-01

    The electron excitation energy transfer from CdSe/ZnS quantum dots to eosin molecules in the polymer matrix of butyral resin is investigated. The main characteristics of energy transfer are determined. By means of luminescence microscopy and correlation spectroscopy methods we found that quantum dots in the polymer are in an aggregate state.

  9. Characterization and modeling of three-dimensional self-healing shape memory alloy-reinforced metal-matrix composites

    Energy Technology Data Exchange (ETDEWEB)

    Manuel, Michele Viola [University of Florida, Gainesville; Zhu, Pingping [Northwestern University, Evanston; Newman, John A. [NASA Langely Research Center (LaRC), Virginia; Wright, M Clara [NASA Kennedy Space Center, FL; Brinson, L Catherine [Northwestern University, Evanston; Kesler, Michael S. [ORNL

    2016-09-10

    In this paper, three-dimensional metal-matrix composites (MMCs) reinforced by shape memory alloy (SMA) wires are modeled and simulated, by adopting an SMA constitutive model accounting for elastic deformation, phase transformation and plastic behavior. A modeling method to create composites with pre-strained SMA wires is also proposed to improve the self-healing ability. Experimental validation is provided with a composite under three-point bending. This modeling method is applied in a series of finite element simulations to investigate the self-healing effects in pre-cracked composites, especially the role of the SMA reinforcement, the softening property of the matrix, and the effect of pre-strain in the SMA. The results demonstrate that SMA reinforcements provide stronger shape recovery ability than other, non-transforming materials. The softening property of the metallic matrix and the pre-strain in SMA are also beneficial to help crack closure and healing. This modeling approach can serve as an efficient tool to design SMA-reinforced MMCs with optimal self-healing properties that have potential applications in components needing a high level of reliability.

  10. (nanoclay and CaSiO3)-reinforced E-glass-reinforced epoxy

    Indian Academy of Sciences (India)

    For instance, Zhang et al. [6] have prepared 30 types of epoxy matrix reinforced with ... the resin in a high-speed metal blade rotation medium. The .... Tests were run for .... Figure 2. Mean effect plots showing the influence of load, nanoclay content and speed on ..... [8] Wang K, Chen L, Wu J, Toh M L, He C and Yee A F 2005.

  11. Mechanical properties of aluminium based metal matrix composites reinforced with graphite nanoplatelets

    Energy Technology Data Exchange (ETDEWEB)

    Alam, Syed Nasimul, E-mail: syedn@nitrkl.ac.in; Kumar, Lailesh

    2016-06-14

    In this work Al-matrix composites reinforced by exfoliated graphite nanoplatelets (xGnP) is fabricated by powder metallurgy route and their microstructure, mechanical properties and sliding wear behaviour were investigated. Here, xGnP has been synthesized from the thermally exfoliated graphite produced from a graphite intercalation compound (GIC) through rapid evaporation of the intercalant at an elevated temperature. The xGnP synthesized was characterized using scanning electron microscope (SEM), high-resolution transmission electron microscope (HRTEM), x-ray diffraction (XRD), atomic force microscopy (AFM), x-ray photoelectron spectroscopy (XPS), differential scanning calorimetry and thermogravimetric analysis (DSC/TGA), Raman spectroscopy and Fourier transform infrared spectroscopy (FTIR). The Al and xGnP powder mixtures were consolidated under a load of 565 MPa followed by sintering at 550 °C for 2 h in an inert atmosphere. Al-1, 2, 3 and 5 wt% xGnP nanocomposites were developed. Results of the wear test show that there was a significant improvement in the wear resistance of the composites up to the addition of 3 wt% of xGnP in the Al matrix. The hardness of the various Al-xGnP composites also shows improvement upto the addition of 1 wt% xGnP beyond which there was a decrease in the hardness of the composites. The tensile strength of the Al-xGnP composites continuously reduced with the addition of xGnP due to the formation of Al{sub 4}C{sub 3} particles at the interface of the Al and xGnP in the composite.

  12. Properties of copper matrix reinforced with nano- and micro-sized Al2O3 particles

    International Nuclear Information System (INIS)

    Rajkovic, Viseslava; Bozic, Dusan; Jovanovic, Milan T.

    2008-01-01

    The mixture of electrolytic copper powder with 5 wt.% of commercial Al 2 O 3 powder (average particle size: 15 and 0.75 μm, respectively) and the inert gas atomized prealloyed copper powder (average particle size: 30 μm) containing 2.5 wt.% aluminum were separately milled in air up to 20 h in the planetary ball mill. During milling aluminum in the prealloyed copper powders was oxidized in situ by internal oxidation with oxygen from the air forming very fine nano-sized Al 2 O 3 particles. The internal oxidation of 2.5 wt.% aluminum generated 4.7 wt.% of Al 2 O 3 in the copper matrix. Powders and compacts were characterized by light and scanning electron microscopy (SEM), electron probe microanalysis (EPMA) and X-ray diffraction analysis. Microhardness and electrical conductivity were also included in measurements. The microhardness of Cu-2.5 wt.% Al compacts was 3.6 times higher than that of compacts processed from electrolytic copper powder. This increase in microhardness is a consequence of a fine dispersion of Al 2 O 3 particles and refined grain structure. The average values of electrical conductivity of compacts processed from Cu-5 wt.% Al 2 O 3 and Cu-2.5 wt.% Al powders previously milled for 20 h and were 88% and 70% IACS, respectively, which is a rather significant increase if compared with values of 60% and 23% IACS of compacts processed from as-received and non-milled powders. The microhardness of 20-h milled compacts decreases with the heat treatment at 800 deg. C. Due to the effect of nano-sized Al 2 O 3 particles Cu-2.5 wt.% Al compacts show lower decrease in microhardness. The results are discussed in terms of the effect of Al 2 O 3 particle size and fine grain structure on the reinforcing of the copper matrix

  13. Comparing the reinforcing effects of a resin modified glassionomer cement, Flowable compomer, and Flowable composite in the restoration of calcium hydroxide-treated immature roots in vitro

    Directory of Open Access Journals (Sweden)

    S Prathibha Rani

    2011-01-01

    Full Text Available One hundred and sixty human permanent central incisors were enlarged to a 120 file size after crown removal procedure to simulate immature teeth. The root canals were filled with calcium hydroxide and stored for 15 days (phase I, 30 days (phase II, 90 days (phase III, and 180 days (Phase IV. At the end of these selected time periods, calcium hydroxide was cleaned off the root canals of forty teeth that were randomly selected and obturated with gutta-percha points in the apical 2 mm of the root canals with a sealer. The specimens were further equally divided into four groups. Unrestored Group I served as control and the root canals of teeth in the other three group specimens were reinforced with resin modified glassionomer cement (RMGIC (Group II, Flowable Compomer (Group III, and Flowable Composite (Group IV, respectively, using a translucent curing post. All specimens were subjected to compressive force using an Instron Testing machine, until fracture occurred. All the materials evaluated substantially reinforced the root specimens compared to the control. At the end of 180 days, Flowable composites showed maximum reinforcement compared to the other groups; however, no significant differences were found between the reinforcement capabilities of Flowable Compomer and RMGIC.

  14. Resin impregnation process for producing a resin-fiber composite

    Science.gov (United States)

    Palmer, Raymond J. (Inventor); Moore, William E. (Inventor)

    1994-01-01

    Process for vacuum impregnation of a dry fiber reinforcement with a curable resin to produce a resin-fiber composite, by drawing a vacuum to permit flow of curable liquid resin into and through a fiber reinforcement to impregnate same and curing the resin-impregnated fiber reinforcement at a sufficient temperature and pressure to effect final curing. Both vacuum and positive pressure, e.g. autoclave pressure, are applied to the dry fiber reinforcement prior to application of heat and prior to any resin flow to compact the dry fiber reinforcement, and produce a resin-fiber composite of reduced weight, thickness and resin content, and improved mechanical properties. Preferably both a vacuum and positive pressure, e.g. autoclave pressure, are also applied during final curing.

  15. The erosion performance of particle reinforced metal matrix composite coatings produced by co-deposition cold gas dynamic spraying

    Science.gov (United States)

    Peat, Tom; Galloway, Alexander; Toumpis, Athanasios; McNutt, Philip; Iqbal, Naveed

    2017-02-01

    This work reports on the erosion performance of three particle reinforced metal matrix composite coatings, co-deposited with an aluminium binder via cold-gas dynamic spraying. The deposition of ceramic particles is difficult to achieve with typical cold spray techniques due to the absence of particle deformation. This issue has been overcome in the present study by simultaneously spraying the reinforcing particles with a ductile metallic binder which has led to an increased level of ceramic/cermet particles deposited on the substrate with thick (>400 μm) coatings produced. The aim of this investigation was to evaluate the erosion performance of the co-deposited coatings within a slurry environment. The study also incorporated standard metallographic characterisation techniques to evaluate the distribution of reinforcing particles within the aluminium matrix. All coatings exhibited poorer erosion performance than the uncoated material, both in terms of volume loss and mass loss. The Al2O3 reinforced coating sustained the greatest amount of damage following exposure to the slurry and recorded the greatest volume loss (approx. 2.8 mm3) out of all of the examined coatings. Despite the poor erosion performance, the WC-CoCr reinforced coating demonstrated a considerable hardness increase over the as-received AA5083 (approx. 400%) and also exhibited the smallest free space length between adjacent particles. The findings of this study reveal that the removal of the AA5083 matrix by the impinging silicon carbide particles acts as the primary wear mechanism leading to the degradation of the coating. Analysis of the wear scar has demonstrated that the damage to the soft matrix alloy takes the form of ploughing and scoring which subsequently exposes carbide/oxide particles to the impinging slurry.

  16. Evaluation of the Technical-Economic Potential of Particle- Reinforced Aluminum Matrix Composites and Electrochemical Machining

    International Nuclear Information System (INIS)

    Schubert, A; Hackert-Oschätzchen, M; Lehnert, N; Götze, U; Herold, F; Schmidt, A; Meichsner, G

    2016-01-01

    Compared to conventional cutting, the processing of materials by electrochemical machining offers some technical advantages like high surface quality, no thermal or mechanical impact on the work piece and preservation of the microstructure of the work piece material. From the economic point of view, the possibility of process parallelization and the absence of any process-related tool wear are mentionable advantages of electrochemical machining. In this study, based on experimental results, it will be evaluated to what extent the electrochemical machining is technically and economically suitable for the finish-machining of particle- reinforced aluminum matrix composites (AMCs). Initial studies showed that electrochemical machining - in contrast to other machining processes - has the potential to fulfil demanding requirements regarding precision and surface quality of products or components especially when applied to AMCs. In addition, the investigations show that processing of AMCs by electrochemical machining requires less energy than the electrochemical machining of stainless steel. Therefore, an evaluation of electrochemically machined AMCs - compared to stainless steel - from a technical and an economic perspective will be presented in this paper. The results show the potential of electro-chemically machined AMCs and contribute to the enhancement of instruments for technical-economic evaluations as well as a comprehensive innovation control. (paper)

  17. Performance of hybrid nano-micro reinforced mg metal matrix composites brake calliper: simulation approach

    Science.gov (United States)

    Fatchurrohman, N.; Chia, S. T.

    2017-10-01

    Most commercial vehicles use brake calliper made of grey cast iron (GCI) which possesses heavy weight. This contributes to the total weight of the vehicle which can lead to higher fuel consumption. Another major problem is GCI calliper tends to deflect during clamping action, known as “bending of bridge”. This will result in extended pedal travel. Magnesium metal matrix composites (Mg-MMC) has a potential application in the automotive industry since it having a lower density, higher strength and very good modulus of elasticity as compared to GCI. This paper proposed initial development of hybrid Mg-MMC brake calliper. This was achieved by analyzing the performance of hybrid nano-micro reinforced Mg-MMC and comparing with the conventional GCI brake calliper. It was performed using simulation in ANSYS, a finite element analysis (FEA) software. The results show that hybrid Mg-MMC has better performance in terms of reduction the weight of the brake calliper, reduction in total deformation/deflection and better ability to withstand equivalent elastic strain.

  18. Influence of Boron on the Creep Behavior and the Microstructure of Particle Reinforced Aluminum Matrix Composites

    Directory of Open Access Journals (Sweden)

    Steve Siebeck

    2018-02-01

    Full Text Available The reinforcement of aluminum alloys with particles leads to the enhancement of their mechanical properties at room temperature. However, the creep behavior at elevated temperatures is often negatively influenced. This raises the question of how it is possible to influence the creep behavior of this type of material. Within this paper, selected creep and tensile tests demonstrate the beneficial effects of boron on the properties of precipitation-hardenable aluminum matrix composites (AMCs. The focus is on the underlying microstructure behind this effect. For this purpose, boron was added to AMCs by means of mechanical alloying. Comparatively higher boron contents than in steel are investigated in order to be able to record their influence on the microstructure including the formation of potential new phases as well as possible. While the newly formed phase Al3BC can be reliably detected by X-ray diffraction (XRD, it is difficult to obtain information about the phase distribution by means of scanning electron microscopy (SEM and scanning transmission electron microscopy (STEM investigations. An important contribution to this is finally provided by the investigation using Raman microscopy. Thus, the homogeneous distribution of finely scaled Al3BC particles is detectable, which allows conclusions about the microstructure/property relationship.

  19. Characterisation of glass matrix composites reinforced with lead zirconate titanate particles

    International Nuclear Information System (INIS)

    Cannillo, Valeria; Manfredini, Tiziano; Montorsi, Monia; Tavoni, Francesca; Minay, Emma J.; Boccaccini, Aldo R.

    2005-01-01

    A new type of glass matrix composite reinforced with ferroelectric particulate secondary phase was investigated. Samples containing lead zirconate titanate (PZT) particles in a silicate lead glass were fabricated. Various sintering strategies were tested in order to optimise the processing route. The densest samples were obtained by hot-pressing. The composites were characterized by means of SEM observations, X-ray diffraction, differential thermal analysis and Vickers indentations. In order to get a deeper insight into the thermo-mechanical behaviour of the material, a FEM based numerical model was prepared and applied. In particular, the crack-particle interaction was assessed and thus possible toughening mechanisms were investigated. By means of the numerical modelling supported by SEM observations, traditional toughening mechanisms (e.g. crack deflection, particle debonding) were ruled out. Since the experimentally measured indentation fracture toughness of the composite is significantly higher than that of the unreinforced glass, the findings suggest that a new toughening mechanism may be active, based on the piezoelectric effect

  20. Damage Assessment in a SiC-fiber reinforced Ceramic Matrix Composite

    Directory of Open Access Journals (Sweden)

    Konstantinos G. Dassios

    2013-01-01

    Full Text Available Assessment of the fracture behavior of a SiC-fbre-reinforced barium osumilite (BMAS ceramic matrix composite tested under static and cyclic tension conditions is reported herein. Notched specimens were used in order to limit material damage within a predefined gauge length. Imposition of successive unloading/reloading loops was found to result in an increase by 20% in material strength as compared to pure tension; the observed increase is attributed to energy dissipation from large-scale interfacial debonding phenomena that dominated the post-elastic tensile behaviour of the composite. Cyclic loading also helped establish the axial residual stress state of the fibres in the composite of tensile nature via a well-defined common intersection point of unloading-reloading cycles. A translation vector approach in the stress-strain plane was successful in establishing the residual stress-free properties of the composite and in reconciling the scatter noted in elastic properties of specimens with respect to theoretical expectations.

  1. Aluminium Matrix Composites Reinforced with Co-continuous Interlaced Phases Aluminium-alumina Needles

    Directory of Open Access Journals (Sweden)

    Elvio de Napole Gregolin

    2002-09-01

    Full Text Available An Al-5SiO2 (5 wt% of SiO2 aluminium matrix fiber composite was produced where the reinforcement consists of fossil silica fibers needles. After being heat-treated at 600 °C, the original fiber morphology was retained but its microstructure changed from solid silica to an interconnected (Al-Si/Al2O3 interlaced structure named co-continuous composite. A technique of powder metallurgy, using commercial aluminium powder and the silica fibers as starting materials, followed by hot extrusion, was used to produce the composite. The co-continuous microstructure was obtained partially or totally on the fibers as a result of the reaction, which occurs during the heat treatment, first by solid diffusion and finally by the liquid Al-Si in local equilibrium, formed with the silicon released by reaction. The internal structure of the fibers was characterized using field emission electron microscope (FEG-SEM and optical microscopy on polished and fractured samples.

  2. Numerical Methods Application for Reinforced Concrete Elements-Theoretical Approach for Direct Stiffness Matrix Method

    Directory of Open Access Journals (Sweden)

    Sergiu Ciprian Catinas

    2015-07-01

    Full Text Available A detailed theoretical and practical investigation of the reinforced concrete elements is due to recent techniques and method that are implemented in the construction market. More over a theoretical study is a demand for a better and faster approach nowadays due to rapid development of the calculus technique. The paper above will present a study for implementing in a static calculus the direct stiffness matrix method in order capable to address phenomena related to different stages of loading, rapid change of cross section area and physical properties. The method is a demand due to the fact that in our days the FEM (Finite Element Method is the only alternative to such a calculus and FEM are considered as expensive methods from the time and calculus resources point of view. The main goal in such a method is to create the moment-curvature diagram in the cross section that is analyzed. The paper above will express some of the most important techniques and new ideas as well in order to create the moment curvature graphic in the cross sections considered.

  3. ′Metal to resin′: A comparative evaluation of conventional band and loop space maintainer with the fiber reinforced composite resin space maintainer in children

    Directory of Open Access Journals (Sweden)

    A Garg

    2014-01-01

    Full Text Available Aims: To compare the clinical efficacy of two space maintainers namely, conventional band and loop and Fiber Reinforced Composite Resin (FRCR space maintainers . Subjects and Methods: Thirty healthy children, aged 5 to 8 years were selected having at least two deciduous molars in different quadrants indicated for extraction or lost previously. FRCR space maintainer was placed in one quadrant and in the other quadrant band and loop space maintainer was cemented. All the patients were recalled at 1 st , 3 rd , and 6 th months for evaluation of both types of space maintainer. Patient acceptability, time taken, and clinical efficacy was recorded. Statistical analysis used: The observations thus obtained were subjected to statistical analysis using Chi- square test and Mann-Whitney U test. Results: Patient acceptability was greater in Group I (FRCR in comparison to Group II (band and loop space maintainer. The time taken by Group I was significantly lower as compared to that of Group II. In Group I, debonding of enamel, composite was the most common complication leading to failure followed by debonding of fiber composite. In Group II, cement loss was the most common complication leading to failure followed by slippage of band and fracture of loop. The success rates of Groups I and Group II weares 63.3% and 36.7%, respectively. Conclusion: The study concluded that FRCRFiber Reinforced Composite Resin (Ribbond space maintainers can be considered as viable alternative to the conventional band and loop space maintainers.

  4. Three-dimensional fabric reinforced concrete finds first use in reactor building

    International Nuclear Information System (INIS)

    Akihama, S.; Nakagava, H.

    1989-01-01

    It is reported about creation of concrete reinforced with synthetic fibers by Japanese firm Kadzima. Synthetic material with three-dimensional orientation of fibers is produced of roving impreganted with synthetic resin. The reinforcement produced is submerged into the concrete matrix. The compression strength of such a material makes up 58 MPa. The new material is used for constructing the nuclear reactor shielding containers

  5. Assessment of thermal shock induced damage in silicon carbide fibre reinforced glass matrix composites

    Directory of Open Access Journals (Sweden)

    Boccaccini, A. R.

    1998-09-01

    Full Text Available The development of microstructural damage in silicon carbide fibre (Nicalon™ reinforced glass matrix composite samples subjected to thermal shock was investigated by using a nondestructive forced resonance technique and fibre push out indentation tests. Thermal shock testing involved quenching samples in a water bath maintained at room temperature from a high temperature (650ºC. Changes in the Young's modulus and internal friction of the samples with increasing number of shocks were measured accurately by the forced resonance technique. Fibre push-out tests showed no significant changes in the properties of the fibre-matrix interface, indicating that damage in the composite was concentrated mainly in the development of matrix microcracking. It was also shown that the internal friction is a very sensitive parameter by which to detect the onset and development of such microcracking. A simple semi-empirical model is proposed to correlate the internal friction level with the microcracking density in the glass matrix. Finally, the relevance of detecting nondestructively the existence of microcracks in the glass matrix, before any significant interfacial degradation occurs, is emphasized, in conextion with the possibility of inducing a crack healing process by a thermal treatment (annealing, taking advantage of the viscous flow properties of the glass.

    El desarrollo de daño microestructural en materiales compuestos de matriz de vidrio reforzados con fibras de carburo de silicio (Nicalon™ sometidos a choque térmico fue investigado mediante la técnica no-destructiva de resonancia forzada y por mediciones de indentación "push-out" de fibras. Los ensayos de choque térmico involucraron el enfriamiento brusco en un baño de agua a temperatura ambiente de las piezas previamente calentadas a una temperatura elevada (650ºC. La técnica de resonancia forzada permitió medir cambios en el módulo de Young de elasticidad y en la fricci

  6. Influence of reinforcement proportion and matrix composition on pitting corrosion behaviour of cast aluminium matrix composites (A3xx.x/SiCp)

    International Nuclear Information System (INIS)

    Pardo, A.; Merino, M.C.; Merino, S.; Viejo, F.; Carboneras, M.; Arrabal, R.

    2005-01-01

    The influence of silicon carbide (SiCp) proportion and matrix composition on four aluminium metal matrix composites (A360/SiC/10p, A360/SiC/20p, A380/SiC/10p, A380/SiC/20p) immersed in 1-3.5 wt% NaCl at 22 deg C was investigated by potentiodynamic polarization. The kinetics of the corrosion process was studied on the basis of gravimetric measurements. The nature of corrosion products was analysed by scanning electron microscopy (SEM) and low angle X-ray diffraction (XRD). The corrosion damage in Al/SiCp composites was caused by pitting attack and by nucleation and growth of Al 2 O 3 . 3H 2 O on the material surface. The main attack nucleation sites were the interface region between the matrix and the reinforcement particles. The corrosion process was influenced more by the concentration of alloy elements in the matrix than by the proportion of SiCp reinforcement and saline concentration

  7. Influence of reinforcement proportion and matrix composition on pitting corrosion behaviour of cast aluminium matrix composites (A3xx.x/SiCp)

    Energy Technology Data Exchange (ETDEWEB)

    Pardo, A. [Departamento de Ciencia de Materiales, Facultad de Quimica, Universidad Complutense, 28040 Madrid (Spain)]. E-mail: anpardo@quim.ucm.es; Merino, M.C. [Departamento de Ciencia de Materiales, Facultad de Quimica, Universidad Complutense, 28040 Madrid (Spain); Merino, S. [Departamento de Tecnologia Industrial, Universidad Alfonso X El Sabio, 28691, Villanueva de la Canada, Madrid (Spain); Viejo, F. [Departamento de Ciencia de Materiales, Facultad de Quimica, Universidad Complutense, 28040 Madrid (Spain); Carboneras, M. [Departamento de Ciencia de Materiales, Facultad de Quimica, Universidad Complutense, 28040 Madrid (Spain); Arrabal, R. [Departamento de Ciencia de Materiales, Facultad de Quimica, Universidad Complutense, 28040 Madrid (Spain)

    2005-07-01

    The influence of silicon carbide (SiCp) proportion and matrix composition on four aluminium metal matrix composites (A360/SiC/10p, A360/SiC/20p, A380/SiC/10p, A380/SiC/20p) immersed in 1-3.5 wt% NaCl at 22 deg C was investigated by potentiodynamic polarization. The kinetics of the corrosion process was studied on the basis of gravimetric measurements. The nature of corrosion products was analysed by scanning electron microscopy (SEM) and low angle X-ray diffraction (XRD). The corrosion damage in Al/SiCp composites was caused by pitting attack and by nucleation and growth of Al{sub 2}O{sub 3} . 3H{sub 2}O on the material surface. The main attack nucleation sites were the interface region between the matrix and the reinforcement particles. The corrosion process was influenced more by the concentration of alloy elements in the matrix than by the proportion of SiCp reinforcement and saline concentration.

  8. Microstructural study and densification analysis of hot work tool steel matrix composites reinforced with TiB{sub 2} particles

    Energy Technology Data Exchange (ETDEWEB)

    Fedrizzi, A., E-mail: anna.fedrizzi@ing.unitn.it [Department of Industrial Engineering, University of Trento, Via Mesiano 77, 38123 Trento (Italy); Pellizzari, M. [Department of Industrial Engineering, University of Trento, Via Mesiano 77, 38123 Trento (Italy); Zadra, M. [K4Sint, Start-up of the University of Trento, Viale Dante 300, 38057 Pergine Valsugana (Italy); Marin, E. [Department of Chemistry, Physics and Environment, University of Udine, Via Cotonificio 108, 33100 Udine (Italy)

    2013-12-15

    Hot work tool steels are characterized by good toughness and high hot hardness but are less wear resistant than other tooling materials, such as high speed steel. Metal matrix composites show improved tribological behavior, but not much work has been done in the field of hot work tool steels. In this paper TiB{sub 2}-reinforced hot work tool steel matrix composites were produced by spark plasma sintering (SPS). Mechanical alloying (MA) was proposed as a suited process to improve the composite microstructure. Density measurements and microstructure confirmed that MA promotes sintering and produces a fine and homogeneous dispersion of reinforcing particles. X-ray diffraction patterns of the sintered composites highlighted the formation of equilibrium Fe{sub 2}B and TiC, as predicted by thermodynamic calculations using Thermo-Calc® software. Scanning electron microscopy as well as scanning Kelvin probe force microscopy highlighted the reaction of the steel matrix with TiB{sub 2} particles, showing the formation of a reaction layer at the TiB{sub 2}-steel interface. Phase investigations pointed out that TiB{sub 2} is not chemically stable in steel matrix because of the presence of carbon even during short time SPS. - Highlights: • TiB{sub 2} reinforced steel matrix composites were produced by spark plasma sintering. • TiB{sub 2} was successfully dispersed in the steel matrix by mechanical alloying. • Steel and TiB{sub 2} react during sintering forming equilibrium Fe{sub 2}B and TiC. • The new phases were investigated by means of AFM, Volta potential and XRD analyses.

  9. Corrosion of Continuous Fiber Reinforced Aluminum Metal Matrix Composites (CF-AMCs)

    Science.gov (United States)

    Tiwari, Shruti

    The first objective of this research is to study the atmospheric corrosion behavior of continuous reinforced aluminum matrix composites (CF-AMCs). The materials used for this research were alumina (Al2O3) and nickel (Ni) coated carbon (C) fibers reinforced AMCs. The major focus is to identify the correlation between atmospheric parameters and the corrosion rates of CF-AMCs in the multitude of microclimates and environments in Hawai'i. The micro-structures of CF-AMCs were obtained to correlate the microstructures with their corrosion performances. Also electrochemical polarization experiments were conducted in the laboratory to explain the corrosion mechanism of CF-AMCs. In addition, CF-AMCs were exposed to seven different test sites for three exposure periods. The various climatic conditions like temperature (T), relative humidity (RH), rainfall (RF), time of wetness (TOW), chloride (Cl- ) and sulfate (SO42-) deposition rate, and pH were monitored for three exposure period. Likewise, mass losses of CF-AMCs at each test site for three exposure periods were determined. The microstructure of the CF-AMCS showed that Al/C/50f MMCs contained a Ni-rich phase in the matrix, indicating that the Ni coating on the C fiber dissolved in the matrix. The intermetallic phases obtained in Al-2wt% Cu/Al 2O3/50f-T6 MMC and Al-2wt%-T6 monolith were rich in Cu and Fe. The intermetallic phases obtained in Al 7075/Al2O3/50f-T6 MMC and Al 7075-T6 monolith also contained traces of Mg, Zn, Ni, and Si. Electrochemical polarization experiment indicated that the Al/Al 2O3/50f Al-2wt% Cu/Al2O3/50f-T6 and Al 7075/Al2O3/50f-T6 MMC showed similar corrosion trends as their respective monoliths pure Al, Al-2wt%-T6 and Al 7075-T6 in both aerated and deaerated condition. Al2O3 fiber, being an insulator, did not have a great effect on the polarization behavior of the composites. Al/C/50f MMCs corroded at a much faster rate as compared to pure Al monolith due to the galvanic effect between C and Al

  10. Morphology and thickness of the diffusion of resin through demineralized or unconditioned dentinal matrix

    Directory of Open Access Journals (Sweden)

    Arrais César Augusto Galvão

    2002-01-01

    Full Text Available The formation of a hybrid layer is the main bonding mechanism of current dentin-bonding systems. This study evaluated the morphology and thickness of the resin-infiltrated dentinal layer after the application of adhesive systems. The dentin-bonding agents were evaluated on flat dentinal preparations confected on the occlusal surfaces of human teeth. The test specimens were prepared and inspected under scanning electron microscopy at a magnification of X 2,000. The adhesive systems were responsible for different hybrid layer thicknesses (p < 0.05, and the mean values were: for Scotchbond MP Plus (SM, 7.41 ± 1.24mum; for Single Bond (SB, 5.55 ± 0.82mum; for Etch & Prime 3.0 (EP, 3.86 ± 1.17mum; and for Clearfil SE Bond (CB, 1.22 ± 0.45mum. The results suggest that the conventional three-step adhesive system (SM was responsible for the thickest hybrid layer, followed by the one-bottle adhesive (SB. The self-etching adhesives, EP and CB, produced the formation of the thinnest hybrid layers.

  11. Obtention and dynamical mechanical behavior of polymer matrix carbon fire reinforced composites; Obtencao e comportamento mecanodinamico de compositos com matriz polimerica reforcada com fibras de carbono

    Energy Technology Data Exchange (ETDEWEB)

    Da Silva, Nelson Marques

    2001-07-01

    Polymer matrix composites reinforced with carbon fibres have been extensively used in the nuclear, aeronautics, automotive and leisure industry. This is due to their superior performance when compared to conventional materials in terms of specific strength and specific modulus (3 to 4 times higher than that of mild steels). However, these materials are anisotropic, requiring characterisation for each process and particular application. In the present work, the evaluation of epoxy resin reinforced with unidirectional and continuous carbon fibres was carried out. The composites materials were obtained by filament winding, with three different cure cycles, with two types of carbon fibres (6000 and 12000 filaments per strand) and with fibres volumetric fraction around 60 %. The evaluation of the composites was undertaken using following techniques: scanning electron microscopy (SEM); dynamic mechanical analysis (DMA); thermogravimetric analysis (TGA), and differential scanning calorimeter (DSC). These techniques allowed the evaluation and comparison of storage modulus, internal energy dissipation, glass transition region and glass transition temperature - Tg, cure cycling. Besides, void volumetric fraction was measured. The results indicate that the DMA is a good alternative technique to DSC and TGA. It provides an indication of the quality of the produced composite, both thermal and mechanical. The technique can assist the quality control of composite components by measuring mechanical and thermal properties - modulus and Tg. The DMA technique was sensitive to cure cycling evaluation. Regarding the obtained composites, the results showed the need for the development of specific cure cycle for each application, establishing a compromise between properties such as storage modulus and internal energy dissipation, and involved costs. The results demonstrated differences between the storage modulus and internal energy dissipation for the two types of used fibres. (author)

  12. Characterization of molybdenum particles reinforced Al6082 aluminum matrix composites with improved ductility produced using friction stir processing

    Energy Technology Data Exchange (ETDEWEB)

    Selvakumar, S., E-mail: lathaselvam1963@gmail.com [Department of Mechanical Engineering, Nehru Institute of Technology, Coimbatore 641105, Tamil Nadu (India); Department of Mechanical Engineering, Anna University, Chennai 600025, Tamil Nadu (India); Dinaharan, I., E-mail: dinaweld2009@gmail.com [Department of Mechanical Engineering Science, University of Johannesburg, Auckland Park Kingsway Campus, Johannesburg 2006 (South Africa); Palanivel, R., E-mail: rpalanivelme@gmail.com [Department of Mechanical Engineering Science, University of Johannesburg, Auckland Park Kingsway Campus, Johannesburg 2006 (South Africa); Ganesh Babu, B., E-mail: profbgb@gmail.com [Department of Mechanical Engineering, Roever College of Engineering and Technology, Perambalur 621212, Tamil Nadu (India)

    2017-03-15

    Aluminum matrix composites (AMCs) reinforced with various ceramic particles suffer a loss in ductility. Hard metallic particles can be used as reinforcement to improve ductility. The present investigation focuses on using molybdenum (Mo) as potential reinforcement for Mo(0,6,12 and 18 vol.%)/6082Al AMCs produced using friction stir processing (FSP). Mo particles were successfully retained in the aluminum matrix in its elemental form without any interfacial reaction. A homogenous distribution of Mo particles in the composite was achieved. The distribution was independent upon the region within the stir zone. The grains in the composites were refined considerably due to dynamic recrystallization and pinning effect. The tensile test results showed that Mo particles improved the strength of the composite without compromising on ductility. The fracture surfaces of the composites were characterized with deeply developed dimples confirming appreciable ductility. - Highlights: •Molybdenum particles used as reinforcement for aluminum composites to improve ductility. •Molybdenum particles were retained in elemental form without interfacial reaction. •Homogeneous dispersion of molybdenum particles were observed in the composite. •Molybdenum particles improved tensile strength without major loss in ductility. •Deeply developed dimples on the fracture surfaces confirmed improved ductility.

  13. Characterization of molybdenum particles reinforced Al6082 aluminum matrix composites with improved ductility produced using friction stir processing

    International Nuclear Information System (INIS)

    Selvakumar, S.; Dinaharan, I.; Palanivel, R.; Ganesh Babu, B.

    2017-01-01

    Aluminum matrix composites (AMCs) reinforced with various ceramic particles suffer a loss in ductility. Hard metallic particles can be used as reinforcement to improve ductility. The present investigation focuses on using molybdenum (Mo) as potential reinforcement for Mo(0,6,12 and 18 vol.%)/6082Al AMCs produced using friction stir processing (FSP). Mo particles were successfully retained in the aluminum matrix in its elemental form without any interfacial reaction. A homogenous distribution of Mo particles in the composite was achieved. The distribution was independent upon the region within the stir zone. The grains in the composites were refined considerably due to dynamic recrystallization and pinning effect. The tensile test results showed that Mo particles improved the strength of the composite without compromising on ductility. The fracture surfaces of the composites were characterized with deeply developed dimples confirming appreciable ductility. - Highlights: •Molybdenum particles used as reinforcement for aluminum composites to improve ductility. •Molybdenum particles were retained in elemental form without interfacial reaction. •Homogeneous dispersion of molybdenum particles were observed in the composite. •Molybdenum particles improved tensile strength without major loss in ductility. •Deeply developed dimples on the fracture surfaces confirmed improved ductility.

  14. Use of hyghly reactive rice husk ash in the production of cement matrix reinforced with Green coconut fiber

    OpenAIRE

    Pereira, C.L.; Savastano, H. Jr; Paya Bernabeu, Jorge Juan; Santos, S. F.; Borrachero Rosado, María Victoria; Monzó Balbuena, José Mª; Soriano Martinez, Lourdes

    2013-01-01

    This study evaluated the influence of partial replacement of Portland cement by rice husk ash (RHA) to enable the use of green coconut husk fiber as reinforcement for cementitious matrix. The use of highly reactive pozzolanic ash contributes for decreasing the alkaline attack on the vegetable fiber, originated from waste materials. The slurry dewatering technique was used for dispersion of the raw materials in aqueous solution, followed by vacuum drainage of water and pressing for the product...

  15. Decellularized Bovine Articular Cartilage Matrix Reinforced by Carboxylated-SWCNT for Tissue Engineering Application

    Directory of Open Access Journals (Sweden)

    Zari Majidi Mohammadie

    2018-01-01

    Full Text Available ABSTRACT Nanotubes with their unique properties have diversified mechanical and biological applications. Due to similarity of dimensions with extracellular matrix (ECM elements, these materials are used in designing scaffolds. In this research, Carboxylated Single-Wall Carbon Nanotubes in optimization of decellularized scaffold of bovine articular cartilage was used. At first, the articular cartilage was decellularized. Then the scaffolds were analyzed in: (i decellularized scaffolds, and (ii scaffolds plunged into homogenous suspension of nanotubes in distilled water, were smeared with Carboxylated-SWCNT. The tissue rings derived from the rabbit's ear were assembled with reinforced scaffolds and they were placed in a culture media for 15 days. The scaffolds in two groups and the assembled scaffolds underwent histologic and electron microscopy. Scanning electron microscopy showed that the structure of ECM of articular cartilage has been maintained well after decellularization. Fourier transform infrared analysis showed that the contents of ECM have not been changed under treatment process. Atomic force microscopy analysis showed the difference in surface topography and roughness of group (ii scaffolds in comparison with group (i. Transmission electron microscopy studies showed the Carboxylated-SWCNT bond with the surface of decellularized scaffold and no penetration of these compounds into the scaffold. The porosity percentage with median rate of 91.04 in group (i scaffolds did not have significant difference with group (ii scaffolds. The electron microscopy observations confirmed migration and penetration of the blastema cells into the group (ii assembled scaffolds. This research presents a technique for provision of nanocomposite scaffolds for cartilage engineering applications.

  16. Reinforcement of esophageal anastomoses with an extracellular matrix scaffold in a canine model.

    Science.gov (United States)

    Nieponice, Alejandro; Gilbert, Thomas W; Badylak, Stephen F

    2006-12-01

    The gastric pull-up procedure, a standard intervention after radical esophagectomy, is associated with high morbidity and mortality due to leaks and stricture. A previous preclinical study showed that an extracellular matrix (ECM) scaffold with autologous muscle tissue could be used to repair a complete circumferential defect in the cervical esophagus. The aim of the present study was to determine if healing of end-to-end anastomoses of the esophagus could be improved by reinforcement with an ECM scaffold. Twelve female mongrel dogs underwent a complete transection of either the cervical esophagus (n = 6) or the gastroesophageal junction (n = 6). A portion of the endomucosa at the anastomotic site was resected and replaced with an ECM scaffold in contact with the subjacent muscle and the muscle was anastomosed. The measured end points included macroscopic and microscopic evaluation and quantification of the esophageal diameter at the anastomotic site. No anastomotic leaks or systemic complications were observed in the ECM-treated animals. Morphologic findings in both groups showed complete mucosal covering of the surgery site. The remodeled esophageal tissue showed angiogenesis and complete epithelialization. Intact, organized layers of muscle tissue were present between the native muscularis externa and the submucosal layer and effectively bridged the transected ends. The ECM scaffold altered the default mechanism of esophageal repair. Scar tissue formation with associated stricture was virtually eliminated, and the esophageal healing response was characterized by the replacement with structurally normal tissue layers. These findings suggest that the high morbidity rate associated with esophagectomy procedures may be reduced by this ECM augmentation procedure at the anastomotic site.

  17. Mechanical characterization of copper coated carbon nanotubes reinforced aluminum matrix composites

    International Nuclear Information System (INIS)

    Maqbool, Adnan; Hussain, M. Asif; Khalid, F. Ahmad; Bakhsh, Nabi; Hussain, Ali; Kim, Myong Ho

    2013-01-01

    In this investigation, carbon nanotube (CNT) reinforced aluminum composites were prepared by the molecular-level mixing process using copper coated CNTs. The mixing of CNTs was accomplished by ultrasonic mixing and ball milling. Electroless Cu-coated CNTs were used to enhance the interfacial bonding between CNTs and aluminum. Scanning electron microscope analysis revealed the homogenous dispersion of Cu-coated CNTs in the composite samples compared with the uncoated CNTs. The samples were pressureless sintered under vacuum followed by hot rolling to promote the uniform microstructure and dispersion of CNTs. In 1.0 wt.% uncoated and Cu-coated CNT/Al composites, compared to pure Al, the microhardness increased by 44% and 103%, respectively. As compared to the pure Al, for 1.0 wt.% uncoated CNT/Al composite, increase in yield strength and ultimate tensile strength was estimated about 58% and 62%, respectively. However, in case of 1.0 wt.% Cu-coated CNT/Al composite, yield strength and ultimate tensile strength were increased significantly about 121% and 107%, respectively. - Graphical Abstract: Copper coated CNTs were synthesized by the electroless plating process. Optimizing the plating bath to (1:1) by wt CNTs with Cu, thickness of Cu-coated CNTs has been reduced to 100 nm. Cu-coated CNTs developed the stronger interfacial bonding with the Al matrix which resulted in the efficient transfer of load. Highlights: • Copper coated CNTs were synthesized by the electroless plating process. • Thickness of Cu-coated CNTs has been reduced to 100 nm by optimized plating bath. • In 1.0 wt.% Cu-coated CNT/Al composite, microhardness increased by 103%. • Cu-coated CNTs transfer load efficiently with stronger interfacial bonding. • In 1.0 wt.% Cu-coated CNT/Al composite, Y.S and UTS increased by 126% and 105%

  18. The effect of particle addition and fibrous reinforcement on epoxy-matrix composites for severe sliding conditions

    DEFF Research Database (Denmark)

    Larsen, Thomas Ricco Ølholm; Løgstrup Andersen, Tom; Thorning, Bent

    2008-01-01

    This paper reports production and tribological testing of epoxy-matrix composites for dry-sliding conditions. The examined composites are produced using the following components: epoxy resin (EP), glass fiber weave (G), carbon/aramid hybrid weave (CA), PTFE particles and nano-scale CuO particles...... are seen when the fibers are parallel and anti-parallel (P-AP) to the sliding direction compared to normal and parallel (N-P). Experiments with incorporating micro-scale PTFE particles and nano-scale CuO particles, respectively, into the epoxy resin along with the carbon/aramid weave shows no difference...... in friction but minor improvements in wear. When micro-scale PTFE particles are incorporated into the neat epoxy resin, i.e. without fibers, an increase in and a decrease in A are measured. When the same is done with nano-CuO a deterioration of both friction and wear properties are seen. At the three roughest...

  19. Al-based metal matrix composites reinforced with Al–Cu–Fe quasicrystalline particles: Strengthening by interfacial reaction

    International Nuclear Information System (INIS)

    Ali, F.; Scudino, S.; Anwar, M.S.; Shahid, R.N.; Srivastava, V.C.; Uhlenwinkel, V.; Stoica, M.; Vaughan, G.; Eckert, J.

    2014-01-01

    Highlights: • Strength of composites is enhanced as the QC-to-ω phase transformation advances. • Yield strength increases from 195 to 400 MPa with QC-to-ω interfacial reaction. • Reducing matrix ligament size explains most of the strengthening. • Improved interfacial bonding and nano ω phase explains divergence from model. - Abstract: The interfacial reaction between the Al matrix and the Al 62.5 Cu 25 Fe 12.5 quasicrystalline (QC) reinforcing particles to form the Al 7 Cu 2 Fe ω-phase has been used to further enhance the strength of the Al/QC composites. The QC-to-ω phase transformation during heating was studied by in situ X-ray diffraction using a high-energy monochromatic synchrotron beam, which permits to follow the structural evolution and to correlate it with the mechanical properties of the composites. The mechanical behavior of these transformation-strengthened composites is remarkably improved as the QC-to-ω phase transformation progresses: the yield strength increases from 195 MPa for the starting material reinforced exclusively with QC particles to 400 MPa for the material where the QC-to-ω reaction is complete. The reduction of the matrix ligament size resulting from the increased volume fraction of the reinforcing phase during the transformation can account for most of the observed improvement in strength, whereas the additional strengthening can be ascribed to the possible presence of nanosized ω-phase particles as well as to the improved interfacial bonding between matrix and particles caused by the compressive stresses arising in the matrix

  20. Al-based metal matrix composites reinforced with Al–Cu–Fe quasicrystalline particles: Strengthening by interfacial reaction

    Energy Technology Data Exchange (ETDEWEB)

    Ali, F. [IFW Dresden, Institut für Komplexe Materialien, Postfach 27 01 16, D-01171 Dresden (Germany); Materials Processing Group, DMME, Pakistan Institute of Engineering and Applied Sciences, P.O. Nilore, Islamabad (Pakistan); Scudino, S., E-mail: s.scudino@ifw-dresden.de [IFW Dresden, Institut für Komplexe Materialien, Postfach 27 01 16, D-01171 Dresden (Germany); Anwar, M.S.; Shahid, R.N. [Materials Processing Group, DMME, Pakistan Institute of Engineering and Applied Sciences, P.O. Nilore, Islamabad (Pakistan); Srivastava, V.C. [Metal Extraction and Forming Division, National Metallurgical Laboratory, Jamshedpur 831007 (India); Uhlenwinkel, V. [Institut für Werkstofftechnik, Universität Bremen, D-28359 Bremen (Germany); Stoica, M. [IFW Dresden, Institut für Komplexe Materialien, Postfach 27 01 16, D-01171 Dresden (Germany); Vaughan, G. [European Synchrotron Radiation Facilities ESRF, BP 220, 38043 Grenoble (France); Eckert, J. [IFW Dresden, Institut für Komplexe Materialien, Postfach 27 01 16, D-01171 Dresden (Germany); TU Dresden, Institut für Werkstoffwissenschaft, D-01062 Dresden (Germany)

    2014-09-01

    Highlights: • Strength of composites is enhanced as the QC-to-ω phase transformation advances. • Yield strength increases from 195 to 400 MPa with QC-to-ω interfacial reaction. • Reducing matrix ligament size explains most of the strengthening. • Improved interfacial bonding and nano ω phase explains divergence from model. - Abstract: The interfacial reaction between the Al matrix and the Al{sub 62.5}Cu{sub 25}Fe{sub 12.5} quasicrystalline (QC) reinforcing particles to form the Al{sub 7}Cu{sub 2}Fe ω-phase has been used to further enhance the strength of the Al/QC composites. The QC-to-ω phase transformation during heating was studied by in situ X-ray diffraction using a high-energy monochromatic synchrotron beam, which permits to follow the structural evolution and to correlate it with the mechanical properties of the composites. The mechanical behavior of these transformation-strengthened composites is remarkably improved as the QC-to-ω phase transformation progresses: the yield strength increases from 195 MPa for the starting material reinforced exclusively with QC particles to 400 MPa for the material where the QC-to-ω reaction is complete. The reduction of the matrix ligament size resulting from the increased volume fraction of the reinforcing phase during the transformation can account for most of the observed improvement in strength, whereas the additional strengthening can be ascribed to the possible presence of nanosized ω-phase particles as well as to the improved interfacial bonding between matrix and particles caused by the compressive stresses arising in the matrix.

  1. Fabrication and Evaluation of Graphite Fiber-Reinforced Polyimide Composite Tube Forms Using Modified Resin Transfer Molding

    Science.gov (United States)

    Exum, Daniel B.; Ilias, S.; Avva, V. S.; Sadler, Bob

    1997-01-01

    The techniques necessary for the fabrication of a complex three-dimensional tubular form using a PMR-type resin have been developed to allow for the construction of several tubes with good physical and mechanical properties. Employing established resin transfer molding practices, the relatively non-hazardous AMB-21 in acetone formulation was used to successfully impregnate four layers of AS4 braided graphite fiber preform previously loaded around an aluminum cylindrical core in an enclosed mold cavity. Using heat and vacuum, the solvent was evaporated to form a prepreg followed by a partial imidization and removal of condensation products. The aluminum core was replaced by a silicone rubber bladder and the cure cycle continued to the final stage of 550 F with a bladder internal pressure of 200 lbs/sq in while simultaneously applying a strong vacuum to the prepreg for removal of any additional imidization products. A combination of several modifications to the standard resin transfer molding methodology enabled the mold to 'breathe', allowing the imidization products a pathway for escape. AMB-21 resin was chosen because of the carcinogenic nature of the primary commercial polyimide PMR-15. The AMB-21 resin was formulated using commercially available monomers or monomer precursors and dissolved in a mixture of methyl alcohol and acetone. The viscosity of the resulting monomer solution was checked by use of a Brookfield rheometer and adjusted by adding acetone to an easily pumpable viscosity of about 600 cP. In addition, several types of chromatographic and thermal analyses were of the braids, and excess handling of the preforms broke some of the microscopic fibers, needlessly decreasing the strength of the finished part. In addition, three dimensional braided preforms with fibers along the length of the tube will be significantly stronger in tension than the braided preforms used in this study.

  2. The Integration of EIS parameters and bulk matrix characterization in studying reinforced cement-based materials

    NARCIS (Netherlands)

    Koleva, D.A.; Van Breugel, K.

    2012-01-01

    Corrosion in reinforced concrete is a major and costly concern, arising from the higher complexity of involved phenomena on different levels of material science (e.g. electrochemistry, concrete material science) and material properties (macro/micro/ nano). Reinforced cement-based systems (e.g.

  3. The integration of eis parameters and bulk matrix characteristics in studying reinforced cement-based materials

    NARCIS (Netherlands)

    Koleva, D.A.; Van Breugel, K.

    2011-01-01

    Corrosion in reinforced concrete is a major and costly concern, arising from the higher complexity of involved phenomena on different levels of material science (e.g. electrochemistry, concrete material science) and material properties (macro/micro/ nano). Reinforced cement-based systems (e.g.

  4. Characterization of Al-Cu alloy reinforced fly ash metal matrix ...

    African Journals Online (AJOL)

    The Al-4.5wt%Cu reinforced 3, 6, 9 and 12wt%fly ash composite was squeeze casted with an applied pressure of 120MPa. The results showed that hardness tensile compression and impact values were increased by increasing weight percentage of fly ash reinforcements during squeeze casting. Porosity and other casting ...

  5. Flax fabric reinforced arylated soy protein composites: A brittle-matrix behaviour

    CSIR Research Space (South Africa)

    Kumar, R

    2012-05-01

    Full Text Available Biocomposites were successfully prepared by the reinforcement of soy protein isolate (SPI) with different weight fractions of woven flax fabric. The flax-fabric-reinforced SPI-based composites were then arylated with 2,2-diphenyl-2-hydroxyethanoic...

  6. Swelling behavior of ion exchange resins incorporated in tri-calcium silicate cement matrix: II. Mechanical analysis

    International Nuclear Information System (INIS)

    Neji, M.; Bary, B.; Le Bescop, P.; Burlion, N.

    2015-01-01

    This paper presents the second part of a study aiming at modelling the mechanical behavior of composites made up of ion exchange resins (IER) solidified in a tri-calcium silicate cement paste (C_3S). Such composites may be subjected to internal pressures due to ion exchange processes between ionic species which are in IER and interstitial solution of the cement paste. The reactive transport model developed in the companion paper is coupled in this study to a multi-scale approach describing the mechanical behavior of the material. It is based on an analogy with thermomechanics for taking in account the IER internal pressures, and on Eshelby-based homogenization techniques to estimate both mechanical and coupling parameters. A laboratory test has been set up to measure the macroscopic strain caused by the swelling phenomenon. The model has been finally implemented in a finite elements software. The simulation of the laboratory tests has been performed and the results have been analyzed and compared to experimental data. - Highlights: • Experimental analysis about mechanical behavior of a composite material. • Chemo-Mechanical-Transport modeling on a composite material made up with IER embedded into cement paste matrix. • Multi-scale modeling.

  7. Mechanical Properties of SiC, Al2O3 Reinforced Aluminium 6061-T6 Hybrid Matrix Composite

    Science.gov (United States)

    Murugan, S. Senthil; Jegan, V.; Velmurugan, M.

    2018-04-01

    This paper contains the investigation of tensile, compression and impact characterization of SiC, Al2O3 reinforced Aluminium 6061-T6 matrix hybrid composite. Hybrid matrix composite fabrication was done by stir casting method. An attempt has been made by keeping Al2O3 percentage (7%) constant and increasing SiC percentage (10, 15, and 20%). After fabricating, the samples were prepared and tested to find out the various mechanical properties like tensile, compressive, and impact strength of the developed composites of different weight % of silicon carbide and Alumina in Aluminium alloy. The main objective of the study is to compare the values obtained and choose the best composition of the hybrid matrix composite from the mechanical properties point of view.

  8. Computerized mathematical model for prediction of resin/fiber composite properties

    International Nuclear Information System (INIS)

    Lowe, K.A.

    1985-01-01

    A mathematical model has been developed for the design and optimization of resin formulations. The behavior of a fiber-reinforced cured resin matrix can be predicted from constituent properties of the formulation and fiber when component interaction is taken into account. A computer implementation of the mathematical model has been coded to simulate resin/fiber response and generate expected values for any definable properties of the composite. The algorithm is based on multistage regression techniques and the manipulation of n-order matrices. Excellent correlation between actual test values and predicted values has been observed for physical, mechanical, and qualitative properties of resin/fiber composites. Both experimental and commercial resin systems with various fiber reinforcements have been successfully characterized by the model. 6 references, 3 figures, 2 tables

  9. Mechanical properties of unidirectional and randomly oriented kenaf bast fibre composites using polypropylene resin matrix

    International Nuclear Information System (INIS)

    Sharifah Hanisah Syed Abd Aziz; Khairul Zaman Mohd Dahlan

    2004-01-01

    Fibres are known to confer strength and rigidity to the weak and brittle matrix and currently, research in composite materials is being directed at using natural fibers instead of synthetic fibres. In this work long and random kenaf fibers were used in the as-received condition and alkalized with a 0.06M NaOH solution. They were combined with polypropylene thin sheets and hot-pressed to form natural fibre composites. The mechanical properties of the composites were investigated to observe the effect of fibre alignment, fibre treatment, and the method of moulding technique used. A general trend was observed whereby alkalized and long fibre composites give higher flexural modulus and flexural strength compared with random mat and untreated fibres. The long fibre composites also gave a higher work of fracture. However, the correlation between fibre surface treatment and the work of fracture was less clear. The method of moulding used also need to be improved to optimize the performance of the composites manufactured as the overall mechanical test result showed some irregularities. Pre-irradiation on the polypropylene pellets before the composite is manufactured will be considered as one of the mechanism in enhancing the mechanical performance of the composites in future work. (Author)

  10. Oxidation resistance in air of 1-D SiC (Hi-nicalon) fibre reinforced silicon nitride ceramic matrix composite

    International Nuclear Information System (INIS)

    Dupel, P.; Veyret, J.B.

    1997-01-01

    The oxidation behaviour of a Si 3 N 4 matrix reinforced with SiC fibres (Hi-nicalon) pre-coated with a 400 nm thick pyrolytic carbon layer has been investigated in dry air in the temperature range 800-1500 C. The same study was performed for individual constituents of the composite (fibre and matrix). Two phenomena are observed in the oxidation behaviour of the composite. At low temperature (T<1200 C), the matrix oxidation is negligible, only the carbon interphase was oxidised creating an annular space between the fibres and the matrix throughout the sample. At high temperature (T≥1300 C) the rate of formation of the oxidation products of the matrix is rapid and a sealing effect is observed. While at these temperatures the interphase is protected in the bulk of the material, the time needed to seal the gap between the fibre and the matrix is too long to prevent its oxidation to a significant depth from the surface. Finally, preliminary results are presented where the consumption of the interphase is completely prevented by applying an external coating which gives oxidation protection from low to high temperature. (orig.)

  11. Thermal behavior of flax and jute reinforced in matrix acrylic composite

    Czech Academy of Sciences Publication Activity Database

    Samal, Sneha Manjaree; Stuchlík, M.; Petrikova, I.

    2017-01-01

    Roč. 131, č. 2 (2017), s. 1-6 ISSN 1388-6150 Institutional support: RVO:68378271 Keywords : flax * jute * acrylic resin * composite * DMA * TG * FTIR Subject RIV: BM - Solid Matter Physics ; Magnetism OBOR OECD: Condensed matter physics (including formerly solid state physics, supercond.) Impact factor: 1.953, year: 2016

  12. Dynamic tensile behavior of two-dimensional carbon fiber reinforced silicon carbide matrix composites

    International Nuclear Information System (INIS)

    Chen Xuan; Li Yulong

    2011-01-01

    Graphical abstract: The dynamic tensile behavior of 2D C/SiC composites was experimentally investigated by means of SHTB. Both the fracture surface and bundle fracture surfaces of composites were observed. The strain rate sensitivity of in-bundle interface was concluded as the dominant contributor to the strain rate sensitivity of the tensile strength. Highlights: → The tensile strength increases with strain rate. → The tensile failure strain remains independent of strain rate. → Macro-structural morphology reveals rough fracture surface under dynamic loading. → SEM morphology reveals integrated bundle pull-out under dynamic loading. → Strain rate sensitivity of in-bundle interface leads to that of the tensile strength. - Abstract: An investigation has been undertaken to determine the dynamic and quasi-static tensile behavior of two-dimensional carbon fiber reinforced silicon carbide matrix (2D-C/SiC) composites by means of the split Hopkinson tension bar and an electronic universal test machine respectively. The results indicate that the tensile strength of 2D C/SiC composites is increased at high strain rate. Furthermore, coated specimens show not only a 15% improvement in tensile strength but heightened strain rate sensitivity compared with uncoated ones. It is also shown that the tensile failure strain is strain rate insensitive and remains around 0.4%. Optical macrograph of failed specimens under dynamic loading revealed jagged fracture surfaces characterized by delamination and crack deviation, together with obvious fiber pull-out/splitting, in contrast with the smooth fracture surfaces under quasi-static loading. Scanning electron microscopy micrograph of fracture surface under dynamic loading clearly displayed integrated bundle pull-out which implies suppressed in-bundle debonding and enhanced in-bundle interfacial strengthening, in contrast with extensive in-bundle debonding under quasi-static loading. Thus we conclude that, with 2D C

  13. Impact Strength of Composite Materials Based on EN AC-44200 Matrix Reinforced with Al2O3 Particles

    Directory of Open Access Journals (Sweden)

    Kurzawa A.

    2017-09-01

    Full Text Available The paper presents the results of research of impact strength of aluminum alloy EN AC-44200 based composite materials reinforced with alumina particles. The research was carried out applying the materials produced by the pressure infiltration method of ceramic preforms made of Al2O3 particles of 3-6μm with the liquid EN AC-44200 Al alloy. The research was aimed at determining the composite resistance to dynamic loads, taking into account the volume of reinforcing particles (from 10 to 40% by volume at an ambient of 23°C and at elevated temperatures to a maximum of 300°C. The results of this study were referred to the unreinforced matrix EN AC-44200 and to its hardness and tensile strength. Based on microscopic studies, an analysis and description of crack mechanics of the tested materials were performed. Structural analysis of a fracture surface, material structures under the crack surfaces of the matrix and cracking of the reinforcing particles were performed.

  14. Effect of natural fibers and bio-resins on mechanical properties in hybrid and non-hybrid composites

    Science.gov (United States)

    Fragassa, Cristiano

    2016-05-01

    The aim of the present experimental investigation was to perform a comparative analysis concerning the influence on mechanical properties of natural fibers and/or bio-resins in reinforced thermoset composites. Flax and basalt fibers were selected as natural reinforcements, as single constituents or in hybrid combination. Glass synthetic fibers were used for comparison. Eco-friendly matrixes, both epoxy or vinylester, were considered and compared with composites based on traditional resins. Samples were fabricated by hand lay-up and resin infusion techniques. Cures were accelerated and controlled by applying heat and pressure in autoclave. Tensile, flexural and impact tests were carried out according to ASTM standards.

  15. Mechanical properties of natural fibre reinforced polymer composites

    Indian Academy of Sciences (India)

    Wintec

    initiated in our laboratory on synthesis and study of pro- perties of Hibiscus sabdariffa fibre reinforced urea– formaldehyde (U–F) resin matrix based biocomposites. 2. Experimental. 2.1 Material and methods. Urea (Qualigens Chemicals Ltd), formaldehyde solution. (Qualigens Chemicals Ltd.) and sodium hydroxide (Quali-.

  16. Mechanical properties of natural fibre reinforced polymer composites

    Indian Academy of Sciences (India)

    In the present communication, a study on the synthesis and mechanical properties of new series of green composites involving Hibiscus sabdariffa fibre as a reinforcing material in urea–formaldehyde (UF) resin based polymer matrix has been reported. Static mechanical properties of randomly oriented intimately mixed ...

  17. Laser surface forming of AlCoCrCuFeNi particle reinforced AZ91D matrix composites

    Science.gov (United States)

    Meng, Guanghui; Yue, T. M.; Lin, Xin; Yang, Haiou; Xie, Hui; Ding, Xu

    2015-07-01

    Traditionally, the laser melt injection (LMI) technique can only be used for forming ceramic particles reinforced metal matrix composites (MMCs) for enhancing surface properties of lightweight engineering materials. In this research, the LMI method was employed to form metal particles reinforced MMCs on AZ91D instead. This was viable because of the unique properties of the AlCoCrCuFeNi high-entropy alloy (HEA) metal particles used. The large difference in melting point between the HEA and the substrate material (AZ91D), and the limited reaction and the lack of fusion between the HEA and Mg have made it possible that a metal particles reinforced AZ91D composite material was produced. The reason of limited reaction was considered mainly due to the relatively high mixing enthalpy between the HEA constituent elements and Mg. Although there was some melting occurred at the particles surface with some solute segregation found in the vicinity close to the surface, intermetallic compounds were not observed. With regard to the wear resistance of the MMCs, it was found that when the volume fraction of the reinforcement phase, i.e. the HEA particles, reached about 0.4, the wear volume loss of the coating was only one-seventh of that of the substrate material.

  18. Theoretical and experimental analysis of the toughening behavior of whisker reinforcement in ceramic matrix composites

    International Nuclear Information System (INIS)

    Becher, P.F.; Hsueh, C.H.; Angelini, P.; Tiegs, T.N.

    1988-01-01

    Analytical solutions are presented describing the experimentally verified toughening of whisker reinforced ceramics. Clear insights are provided into the interrelationships of whiskers, matrices, and interfaces in the case of strong interfaces with minimized whisker pullout

  19. Nonequilibrium Alloying of Aluminum for Improving the Corrosion Resistance of Graphite-Reinforced Metal Matrix Composites

    National Research Council Canada - National Science Library

    Shaw, Barbara

    1994-01-01

    .... Unfortunately, MMCs, especially Gr reinforced composites, are extremely susceptible to corrosion with severe attack in chloride-containing environments occurring in as little time as several weeks for Gr/Al composites...

  20. Radiation processing for PTFE composite reinforced with carbon fiber

    International Nuclear Information System (INIS)

    Akihiro Oshima; Akira Udagawa; Yousuke Morita

    1999-01-01

    The present work is an attempt to evaluate the performance of crosslinked PTFE as a polymer matrix for carbon fiber-reinforced composite materials. The carbon fiber-reinforced PTFE pre-composite, which is laminated with PTFE fine powder, is crosslinked by electron beam irradiation. Mechanical and frictional properties of the crosslinked PTFE composite obtained are higher than those of PTFE resin. The crosslinked PTFE composite with high mechanical and radiation resistant performance is obtained by radiation crosslinking process

  1. A constitutive model for particulate-reinforced titanium matrix composites subjected to high strain rates and high temperatures

    Directory of Open Access Journals (Sweden)

    Song Wei-Dong

    2013-01-01

    Full Text Available Quasi-static and dynamic tension tests were conducted to study the mechanical properties of particulate-reinforced titanium matrix composites at strain rates ranging from 0.0001/s to 1000/s and at temperatures ranging from 20 °C to 650 °C Based on the experimental results, a constitutive model, which considers the effects of strain rate and temperature on hot deformation behavior, was proposed for particulate-reinforced titanium matrix composites subjected to high strain rates and high temperatures by using Zener-Hollomon equations including Arrhenius terms. All the material constants used in the model were identified by fitting Zener-Hollomon equations against the experimental results. By comparison of theoretical predictions presented by the model with experimental results, a good agreement was achieved, which indicates that this constitutive model can give an accurate and precise estimate for high temperature flow stress for the studied titanium matrix composites and can be used for numerical simulations of hot deformation behavior of the composites.

  2. Influence of reinforcement grade and matrix composition on corrosion resistance of cast aluminium matrix composites (A3xx.x/SiCp) in a humid environment

    Energy Technology Data Exchange (ETDEWEB)

    Pardo, A.; Viejo, F.; Carboneras, M. [Departamento de Ciencia de Materiales, Facultad de Quimica Universidad Complutense, 28040, Madrid (Spain); Merino, M.C. [Departamento de Ciencia de Materiales, Facultad de Quimica Universidad Complutense, 28040, Madrid (Spain); Departamento de Tecnologia Industrial, Universidad Alfonso X El Sabio, 28691, Villanueva de la Canada, Madrid (Spain); Lopez, M.D. [Escuela Superior de Ciencias Experimentales y Tecnologia, Universidad Rey Juan Carlos, 28931, Mostoles, Madrid (Spain); Merino, S. [Departamento de Tecnologia Industrial, Universidad Alfonso X El Sabio, 28691, Villanueva de la Canada, Madrid (Spain)

    2003-05-01

    A study of the influence of the silicon carbide (SiC{sub p}) proportion and the matrix concentration of four aluminium metal matrix composites (A360/SiC/10p, A360/SiC/20p, A380/SiC/10p, A380/SiC/20p) exposed to high relative humid environment was carried out under simulation in a climatic chamber. The matrix of A360/SiC/xxp composites was virtually free of copper while the A380/SiC/xxp matrix contained 3.13-3.45wt% Cu and 1.39-1.44wt% Ni. The kinetics of the corrosion process was studied on the basis of gravimetric tests. The nature of corrosion products was analysed by Scanning Electron Microscopy (SEM) and Low Angle X-Ray Diffraction (XRD) before and after accelerated testing to determine the influence of microstructural changes on corrosion behaviour during exposure to the corrosive environment. The corrosion damage to Al/SiCp composites was low at 80% Relative Humidity (RH) and increased with temperature, SiCp proportion, relative humidity and Cu matrix concentration. The main attack nucleation sites were the interface region between the matrix and the reinforcement particles. The corrosion process was influenced more by the concentration of alloy elements in the matrix than by the proportion of SiCp reinforcement. (Abstract Copyright [2003], Wiley Periodicals, Inc.) [German] Eine Studie zum Einfluss des Siliziumkarbidanteils (SiCp) und der Zusammensetzung des Grundwerkstoffs von vier Aluminiummatrixverbundwerkstoffen (A360/SiC/10p, A360/SiC/20p, A380/SiC/10p, A380/SiC/20p), die in Umgebungen mit relativ hoher Feuchtigkeit ausgelagert waren, wurde unter simulierten Bedingungen in einer Klimakammer durchgefuehrt. Die Matrix des A360/SiC/xxp-Verbundwerkstoffs war praktisch Kupfer-frei waehrend die A380/SiC/xxp Matrix 3,13-3,45 Gew.-% Cu und 1,39-1,44 Gew.-% Ni enthielt. Die Kinetik des Korrosionsprozesses wurde auf der Basis von gravimetrischen Messungen studiert. Die Beschaffenheit der Korrosionsprodukte wurde mittelt REM-Untersuchungen und

  3. The Effect of Tow Shearing on Reinforcement Positional Fidelity in the Manufacture of a Continuous Fiber Reinforced Thermoplastic Matrix Composite via Pultrusion-Like Processing of Commingled Feedstock

    Science.gov (United States)

    Warlick, Kent M.

    While the addition of short fiber to 3D printed articles has increased structural performance, ultimate gains will only be realized through the introduction of continuous reinforcement placed along pre-planned load paths. Most additive manufacturing research focusing on the addition of continuous reinforcement has revolved around utilization of a prefrabricated composite filament or a fiber and matrix mixed within a hot end prior to deposition on a printing surface such that conventional extrusion based FDM can be applied. Although stronger 3D printed parts can be made in this manner, high quality homogenous composites are not possible due to fiber dominated regions, matrix dominated regions, and voids present between adjacent filaments. Conventional composite manufacturing processes are much better at creating homogeneous composites; however, the layer by layer approach in which they are made is inhibiting the alignment of reinforcement with loads. Automated Fiber Placement techniques utilize in plane bending deformation of the tow to facilitate tow steering. Due to buckling fibers on the inner radius of curves, manufacturers recommend a minimum curvature for path placement with this technique. A method called continuous tow shearing has shown promise to enable the placement of tows in complex patterns without tow buckling, spreading, and separation inherent in conventional forms of automated reinforcement positioning. The current work employs fused deposition modeling hardware and the continuous tow shearing technique to manufacture high quality fiber reinforced composites with high positional fidelity, varying continuous reinforcement orientations within a layer, and plastic elements incorporated enabling the ultimate gains in structural performance possible. A mechanical system combining concepts of additive manufacturing with fiber placement via filament winding was developed. Paths with and without tension inherent in filament winding were analyzed through

  4. Dynamic shear-lag model for understanding the role of matrix in energy dissipation in fiber-reinforced composites.

    Science.gov (United States)

    Liu, Junjie; Zhu, Wenqing; Yu, Zhongliang; Wei, Xiaoding

    2018-07-01

    Lightweight and high impact performance composite design is a big challenge for scientists and engineers. Inspired from well-known biological materials, e.g., the bones, spider silk, and claws of mantis shrimp, artificial composites have been synthesized for engineering applications. Presently, the design of ballistic resistant composites mainly emphasizes the utilization of light and high-strength fibers, whereas the contribution from matrix materials receives less attention. However, recent ballistic experiments on fiber-reinforced composites challenge our common sense. The use of matrix with "low-grade" properties enhances effectively the impact performance. In this study, we establish a dynamic shear-lag model to explore the energy dissipation through viscous matrix materials in fiber-reinforced composites and the associations of energy dissipation characteristics with the properties and geometries of constituents. The model suggests that an enhancement in energy dissipation before the material integrity is lost can be achieved by tuning the shear modulus and viscosity of a matrix. Furthermore, our model implies that an appropriately designed staggered microstructure, adopted by many natural composites, can repeatedly activate the energy dissipation process and thus improve dramatically the impact performance. This model demonstrates the role of matrix in energy dissipation, and stimulates new advanced material design concepts for ballistic applications. Biological composites found in nature often possess exceptional mechanical properties that man-made materials haven't be able to achieve. For example, it is predicted that a pencil thick spider silk thread can stop a flying Boeing airplane. Here, by proposing a dynamic shear-lag model, we investigate the relationships between the impact performance of a composite with the dimensions and properties of its constituents. Our analysis suggests that the impact performance of fiber-reinforced composites could improve

  5. Effectively enhanced load transfer by interfacial reactions in multi-walled carbon nanotube reinforced Al matrix composites

    International Nuclear Information System (INIS)

    Zhou, Weiwei; Yamaguchi, Tatsuya; Kikuchi, Keiko; Nomura, Naoyuki; Kawasaki, Akira

    2017-01-01

    The thermal expansion response of multi-walled carbon nanotube (MWCNT) reinforced Al matrix composites was employed to discuss the improvement of the load transfer at the interface between the MWCNTs and the Al matrix. An aluminum carbide (Al_4C_3) nanostructure at the end of the MWCNTs, incorporated in the Al matrix, was produced by appropriate heat-treatment. The stress contrast around the Al_4C_3 observed in the high-resolution transmission electron microscopy (HRTEM) image revealed the evidence of a trace of friction, which would lead to the enhancement of the anchor effect from the Al matrix. This anchor effect of Al_4C_3 may hinder the local interfacial slippage and constrain the deformation of the Al matrix. As a result, the thermal expansion behavior became linear and reversible under cyclic thermal load. It is concluded that the formation of Al_4C_3 could effectively enhance the load transfer in MWCNT/Al composites. The yield strength of MWCNT/Al composites was substantially increased under the appropriate quantity of Al_4C_3 produced at the MWCNT-Al interface by precisely controlled heat-treatment.

  6. Field assisted sintering of refractory carbide ceramics and fiber reinforced ceramic matrix composites

    Science.gov (United States)

    Gephart, Sean

    materials. While FAST sintered materials showed higher average values, in general they also showed consistently larger variation in the scattered data and consequently larger standard deviation for the resulting material properties. In addition, dynamic impact testing (V50 test) was conducted on the resulting materials and it was determined that there was no discernable correlation between observed mechanical properties of the ceramic materials and the resulting dynamic testing. Another study was conducted on the sintering of SiC and carbon fiber reinforced SiC ceramic matrix composites (CMC) using FAST. There has been much interest recently in fabricating high strength, low porosity SiC CMC.s for high temperature structural applications, but the current methods of production, namely chemical vapor infiltration (CVI), melt infiltration (MI), and polymer infiltration and pyrolysis (PIP), are considered time consuming and involve material related shortcomings associated with their respective methodologies. In this study, SiC CMC.s were produced using the 25 ton laboratory unit with a target sample size of 40 mm diameter and 3 mm thickness, as well as on the larger 250 ton industrial FAST system targeting a sample size of 101.6 x 101.6 x 3 mm3 to investigate issues associated with scaling. Several sintering conditions were explored including: pressure of 35-65 MPa, temperature of 1700-1900°C, and heating rates between 50-400°C/min. The SiC fibers used in this study were coated using chemical vapor deposition (CVD) with boron nitride (BN) and pyrolytic carbon to act as a barrier layer and preserve the integrity of the fibers during sintering. Then the barrier coating was coated by an outer layer of SiC to enhance the bonding between the fibers and the SiC matrix. Microstructures of the sintered samples were examined by FE-SEM. Mechanical properties including flexural strength-deflection and stress-strain were characterized using 4-point bend testing. Tensile testing was

  7. Properties of modified polysiloxane based ceramic matrix for long fibre reinforced composite materials

    Czech Academy of Sciences Publication Activity Database

    Chlup, Zdeněk; Černý, Martin; Strachota, Adam; Kozák, Vladislav

    2011-01-01

    Roč. 40, 6-7 (2011), s. 380-385 ISSN 1465-8011 R&D Projects: GA ČR GA106/09/1101 Institutional research plan: CEZ:AV0Z20410507; CEZ:AV0Z30460519; CEZ:AV0Z40500505 Keywords : Polysiloxane resin * Pyrolysis * Indentation Subject RIV: JI - Composite Materials Impact factor: 0.597, year: 2011

  8. Buttressing staples with cholecyst-derived extracellular matrix (CEM) reinforces staple lines in an ex vivo peristaltic inflation model.

    LENUS (Irish Health Repository)

    Burugapalli, Krishna

    2008-11-01

    Staple line leakage and bleeding are the most common problems associated with the use of surgical staplers for gastrointestinal resection and anastomotic procedures. These complications can be reduced by reinforcing the staple lines with buttressing materials. The current study reports the potential use of cholecyst-derived extracellular matrix (CEM) in non-crosslinked (NCEM) and crosslinked (XCEM) forms, and compares their mechanical performance with clinically available buttress materials [small intestinal submucosa (SIS) and bovine pericardium (BP)] in an ex vivo small intestine model.

  9. Effect of gamma radiation on the magnetic properties of a carbon-fiber-reinforced plastic with a polysulfone matrix

    International Nuclear Information System (INIS)

    Rodin, Yu.P.; Arkhipov, A.A.; Korkhov, V.P.; Pudnik, V.V.

    1994-01-01

    In the present article, the authors report results of a study of the change in the magnetic susceptibility of a carbon-fiber-reinforced plastic based on a thermoplastic matrix -- aromatic polysulfone -- in relation to the absorbed dose of γ-radiation. The study results show that the change in the magnetic susceptibility of specimens which have absorbed different doses of gamma radiation correlates with the change in their mechanical properties, thermal behavior, and structural changes. A method is described for measuring susceptibility which can be used successfully to study the structure and properties of polymer materials and composites based on them. 3 refs., 3 figs

  10. Characteristics of hot-pressed fiber-reinforced ceramics with SiC matrix

    Science.gov (United States)

    Miyoshi, Tadahiko; Kodama, Hironori; Sakamoto, Hiroshi; Goto, Akihiro; Iijima, Shiroo

    1989-11-01

    Silicon carbide ceramics’ matrix composites with SiC or C filaments were fabricated through hot pressing, and the effects of the filament pullout on their fracture toughness were experimentally investigated. The C-rich coating layers on the SiC filaments were found to have a significant effect on the frictional stress at the filament/matrix interfaces, through assising the filamet pullout from the matrix. Although the coating layers were apt to burn out in the sintering process of SiC matrix compposites, a small addition of carbon to the raw materials was found to be effective for the retention of the layers on the fibers, thus increasing the fracture toughness of the composites. The fracture toughness of the C filament/SiC matrix composite increased with temperature due to the larger interfacial frictional stress at higher temperatures, because of the higher thermal expansion of the filament in the radial direction than that of the matrix.

  11. Properties and performance of polysiloxane-derived ceramic matrix in heat resistant composites reinforced with R-glass or fine ceramic fibres

    Czech Academy of Sciences Publication Activity Database

    Černý, Martin; Glogar, Petr; Sucharda, Zbyněk; Machovič, V.

    2005-01-01

    Roč. 49, č. 3 (2005), s. 145-152 ISSN 0862-5468 R&D Projects: GA ČR(CZ) GA106/02/0177; GA ČR(CZ) GP106/02/P025 Institutional research plan: CEZ:AV0Z30460519 Keywords : polysiloxane resin * fibre-reinforced composite * mechanical properties Subject RIV: JH - Ceramic s, Fire-Resistant Materials and Glass Impact factor: 0.463, year: 2005

  12. Interfacial characteristics and fracture behavior of spark-plasma-sintered TiNi fiber-reinforced 2024Al matrix composites

    International Nuclear Information System (INIS)

    Dong, Peng; Wang, Zhe; Wang, Wenxian; Chen, Shaoping; Zhou, Jun

    2017-01-01

    Embedding of shape memory alloy (SMA) fibers into materials to fabricate SMA composites has attracted considerable attention because of the potential applicability of these composites in smart systems and structures. In this study, 2024Al matrix composites reinforced by continuous TiNi SMA fibers were fabricated using spark plasma sintering (SPS). The interface between the fibers and matrix consisted of a bilayer. The layer close to the fiber consisted of a multiple phase mixture, and the other layer exhibited a periodic morphology resulting from the alternating phases of Al 3 Ti and Al 3 Ni. In addition, a small quantity of TiO 2 phases was also observed in the interface layer. Based on detailed interface studies of the orientation relationships between the Al 3 Ti, Al 3 Ni, and TiO 2 phases and the atomic correspondence at phase boundaries, the effects of the interface phases on the fracture behavior of the composites were demonstrated.

  13. Stainless steel fibre reinforced aluminium matrix composites processed by squeeze casting: relationship between processing conditions and interfacial microstructure

    International Nuclear Information System (INIS)

    Colin, C.; Marchal, Y.; Boland, F.; Delannay, F.

    1993-01-01

    This work investigates the influence of some processing parameters on the extent of interfacial reaction in squeeze cast aluminium matrix composites reinforced with 12 μm diameter, continuous stainless steel fibres. The average thickness of the reaction layer at fibre/matrix interfaces was measured by image analysis. When casting was made in a die at room temperature, the thickness of the reaction layer was affected on a distance of several mm from the lateral surface or from the bottom of the preform. The results indicate that the major part of the reaction occurs before solidification of the liquid metal. The control of the extent of interfacial reaction can be achieved through optimization of both infiltration parameters and features of the preform such as the volume fraction of the fibres. (orig.)

  14. Microstructure and mechanical properties of Al-Mg-Si-Cu matrix composites reinforced with AINp. processed by extrusion of powders

    International Nuclear Information System (INIS)

    Ortiz, J. L.; Amigo, V.; Salvador, M. D.; Perz, C. R.

    2000-01-01

    This article presents an experimental investigation on the structure and mechanical properties of an Al-Mg-Si-Cu P/M alloy reinforced with 5%, 10% and 15% aluminum nitride, produced by extrusion of cold compacted powders mixtures. Mechanical properties in as extruded and T6 conditions are compared. Differential Scanning Calorimetry and Dilatometric analysis were conducted to gain further insight into the precipitation process of these materials. Low cost 6061 Al/AINp composites can be produced with rate and small porosity by extrusion of cold compacted shapes without canning. The mechanical properties of the MMCs obtained by this process have limitations for high particles fractions because of clustering effects. All materials are always harder than the matrix and shows a similar behavior during aging processes but kinetics is changed. Potential applications of dilatometric techniques in the aging investigations of aluminum alloys and aluminum matrix composites have been established. (Author) 23 refs

  15. Part I. Corrosion studies of continuous alumina fiber reinforced aluminum-matrix composites. Part II. Galvanic corrosion between continuous alumina fiber reinforced aluminum-matrix composites and 4340 steel

    Science.gov (United States)

    Zhu, Jun

    Part I. The corrosion performance of continuous alumina fiber reinforced aluminum-matrix composites (CF-AMCs) was investigated in both the laboratory and field environments by comparing them with their respective monolithic matrix alloys, i.e., pure Al, A1-2wt%Cu T6, and Al 6061 T6. The corrosion initiation sites were identified by monitoring the changes in the surface morphology. Corrosion current densities and pH profiles at localized corrosion sites were measured using the scanning-vibrating electrode technique and the scanning ion-selective electrode technique, respectively. The corrosion damage of the materials immersed in various electrolytes, as well as those exposed in a humidity chamber and outdoor environments, was evaluated. Potentiodynamic polarization behavior was also studied. The corrosion initiation for the composites in 3.15 wt% NaCl occurred primarily around the Fe-rich intermetallic particles, which preferentially existed around the fiber/matrix interface on the composites. The corrosion initiation sites were also caused by physical damage (e.g., localized deformation) to the composite surface. At localized corrosion sites, the buildup of acidity was enhanced by the formation of micro-crevices resulting from fibers left in relief as the matrix corroded. The composites that were tested in exposure experiments exhibited higher corrosion rates than their monolithic alloys. The composites and their monolithic alloys were subjected to pitting corrosion when anodically polarized in the 3.15 wt% NaCl, while they passivated when anodically polarized in 0.5 M Na2SO4. The experimental results indicated that the composites exhibited inferior corrosion resistance compared to their monolithic matrix alloys. Part II. Galvanic corrosion studies were conducted on CF-AMCs coupled to 4340 steel since CF-AMCs have low density and excellent mechanical properties and are being considered as potential jacketing materials for reinforcing steel gun barrels. Coupled and

  16. Strain redistribution around holes and notches in fiber-reinforced cross-woven brittle matrix composites

    DEFF Research Database (Denmark)

    Jacobsen, Torben Krogsdal; Brøndsted, Povl

    1997-01-01

    Mechanics, and an identification procedure based on a uni-axial tensile test and a shear test the strain redistribution around a hole or a notch due to matrix cracking can be predicted. Damage due to fiber breakage is not included in the model. Initial matrix damage in the C-f/SiCm material has...

  17. REINFORCED COMPOSITE PANEL

    DEFF Research Database (Denmark)

    2003-01-01

    A composite panel having front and back faces, the panel comprising facing reinforcement, backing reinforcement and matrix material binding to the facing and backing reinforcements, the facing and backing reinforcements each independently comprising one or more reinforcing sheets, the facing rein...... by matrix material, the facing and backing reinforcements being interconnected to resist out-of-plane relative movement. The reinforced composite panel is useful as a barrier element for shielding structures, equipment and personnel from blast and/or ballistic impact damage....

  18. Impact damage, hardness and tribology characterization of epoxy resin based composites reinforced with basalt fibers in combination with TiO_2, BaSO_4 and SiC

    International Nuclear Information System (INIS)

    Babu, T. Narendiranath; Mangalaraja, R.V.; Saravanan, S.; Prabha, D. Rama

    2016-01-01

    Impact damage, hardness characterization, frictional and wear behavior of epoxy resin based composites reinforced with basalt fibers in combination with TiO_2, BaSO_4 and SiC were investigated using an impact testing machine, a hardness testing machine and a pin on disc machine. The basalt contained different fillers and short fibers whose presence varied in steps of weight percentage from 23 % to 50 %. It was fabricated using the conventional hand-layup technique followed by the light compression moulding technique. The frictional behavior of the composite specimen was determined by testing on a pin on disc test machine under different operating conditions. The present investigation focused on the determination of the friction coefficient of epoxy resin based composites reinforced with basalt fibers in combination with the fillers. The effects of basalt short fibers content and load were examined under dry conditions. The results showed that the friction coefficient decreased with the filler contents increase. The hardness and the impact damage of epoxy resin reinforced with basalt fiber was examined and it was found that its reinforcement with basalt fiber along with fillers such as titanium oxide, silicon carbide, barium sulphate and graphite made it more advantageous than other specimens. Keywords: basalt fiber, impact behavior, hardness, wear resistance.

  19. Predicting Mechanical Properties of Metal Matrix Syntactic Foams Reinforced with Ceramic Spheres

    Science.gov (United States)

    2012-01-01

    predicting the properties of interest listed above. Kiser et al. [12] extended a metal foam model to account for ceramic reinforcement to predict the...Daoud A. J Alloys Compd. 2009; 487:618. 11. Drury WJ, Rickles SA, Sanders Jr TH, Cochran JK. In Light-Weight Alloys for Aerospace Applications, ed. Loe

  20. [Fusion implants of carbon fiber reinforced plastic].

    Science.gov (United States)

    Früh, H J; Liebetrau, A; Bertagnoli, R

    2002-05-01

    Carbon fiber reinforced plastics (CFRP) are used in the medical field when high mechanical strength, innovative design, and radiolucency (see spinal fusion implants) are needed. During the manufacturing process of the material CFRP carbon fibers are embedded into a resin matrix. This resin material could be thermoset (e.g., epoxy resin EPN/DDS) or thermoplastic (e.g., PEAK). CFRP is biocompatible, radiolucent, and has higher mechanical capabilities compared to other implant materials. This publication demonstrates the manufacturing process of fusion implants made of a thermoset matrix system using a fiber winding process. The material has been used clinically since 1994 for fusion implants of the cervical and lumbar spine. The results of the fusion systems CORNERSTONE-SR C (cervical) and UNION (lumbar) showed no implant-related complications. New implant systems made of this CFRP material are under investigation and are presented.

  1. Stress transfer around a broken fiber in unidirectional fiber-reinforced composites considering matrix damage evolution and interface slipping

    Science.gov (United States)

    Yang, Zhong; Zhang, BoMing; Zhao, Lin; Sun, XinYang

    2011-02-01

    A shear-lag model is applied to study the stress transfer around a broken fiber within unidirectional fiber-reinforced composites (FRC) subjected to uniaxial tensile loading along the fiber direction. The matrix damage and interfacial debonding, which are the main failure modes, are considered in the model. The maximum stress criterion with the linear damage evolution theory is used for the matrix. The slipping friction stress is considered in the interfacial debonding region using Coulomb friction theory, in which interfacial clamping stress comes from radial residual stress and mismatch of Poisson's ratios of constituents (fiber and matrix). The stress distributions in the fiber and matrix are obtained by the shear-lag theory added with boundary conditions, which includes force continuity and displacement compatibility constraints in the broken and neighboring intact fibers. The result gives axial stress distribution in fibers and shear stress in the interface and compares the theory reasonably well with the measurement by a polarized light microscope. The relation curves between damage, debonding and ineffective region lengths with external strain loading are obtained.

  2. Preparation of nickel-coated titanium carbide particulates and their use in the production of reinforced iron matrix composites

    International Nuclear Information System (INIS)

    Yi, Danqing; Yu, Pengchao; Hu, Bin; Liu, Huiqun; Wang, Bin; Jiang, Yong

    2013-01-01

    Highlights: • Ni-coated TiC composite powders were prepared by electroless plating. • Iron-based composites reinforced by TiC particles was prepared by HIP. • Mechanical and wear properties were improved with the addition of Ni-coated TiC. • The nickel coating promotes the formation and growth of sintering neck. - Abstract: Ni-coated titanium carbide (TiC) composite powders were prepared by electroless plating (EP). Further, using hot isostatic pressing (HIP), iron matrix composites reinforced with 4 wt% Ni-coated TiC particulates with relative density close to 100% were prepared. The microstructure and phase composition of the Ni-coated powders and the composites were analyzed using X-ray diffraction, scanning electron microscopy, and energy dispersive X-ray spectroscopy. The results showed that the TiC particles were distributed uniformly in the matrix and were free of segregation or coarsening. Compared to the TiC particles without Ni coating, the reinforced iron-based composites containing the Ni-coated particles showed higher relative densities and better mechanical properties. The density, hardness, tensile strength, and elongation were enhanced to 99.98%, 243 HV, 565 MPa, and 11.7%, respectively in composites containing Ni-coated TiC particles from 99.70%, 210 HV, 514 MPa, and 10.3%, respectively in composites that were prepared using particles without Ni coating. In addition, the mass losses in the composites containing the Ni-coated particles were reduced by 32–75% in the abrasive wear test with various vertical loads. We propose that the nickel coatings on the particulates had a beneficial effect on the microstructure and properties of the reinforced iron-based composites is due to promotion of neck formation and growth between TiC and iron powders during sintering, which enhanced the density of the sintered compact and the bonding strength between the TiC particles and the iron matrix

  3. A comparative evaluation of fracture resistance of endodontically treated teeth, with variable marginal ridge thicknesses, restored with composite resin and composite resin reinforced with Ribbond: An in vitro study

    Directory of Open Access Journals (Sweden)

    Vaishali Kalburge

    2013-01-01

    Full Text Available Background: The anatomic shape of maxillary premolars show a tendency towards separation of their cusps during mastication after endodontic treatment. Preservation of the marginal ridge of endodontically treated and restored premolars can act as a strengthening factor and improve the fracture resistance. Objectives: To evaluate the effect of varying thickness of marginal ridge on the fracture resistance of endodontically treated maxillary premolars restored with composite and Ribbond reinforced composites. Materials and Methods: One hundred and twenty, freshly extracted, non carious human mature maxillary premolars were selected for this experimental in vitro study. The teeth were randomly assigned in to twelve groups ( n = 10. Group 1 received no preparation. All the premolars in other groups were root canal treated. In subgroups of 3 and 4, DO cavities were prepared while MOD cavities were prepared for all subgroups of group 2, the dimensions of the proximal boxes were kept uniform. In group 3 and 4 the dimensions of the mesial marginal ridge were measured using a digital Vernier caliper as 2 mm, 1.5 mm, 1 mm and 0.5 mm in the respective subgroups. All samples in groups 2.2 and all the subgroups of 3 were restored with a dentin bonding agent and resin composite. The teeth in group 2.3 and all subgroups of 4 were restored with composite reinforced with Ribbond fibers. The premolars were submitted to axial compression up to failure at 45 degree angle to a palatal cusp in universal testing machine. The mean load necessary to fracture was recorded in Newtons and the data was analysed. Results: There was a highly significant difference between mean values of force required to fracture teeth in group 1 and all subgroups of group 2, 3 and 4 (i.e., P < 0.01 Conclusion: On the basis of static loading, preserving the mesial marginal ridge with thicknesses of mm, 1.5 mm, 1 mm and 0.5 mm, composite restored and Ribbond reinforced composite restored

  4. Synchrotron X-ray diffraction measurements of internal stresses during loading of steel-based metal matrix composites reinforced with TiB2 particles

    International Nuclear Information System (INIS)

    Bacon, D.H.; Edwards, L.; Moffatt, J.E.; Fitzpatrick, M.E.

    2011-01-01

    Highlights: → Synchrotron X-ray diffraction was used to measure internal stresses in Fe-TiB 2 MMCs. → Samples of the MMCs were loaded to failure in situ in the X-ray beam. → The results show good elastic load transfer from the matrix to the reinforcement. → There is good agreement with the predicted elastic stresses from Eshelby modeling. → During plastic deformation there is increasing load transfer to the reinforcement. - Abstract: High-energy synchrotron X-ray diffraction was used to measure the internal strain evolution in the matrix and reinforcement of steel-based metal matrix composites reinforced with particulate titanium diboride (TiB 2 ). Two systems were studied: a 316L matrix with 25% TiB 2 by volume and a W1.4418 matrix with 10% reinforcement. In situ loading experiments were performed, where the materials were loaded uniaxially in the X-ray beam. The results show the strain partitioning between the phases in the elastic regime, and the evolution of the strain partitioning once plasticity occurs. The results are compared with results from Eshelby modelling, and very good agreement is seen between the measured and modelled response for elastic loading of the material. Heat treatment of the 316-based material did not affect the elastic internal strain response.

  5. Anodization Mechanism on SiC Nanoparticle Reinforced Al Matrix Composites Produced by Power Metallurgy

    OpenAIRE

    Ferreira, Sonia C.; Conde, Ana; Arenas, Mar?a A.; Rocha, Luis A.; Velhinho, Alexandre

    2014-01-01

    Specimens of aluminum-based composites reinforced by silicon carbide nanoparticles (Al/SiCnp) produced by powder metallurgy (PM) were anodized under voltage control in tartaric-sulfuric acid (TSA). In this work, the influence of the amount of SiCnp on the film growth during anodizing was investigated. The current density versus time response and the morphology of the porous alumina film formed at the composite surface are compared to those concerning a commercial aluminum alloy (AA1050) anodi...

  6. Influence of the molecular structure on hydrolyzability of epoxy resins

    International Nuclear Information System (INIS)

    Pays, M.F.

    1996-01-01

    EDF has decided to use glass reinforced composites for certain pipework in Pressurized Water Reactors (service water, emergency-supplied service water, fine pipe works, etc...) as a replacement for traditional materials. In practice, steel is prone to rapid corrosion in these circuits; introducing composites could prove economically viable if their long term behaviour can be demonstrated. However, composite materials can undergo deterioration in service through hydrolysis of the resin or the fibre-matrix interface. Different resins can be chosen depending on the programmed use. A first study has covered the hydrolyzability of polyester and vinyl ester resins. The present document undertakes the resistance to hydrolysis of epoxy resins, concentrating on those reputed to withstand high temperatures. This research uses model monomer, linking the molecular structure of the materials to their resistance to hydrolysis. (author)

  7. Oligosilylarylnitrile: The Thermoresistant Thermosetting Resin with High Comprehensive Properties.

    Science.gov (United States)

    Wang, Mingcun; Ning, Yi

    2018-04-11

    One of the highest thermoresistant thermosetting resins ever studied so far, oligosilylarylnitrile resin, was investigated first in this study. Oligosilylarylnitrile was synthesized by lithium-reduced Wurtz-Fittig condensation reaction, and the prepared viscous resin exhibited moderate rheological behaviors while heated purely or together with 20% polysilazane as a cross-linking agent. The thermal curing temperatures were found by differential scanning calorimetry at 268 °C (pure) and 158 °C (with the polysilazane cross-linking agent), which is comparably close to that of polysilylarylacetylene resin (normally at 220-250 °C) but much lower than those of polyimide and phthalonitrile resins (normally >300 °C), indicating the admirable material processability of oligosilylnitrile. The cured oligosilylarylnitrile resins have extremely high thermal resistance, indicated by the results of thermogravimetric analysis (the mass residue at 800 °C is >90% under N 2 ) and dynamic mechanical analysis (the glass-transition temperature is >420 °C). The mechanical property of the oligosilylarylnitrile-matrixed silica-cloth reinforced laminate is comparably close to those of polyimide and phthalonitrile but much higher than that of polysilylarylacetylene, indicating the enviable thermal and mechanical properties of oligosilylnitrile. Thus, among the high-temperature resins ever studied so far, the oligosilylarylnitrile resin was found to have the almost best comprehensive characteristics of processability and properties.

  8. Effect of re-melting on particle distribution and interface formation in SiC reinforced 2124Al matrix composite

    Energy Technology Data Exchange (ETDEWEB)

    Mandal, Durbadal, E-mail: durbadal73@yahoo.co.in [MEF Division, CSIR-National Metallurgical Laboratory, Jamshedpur 831007 (India); Viswanathan, Srinath [Dept of Metallurgical and Materials Engineering, University of Alabama, Tuscaloosa, AL (United States)

    2013-12-15

    The interface between metal matrix and ceramic reinforcement particles plays an important role in improving properties of the metal matrix composites. Hence, it is important to find out the interface structure of composite after re-melting. In the present investigation, the 2124Al matrix with 10 wt.% SiC particle reinforced composite was re-melted at 800 °C and 900 °C for 10 min followed by pouring into a permanent mould. The microstructures reveal that the SiC particles are distributed throughout the Al-matrix. The volume fraction of SiC particles varies from top to bottom of the composite plate and the difference increases with the decrease of re-melting temperature. The interfacial structure of re-melted 2124Al–10 wt.%SiC composite was investigated using scanning electron microscopy, an electron probe micro-analyzer, a scanning transmission electron detector fitted with scanning electron microscopy and an X-ray energy dispersive spectrometer. It is found that a thick layer of reaction product is formed at the interface of composite after re-melting. The experimental results show that the reaction products at the interface are associated with high concentration of Cu, Mg, Si and C. At re-melting temperature, liquid Al reacts with SiC to form Al{sub 4}C{sub 3} and Al–Si eutectic phase or elemental Si at the interface. High concentration of Si at the interface indicates that SiC is dissociated during re-melting. The X-ray energy dispersive spectrometer analyses confirm that Mg- and Cu-enrich phases are formed at the interface region. The Mg is segregated at the interface region and formed MgAl{sub 2}O{sub 4} in the presence of oxygen. The several elements identified at the interface region indicate that different types of interfaces are formed in between Al matrix and SiC particles. The Al–Si eutectic phase is formed around SiC particles during re-melting which restricts the SiC dissolution. - Highlights: • Re-melted composite shows homogeneous particle

  9. Processing and characterization of laser sintered hybrid B4C/cBN reinforced Ti-based metal matrix composite

    Science.gov (United States)

    Gupta, Ankit; Hussain, Manowar; Misra, Saurav; Das, Alok Kumar; Mandal, Amitava

    2018-06-01

    The purpose of this study is to make a boron carbide (B4C) and cubic boron nitride (cBN) reinforced Ti6Al4V metal matrix composites (MMC's) by direct metal laser sintering (DMLS) technique using the continuous wave (CW) SPI fiber laser and to check the feasibility of the formation of three dimensional objects by this process. For this study, the process parameters like laser power density (3.528-5.172 W/cm2 (×104), scanning speed (3500-4500 mm/min), composition of the reinforced materials B4C (5-25% by volume) and cBN (3% by volume) were taken as input variables and hatching gap (0.2 mm), spot diameter (0.4 mm), layer thickness (0.4 mm) were taken as constant. It was analyzed that surface characteristic, density and the mechanical properties of sintered samples were greatly influenced by varying the input process parameters. Field emission scanning electron microscopy (FESEM), Energy dispersive X-ray spectroscopy (EDX) and X-Ray diffraction (XRD) were performed for microstructural analysis, elemental analysis, and recognition of intermetallic compounds respectively. Mechanical properties like micro-hardness & wear rate were examined by Vickers micro-hardness tester & pin on disc arrangement respectively. From hardness tests, it was observed that hardness property of the sintered specimens was increased as compared to the parent material. The XRD results show that there is a good affinity between Ti6Al4V-B4C-cBN to produce various intermetallic compounds which themselves enhance the mechanical properties of the samples. From FESEM analysis, we can conclude that there is a uniform distribution of reinforcements in the titanium alloy matrix. Furthermore, the coefficient of friction (COF) was characterized by the irregular pattern and it tends to decrease with an increase in the volume % of reinforcement. The results obtained in this work may be useful in preparing the MMC's with improved mechanical properties and overall characteristics.

  10. Microstructure and wear characterization of aluminum matrix composites reinforced with industrial waste fly ash particulates synthesized by friction stir processing

    Energy Technology Data Exchange (ETDEWEB)

    Dinaharan, I., E-mail: dinaweld2009@gmail.com [Department of Mechanical Engineering Science, University of Johannesburg, Auckland Park Kingsway Campus, Johannesburg 2006 (South Africa); Nelson, R., E-mail: nelson.90.mech@gmail.com [Department of Mechanical Engineering, Karunya University, Coimbatore 641114, Tamil Nadu (India); Vijay, S.J., E-mail: vijayjoseph.2001@gmail.com [Center for Research in Metallurgy, School of Mechanical Sciences, Karunya University, Coimbatore 641114, Tamil Nadu (India); Akinlabi, E.T., E-mail: etakinlabi@uj.ac.za [Department of Mechanical Engineering Science, University of Johannesburg, Auckland Park Kingsway Campus, Johannesburg 2006 (South Africa)

    2016-08-15

    Fly ash (FA) is a waste product of coal combustion in thermal power plants which is available in massive quantities all over the world causing land pollution. This paper reports the characterization of AA6061 aluminum matrix composites (AMCs) reinforced with FA particles synthesized using friction stir processing (FSP). The volume fraction of FA particles was varied from 0 to 18 in steps of 6. The prepared AMCs were characterized using optical microscopy (OM), scanning electron microscopy (SEM) and electron backscattered diagram (EBSD). The wear rate was estimated using a pin-on-disc wear apparatus. FA particles were observed to be distributed homogeneously in the AMC irrespective of the location within the stir zone. The EBSD micrographs revealed remarkable grain refinement in the AMC. The incorporation of FA particles enhanced the microhardness and wear resistance of the AMC. The strengthening mechanisms of the AMC were discussed and correlated to the observed microstructures. The wear mechanisms were identified by characterizing the wear debris and worn surfaces. - Highlights: •Industrial waste fly ash was used to produce aluminum matrix composites. •Friction stir processing was used to produce AA6061/Fly Ash composite. •Fly ash particles refined the grains of aluminum matrix. •Fly ash particles enhanced the hardness and wear resistance. •Successful utilization of fly ash to make aluminum composites reduces land pollution.

  11. Effects of fiber length on mechanical properties and fracture behavior of short carbon fiber reinforced geopolymer matrix composites

    International Nuclear Information System (INIS)

    Lin Tiesong; Jia Dechang; He Peigang; Wang Meirong; Liang Defu

    2008-01-01

    A kind of sheet-like carbon fiber preform was developed using short fibers (2, 7 and 12 mm, respectively) as starting materials and used to strengthen a geopolymer. Mechanical properties, fracture behavior, microstructure and toughening mechanisms of the as-prepared composites were investigated by three-point bending test, optical microscope and scanning electron microscopy. The results show that the short carbon fibers disperse uniformly in geopolymer matrix. The C f /geopolymer composites exhibit apparently improved mechanical properties and an obvious noncatastrophic failure behavior. The composite reinforced by the carbon fibers of 7 mm in length shows a maximum flexural strength as well as the highest work of facture, which are nearly 5 times and more than 2 orders higher than that of the geopolymer matrix, respectively. The predominant strengthening and toughening mechanisms are attributed to the apparent fiber bridging and pulling-out effect based on the weak fiber/matrix interface as well as the sheet-like carbon fiber preform

  12. Evaluation of dry sliding wear behavior of silicon particles reinforced aluminum matrix composites

    International Nuclear Information System (INIS)

    Sun Zhiqiang; Zhang Di; Li Guobin

    2005-01-01

    This paper reports a study on the wear property of powder metallurgy aluminum matrix composites 9Si/Al-Cu-Mg. A on rock wear-testing machine is used to evaluate the wear property of the composites, in which a GCrl5 steel ring is used as the counter face material. The wear behavior of the composites under different conditions is studied. The optical microscope and scanning electron microscope are used to analyze the worn surfaces and the subsurface of the composites in order to research the wear mechanism of the composites. Results indicate that the weight loss of the composite were lower than that of the matrix alloy

  13. Modification of a Phenolic Resin with Epoxy- and Methacrylate-Functionalized Silica Sols to Improve the Ablation Resistance of Their Glass Fiber-Reinforced Composites

    Directory of Open Access Journals (Sweden)

    Yu Hu

    2014-01-01

    Full Text Available Functionalized silica sols were obtained by the hydrolytic condensation of (γ-methacryloxypropyltrimethoxysilane (MPMS, (γ-glycidyloxypropyltrimethoxysilane (GPMS and tetraethoxysilane (TEOS. Three different sols were obtained: MPS (derived from MPMS and TEOS, GPS-MPS (derived from GPMS, MPMS and TEOS, and GPSD (derived from GPMS, TEOS and diglycidyl ether of bisphenol A, DGEBA. These silica sols were mixed with a phenolic resin (PR. Ethylenediamine was used as a hardener for epoxy-functionalized sols and benzoyl peroxide was used as an initiator of the free-radical polymerization of methacrylate-functionalized silica sols. Glass fiber-reinforced composites were obtained from the neat PR and MPS-PR, GPS-MPS-PR and GPSD-PR. The resulting composites were evaluated as ablation resistant materials in an acetylene-oxygen flame. A large increase in the ablation resistance was observed when the PR was modified by the functionalized silica sols. The ablation resistance of the composites decreased as follows: GPSD-PR > MPS-PR > GPS-MPS-PR > PR.

  14. X-ray microtomography of damage in particle-reinforced metal matrix composites

    International Nuclear Information System (INIS)

    Mummery, P.M.; Derby, B.; Anderson, P.; Davis, G.; Elliott, J.C.

    1993-01-01

    The damage which occurs on plastic straining of silicon carbide particle-reinforced aluminium alloys has been characterised using x-ray microtomography. The technique is used to provide density measurements as a function of strain in addition to imaging the internal structure with a resolution of ∼15μm. This allows a much more accurate determination of microstructural damage in terms of void growth than is available from measurements of density using buoyancy methods or from elastic modulus decrease. These data can be combined with acoustic emission measurements during straining to allow damage nucleation and growth contributions to be separated. (orig.)

  15. Conditions for pseudo strain-hardening in fiber reinforced brittle matrix composites

    International Nuclear Information System (INIS)

    Li, V.C.; Wu, H.W.

    1992-01-01

    Apart from imparting increased fracture toughness, one of the useful purposes of reinforcing brittle matrices with fibers is to create enhanced composite strain capacity. This paper reviews the conditions underwhich such a composite will exhibit the pseudo strain-hardening phenomenon. The presentation is given in a unified manner for both continuous aligned and discontinuous random fiber composites. It is demonstrated that pseudo strain hardening can be practically designed for both gills of composites by proper tailoring of material structures. 18 refs., 8 figs., 2 tabs

  16. Characterization of Al-Cu alloy reinforced fly ash metal matrix ...

    African Journals Online (AJOL)

    user

    Graphite crucible was used for melting of matrix alloy, and the addition and mixing of particulates were made into ... specimen was cut as per ASTM-E23 by diamond blade using CNC machine. ... there will be no change in the size of the flyash.

  17. Assessment Stability and Informative of Diagnostic Matrix in Analysis States of Reinforced Concrete Slab

    Directory of Open Access Journals (Sweden)

    Sokolov Vladimir

    2016-01-01

    Full Text Available In this article was examined the issues of sustainability and informative of diagnostic matrix, which are used when it is necessary to determinate the technical condition of constructions. Determination based on the mathematical instrument of technical diagnostics. One of the most widespread methods of technical diagnostics – a statistical method of Bayes is used.

  18. Bibliography on Ceramic Matrix Composites and Reinforcing Whiskers, Platelets, and Fibers, 1970-1990

    Science.gov (United States)

    1993-08-01

    Triphasic Sol-Gel Route 2.2.3.8 Srikanth, V. Ravindranathan, P. Crystallization of Gel-Derived Mullite-Zirconia Rani, L. Roy, R. Composites Metal and...179 9.8.1 ArmorMaterials 9.8.1.5 Ceramic Matrix Composite Reactor /Radiator 9.8.1.1 Armor Structures Development and Current Status of Armor Pacquette, E

  19. Interfacial bonding and friction in silicon carbide (filament)-reinforced ceramic- and glass-matrix composites

    International Nuclear Information System (INIS)

    Bright, J.D.; Shetty, D.K.

    1989-01-01

    This paper reports interfacial shear strength and interfacial sliding friction stress assessed in unidirectional SiC-filament-reinforced reaction-bonded silicon nitride (RBSN) and borosilicate glass composites and 0/90 cross-ply reinforced borosilicate glass composite using a fiber pushout test technique. The interface debonding load and the maximum sliding friction load were measured for varying lengths of the embedded fibers by continuously monitoring the load during debonding and pushout of single fibers in finite-thickness specimens. The dependences of the debonding load and the maximum sliding friction load on the initial embedded lengths of the fibers were in agreement with nonlinear shear-lag models. An iterative regression procedure was used to evaluate the interfacial properties, shear debond strength (τ d ), and sliding friction stress (τ f ), from the embedded fiber length dependences of the debonding load and the maximum frictional sliding load, respectively. The shear-lag model and the analysis of sliding friction permit explicit evaluation of a coefficient of sliding friction (μ) and a residual compressive stress on the interface (σ 0 ). The cross-ply composite showed a significantly higher coefficient of interfacial friction as compared to the unidirectional composites

  20. Standard Guide for Identification of Fiber-Reinforced Polymer-Matrix Composite Materials in Databases

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2000-01-01

    1.1 This guide establishes essential and desirable data elements for fiber-reinforced composite materials for two purposes: to establish the material identification component of data-reporting requirements for test reporting and to provide information for the design of material property databases. 1.1.1 This guide is the first part of a two-part modular approach. The first part serves to identify the material and the second part serves to describe testing procedures and variables and to record results. 1.1.2 For mechanical testing, the related document is Guide E 1434. The interaction of this guide with Guide E 1434 is emphasized by the common numbering of data elements. Data Elements A1 through G13 are included in this guide, and numbering of data elements in Guide E 1434 begins with H1 for the next data element block. This guide is most commonly used in combination with a guide for reporting the test procedures and results such as Guide E 1434. 1.2 These guidelines are specific to fiber-reinforced polyme...

  1. Contributions in the Preparation and Processing of Composite Material Type Silumin 3 - Reinforced Matrix with S235JR Steel Mesh

    Directory of Open Access Journals (Sweden)

    Remus Belu-Nica

    2015-07-01

    Full Text Available In the paper are presented concrete data on developing technological batches of metal composite material (MCM type Silumin 3-reinforced matrix with steel mesh S235JR, with the indicating of the parameter and of the distinct stages of work. The samples from prepared batches were cut along and across by water jet abrasive process and were subjected to a destructive testing program and microstructural examination, obtaining results in concordance with the desired quality. The abrasive material used for cut was GMA granite with the average mesh of 80, the particle size ranging between 150-300 µm, density 2300 kg/m3 and melting point 1240°C.

  2. Microstructure and mechanical properties of carbon nanotubes reinforced aluminum matrix composites synthesized via equal-channel angular pressing

    Energy Technology Data Exchange (ETDEWEB)

    Zare, Hassan [Department of Materials Engineering, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of); Jahedi, Mohammad, E-mail: mohammad.jahedi@unh.edu [Department of Mechanical Engineering, University of New Hampshire, Durham, NH 03824 (United States); Toroghinejad, Mohammad Reza; Meratian, Mahmoud [Department of Materials Engineering, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of); Knezevic, Marko [Department of Mechanical Engineering, University of New Hampshire, Durham, NH 03824 (United States)

    2016-07-18

    In this work, 2 vol% carbon nanotubes (CNTs) reinforced aluminum (Al) matrix composites of superior microstructural homogeneity are successfully synthesized using Bc equal-channel angular extrusion (ECAP) route. The key step in arriving at high level of homogeneous distribution of CNTs within Al was preparation of the powder using simultaneous attrition milling and ultra-sonication processes. Microstructure as revealed by electron microscopy and absence of Vickers hardness gradients across the material demonstrate that the material reached the homogeneous state in terms of CNT distribution, porosity distribution, and grain structure after eight ECAP passes. To facilitate comparison of microstructure and hardness, samples of Al were processed under the same ECAP conditions. Significantly, the composite containing only 2 vol% exhibits 20% increase in hardness relative to the Al samples.

  3. Particle-Reinforced Aluminum Matrix Composites (AMCs—Selected Results of an Integrated Technology, User, and Market Analysis and Forecast

    Directory of Open Access Journals (Sweden)

    Anja Schmidt

    2018-02-01

    Full Text Available The research and development of new materials such as particle-reinforced aluminum matrix composites (AMCs will only result in a successful innovation if these materials show significant advantages not only from a technological, but also from an economic point of view. Against this background, in the Collaborative Research Center SFB 692, the concept of an integrated technology, user, and market analysis and forecast has been developed as a means for assessing the technological and commercial potential of new materials in early life cycle stages. After briefly describing this concept, it is applied to AMCs and the potential field of manufacturing aircraft components. Results show not only technological advances, but also considerable economic potential—the latter one primarily resulting from the possible weight reduction being enabled by the increased yield strength of the new material.

  4. Microstructure characteristics of nickel reinforced metal matrix composites (Ni/AC8A) by low-pressure metal infiltration process

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hyun Jun; Rong, Hua Wei; Jun, Ji Ang; Park, Sung Ho; Huh, Sun Chul; Park, Won Jo [Gyeongsang National University, Jinju (Korea, Republic of)

    2009-07-01

    MMCs(Metal Matrix Composites) can obtain mechanical characteristics of application purposes that a single material is difficult to obtain. Al alloy composite material that nickel is added by reinforcement is used for piston of diesel engine, because high temperature properties, strength, corrosion resistant are improved excellently than existent Al alloy. And, in case of processing, interface between Ni and Al improves wear resistant by intermetallic compound of high hardness. Also, in the world, industrial circles are proceeding research to apply excellent composite material. Existent process methods of MMC using preform were manufactured by high-pressure. But, it cause deformation of preform or fault of completed MMC. Using low-pressure as infiltration pressure can prevent this problem, and there is an advantage that is able to reduce the cost of production by small scale of production equipment. Accordingly, process methods of MMC have to consider low-pressure infiltration for the strength of preform, and nowadays, there are many studies about reducing infiltration pressure. In this study produced Al composite material that Ni is added by reinforcement by low-pressure infiltration, and observed microstructure of completed MMCs.

  5. Modelling of the interaction between chemical and mechanical behaviour of ion exchange resins incorporated into a cement-based matrix

    Directory of Open Access Journals (Sweden)

    Le Bescop P.

    2013-07-01

    Full Text Available In this paper, we present a predictive model, based on experimental data, to determine the macroscopic mechanical behavior of a material made up of ion exchange resins solidified into a CEM III cement paste. Some observations have shown that in some cases, a significant macroscopic expansion of this composite material may be expected, due to internal pressures generated in the resin. To build the model, we made the choice to break down the problem in two scale’s studies. The first deals with the mechanical behavior of the different heterogeneities of the composite, i.e. the resin and the cement paste. The second upscales the information from the heterogeneities to the Representative Elementary Volume (REV of the composite. The heterogeneities effects are taken into account in the REV by applying a homogenization method derived from the Eshelby theory combined with an interaction coefficient drawn from the poroelasticity theory. At the first scale, from the second thermodynamic law, a formulation is developed to estimate the resin microscopic swelling. The model response is illustrated on a simple example showing the impact of the calculated internal pressure, on the macroscopic strain.

  6. Fabrication of in-situ grown graphene reinforced Cu matrix composites

    Science.gov (United States)

    Chen, Yakun; Zhang, Xiang; Liu, Enzuo; He, Chunnian; Shi, Chunsheng; Li, Jiajun; Nash, Philip; Zhao, Naiqin

    2016-01-01

    Graphene/Cu composites were fabricated through a graphene in-situ grown approach, which involved ball-milling of Cu powders with PMMA as solid carbon source, in-situ growth of graphene on flaky Cu powders and vacuum hot-press sintering. SEM and TEM characterization results indicated that graphene in-situ grown on Cu powders guaranteed a homogeneous dispersion and a good combination between graphene and Cu matrix, as well as the intact structure of graphene, which was beneficial to its strengthening effect. The yield strength of 244 MPa and tensile strength of 274 MPa were achieved in the composite with 0.95 wt.% graphene, which were separately 177% and 27.4% enhancement over pure Cu. Strengthening effect of in-situ grown graphene in the matrix was contributed to load transfer and dislocation strengthening. PMID:26763313

  7. Plasma Transferred ARC (PTA Hardfacing of Recycled Hardmetal Reinforced Nickel-matrix Surface Composites

    Directory of Open Access Journals (Sweden)

    Arkadi ZIKIN

    2012-03-01

    Full Text Available The aim of this work was to apply coarse recycled hardmetal particles in combination with Ni-based matrix to produce wear resistant metal matrix composite (MMC thick coatings using plasma transferred arc hardfacing (PTA technology. Assignment of hardmetal waste as initial material can significantly decrease the production costs and improve the mechanical properties of coatings and, consequently, increase their wear resistance. The microstructure of MMC fabricated from a recycled powder was examined by optical and SEM/EDS microscopes, whereas quantitative analyses were performed by image analysis method. Micro-mechanical properties, including hardness and elastic modulus of features, were measured by nanoindentation. Furthermore, behaviour of materials subjected to abrasive and impact conditions was studied. Results show the recycled powder provides hardfacings of high quality which can be successfully used in the fabrication of wear resistant MMC coatings by PTA-technology.DOI: http://dx.doi.org/10.5755/j01.ms.18.1.1334

  8. EVALUATION OF EFFECTIVE PROPERTIES OF BASALT TEXTILE REINFORCED CERAMIC MATRIX COMPOSITES

    Directory of Open Access Journals (Sweden)

    Soňa Valentová

    2017-11-01

    Full Text Available The present paper is concerned with the analysis of a ceramic matrix composite, more specifically the plain weave textile fabric composite made of basalt fibers embedded into the pyrolyzed polysiloxane matrix. Attention is paid to the determination of effective elastic properties of the yarn via homogenization based on the Mori-Tanaka averaging scheme and the 1st order numerical homogenization method adopting a suitable representative computational model. The latter approach is then employed to simulate the response of the yarn when loaded beyond the elastic limits. The required mechanical properties of individual material phases are directly measured using nanoindentation with in-build scanning probe microscopy. Applicability of the proposed computational methodology is supported by the analysis of a unidirectional fibrous composite, representing the yarn, subjected to a macroscopically uniform strain.

  9. A new method for soldering particle-reinforced aluminum metal matrix composites

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Jinbin; Mu, Yunchao [Zhongyuan University of Technology, Zhengzhou 450007 (China); Luo, Xiangwei [Zhengzhou University, Zhengzhou 450002 (China); Niu, Jitai, E-mail: niujitai@163.com [Zhongyuan University of Technology, Zhengzhou 450007 (China)

    2012-12-01

    Highlights: Black-Right-Pointing-Pointer Soldering of 55% SiCp/Al composite and Kovar is first achieved in the world. Black-Right-Pointing-Pointer The nickel plating is required on the surface of the composites before soldering. Black-Right-Pointing-Pointer Low welding temperature is set to avoid overheating of the matrix. Black-Right-Pointing-Pointer Chemical and metallurgical bonding of composites and Kovar is carried out. Black-Right-Pointing-Pointer High tension strength of 225 MPa in soldering seam has been obtained. - Abstract: Soldering of aluminum metal matrix composites (Al-SiC) to other structural materials, or even to themselves, has proved unsuccessful mainly due to the poor wetting of these composites by conventional soldering alloys. This paper reports a new approach, which improves the wetting properties of these composites by molting solder alloys to promote stronger bonds. The new approach relies on nickel-plating of the composite's faying surface prior to application of a solder alloy. Based on this approach, an aluminum metal matrix composite containing 55 vol.% SiC particles is successfully soldered to a Fe-Ni-Co alloy (commercially known as Kovar 4J29). The solder material is a zinc-based alloy (Zn-Cd-Ag-Cu) with a melting point of about 400 Degree-Sign C. Microscopic examinations of the aluminum metal matrix composites (Al-MMCs)-Kovar interfaces show that the nickel-plating, prior to soldering, could noticeably enhance the reaction between the molten solder and composites. The fractography of the shear-tested samples revealed that fracture occurs within the composite (i.e. cohesive failure), indicating a good adhesion between the solder alloy and the Al-SiC composite.

  10. A new method for soldering particle-reinforced aluminum metal matrix composites

    International Nuclear Information System (INIS)

    Lu, Jinbin; Mu, Yunchao; Luo, Xiangwei; Niu, Jitai

    2012-01-01

    Highlights: ► Soldering of 55% SiCp/Al composite and Kovar is first achieved in the world. ► The nickel plating is required on the surface of the composites before soldering. ► Low welding temperature is set to avoid overheating of the matrix. ► Chemical and metallurgical bonding of composites and Kovar is carried out. ► High tension strength of 225 MPa in soldering seam has been obtained. - Abstract: Soldering of aluminum metal matrix composites (Al–SiC) to other structural materials, or even to themselves, has proved unsuccessful mainly due to the poor wetting of these composites by conventional soldering alloys. This paper reports a new approach, which improves the wetting properties of these composites by molting solder alloys to promote stronger bonds. The new approach relies on nickel-plating of the composite's faying surface prior to application of a solder alloy. Based on this approach, an aluminum metal matrix composite containing 55 vol.% SiC particles is successfully soldered to a Fe–Ni–Co alloy (commercially known as Kovar 4J29). The solder material is a zinc-based alloy (Zn–Cd–Ag–Cu) with a melting point of about 400 °C. Microscopic examinations of the aluminum metal matrix composites (Al-MMCs)–Kovar interfaces show that the nickel-plating, prior to soldering, could noticeably enhance the reaction between the molten solder and composites. The fractography of the shear-tested samples revealed that fracture occurs within the composite (i.e. cohesive failure), indicating a good adhesion between the solder alloy and the Al–SiC composite.

  11. Acoustic emission characterization of fracture toughness for fiber reinforced ceramic matrix composites

    International Nuclear Information System (INIS)

    Mei, Hui; Sun, Yuyao; Zhang, Lidong; Wang, Hongqin; Cheng, Laifei

    2013-01-01

    The fracture toughness of a carbon fiber reinforced silicon carbide composite was investigated relating to classical critical stress intensity factor K IC , work of fracture, and acoustic emission energy. The K IC was obtained by the single edge notch beam method and the work of fracture was calculated using the featured area under the load–displacement curves. The K IC , work of fracture, and acoustic emission energy were compared for the composites before and after heat treatment and then analyzed associated with toughening microstructures of fiber pullout. It indicates that the work of fracture and acoustic emission energy can be more suitable to reflect the toughness rather than the traditional K IC , which has certain limitation for the fracture toughness characterization of the crack tolerant fiber ceramic composites.

  12. Evaluation of Mechanical Properties of MWCNT / Nanoclay Reinforced Aluminium alloy Metal Matrix Composite

    Science.gov (United States)

    Ratna Kumar, P. S. Samuel; Robinson Smart, D. S.; Alexis, S. John

    2018-04-01

    Aluminium alloy 5083 (AA5083) is a widely used material in aerospace, marine, defence and structural applications were mechanical and corrosion resistance property plays a vital role. For the present work, MWCNT / Nanoclay (montmorillonite (MMT) K10) mixed with AA5083 for different composition in weight percentage to enhance the mechanical property. Semi-solid state casting method (Compo-casting) was used to fabricate the composite materials. By using Field-emission scanning electron microscope (FESEM) the uniform dispersion of the reinforcement and microstructure were studied. Finally, the addition of Nanoclay shows decrease in tensile strength compared to the AA5083 / MWCNT composites and hardness value of the composites (AA5083 / MWCNT and AA5083 / Nanoclay) was found to increase significantly.

  13. Microstructure and mechanical properties of TiC0.5 reinforced copper matrix composites

    International Nuclear Information System (INIS)

    Li, Mengqi; Zhai, Hongxiang; Huang, Zhenying; Liu, Xiaohan; Zhou, Yang; Li, Shibo; Li, Cuiwei

    2013-01-01

    Cu–Al alloy matrix composites containing in-situ TiC 0.5 particles were fabricated by sintering of a mixture of Cu and Ti 2 AlC powders at 1150 °C for 60 min in Ar atmosphere. The micron-sized Ti 2 AlC particles were decomposed into submicron TiC 0.5 grains during the sintering process, meanwhile, Al atoms entered into Cu to form Cu–Al alloy matrix. It was shown that the Cu–Al alloy matrix also consisted of ultrafine grains. Compression tests indicate TiC 0.5 particles can improve mechanical properties significantly, and the ductility maintains at a comparatively high level. The fracture strength of 40Ti 2 AlC/Cu sample reaches 1126 MPa with 12.8% fracture strain. The 20Ti 2 AlC/Cu and 30Ti 2 AlC/Cu samples keep undamaged even after the strain of 26.7%

  14. Microstructure and mechanical properties of TiC{sub 0.5} reinforced copper matrix composites

    Energy Technology Data Exchange (ETDEWEB)

    Li, Mengqi; Zhai, Hongxiang, E-mail: hxzhai@sina.com; Huang, Zhenying; Liu, Xiaohan; Zhou, Yang; Li, Shibo; Li, Cuiwei

    2013-12-20

    Cu–Al alloy matrix composites containing in-situ TiC{sub 0.5} particles were fabricated by sintering of a mixture of Cu and Ti{sub 2}AlC powders at 1150 °C for 60 min in Ar atmosphere. The micron-sized Ti{sub 2}AlC particles were decomposed into submicron TiC{sub 0.5} grains during the sintering process, meanwhile, Al atoms entered into Cu to form Cu–Al alloy matrix. It was shown that the Cu–Al alloy matrix also consisted of ultrafine grains. Compression tests indicate TiC{sub 0.5} particles can improve mechanical properties significantly, and the ductility maintains at a comparatively high level. The fracture strength of 40Ti{sub 2}AlC/Cu sample reaches 1126 MPa with 12.8% fracture strain. The 20Ti{sub 2}AlC/Cu and 30Ti{sub 2}AlC/Cu samples keep undamaged even after the strain of 26.7%.

  15. Fatigue failure load of two resin-bonded zirconia-reinforced lithium silicate glass-ceramics: Effect of ceramic thickness.

    Science.gov (United States)

    Monteiro, Jaiane Bandoli; Riquieri, Hilton; Prochnow, Catina; Guilardi, Luís Felipe; Pereira, Gabriel Kalil Rocha; Borges, Alexandre Luiz Souto; de Melo, Renata Marques; Valandro, Luiz Felipe

    2018-06-01

    To evaluate the effect of ceramic thickness on the fatigue failure load of two zirconia-reinforced lithium silicate (ZLS) glass-ceramics, adhesively cemented to a dentin analogue material. Disc-shaped specimens were allocated into 8 groups (n=25) considering two study factors: ZLS ceramic type (Vita Suprinity - VS; and Celtra Duo - CD), and ceramic thickness (1.0; 1.5; 2.0; and 2.5mm). A trilayer assembly (ϕ=10mm; thickness=3.5mm) was designed to mimic a bonded monolithic restoration. The ceramic discs were etched, silanized and luted (Variolink N) into a dentin analogue material. Fatigue failure load was determined using the Staircase method (100,000 cycles at 20Hz; initial fatigue load ∼60% of the mean monotonic load-to-failure; step size ∼5% of the initial fatigue load). A stainless-steel piston (ϕ=40mm) applied the load into the center of the specimens submerged in water. Fractographic analysis and Finite Element Analysis (FEA) were also performed. The ceramic thickness influenced the fatigue failure load for both ZLS materials: Suprinity (716N up to 1119N); Celtra (404N up to 1126N). FEA showed that decreasing ceramic thickness led to higher stress concentration on the cementing interface. Different ZLS glass-ceramic thicknesses influenced the fatigue failure load of the bonded system (i.e. the thicker the glass ceramic is, the higher the fatigue failure load will be). Different microstructures of the ZLS glass-ceramics might affect the fatigue behavior. FEA showed that the thicker the glass ceramic is, the lower the stress concentration at the tensile surface will be. Copyright © 2018 The Academy of Dental Materials. Published by Elsevier Inc. All rights reserved.

  16. Effect of heat treatment on microstructure and interface of SiC particle reinforced 2124 Al matrix composite

    Energy Technology Data Exchange (ETDEWEB)

    Mandal, Durbadal, E-mail: durbadal73@yahoo.co.in [MEF Division, CSIR-National Metallurgical Laboratory, Jamshedpur 831007 (India); Viswanathan, Srinath [Dept of Metallurgical and Materials Engineering, University of Alabama, Tuscaloosa, AL (United States)

    2013-11-15

    The microstructure and interface between metal matrix and ceramic reinforcement of a composite play an important role in improving its properties. In the present investigation, the interface and intermetallic compound present in the samples were characterized to understand structural stability at an elevated temperature. Aluminum based 2124 alloy with 10 wt.% silicon carbide (SiC) particle reinforced composite was prepared through vortex method and the solid ingot was deformed by hot rolling for better particle distribution. Heat treatment of the composite was carried out at 575 °C with varying holding time from 1 to 48 h followed by water quenching. In this study, the microstructure and interface of the SiC particle reinforced Al based composites have been studied using optical microscopy, scanning electron microscopy (SEM) coupled with energy dispersive X-ray spectroscopy (EDS), electron probe micro-analyzer (EPMA) associated with wavelength dispersive spectroscopy (WDS) and transmission electron microscopy (TEM) to identify the precipitate and intermetallic phases that are formed during heat treatment. The SiC particles are uniformly distributed in the aluminum matrix. The microstructure analyses of Al–SiC composite after heat treatment reveal that a wide range of dispersed phases are formed at grain boundary and surrounding the SiC particles. The energy dispersive X-ray spectroscopy and wavelength dispersive spectroscopy analyses confirm that finely dispersed phases are CuAl{sub 2} and CuMgAl{sub 2} intermetallic and large spherical phases are Fe{sub 2}SiAl{sub 8} or Al{sub 15}(Fe,Mn){sub 3}Si. It is also observed that a continuous layer enriched with Cu and Mg of thickness 50–80 nm is formed at the interface in between Al and SiC particles. EDS analysis also confirms that Cu and Mg are segregated at the interface of the composite while no carbide is identified at the interface. - Highlights: • The composite was successfully heat treated at 575°C for 1

  17. Fatigue Life and Microstructure after Multiple Remelting of A359 Matrix Composites Reinforced with SiC Particles

    Directory of Open Access Journals (Sweden)

    Klasik A.

    2016-12-01

    Full Text Available The article presents the results of fatigue life tests and microstructure examinations of A359 alloy matrix composites (F3S.10S and F3S.30S containing 10 and 30wt% of SiC particles, subjected to multiple remelting by conventional gravity casting. Mechanical characteristics were determined in a modified low cycle fatigue (MLCF test, enabling rapid estimation of fatigue life and other mechanical parameters in practice of any material. Qualitative and quantitative metallographic examinations were also carried out. The quantitative evaluation of microstructure was performed by computer image analysis. A set of geometrical parameters of the reinforcing particles, pores and eutectic precipitates present in the metal matrix was determined. The relationships between the mechanical parameters, structural characteristics and the number of remelting operations were presented. It was found that up to the fourth remelting, the mechanical characteristics, including fatigue life, are slightly deteriorated but decrease gradually in the subsequent operations of remelting. The observed effect is mainly due to the shrinkage porosity occurring as a result of gravity casting. To eliminate this defect, the use of squeeze casting process was recommended. It has also been shown that multiple remelting can be an easy and economically well-founded alternative to other more expensive recycling methods.

  18. Oxidation effects on the mechanical properties of SiC fiber-reinforced reaction-bonded silicon nitride matrix composites

    Science.gov (United States)

    Bhatt, Ramakrishna T.

    1989-01-01

    The room temperature mechanical properties of SiC fiber reinforced reaction bonded silicon nitride composites were measured after 100 hrs exposure at temperatures to 1400 C in nitrogen and oxygen environments. The composites consisted of approx. 30 vol percent uniaxially aligned 142 micron diameter SiC fibers in a reaction bonded Si3N4 matrix. The results indicate that composites heat treated in a nitrogen environment at temperatures to 1400 C showed deformation and fracture behavior equivalent to that of the as-fabricated composites. Also, the composites heat treated in an oxidizing environment beyond 400 C yielded significantly lower tensile strength values. Specifically in the temperature range from 600 to 1000 C, composites retained approx. 40 percent of their as-fabricated strength, and those heat treated in the temperatures from 1200 to 1400 C retained 70 percent. Nonetheless, for all oxygen heat treatment conditions, composite specimens displayed strain capability beyond the matrix fracture stress; a typical behavior of a tough composite.

  19. Interfacial characteristics and fracture behavior of spark-plasma-sintered TiNi fiber-reinforced 2024Al matrix composites

    Energy Technology Data Exchange (ETDEWEB)

    Dong, Peng, E-mail: dongpeng@tyut.edu.cn [College of Materials Science and Engineering, Taiyuan University of Technology, Taiyuan 030024 (China); Shanxi Key Laboratory of Advanced Magnesium-Based Materials, Taiyuan 030024 (China); Wang, Zhe [School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001 (China); Wang, Wenxian [College of Materials Science and Engineering, Taiyuan University of Technology, Taiyuan 030024 (China); Shanxi Key Laboratory of Advanced Magnesium-Based Materials, Taiyuan 030024 (China); Chen, Shaoping [College of Materials Science and Engineering, Taiyuan University of Technology, Taiyuan 030024 (China); Zhou, Jun [Department of Mechanical Engineering, Pennsylvania State University Erie, Erie, PA 16563 (United States)

    2017-04-13

    Embedding of shape memory alloy (SMA) fibers into materials to fabricate SMA composites has attracted considerable attention because of the potential applicability of these composites in smart systems and structures. In this study, 2024Al matrix composites reinforced by continuous TiNi SMA fibers were fabricated using spark plasma sintering (SPS). The interface between the fibers and matrix consisted of a bilayer. The layer close to the fiber consisted of a multiple phase mixture, and the other layer exhibited a periodic morphology resulting from the alternating phases of Al{sub 3}Ti and Al{sub 3}Ni. In addition, a small quantity of TiO{sub 2} phases was also observed in the interface layer. Based on detailed interface studies of the orientation relationships between the Al{sub 3}Ti, Al{sub 3}Ni, and TiO{sub 2} phases and the atomic correspondence at phase boundaries, the effects of the interface phases on the fracture behavior of the composites were demonstrated.

  20. EB treatment of carbon nanotube-reinforced polymer composites

    International Nuclear Information System (INIS)

    Szebényi, G.; Romhány, G.; Vajna, B.; Czvikovszky, T.

    2012-01-01

    A small amount — less than 0.5% — carbon nanotube reinforcement may improve the mechanical properties of epoxy based composite materials significantly. The basic technical problem on one side is the dispersion of the nanotubes into the viscous matrix resin, namely, the fine powder-like — less than 100 nanometer diameter — nanotubes are prone to form aggregates. On the other side, the good connection between the nanofiber and matrix, which is determining the success of the reinforcement, requires some efficient adhesion promoting treatment. The goal of our research was to give one such treatment capable of industrial size application. A two step curing epoxy/vinylester resin process technology has been developed where the epoxy component has been cured conventionally, while the vinylester has been cured by electron treatment afterwards. The sufficient irradiation dose has been selected according to Raman spectroscopy characterization. Using the developed hybrid resin system hybrid composites containing carbon fibers and multiwalled carbon nanotubes have been prepared. The effect of the electron beam induced curing of the vinylester resin on the mechanical properties of the composites has been characterized by three point bending and interlaminar shear tests, which showed clearly the superiority of the developed resin system. The results of the mechanical tests have been supported by AFM studies of the samples, which showed that the difference in the viscoelastic properties of the matrix constituents decreased significantly by the electron beam treatment.

  1. Fabrication and properties of CNTs reinforced polymeric matrix nanocomposites for sports applications

    International Nuclear Information System (INIS)

    Rasheed, A.; Khalid, F. A.

    2013-01-01

    The polymeric matrix composites have found extensive applications in sports because of high strength to weight ratio, ease of processing, and longer life. This work was carried out to study the properties of different sections of composite field hockey sticks and the influence of carbon nanotubes on their properties. The samples were fabricated by compression molding process. The increase in mechanical properties by the incorporation of carbon nanotubes is correlated with the process parameters to consider enhancement in the overall performance of the stick sections. (author)

  2. Fabrication and properties of CNTs reinforced polymeric matrix nanocomposites for sports applications

    International Nuclear Information System (INIS)

    Rasheed, A; Khalid, F A

    2014-01-01

    The polymeric matrix composites have found extensive applications in sports because of high strength to weight ratio, ease of processing, and longer life. This work was carried out to study the properties of different sections of composite field hockey sticks and the influence of carbon nanotubes on their properties. The samples were fabricated by compression molding process. The increase in mechanical properties by the incorporation of carbon nanotubes is correlated with the process parameters to consider enhancement in the overall performance of the stick sections

  3. Sisal fibre pull-out behaviour as a guide to matrix selection for the production of sisal fibre reinforced cement matrix composites

    CSIR Research Space (South Africa)

    Mapiravana, Joe

    2011-12-01

    Full Text Available Natural fibre reinforced cement composites are promising potential materials for use in panelised construction. The structural properties of these composite materials are yet to be fully understood. As the role of the natural fibre is to reinforce...

  4. Compaction study of particulate iron-chromium matrix composite reinforced with alumina

    International Nuclear Information System (INIS)

    Saidatulakmar Shamsuddin; Shamsul Baharin Jamaludin; Zuhailawati Hussain; Zainal Arifin Ahmad

    2007-01-01

    Recently, a sharper focus on cost reduction in producing advanced composites systems has increased and leads to an interest in ferrous matrix composite which is cheaper compared to Cobalt, Nickel and their alloys that are scarce, expensive and their dust is especially harmful. In the present investigation, Fe-Cr-Al 2 O 3 composite was prepared using conventional powder metallurgy technique; mixing, compaction and sintering. Consolidation of particulate materials is dependent on the compaction process. As load is increased, the number of contacting asperities increases and they flatten and grow to form a planar contact surface. These asperities eventually merge to form bonding surfaces between particles. This paper focused on finding the optimum compaction parameter in a uniaxial pressing. Six different pressure were studied; (250, 375, 500, 625, 750 and 875)MPa. experimental results show that the optimum compaction parameter is 750 MPa that produced highest linear shrinkage, highest bulk density, lowest porosity and highest hardness value. Every sample has formed binary alloy of Fe-Cr alloy, confirmed by XRD and alumina are homogeneously distributed in the Fe-Cr matrix revealed by optical micrograph and SEM. from EDX, the composites consist of iron, chromium and alumina. (author)

  5. High-energy ion implantation of polymeric fibers for modification of reinforcement-matrix adhesion

    International Nuclear Information System (INIS)

    Grummon, D.S.; Schalek, R.; Ozzello, A.; Kalantar, J.; Drzal, L.T.

    1991-01-01

    We have previously reported on the effect of high-energy ion irradiation of ultrahigh molecular weight polyethylene (UHMW-PE), and Kevlar-49 polyaramid fibers, on fiber-matrix adhesion and interfacial shear strength (ISS) in epoxy matrix composites. Irradiation of UHMW-PE fibers produced large improvements in interfacial shear strength, without degrading fiber tensile strength. ISS was not generally affected in irradiated Kevlar-49, and fiber tensile strength decreased. The divergence in response between polyaramid and polyethylene relates both to differences in the mesoscopic structure of the individual fibers, and to the different forms of beam induced structural modification favored by the individual polymer chemistries. Here we report results of surface energy measurements, infrared spectroscopy analysis, and X-ray photoelectron spectroscopy studies on UHMW-PE and polyaramid fibers, irradiated to fluences between 2x10 12 and 5x10 15 cm -2 with N + , Ar + , Ti + , Na + , and He + at energies between 30 and 400 keV. UHMW-PE fibers showed a pronounced increase in the polar component of surface energy which could be associated with carbonyl, hydroxyl and hydroperoxide groups at the surface. Kevlar, on the other hand, tended toward carbonization and showed a decrease in nitrogen and oxygen concentrations and a sharp drop in polar surface energy. (orig.)

  6. Microstructure and Mechanical Behaviour of Stir-Cast Al-Mg-Sl Alloy Matrix Hybrid Composite Reinforced with Corn Cob Ash and Silicon Carbide

    Directory of Open Access Journals (Sweden)

    Oluwagbenga Babajide Fatile

    2014-10-01

    Full Text Available In this present study, the microstructural and mechanical behaviour of Al-Mg-Si alloy matrix composites reinforced with silicon carbide (SiC and Corn cob ash (An agro‑waste was investigated. This research work was aimed at assessing the suitability of developing low cost- high performance Al-Mg-Si hybrid composite. Silicon carbide (SiC particulates added with 0,1,2,3 and 4 wt% Corn cob ash (CCA were utilized to prepare 10 wt% of the reinforcing phase with Al-Mg-Si alloy as matrix using two-step stir casting method. Microstructural characterization, density measurement, estimated percent porosity, tensile testing, and micro‑hardness measurement were used to characterize the composites produced. From the results obtained, CCA has great potential to serve as a complementing reinforcement for the development of low cost‑high performance aluminum hybrid composites.

  7. ECAP consolidation of Al matrix composites reinforced with in-situ γ-Al{sub 2}O{sub 3} nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Casati, R., E-mail: riccardo.casati@polimi.it [Department of Mechanical Engineering, Politecnico di Milano, Via La Masa 1, Milano (Italy); Fabrizi, A. [Department of Management and Engineering, Università di Padova, Stradella S. Nicola 3, Vicenza (Italy); Tuissi, A. [CNR-IENI, Corso Promessi Sposi 29, Lecco (Italy); Xia, K. [Department of Mechanical Engineering, University of Melbourne, Victoria 3010 (Australia); Vedani, M. [Department of Mechanical Engineering, Politecnico di Milano, Via La Masa 1, Milano (Italy)

    2015-11-11

    This work is aimed at proposing a method to prepare aluminum matrix composites reinforced with γ-Al{sub 2}O{sub 3} nanoparticles and at describing the effects of an in-situ reaction on the resulting nano-reinforcement dispersed throughout the metal matrix. Al nano- and micro-particles were used as starting materials. They were consolidated by equal channel angular pressing (ECAP) in as-received conditions and after undergoing high-energy ball milling. Further, γ-Al{sub 2}O{sub 3} reinforcing nanoparticles were produced in-situ from the hydroxide layer that covered the Al powder particles. The powder particle morphology and the composites microstructures were investigated by electron microscopy. The transformation process was monitored by X-ray diffraction, differential scanning calorimetry and thermo-gravimetric analysis.

  8. Effect of bagasse ash reinforcement on dry sliding wear behaviour of polymer matrix composites

    International Nuclear Information System (INIS)

    Aigbodion, V.S.; Hassan, S.B.; Agunsoye, J.O.

    2012-01-01

    Highlights: → The influence of wear parameters on the wear rate of RLDPE were investigated. → The predicted wear rate of the RLDPE and it composites were found to lie close to that experimentally observed ones. → The results showed that the addition of bagasse ash as filler materials in RLDPE composites increase the wear resistance. -- Abstract: The tribological behaviour of recycled low density polyethylene (RLDPE) polymer composites with bagasse ash particles as a reinforcement was studied using a pin-on-disc wear rig under dry sliding conditions. The influence of wear parameters like, applied load, sliding speed, sliding distance and percentage of bagasse ash fillers, on the wear rate were investigated. A plan of experiments was performed to acquire data in a controlled way. Scanning electron microscope was used to analyse the worn surface of the samples. Linear regression equation and analysis of variance (ANOVA) were employed to investigate the influence of process parameters on the wear rate of the samples. The predicted wear rate of the RLDPE and it composites were found to lie close to that experimentally observed ones. The confirmation of the experiments conducted using ANOVA to verify the optimal testing parameters show that sliding speed and applied load had significant effect on the wear rate. The results showed that the addition of bagasse ash as filler materials in RLDPE composites increase the wear resistance of the composite greatly.

  9. EXPERIMENTAL INVESTIGATION ON TRIBOLOGICAL CHARACTERISTICS OF SILICON NITRIDE REINFORCED ALUMINIUM METAL MATRIX COMPOSITES

    Directory of Open Access Journals (Sweden)

    D. BHUVANESH

    2017-05-01

    Full Text Available Aluminium alloy (LM25 reinforced with silicon nitride was fabricated by liquid metallurgy route. The fabricated composite was investigated for dry sliding wear behaviour by conducting experiments using pin-on-disc tribometer. Set of experiments were planned using Taguchi’s technique and data analysis was carried out using L27 orthogonal array. Analysis of Variance (ANOVA technique was used to determine the significance of parameter with respect to wear rate. Signal-to-Noise ratio was employed to detect the most and least influential parameter as well as their level of influence. ‘Smaller the wear’ characteristic was chosen for the analysis of dry sliding wear. Results implied that, the load has the primary effect on the wear succeeded by the effect of sliding velocity and sliding distance. Scanning Electronic Microscopic studies were carried out on worn surfaces to understand the wear mechanism.Tribological results indicated that LM25 aluminium alloy could be better utilized as a material for piston, rotor and bearings for long life in low speed applications.

  10. Cyclic saturation behavior of tungsten monofilament-reinforced monocrystalline copper matrix composites

    International Nuclear Information System (INIS)

    Zhang, J.; Laird, C.

    1999-01-01

    Studies on saturation behavior produced by cyclic deformation have been conducted on tungsten monofilament-reinforced monocrystalline copper composites. The effect of the fiber on strain localization has been investigated using interferometry. For a given applied strain amplitude, local strain and volume fraction of the persistent slip bands (PSBs) in the composite appeared no different from those observed in monolithic copper single crystals. However, the distribution of the PSBs was observed to be more uniform, and the total number of PSBs is substantially higher than that in monolithic crystals. The PSBs appeared mostly in the form of micro-PSBs or macro-PSBs with very limited width. Instead of expanding existing PSBs, new PSBs were more likely to nucleate at new locations during cyclic deformation. The volume fraction and width of the PSBs were observed to increase during saturation, which indicates that some of the PSBs become aged and new PSBs form in order to continue to carry the plastic strain. A rule of mixtures model was established to link the cyclic stress-strain response of the monocrystalline composites to the behavior of monolithic single crystals and fibers. The results calculated from the model show very good agreement with the experimental data

  11. Effects of High-Temperature Annealing in Air on Hi-Nicalon Fiber-Reinforced Celsian Matrix Composites

    Science.gov (United States)

    Bansal, Narottam P.

    2008-01-01

    BN/SiC-coated Hi-Nicalon fiber-reinforced celsian matrix composites (CMC) were annealed for 100 h in air at various temperatures to 1200 C, followed by flexural strength measurements at room temperature. Values of yield stress and strain, ultimate strength, and composite modulus remain almost unchanged for samples annealed up to 1100 C. A thin porous layer formed on the surface of the 1100 C annealed sample and its density decreased from 3.09 to 2.90 g/cu cm. The specimen annealed at 1200 C gained 0.43 wt%, was severely deformed, and was covered with a porous layer of thick shiny glaze which could be easily peeled off. Some gas bubbles were also present on the surface. This surface layer consisted of elongated crystals of monoclinic celsian and some amorphous phase(s). The fibers in this surface ply of the CMC had broken into small pieces. The fiber-matrix interface strength was characterized through fiber push-in technique. Values of debond stress, alpha(sub d), and frictional sliding stress, tau(sub f), for the as-fabricated CMC were 0.31+/-0.14 GPa and 10.4+/-3.1 MPa, respectively. These values compared with 0.53+/-0.47 GPa and 8.33+/-1.72 MPa for the fibers in the interior of the 1200 C annealed sample, indicating hardly any change in fiber-matrix interface strength. The effects of thermal aging on microstructure were investigated using scanning electron microscopy. Only the surface ply of the 1200 C annealed specimens had degraded from oxidation whereas the bulk interior part of the CMC was unaffected. A mechanism is proposed explaining the various steps involved during the degradation of the CMC on annealing in air at 1200 C.

  12. Microstructure evolution and mechanical properties of a particulate reinforced magnesium matrix composites forged at elevated temperatures

    International Nuclear Information System (INIS)

    Deng, K.K.; Wu, K.; Wang, X.J.; Wu, Y.W.; Hu, X.S.; Zheng, M.Y.; Gan, W.M.; Brokmeier, H.G.

    2010-01-01

    SiCp/AZ91 magnesium matrix composite was fabricated by stir casting. The as-cast ingots were cut into cylindrical billets, and then forged at different temperatures (320, 370, 420, 470 and 520 deg. C) at a constant RAM speed of 15 mm/s with 50% reduction. The microstructure evolution of the composites during forging was investigated by optical microscope, scanning electron microscope, and transmission electron microscope. The texture of the forged composites was measured by neutron diffraction. Mechanical properties of the composite at different forging temperatures were tested by tensile tests at room temperature. It was found that a strong basal plane texture formed during forging, and the intensity of basal plane texture weakened as forging temperatures increased. The particle distribution in the composite was significantly improved by hot forging. Typical microstructures were obtained after forging at different temperatures and the composite with different microstructures offered different mechanical properties during tensile test.

  13. Friction and wear behavior of TiC particle reinforced ZA43 matrix composites

    Institute of Scientific and Technical Information of China (English)

    谢贤清; 张荻; 刘金水; 吴人洁

    2001-01-01

    TiC/ZA43 composites were fabricated by XDTM and stirring-casting techniques. The tribology properties of the unreinforced ZA43 alloy and the composites were studied by using a block-on-ring apparatus. Experimental results show that the incorporation of TiC particles improves the microstructure of ZA43 matrix alloy. The coefficient of friction μ and the width of worn groove decrease with the increase of TiC volume fraction φ(TiC). The width of worn groove and μ of the composite during wear testing increase with increasing the applied load. Metallographic examinations reveal that unreinforced ZA43 alloy has deep ploughing grooves with obvious adhesion phenomenon, whereas TiC/ZA43 composites have smooth worn surface. Delamination formation is related to the fatigue cracks and the shear cracks on the surface.

  14. Studies on SiC(p) reinforced Al-Al sub 3 Ni eutectic matrix composites

    International Nuclear Information System (INIS)

    Masrom, A.K.; Foo, L.C.; Ismail, A.B.

    1996-01-01

    An investigation on processing of Al-5.69wt% Ni eutectic with SiC particulate composites is reported. The intermetallic composites are prepared by elemental powder metallurgy route and sintered at two different temperatures, i.e., 600 degree C and 620 degree C. Results show that the metal matrix was Al-Al sub 3 Ni eutectic. The phase analysis by XRD identified the presence of Al sub 3 Ni and Al as dominant phases together with silicon and Al sub 4 C sub 3 phase as minor phases. The Al sub 4 C sub 3 and Si phases are formed during sintering due to SiC-Al interface reaction. SEM micrographs also reveal the formation of microvoid surrounding the SiC particle

  15. Design feasibility study of a divertor component reinforced with fibrous metal matrix composite laminate

    International Nuclear Information System (INIS)

    You, J.-H.

    2005-01-01

    Fibrous metal matrix composites possess advanced mechanical properties compared to conventional alloys. It is expected that the application of these composites to a divertor component will enhance the structural reliability. A possible design concept would be a system consisting of tungsten armour, copper composite interlayer and copper heat sink where the composite interlayer is locally inserted into the highly stressed domain near the bond interface. For assessment of the design feasibility of the composite divertor concept, a non-linear multi-scale finite element analysis was performed. To this end, a micro-mechanics algorithm was implemented into a finite element code. A reactor-relevant heat flux load was assumed. Focus was placed on the evolution of stress state, plastic deformation and ductile damage on both macro- and microscopic scales. The structural response of the component and the micro-scale stress evolution of the composite laminate were investigated

  16. Design feasibility study of a divertor component reinforced with fibrous metal matrix composite laminate

    Energy Technology Data Exchange (ETDEWEB)

    You, J.-H. [Max-Planck-Institut fuer Plasmaphysik, EURATOM Association, Boltzmannstr. 2, D-85748 Garching (Germany)]. E-mail: j.h.you@ipp.mpg.de

    2005-01-01

    Fibrous metal matrix composites possess advanced mechanical properties compared to conventional alloys. It is expected that the application of these composites to a divertor component will enhance the structural reliability. A possible design concept would be a system consisting of tungsten armour, copper composite interlayer and copper heat sink where the composite interlayer is locally inserted into the highly stressed domain near the bond interface. For assessment of the design feasibility of the composite divertor concept, a non-linear multi-scale finite element analysis was performed. To this end, a micro-mechanics algorithm was implemented into a finite element code. A reactor-relevant heat flux load was assumed. Focus was placed on the evolution of stress state, plastic deformation and ductile damage on both macro- and microscopic scales. The structural response of the component and the micro-scale stress evolution of the composite laminate were investigated.

  17. Numerical Modeling of Fiber-Reinforced Metal Matrix Composite Processing by the Liquid Route: Literature Contribution

    Science.gov (United States)

    Lacoste, Eric; Arvieu, Corinne; Mantaux, Olivier

    2018-04-01

    One of the technologies used to produce metal matrix composites (MMCs) is liquid route processing. One solution is to inject a liquid metal under pressure or at constant rate through a fibrous preform. This foundry technique overcomes the problem of the wettability of ceramic fibers by liquid metal. The liquid route can also be used to produce semiproducts by coating a filament with a molten metal. These processes involve physical phenomena combined with mass and heat transfer and phase change. The phase change phenomena related to solidification and also to the melting of the metal during the process notably result in modifications to the permeability of porous media, in gaps in impregnation, in the appearance of defects (porosities), and in segregation in the final product. In this article, we provide a state-of-the-art review of numerical models and simulation developed to study these physical phenomena involved in MMC processing by the liquid route.

  18. Three-Dimensional Nanoporous Cellulose Gels as a Flexible Reinforcement Matrix for Polymer Nanocomposites.

    Science.gov (United States)

    Shi, Zhuqun; Huang, Junchao; Liu, Chuanjun; Ding, Beibei; Kuga, Shigenori; Cai, Jie; Zhang, Lina

    2015-10-21

    With the world's focus on utilization of sustainable natural resources, the conversion of wood and plant fibers into cellulose nanowhiskers/nanofibers is essential for application of cellulose in polymer nanocomposites. Here, we present a novel fabrication method of polymer nanocomposites by in-situ polymerization of monomers in three-dimensionally nanoporous cellulose gels (NCG) prepared from aqueous alkali hydroxide/urea solution. The NCG have interconnected nanofibrillar cellulose network structure, resulting in high mechanical strength and size stability. Polymerization of the monomer gave P(MMA/BMA)/NCG, P(MMA/BA)/NCG nanocomposites with a volume fraction of NCG ranging from 15% to 78%. SEM, TEM, and XRD analyses show that the NCG are finely distributed and preserved well in the nanocomposites after polymerization. DMA analysis demonstrates a significant improvement in tensile storage modulus E' above the glass transition temperature; for instance, at 95 °C, E' is increased by over 4 orders of magnitude from 0.03 MPa of the P(MMA/BMA) up to 350 MPa of nanocomposites containing 15% v/v NCG. This reinforcement effect can be explained by the percolation model. The nanocomposites also show remarkable improvement in solvent resistance (swelling ratio of 1.3-2.2 in chloroform, acetone, and toluene), thermal stability (do not melt or decompose up to 300 °C), and low coefficients of thermal expansion (in-plane CTE of 15 ppm·K(-1)). These nanocomposites will have great promising applications in flexible display, packing, biomedical implants, and many others.

  19. Metal-Matrix Hardmetal/Cermet Reinforced Composite Powders for Thermal Spray

    Directory of Open Access Journals (Sweden)

    Dmitri GOLJANDIN

    2012-03-01

    Full Text Available Recycling of materials is becoming increasingly important as industry response to public demands, that resources must be preserved and environment protected. To produce materials competitive in cost with primary product, secondary producers have to pursue new technologies and other innovations. For these purposes different recycling technologies for composite materials (oxidation, milling, remelting etc are widely used. The current paper studies hardmetal/cermet powders produced by mechanical milling technology. The following composite materials were studied: Cr3C2-Ni cermets and WC-Co hardmetal. Different disintegrator milling systems for production of powders with determined size and shape were used. Chemical composition of produced powders was analysed.  To estimate the properties of recycled hardmetal/cermet powders, sieving analysis, laser granulometry and angularity study were conducted. To describe the angularity of milled powders, spike parameter–quadric fit (SPQ was used and experiments for determination of SPQ sensitivity and precision to characterize particles angularity were performed. Images used for calculating SPQ were taken by SEM processed with Omnimet Image Analyser 22. The graphs of grindability and angularity were composed. Composite powders based on Fe- and Ni-self-fluxing alloys for thermal spray (plasma and HVOF were produced. Technological properties of powders and properties of thermal sprayed coatings from studied powders were investigated. The properties of spray powders reinforced with recycled hardmetal and cermet particles as alternatives for cost-sensitive applications were demonstrated.DOI: http://dx.doi.org/10.5755/j01.ms.18.1.1348

  20. Fibre reinforced composites '84; Proceedings of the International Conference, University of Liverpool, England, April 3-5, 1984

    Energy Technology Data Exchange (ETDEWEB)

    1984-01-01

    Among the topics discussed are phenolic resin matrix composites for high temperature and fire-exposure applications, novel resins for fiber-reinforced composite productivity improvement, the use of engineering textiles for mechanical property improvement in composites, the significance of aramid fiber reinforcement in composites, the energy absorption properties of Sheet Metal Compounds (SMCs) under crash conditions, and SMC impact behavior variations with temperature. Also covered are CFRP applications in high performance structures, composite helicopter main rotor blade technology, composite vehicular leaf springs, carbon fiber-reinforced thermoplastics, filament winding development status, the injection processing of fiber-reinforced thermoplastics, civil aircraft composite structure certification, composite radomes, design procedures for short fiber-reinforced thermoplastics, the strength limitations of mechanically fastened lap joints, environmental fatigue and creep in glass-reinforced materials, the effects of moisture on high performance laminates, the environmental behavior of SMC, and corrugated composites.

  1. Performance Evaluation of PCD Insert 1600 Grade on Turning of Al 6061 Reinforced with 7.5% ZrB2 Metal Matrix Composite

    Directory of Open Access Journals (Sweden)

    Ramanathan M.

    2016-01-01

    Full Text Available Aluminum matrix composite is the innovation of high performance material technology and it has superior interfacial integrity and thermodynamic stability between the matrix and reinforcement. Making the engineering components from this composite material require subsequent machining operations. This paper presents the detailed experimental investigation of the machining behaviour in turning of Al 6061-7.5% ZrB2 Metal Matrix Composite (MMC by using Poly Crystalline Diamond (PCD insert of 1600 grade. The effect of ZrB2 reinforcement particles on machinability behaviour need to be studied. It is concluded that the feed rate has great influence on surface roughness and depth of cut has great influence on cutting force. The confirmation experiment indicates that there is a good agreement between the estimated value and experimental Value. Tool wear study also carried out for time duration of 15 minutes.

  2. Effects of particle/matrix interfaces on the mechanical properties for SiCp or YAl2p reinforced Mg–Li composites

    International Nuclear Information System (INIS)

    Zhang, Q.Q.; Wu, G.Q.; Huang, Z.; Tao, Y.

    2014-01-01

    Highlights: • The particle/matrix interfaces in Mg–Li matrix composites are characterized. • The different reinforcement types with intermetallics and ceramics are considered. • The failure behaviors for the composites are successfully studied. • The effect of particle/matrix interface on the mechanical properties is discussed. -- Abstract: YAl 2p or SiC P reinforced Mg–14Li–3Al (LA143) matrix composites were prepared by stir-casting. The composites were subjected to fracture toughness and tensile tests. The particle/matrix interfaces were investigated by nanoindentation combined with scanning electron microscopy (SEM). The effects of the particle/matrix interfaces on the mechanical properties of the composites were discussed through a unit cell model with a transition interface layer. The results show that a transition interface layer with smoother hardness and modulus gradient is developed in the YAl 2 /LA143 composite. Both the fracture toughness and ductility for the YAl 2 /LA143 composite are higher than those for the SiC/LA143 composite. The failure behavior is determined by particle breakage with little interfacial breakage for the YAl 2 /LA143 composite, while being due to interfacial breakage for the SiC/LA143 composite. The superiority of the mechanical properties for the YAl 2 /LA143 composite may result from the failure behavior of particle breakage, which are correlated to the better physical compatibility between the YAl 2 intermetallics and LA143 matrix

  3. Electrical Resistance Based Damage Modeling of Multifunctional Carbon Fiber Reinforced Polymer Matrix Composites

    Science.gov (United States)

    Hart, Robert James

    In the current thesis, the 4-probe electrical resistance of carbon fiber-reinforced polymer (CFRP) composites is utilized as a metric for sensing low-velocity impact damage. A robust method has been developed for recovering the directionally dependent electrical resistivities using an experimental line-type 4-probe resistance method. Next, the concept of effective conducting thickness was uniquely applied in the development of a brand new point-type 4-probe method for applications with electrically anisotropic materials. An extensive experimental study was completed to characterize the 4-probe electrical resistance of CFRP specimens using both the traditional line-type and new point-type methods. Leveraging the concept of effective conducting thickness, a novel method was developed for building 4-probe electrical finite element (FE) models in COMSOL. The electrical models were validated against experimental resistance measurements and the FE models demonstrated predictive capabilities when applied to CFRP specimens with varying thickness and layup. These new models demonstrated a significant improvement in accuracy compared to previous literature and could provide a framework for future advancements in FE modeling of electrically anisotropic materials. FE models were then developed in ABAQUS for evaluating the influence of prescribed localized damage on the 4-probe resistance. Experimental data was compiled on the impact response of various CFRP laminates, and was used in the development of quasi- static FE models for predicting presence of impact-induced delamination. The simulation-based delamination predictions were then integrated into the electrical FE models for the purpose of studying the influence of realistic damage patterns on electrical resistance. When the size of the delamination damage was moderate compared to the electrode spacing, the electrical resistance increased by less than 1% due to the delamination damage. However, for a specimen with large

  4. Admixtures in Cement-Matrix Composites for Mechanical Reinforcement, Sustainability, and Smart Features

    Science.gov (United States)

    Bastos, Guillermo; Patiño-Barbeito, Faustino; Patiño-Cambeiro, Faustino; Armesto, Julia

    2016-01-01

    For more than a century, several inclusions have been mixed with Portland cement—nowadays the most-consumed construction material worldwide—to improve both the strength and durability required for construction. The present paper describes the different families of inclusions that can be combined with cement matrix and reviews the achievements reported to date regarding mechanical performance, as well as two other innovative functionalities of growing importance: reducing the high carbon footprint of Portland cement, and obtaining new smart features. Nanomaterials stand out in the production of such advanced features, allowing the construction of smart or multi-functional structures by means of thermal- and strain-sensing, and photocatalytic properties. The first self-cleaning concretes (photocatalytic) have reached the markets. In this sense, it is expected that smart concretes will be commercialized to address specialized needs in construction and architecture. Conversely, other inclusions that enhance strength or reduce the environmental impact remain in the research stage, in spite of the promising results reported in these issues. Despite the fact that such functionalities are especially profitable in the case of massive cement consumption, the shift from the deeply established Portland cement to green cements still has to overcome economic, institutional, and technical barriers. PMID:28774091

  5. Boron carbide reinforced aluminium matrix composite: Physical, mechanical characterization and mathematical modelling

    International Nuclear Information System (INIS)

    Shirvanimoghaddam, K.; Khayyam, H.; Abdizadeh, H.; Karbalaei Akbari, M.; Pakseresht, A.H.; Ghasali, E.; Naebe, M.

    2016-01-01

    This paper investigates the manufacturing of aluminium–boron carbide composites using the stir casting method. Mechanical and physical properties tests to obtain hardness, ultimate tensile strength (UTS) and density are performed after solidification of specimens. The results show that hardness and tensile strength of aluminium based composite are higher than monolithic metal. Increasing the volume fraction of B_4C, enhances the tensile strength and hardness of the composite; however over-loading of B_4C caused particle agglomeration, rejection from molten metal and migration to slag. This phenomenon decreases the tensile strength and hardness of the aluminium based composite samples cast at 800 °C. For Al-15 vol% B_4C samples, the ultimate tensile strength and Vickers hardness of the samples that were cast at 1000 °C, are the highest among all composites. To predict the mechanical properties of aluminium matrix composites, two key prediction modelling methods including Neural Network learned by Levenberg–Marquardt Algorithm (NN-LMA) and Thin Plate Spline (TPS) models are constructed based on experimental data. Although the results revealed that both mathematical models of mechanical properties of Al–B_4C are reliable with a high level of accuracy, the TPS models predict the hardness and tensile strength values with less error compared to NN-LMA models.

  6. Hydrophobic silica nanoparticles as reinforcing filler for poly (lactic acid polymer matrix

    Directory of Open Access Journals (Sweden)

    Pilić Branka M.

    2016-01-01

    Full Text Available Properties of poly (lactic acid (PLA and its nanocomposites, with silica nanoparticles (SiO2, as filler were investigated. Neat PLA films and PLA films with different percentage of hydrophobic fumed silica nanoparticles (0.2, 0.5, 1, 2, 3 and 5 wt. % were prepared by solution casting method. Several tools were used to characterize the influence of different silica content on crystalline behavior, and thermal, mechanical and barrier properties of PLA/SiO2 nanocomposites. Results from scanning electron microscope (SEM showed that the nanocomposite preparation and selection of specific hydrophobic spherical nano filler provide a good dispersion of the silica nanoparticles in the PLA matrix. Addition of silica nanoparticles improved mechanical properties, the most significant improvement being observed for lowest silica content (0.2wt.%. Barrier properties were improved for all measured gases at all loadings of silica nanoparticles. The degree of crystallinity for PLA slightly increased by adding 0.2 and 0.5 wt. % of nano filler. [Projekat Ministarstva nauke Republike Srbije, br. III46001

  7. Thermosetting polyimide resin matrix composites with interpenetrating polymer networks for precision foil resistor chips based on special mechanical performance requirements

    Energy Technology Data Exchange (ETDEWEB)

    Wang, X.Y., E-mail: wxy@tju.edu.cn [School of Electronic Information Engineering, Tianjin University, Tianjin 300072 (China); Ma, J.X.; Li, C.G. [School of Electronic Information Engineering, Tianjin University, Tianjin 300072 (China); Wang, H.X. [ZHENGHE electronics Co., Ltd, Jining 272023 (China)

    2014-04-01

    Highlights: • Macromolecular materials were chosen to modify thermosetting polyimide (TSPI). • The formation of IPN structure in TSPI composite polymers was discussed. • The special mechanical properties required were the main study object. • The desired candidate materials should have proper hardness and toughness. • The specific mechanical data are quantitatively determined by experiments. - Abstract: Based on interpenetrating networks (IPNs) different macromolecular materials such as epoxy, phenolic, and silicone resin were chosen to modify thermosetting polyimide (TSPI) resin to solve the lack of performance when used for protecting precision foil resistor chips. Copolymerization modification, controlled at curing stage, was used to prepare TSPI composites considering both performance and process requirements. The mechanical properties related to trimming process were mainly studied due to the special requirements of the regularity of scratch edges caused by a tungsten needle. The analysis on scratch edges reveals that the generation and propagation of microcracks caused by scratching together with crack closure effect may lead to regular scratch traces. Experiments show that the elongation at break of TSPI composites is the main reason that determines the special mechanical properties. The desired candidate materials should have proper hardness and toughness, and the specific mechanical data are that the mean elongation at break and tensile strength of polymer materials are in the range of 9.2–10.4% and 100–107 MPa, respectively. Possible reasons for the effect of the modifiers chosen on TSPI polymers, the reaction mechanisms on modified TSPI resin and the IPN structure in TSPI composite polymers were discussed based on IR and TG analysis.

  8. Thermosetting polyimide resin matrix composites with interpenetrating polymer networks for precision foil resistor chips based on special mechanical performance requirements

    International Nuclear Information System (INIS)

    Wang, X.Y.; Ma, J.X.; Li, C.G.; Wang, H.X.

    2014-01-01

    Highlights: • Macromolecular materials were chosen to modify thermosetting polyimide (TSPI). • The formation of IPN structure in TSPI composite polymers was discussed. • The special mechanical properties required were the main study object. • The desired candidate materials should have proper hardness and toughness. • The specific mechanical data are quantitatively determined by experiments. - Abstract: Based on interpenetrating networks (IPNs) different macromolecular materials such as epoxy, phenolic, and silicone resin were chosen to modify thermosetting polyimide (TSPI) resin to solve the lack of performance when used for protecting precision foil resistor chips. Copolymerization modification, controlled at curing stage, was used to prepare TSPI composites considering both performance and process requirements. The mechanical properties related to trimming process were mainly studied due to the special requirements of the regularity of scratch edges caused by a tungsten needle. The analysis on scratch edges reveals that the generation and propagation of microcracks caused by scratching together with crack closure effect may lead to regular scratch traces. Experiments show that the elongation at break of TSPI composites is the main reason that determines the special mechanical properties. The desired candidate materials should have proper hardness and toughness, and the specific mechanical data are that the mean elongation at break and tensile strength of polymer materials are in the range of 9.2–10.4% and 100–107 MPa, respectively. Possible reasons for the effect of the modifiers chosen on TSPI polymers, the reaction mechanisms on modified TSPI resin and the IPN structure in TSPI composite polymers were discussed based on IR and TG analysis

  9. Preparation and mechanical properties of unidirectional boron nitride fibre reinforced silica matrix composites

    International Nuclear Information System (INIS)

    Li, Duan; Zhang, Chang-Rui; Li, Bin; Cao, Feng; Wang, Si-Qing

    2012-01-01

    Highlights: → BN fibres hardly degrade when exposed at elevated temperatures. → Few researches have related to BN f /SiO 2 composites. → BN f /SiO 2 composites have fine high-temperature mechanical properties. → Self-healing properties of fused SiO 2 and B 2 O 3 may contribute to the properties. -- Abstract: The unidirectional BN f /SiO 2 composites were prepared via sol-gel method, and the structure, composition and mechanical properties were studied. The results show that the composites consist of BN fibres and α-cristobalite matrix probably as well as the interface phases of Si 3 N 4 and B 2 O 3 . The composites have a density of 1.70 g cm -3 and an open porosity of 20.8%. The average flexural strength, elastic modulus and fracture toughness at room temperature are 51.2 MPa, 23.2 GPa and 1.46 MPa m 1/2 , respectively. The composites show a very plane fracture surface with practically no pulled-out fibres. The mechanical properties of BN f /SiO 2 composites at 300-1000 o C are desirable, with the maximum flexural strength and residual ratio being 80.2 MPa and 156.8% at 500 o C, respectively, while it is a sharply reduced trend as for SiO 2f /SiO 2 composites. The high thermal stability of BN fibres and self-healing properties caused by the fused SiO 2 and B 2 O 3 enable the composites fine high-temperature mechanical properties.

  10. Microstructure and properties of TiB2-TiB reinforced titanium matrix composite coating by laser cladding

    Science.gov (United States)

    Lin, Yinghua; Yao, Jianhua; Lei, Yongping; Fu, Hanguang; Wang, Liang

    2016-11-01

    TiB2 particle and TiB short fiber reinforced titanium matrix composite coatings were prepared utilizing in situ synthesized technique by laser cladding on the surface of Ti6Al4V alloy. Through the experiment, it was found that the surface of the single-track coatings appeared in the depression, but it can be improved by laser track overlapping. With the increase of laser power density, the amount of TiB short fiber was increased, and the distribution of TiB2 and TiB became more uniform from the top to bottom. The micro-hardness of TiB2/TiB coating showed a gradient decreasing trend, and the average micro-hardness of the coatings was two-fold higher than that of the substrate. Due to the strengthening effect of TiB2 particle and TiB short fiber, the wear volume loss of the center of the coating was approximately 30% less than that of the Ti-6Al-4V substrate, and the wear mechanism of the coating was mild fatigue particle detachment.

  11. Unusual tensile behaviour of fibre-reinforced indium matrix composite and its in-situ TEM straining observation

    International Nuclear Information System (INIS)

    Luo, Xin; Peng, Jianchao; Zandén, Carl; Yang, Yanping; Mu, Wei; Edwards, Michael; Ye, Lilei; Liu, Johan

    2016-01-01

    Indium-based thermal interface materials are superior in thermal management applications of electronic packaging compared to their polymer-based counterparts. However, pure indium has rather low tensile strength resulting in poor reliability. To enhance the mechanical properties of such a material, a new composite consisting of electrospun randomly oriented continuous polyimide fibres and indium was fabricated. The composite has been characterised by tensile tests and in-situ transmission electron microscopy straining observations. It is shown that the composite's ultimate tensile strength at 20 °C is five times higher than that of pure indium, and the strength of the composite exceeds the summation of strengths of the individual components. Furthermore, contrary to most metallic matrix materials, the ultimate tensile strength of the composite decreases with the increased strain rate in a certain range. The chemical composition and tensile fracture of the novel composite have been analysed comprehensively by means of scanning transmission electron microscopy and scanning electron microscopy. A strengthening mechanism based on mutually reinforcing structures formed by the indium and surrounding fibres is also presented, underlining the effect of compressing at the fibre/indium interfaces by dislocation pileups and slip pinning.

  12. Study of matrix micro-cracking in nano clay and acrylic tri-block-copolymer modified epoxy/basalt fiber-reinforced pressure-retaining structures

    Directory of Open Access Journals (Sweden)

    2011-10-01

    Full Text Available In fiber-reinforced polymer pressure-retaining structures, such as pipes and vessels, micro-level failure commonly causes fluid permeation due to matrix cracking. This study explores the effect of nano-reinforcements on matrix cracking in filament-wound basalt fiber/epoxy composite structures. The microstructure and mechanical properties of bulk epoxy nanocomposites and hybrid fiber-reinforced composite pipes modified with acrylic tri-block-copolymer and organophilic layered silicate clay were investigated. In cured epoxy, the tri-block-copolymer phase separated into disordered spherical micelle inclusions; an exfoliated and intercalated structure was observed for the nano-clay. Block-copolymer addition significantly enhanced epoxy fracture toughness by a mechanism of particle cavitation and matrix shear yielding, whereas toughness remained unchanged in nano-clay filled nanocomposites due to the occurrence of lower energy resistance phenomena such as crack deflection and branching.Tensile stiffness increased with nano-clay content, while it decreased slightly for block-copolymer modified epoxy. Composite pipes modified with either the organic and inorganic nanoparticles exhibited moderate improvements in leakage failure strain (i.e. matrix cracking strain; however, reductions in functional and structural failure strength were observed.

  13. Viscoelastic behavior of multiwalled carbon nanotubes into phenolic resin

    Energy Technology Data Exchange (ETDEWEB)

    Botelho, Edson Cocchieri; Costa, Michelle Leali; Braga, Carlos Isidoro, E-mail: ebotelho@feg.unesp.br [Universidade Estadual Paulista Julio de Mesquita Filho (UNESP), Guaratingueta, SP (Brazil). Dept. de Materiais e Tecnologia; Burkhart, Thomas [Institut fuer Verbundwerkstoffe GmbH, Kaiserslautern, (Germany); Lauke, Bernd [Leibniz-Institut fuer Polymerforschung, Dresden (Germany)

    2013-11-01

    Nanostructured polymer composites have opened up new perspectives for multi-functional materials. In particular, carbon nanotubes (CNTs) have the potential applications in order to improve mechanical and electrical performance in composites with aerospace application. This study focuses on the viscoelastic evaluation of phenolic resin reinforced carbon nanotubes, processed by using two techniques: aqueous-surfactant solution and three roll calender (TRC) process. According to our results a relative small amount of CNTs in a phenolic resin matrix is capable of enhancing the viscoelastic properties significantly and to modify the thermal stability. Also has been observed that when is used TRC process, the incorporation and distribution of CNT into phenolic resin is more effective when compared with aqueous solution dispersion process. (author)

  14. Multiply fully recyclable carbon fibre reinforced heat-resistant covalent thermosetting advanced composites.

    Science.gov (United States)

    Yuan, Yanchao; Sun, Yanxiao; Yan, Shijing; Zhao, Jianqing; Liu, Shumei; Zhang, Mingqiu; Zheng, Xiaoxing; Jia, Lei

    2017-03-02

    Nondestructive retrieval of expensive carbon fibres (CFs) from CF-reinforced thermosetting advanced composites widely applied in high-tech fields has remained inaccessible as the harsh conditions required to recycle high-performance resin matrices unavoidably damage the structure and properties of CFs. Degradable thermosetting resins with stable covalent structures offer a potential solution to this conflict. Here we design a new synthesis scheme and prepare a recyclable CF-reinforced poly(hexahydrotriazine) resin matrix advanced composite. The multiple recycling experiments and characterization data establish that this composite demonstrates performance comparable to those of its commercial counterparts, and more importantly, it realizes multiple intact recoveries of CFs and near-total recycling of the principal raw materials through gentle depolymerization in certain dilute acid solution. To our best knowledge, this study demonstrates for the first time a feasible and environment-friendly preparation-recycle-regeneration strategy for multiple CF-recycling from CF-reinforced advanced composites.

  15. Oxygen index tests of thermosetting resins

    Science.gov (United States)

    Gilwee, W. J., Jr.; Parker, J. A.; Kourtides, D. A.

    1980-01-01

    The flammability characteristics of nine thermosetting resins under evaluation for use in aircraft interiors are described. These resins were evaluated using the Oxygen Index (ASTM 2863) testing procedure. The test specimens consisted of both neat resin and glass reinforced resin. When testing glass-reinforced samples it was observed that Oxygen Index values varied inversely with resin content. Oxygen values were also obtained on specimens exposed to temperatures up to 300 C. All specimens experienced a decline in Oxygen Index when tested at an elevated temperature.

  16. Crack and wear behavior of SiC particulate reinforced aluminium based metal matrix composite fabricated by direct metal laser sintering process

    International Nuclear Information System (INIS)

    Ghosh, Subrata Kumar; Saha, Partha

    2011-01-01

    In this investigation, crack density and wear performance of SiC particulate (SiCp) reinforced Al-based metal matrix composite (Al-MMC) fabricated by direct metal laser sintering (DMLS) process have been studied. Mainly, size and volume fraction of SiCp have been varied to analyze the crack and wear behavior of the composite. The study has suggested that crack density increases significantly after 15 volume percentage (vol.%) of SiCp. The paper has also suggested that when size (mesh) of reinforcement increases, wear resistance of the composite drops. Three hundred mesh of SiCp offers better wear resistance; above 300 mesh the specific wear rate increases significantly. Similarly, there has been no improvement of wear resistance after 20 vol.% of reinforcement. The scanning electron micrographs of the worn surfaces have revealed that during the wear test SiCp fragments into small pieces which act as abrasives to result in abrasive wear in the specimen.

  17. Change in the structure and properties of carbon fiber-reinforced plastic with a polysulfone matrix under the effect of gamma irradiation

    International Nuclear Information System (INIS)

    Arkhipov, A.A.; Korkhov, V.P.; Pudnik, V.V.; Rodin, Yu.P.

    1993-01-01

    This article presents the results of studying the change in the structure and properties of carbon fiber-reinforced plastic with a thermoplastic matrix -- aromatic polysulfone -- as a function of the absorbed dose of gamma radiation. In view of the presence in the polysulfone macromolecules and in carbon fibers of a large number of aromatic rings and double bonds providing high radiation resistance of the composite, irradiation was carried out up to large values of absorbed doses (10 9 rad). Specimens of orthogonally reinforced composite KTMU-1 with a thickness of 1.3 mm made from aromatic polysulfone PSF-150 and carbon ribbon that absorbed various gamma radiation dosages were used. It was found that structural transformations under the effect of gamma radiation did not have a substantial effect on the mechanical properties of carbon fiber-reinforced plastic. 2 refs., 3 figs., 3 tabs

  18. Effect of fiber coatings on room and elevated temperature mechanical properties of Nicalon trademark fiber reinforced Blackglas trademark ceramic matrix composites (CMCs)

    International Nuclear Information System (INIS)

    Aly, E.I.; Freitag, D.W.; Littlefield, J.E.

    1993-01-01

    With the development of silicon organometallic preceramic polymers as precursors for producing oxidation resistant ceramic matrices, through the polymer pyrolysis route, the fabrication of lightweight, complex advanced aircraft and missile structures from fiber reinforced composites is increasingly becoming more feasible. Besides refinement of processing techniques, the potential for achieving this objective depends upon identifying and developing the proper debond barrier coating layer, between the fiber and the matrix, for optimization of strength, toughness, and durability properties. Blackglas trademark based CMC's reinforced with Nicalon trademark SiC fibers with different types of coatings were fabricated. Coating schemes evaluated include CVD applied single layer boron nitride (BN) composition, dual-layer coatings of BN/SiC, and triple-layer coatings of SiC BN/SiC. Results of tensile and flexural property tests, scanning electron microscopy (SEM) of fracture surfaces, and auger electron spectroscopy (AES) microanalysis of the fiber/matrix interface have been discussed

  19. Mechanical and physical properties of carbon-graphite fiber-reinforced polymers intended for implant suprastructures.

    Science.gov (United States)

    Segerström, Susanna; Ruyter, I Eystein

    2007-09-01

    Mechanical properties and quality of fiber/matrix adhesion of poly(methyl methacrylate) (PMMA)-based materials, reinforced with carbon-graphite (CG) fibers that are able to remain in a plastic state until polymerization, were examined. Tubes of cleaned braided CG fibers were treated with a sizing resin. Two resin mixtures, resin A and resin B, stable in the fluid state and containing different cross-linking agents, were reinforced with CG fiber loadings of 24, 36, and 47 wt% (20, 29, and 38 vol.%). In addition, resin B was reinforced with 58 wt% (47 vol.%). After heat-polymerization, flexural strength and modulus were evaluated, both dry and after water storage. Coefficient of thermal expansion, longitudinally and in the transverse direction of the specimens, was determined. Adhesion between fibers and matrix was evaluated with scanning electron microscopy (SEM). Flexural properties and linear coefficient of thermal expansion were similar for both fiber composites. With increased fiber loading, flexural properties increased. For 47 wt% fibers in polymer A the flexural strength was 547.7 (28.12) MPa and for polymer B 563.3 (89.24) MPa when water saturated. Linear coefficient of thermal expansion was for 47 wt% CG fiber-reinforced polymers; -2.5 x 10(-6) degrees C-1 longitudinally and 62.4 x 10(-6) degrees C-1 in the transverse direction of the specimens. SEM revealed good adhesion between fibers and matrix. More porosity was observed with fiber loading of 58 wt%. The fiber treatment and the developed resin matrices resulted in good adhesion between CG fibers and matrix. The properties observed indicate a potential for implant-retained prostheses.

  20. Thermal stability relationships between PMR-15 resin and its composites

    Science.gov (United States)

    Bowles, Kenneth J.; Jayne, Douglas; Leonhardt, Todd A.; Bors, Dennis

    1993-01-01

    A study was conducted to investigate the relationship between the thermo-oxidative stability of PMR-15 matrix resin and the stability of graphite-fiber-reinforced composites that contain this resin as the matrix material. Three areas were investigated. The first was the effect of fiber/matrix interfacial bond strength on the isothermal aging weight loss of composites. By using type-A graphite fibers produced by Hercules, it was possible to study composites reinforced with fibers that were processed to receive different surface treatments. One of the fibers was untreated, a second fiber was treated by oxidation to enhance fiber/matrix bonding, and the third type of fiber was coated with an epoxy sizing. These treatments produced three significantly different interfacial bond strengths. The epoxy sizing on the third fiber was quickly oxidized from the bare fiber surfaces at 288, 316, and 343 C. The weight loss due to the removal of the sizing was constant at 1.5 percent. This initial weight loss was not observed in thermo-oxidative stability studies of composites. The PMR-15 matrix satisfactorily protected the reinforcemnt at all three temperatures.

  1. Matrix effect on leaching of Bisphenol A diglycidyl ether (BADGE) from epoxy resin based inner lacquer of aluminium tubes into semi-solid dosage forms.

    Science.gov (United States)

    Lipke, Uwe; Haverkamp, Jan Boris; Zapf, Thomas; Lipperheide, Cornelia

    2016-04-01

    To study the impact of different semi-solid dosage form components on the leaching of Bisphenol A (BPA) and Bisphenol A diglycidyl ether (BADGE) from the epoxy resin-based inner lacquer of aluminium tubes, the tubes were filled with different matrix preparations and stored at an elevated temperature. Despite compliance with the European Standards EN 15348 and EN 15766 on porosity and polymerisation of internal coatings of aluminium tubes, the commercially available tubes used in the study contained an increased amount of polymerisation residues, such as unbound BPA, BADGE and BADGE derivatives in the lacquer, as determined by acetonitrile extraction. Storage of Macrogol ointments in these tubes resulted in an almost quantitative migration of the unbound polymerisation residues from the coating into the ointment. In addition, due to alterations observed in the RP-HPLC chromatograms of the matrix spiked with BADGE and BADGE derivatives it is supposed that the leachates can react with formulation components. The contamination of the medicinal product by BPA, BADGE and BADGE derivatives can be precluded by using aluminium tubes with an internal lacquer with a low degree of unbound polymerisation residues. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

  2. Investigation of the Self-Healing Behavior of Sn-Bi Metal Matrix Composite Reinforced with NiTi Shape Memory Alloy Strips Under Flexural Loading

    Science.gov (United States)

    Poormir, Mohammad Amin; Khalili, Seyed Mohammad Reza; Eslami-Farsani, Reza

    2018-06-01

    Utilizing intelligent materials such as shape memory alloys as reinforcement in metal matrix composites is a novel method to mimic self-healing behavior. In this study, the bending behavior of a self-healing metal matrix composite made from Sn-13 wt.% Bi alloy as matrix and NiTi shape memory alloy (SMA) strips as reinforcement is investigated. Specimens were fabricated in different reinforcement vol.% (0.78, 1.55, 2.33) and in various pre-strains (0, 2, 6%) and were healed at three healing temperatures (170°C, 180°C, 190°C). Results showed that shape recovery was accomplished in all the specimens, but not all of them were able to withstand second loading after healing. Only specimens with 2.33 vol.% of SMA strips, 1.55 vol.% of SMA, and 6% pre-strain could endure bending force after healing, and they gained 35.31-51.83% of bending force self-healing efficiency.

  3. EB treatment of carbon nanotube-reinforced polymer composites

    International Nuclear Information System (INIS)

    Szebenyi, G.; Romhany, G.; Czvikovszky, T.; Vajna, B.

    2011-01-01

    Complete text of publication follows. A small amount - less than 0.5% - carbon nanotube reinforcement may improve significantly the mechanical properties of epoxy based composite materials. The basic technical problem is on one side the dispersion of the nanotubes into the viscous matrix resin. Namely the fine, powder-like - less than 100 nanometer diameter - nanotubes are prone to form aggregates. On the other side, the good connection between the nanofiber and matrix, - which is determining the success of the reinforcement, - requires some efficient adhesion promoting treatment. After an elaborate masterbatch mixing technology we applied Electron Beam treatment of epoxy-matrix polymer composites containing carbon nanotubes in presence of vinylester resins. The Raman spectra of vinylester-epoxy mixtures treated by an 8 MeV EB showed the advantage of the electron treatment. Even in the case of partially immiscible epoxy and vinylester resins, the anchorage of carbon nanotubes reflects improvement if a reasonable 25 kGy EB dose is applied. Atomic Force Microscopy as well as mechanical tests on flexural and impact properties confirm the benefits of EB treatment. Simultaneous application of multiwall carbon nanotubes and 'conventional' carbon fibers as reinforcement in vinylester modified epoxies results in new types of hybrid nanocomposites as engineering materials. The bending- and interlaminar properties of such hybrid systems showed the beneficial effect of the EB treatment. Acknowledgement: This work has been supported by the New Hungary Development Plan (Project ID: TAMOP-4.2.1/B-09/1/KMR-2010-0002).

  4. Bamboo reinforced polymer composite - A comprehensive review

    Science.gov (United States)

    Roslan, S. A. H.; Rasid, Z. A.; Hassan, M. Z.

    2018-04-01

    Bamboo has greatly attention of researchers due to their advantages over synthetic polymers. It is entirely renewable, environmentally-friendly, non-toxic, cheap, non-abrasive and fully biodegradable. This review paper summarized an oveview of the bamboo, fiber extraction and mechanical behavior of bamboo reinforced composites. A number of studies proved that mechanical properties of bamboo fibers reinforced reinforced polymer composites are excellent and competent to be utilized in high-tech applications. The properties of the laminate are influenced by the fiber loading, fibre orientation, physical and interlaminar adhesion between fibre and matrix. In contrast, the presence of chemical constituents such as cellulose, lignin, hemicellulose and wax substances in natural fibres preventing them from firmly binding with polymer resin. Thus, led to poor mechanical properties for composites. Many attempt has been made in order to overcome this issue by using the chemical treatment.

  5. Contact allergy to epoxy resin

    DEFF Research Database (Denmark)

    Bangsgaard, Nannie; Thyssen, Jacob Pontoppidan; Menné, Torkil

    2012-01-01

    Background. Epoxy resin monomers are strong skin sensitizers that are widely used in industrial sectors. In Denmark, the law stipulates that workers must undergo a course on safe handling of epoxy resins prior to occupational exposure, but the effectiveness of this initiative is largely unknown...... in an educational programme. Conclusion. The 1% prevalence of epoxy resin contact allergy is equivalent to reports from other countries. The high occurrence of epoxy resin exposure at work, and the limited use of protective measures, indicate that reinforcement of the law is required....

  6. Trace metals analysis in estuarine and seawater by ICP-MS using on line preconcentration and matrix elimination with chelating resin.

    Science.gov (United States)

    Nicolaı, M; Rosin, C; Tousset, N; Nicolai, Y

    1999-09-13

    The main difficulties of trace metals analysis in estuarine and seawater stem from their very low concentration (mug/l to sub-mug/l), and, by contrast, the high salt content (up to 38 g/l in the Mediterranean Sea). ICP-MS allows multi-elemental analysis and offers great sensitivity, but may be strongly affected by matrix effects induced by high salt contents (> 1 g/l). To perform trace metals analysis both in riverine, estuarine and seawater, we have developed a hyphenated method: ion chelation chromatography coupled on-line with ICP-MS. Iminodiacetate resin, Metpac CC-1 (Dionex), was used to concentrate most of the trace metals, and to separate them from alkaline and alkaline-earth metals. Behaviour of 17 elements (Pb, Cu, Cd, Ni, U, Cr, Mn, Al, Co, Ga, In, Zn, V, Tl, Bi, Ag and Sn) towards the resin was qualitatively investigated. A method validation, partly derived from AFNOR standard XPT 90-210, was carried out on 12 elements (Pb, Cu, Cd, Ni, U, Cr, Mn, Al, Co, Ga, Bi and In). Replicate measurements of multi-elemental standard solutions were used to check linearity, and to determine repeatability and detection limits. Method accuracy was then assessed by analysing two certified materials: a synthetic freshwater (SRM 1643d), and a natural filtered coastal seawater (NRCC CASS-3). An application assay of natural samples from the Rhône river (France) was eventually carried out, and the analytical results were found to be consistent with previous works.

  7. Characterizing the influence of matrix ductility on damage phenomenology in continuous fiber-reinforced thermoplastic laminates undergoing quasi-static indentation

    KAUST Repository

    Yudhanto, Arief

    2017-12-12

    The use of thermoplastic matrix was known to improve the impact properties of laminated composites. However, different ductility levels can exist in a single family of thermoplastic matrix, and this may consequently modify the damage phenomenology of thermoplastic composites. This paper focuses on the effect of matrix ductility on the out-of-plane properties of thermoplastic composites, which was studied through quasi-static indentation (QSI) test that may represent impact problem albeit the speed difference. We evaluated continuous glass-fiber reinforced polypropylene thermoplastic composites (GFPP), and selected homopolymer PP and copolymer PP that represent ductile and less ductile matrices, respectively. Several cross-ply laminates were selected to study the influence of ply thicknesses and relative orientation of interfaces on QSI properties of GFPP. It is expected that GFPP with ductile matrix improves energy absorption of GFPP. However, the damage mechanism is completely different between GFPP with ductile and GFPP with less ductile matrices. GFPP with ductile matrix exhibits smaller damage zone in comparison to the one with less ductile matrix. Higher matrix ductility inhibits the growth of ply cracking along the fiber, and this causes the limited size of delamination. The stacking sequence poses more influence on less ductile composites rather than the ductile one.

  8. Radiation processing for carbon fiber-reinforced polytetrafluoroethylene composite materials

    International Nuclear Information System (INIS)

    Oshima, Akihiro; Udagawa, Akira; Morita, Yousuke

    2001-01-01

    The present work is an attempt to evaluate the performance of the fiber composites with crosslinked polytetrafluoroethylene (PTFE) as a polymer matrix by radiation. The uni-directional carbon fiber-reinforced composites were fabricated with PTFE fine powder impregnation method and then crosslinked by electron beams irradiation under selective conditions. The carbon fiber-reinforced crosslinked PTFE composites show good mechanical properties compared with crosslinked PTFE. The radiation resistance of crosslinked PTFE composites is improved more than that of crosslinked resin without fiber. (author)

  9. Influence of fiber upon the radiation degradation of fiber-reinforced plastics

    International Nuclear Information System (INIS)

    Udagawa, Akira

    1992-01-01

    Influences of fiber upon the radiation degradation of fiber-reinforced plastics were investigated by using 2 MeV electrons. Radiation resistances were evaluated from the three-point bending strength of the fiber laminates which used bisphenol A-type epoxy resin as a matrix. Carbon fiber laminates had higher radiation resistance values than the laminates made of glass fiber. Model laminates using polyethylene as a matrix were prepared in order to examine the differences between carbon fiber and glass fiber filler, the relation between gel fraction and absorbed dose was established. When the polyethylene was filled in the carbon fiber, forming the gel was strikingly delayed. This result suggests that radiation protective action existing in carbon fiber to matrix resin is the main cause of the higher radiation resistance of carbon fiber reinforced plastics. (author)

  10. Structure evolutions in a Ti–6Al–4V matrix composite reinforced with TiB, characterised using high energy X-ray diffraction

    International Nuclear Information System (INIS)

    Ropars, Ludovic; Dehmas, Moukrane; Gourdet, Sophie; Delfosse, Jérôme; Tricker, David; Aeby-Gautier, Elisabeth

    2015-01-01

    Highlights: • In-situ high energy X-ray diffraction used during different thermal treatments. • Kinetics of phase evolutions characterised for the matrix and for the borides. • Conversion from TiB 2 to TiB-B27 via a metastable structure TiB-B f . • Strong effect of the process on the matrix phases evolutions and microstructure. - Abstract: A titanium matrix composite reinforced with TiB was produced using powder metallurgy. A Ti–6Al–4V alloy was chosen to be the matrix, and 12 wt.% of TiB 2 was used as the boron source for the solid state formation of TiB. The TiB 2 to TiB conversion reaction was studied using an in situ high energy X-ray diffraction technique while heat treating the composite. The TiB 2 (space group: P6/mmm) converts into TiB-B27 (Pnma), via TiB-B f (Cmcm). The metastable character of B f is confirmed here; it is the first phase formed during the conversion and it progressively converts into B27 during elevated temperature heat treatment. A modification of the phase transformation kinetics in the matrix and of the composite β transus temperature (T β = 1275 °C) was also observed, mainly due to gas contamination and intensive work hardening as a result of the mechanical alloying process used to manufacture the material and to a modification of the matrix equilibria

  11. Improving the corrosion wear resistance of AISI 316L stainless steel by particulate reinforced Ni matrix composite alloying layer

    Science.gov (United States)

    Xu, Jiang; Zhuo, Chengzhi; Tao, Jie; Jiang, Shuyun; Liu, Linlin

    2009-01-01

    In order to overcome the problem of corrosion wear of AISI 316L stainless steel (SS), two kinds of composite alloying layers were prepared by a duplex treatment, consisting of Ni/nano-SiC and Ni/nano-SiO2 predeposited by brush plating, respectively, and subsequent surface alloying with Ni-Cr-Mo-Cu by a double glow process. The microstructure of the two kinds of nanoparticle reinforced Ni-based composite alloying layers was investigated by means of SEM and TEM. The electrochemical corrosion behaviour of composite alloying layers compared with the Ni-based alloying layer and 316L SS under different conditions was characterized by potentiodynamic polarization test and electrochemical impedance spectroscopy. Results showed that under alloying temperature (1000 °C) conditions, amorphous nano-SiO2 particles still retained the amorphous structure, whereas nano-SiC particles were decomposed and Ni, Cr reacted with SiC to form Cr6.5Ni2.5Si and Cr23C6. In static acidic solution, the corrosion resistance of the composite alloying layer with the brush plating Ni/nano-SiO2 particles interlayer is lower than that of the Ni-based alloying layer. However, the corrosion resistance of the composite alloying layer with the brush plating Ni/nano-SiO2 particles interlayer is prominently superior to that of the Ni-based alloying layer under acidic flow medium condition and acidic slurry flow condition. The corrosion resistance of the composite alloying layer with the brush plating Ni/nano-SiC particles interlayer is evidently lower than that of the Ni-based alloying layer, but higher than that of 316L SS under all test conditions. The results show that the highly dispersive nano-SiO2 particles are helpful in improving the corrosion wear resistance of the Ni-based alloying layer, whereas carbides and silicide phase are deleterious to that of the Ni-based alloying layer due to the fact that the preferential removal of the matrix around the precipitated phase takes place by the chemical

  12. The effect of TiB2 reinforcement on the mechanical properties of an Al-Cu-Li alloy-based metal-matrix composite

    Science.gov (United States)

    1991-01-01

    The addition of ceramic particles to aluminum based alloys can substantially improve mechanical properties, especially Young's modulus and room and elevated temperature strengths. However, these improvements typically occur at the expense of tensile ductility. The mechanical properties are evaluated to a metal matrix composite (MMC) consisting of an ultrahigh strength aluminum lithium alloy, Weldalite (tm) 049, reinforced with TiB2 particles produced by an in situ precipitation technique called the XD (tm) process. The results are compared to the behavior of a nonreinforced Weldalite 049 variant. It is shown that both 049 and 049-TiB2 show very attractive warm temperature properties e.g., 625 MPa yield strength at 150 C after 100 h at temperature. Weldalite 049 reinforced with a nominal 4 v pct. TiB2 shows an approx. 8 pct. increase in modulus and a good combination of strength (529 MPa UTS) and ductility (6.5 pct.) in the T3 temper. And the high ductility of Weldalite 049 in the naturally aged and underaged tempers makes the alloy a good, high strength matrix for ceramic reinforcement.

  13. Effect of type and percentage of reinforcement for optimization of the cutting force in turning of Aluminium matrix nanocomposites using response surface methodologies

    Energy Technology Data Exchange (ETDEWEB)

    Priyadarshi, Devinder [DAV Institute of Engineering and Technology, Jalandhar (India); Sharma, Rajesh Kumar [Institute of Technology, Hamirpur (India)

    2016-03-15

    Aluminium matrix composites (AMCs) now hold a significant share of raw materials in many applications. It is of prime importance to study the machinability of such composites so as to enhance their applicability. Sufficient work has been done for studying the machining of AMCs with particle reinforcements of micron range. This paper presents the study of AMCs with particle reinforcement of under micron range i.e. nanoparticles. This paper brings out the results of an experimental investigation of type and weight percent of nanoparticles on the tangential cutting force during turning operation. SiC, Gr and SiC-Gr (in equal proportions) were used with Al-6061 alloy as the matrix phase. The results indicate that composites with SiC require greater cutting force followed by hybrid and then Gr. Increase in the weight percent also significantly affected the magnitude of cutting force. RSM was used first to design and analyze the experiments and then to optimize the turning process and obtain optimal conditions of weight and type of reinforcements for turning operation.

  14. Fiber-reinforced ceramic matrix composites processed by a hybrid technique based on chemical vapor infiltration, slurry impregnation and spark plasma sintering

    International Nuclear Information System (INIS)

    Magnant, J.; Pailler, R.; Le Petitcorps, Y.; Maille, L.; Guette, A.; Marthe, J.

    2013-01-01

    Fabrication of multidirectional continuous carbon and silicon carbide fiber reinforced ceramic matrix composites (CMC) by a new short time hybrid process was studied. This process is based, first, on the deposition of fiber interphase and coating by chemical vapor infiltration, next, on the introduction of silicon nitride powders into the fibrous preform by slurry impregnation and, finally, on the densification of the composite by liquid phase spark plasma sintering (LP-SPS). The homogeneous introduction of the ceramic charges into the multidirectional fiber pre-forms was realized by slurry impregnation from highly concentrated and well-dispersed aqueous colloid suspensions. The chemical degradation of the carbon fibers during the fabrication was prevented by adapting the sintering pressure cycle. The composites manufactured are dense. Microstructural analyses were conducted to explain the mechanical properties achieved. One main important result of this study is that LP-SPS can be used in some hybrid processes to densify fiber reinforced CMC. (authors)

  15. Microwave combustion synthesis of in situ Al{sub 2}O{sub 3} and Al{sub 3}Zr reinforced aluminum matrix composites

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Heguo, E-mail: zhg1200@sina.com [College of Materials Science and Engineering, Nanjing University of Science and Technology, Nanjing 210094 (China); Key Laboratory of Advanced Micro-Nano Materials and Technology, Jiangsu Province Higher Education Institutions, 210094 (China); Synergetic Center for Advanced Materials Research, Jiangsu Province Higher Education Institutions, 210094 (China); Hua, Bo; Cui, Tao; Huang, Jiewen; Li, Jianliang [College of Materials Science and Engineering, Nanjing University of Science and Technology, Nanjing 210094 (China); Xie, Zonghan, E-mail: zonghan.xie@adelaide.edu.au [School of Mechanical & Electrical Engineering, Wuhan Institute of Technology, Wuhan 430073 (China); School of Mechanical Engineering, University of Adelaide, SA 5005 (Australia)

    2015-08-15

    Al{sub 2}O{sub 3} and Al{sub 3}Zr reinforced aluminum matrix composites were fabricated from Al and ZrO{sub 2} powders by SiC assisted microwave combustion synthesis. The microstructure and reaction pathways were analyzed by using differential scanning calorimetry (DSC), X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and energy dispersive spectroscopy (EDS). The results showed that the heating rate during microwave synthesis was very high and the entire process took several minutes and that the ignition temperature of the reaction was much lower than that of conventional methods. In addition, the resulting microstructure was found to be finer than that prepared by the conventional methods and no cracks can be seen in the Al{sub 3}Zr reinforcements. As such, the newly developed composites have potential for safety-critical applications where catastrophic failure is not tolerated.

  16. Interface and its effect on the interlaminate shear strength of novel glass fiber/hyperbranched polysiloxane modified maleimide-triazine resin composites

    International Nuclear Information System (INIS)

    Liu Ping; Guan Qingbao; Gu Aijuan; Liang Guozheng; Yuan Li; Chang Jianfei

    2011-01-01

    Interface is Key topic of developing advanced fiber reinforced polymeric composites. Novel advanced glass woven fabric (GF) reinforced composites, coded as GF/mBT, were prepared, of which the matrix resin was hyperbranched polysiloxane (HBPSi) modified maleimide-triazine (mBT) resin. The influence of the composition of the matrix on the interfacial nature of the GF/mBT composites were studied and compared with that of the composite based on GF and BT resin using contact angle, X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM), and dielectric properties over wide frequency and temperature ranges. Results show that the interfacial nature of the composites is dependent on the chemistries of the matrices, mBT matrices have better interfacial adhesion with GF than BT resin owing to the formation of chemical and hydrogen bonds between mBT resin and GF; while in the case of mBT resins, the content of HBPSi also plays an important role on the interfacial feature and thus the macro-performance. Specifically, with increasing the content of HBPSi in the matrix, the interlaminate shear strength of corresponding composites significantly improves, demonstrating that better interfacial adhesion guarantees outstanding integrated properties of the resultant composites.

  17. Effect of nanoparticles and nanofibers on Mode I fracture toughness of fiber glass reinforced polymeric matrix composites

    International Nuclear Information System (INIS)

    Kelkar, Ajit D.; Mohan, Ram; Bolick, Ronnie; Shendokar, Sachin

    2010-01-01

    Graphical abstract: Use of alumina nanoparticles and TEOS electrospun nanofibers at the interfaces of glass fiber plies to develop delamination resistant epoxy polymeric composites and compare their Mode I fracture toughness characteristics. - Abstract: In the recent past, the research involving the fabrication and processing of reinforced polymer nanocomposites has increased significantly. These new materials are enabling in the discovery, development and incorporation of improved nanocomposite materials with effective manufacturing methodologies for several defense and industrial applications. These materials eventually will allow the full utilization of nanocomposites in not only reinforcing applications but also in multifunctional applications where sensing and the unique optical, thermal, electrical and magnetic properties of nanoparticles can be combined with mechanical reinforcement to offer the greatest opportunities for significant advances in material design and function. This paper presents two methods and material systems for processing and integration of the nanomaterial constituents, namely: (a) dispersing alumina nanoparticles using high energy mixing (using ultrasonication, high shear mixing and pulverization) and (b) electrospinning technique to manufacture nanofibers. These reinforced polymer nanocomposites and the processing methodologies are likely to provide effective means of improving the interlaminar properties of woven fiber glass composites compared to the traditional methods such as stitching and Z-pinning. The electrospinning technology relies on the creation of nanofibers with improved molecular orientation with reduced concentration of fiber imperfections and crystal defects. Electrospinning process utilizes surface tension effects created by electrostatic forces acting on liquid droplets, creating numerous nanofibers. These nanofibers thus have potential to serve as through-the-thickness reinforcing agents in woven composites. While

  18. Impact Strength of Composite Materials Based on EN AC-44200 Matrix Reinforced with Al2O3 Particles

    OpenAIRE

    Kurzawa A.; Kaczmar J.W.

    2017-01-01

    The paper presents the results of research of impact strength of aluminum alloy EN AC-44200 based composite materials reinforced with alumina particles. The research was carried out applying the materials produced by the pressure infiltration method of ceramic preforms made of Al2O3 particles of 3-6μm with the liquid EN AC-44200 Al alloy. The research was aimed at determining the composite resistance to dynamic loads, taking into account the volume of reinforcing particles (from 10 to 40% by ...

  19. Influence of the Sr and Mg Alloying Additions on the Bonding Between Matrix and Reinforcing Particles in the AlSi7Mg/SiC-Cg Hybrid Composite

    Directory of Open Access Journals (Sweden)

    Dolata A. J.

    2016-06-01

    Full Text Available The aim of the work was to perform adequate selection of the phase composition of the composite designated for permanent - mould casting air compressor pistons. The hybrid composites based on AlSi7Mg matrix alloy reinforced with mixture of silicon carbide (SiC and glassy carbon (Cg particles were fabricated by the stir casting method. It has been shown that the proper selection of chemical composition of matrix alloy and its modification by used magnesium and strontium additions gives possibility to obtain both the advantageous casting properties of composite suspensions as well as good bonding between particles reinforcements and matrix.

  20. Effect of rare earth oxide addition on microstructures of ultra-fine WC-Co particulate reinforced Cu matrix composites prepared by direct laser sintering

    International Nuclear Information System (INIS)

    Gu Dongdong; Shen Yifu; Zhao Long; Xiao Jun; Wu Peng; Zhu Yongbing

    2007-01-01

    This paper presents a detailed investigation into the influence of the rare earth (RE) oxide (La 2 O 3 ) addition upon the densification and the resultant microstructural characteristics of the submicron WC-Co particulate reinforced Cu matrix composites prepared by direct laser sintering. It is found that the relative density of the laser sintered sample with 1 wt.% La 2 O 3 addition increased by 11.5% as compared with the sample without RE addition. The addition of RE element favored the microstructural refinement and improved the particulate dispersion homogeneity and the particulate/matrix interfacial coherence. The metallurgical functions of the RE element in improving the sinterability were also addressed. It shows that due to the unique properties of RE element such as high surface activity and large atomic radius, the addition of trace RE element can decrease the surface tension of the melt, resist the grain growth coarsening and increase the heterogeneous nucleation rate during laser sintering

  1. Fracture behaviour of mullite fibre reinforced-mullite matrix composites under quasi-static and ballistic impact loading

    Czech Academy of Sciences Publication Activity Database

    Boccaccini, A. R.; Atiq, S.; Boccaccini, D. N.; Dlouhý, Ivo; Kaya, C.

    č. 65 (2005), s. 325-333 ISSN 0266-3538 R&D Projects: GA AV ČR IAA2041003 Keywords : ceramic matrix composites * mullite matrix * toughness Subject RIV: JL - Materials Fatigue, Friction Mechanics Impact factor: 2.184, year: 2005

  2. Disposal of bead ion exchange resin wastes

    International Nuclear Information System (INIS)

    Gay, R.L.; Granthan, L.F.

    1985-01-01

    Bead ion exchange resin wastes are disposed of by a process which involves spray-drying a bead ion exchange resin waste in order to remove substantially all of the water present in such waste, including the water on the surface of the ion exchange resin beads and the water inside the ion exchange resin beads. The resulting dried ion exchange resin beads can then be solidified in a suitable solid matrix-forming material, such as a polymer, which solidifies to contain the dried ion exchange resin beads in a solid monolith suitable for disposal by burial or other conventional means

  3. Modelling of high temperature interfacial reactions in continuously reinforced Ti/SiC metal matrix composites (MMCs)

    International Nuclear Information System (INIS)

    Fox, K.M.

    1993-01-01

    Previous experimental work by Gundel and Wawner showed that the matrix alloy has a strong effect on reaction layer growth in Ti alloy/SCS-6 composite systems. A finite difference technique was used to model the reaction layer growth, which predicts the same trends as those exhibited by the experimental data. Matrix alloying elements such as Mo and Cr in metastable β alloys will affect the equilibrium compositions and diffusivities in the matrix, but matrix diffusion is not found to be rate controlling. Regular solution thermodynamic models indicate that the main affect of matrix composition is in controlling carbon-flux through the reaction layer by altering equilibrium C-TiC-Ti interfacial compositions. (orig.)

  4. Influence of matrix ductility and fibre architecture on the repeated impact response of glass-fibre-reinforced laminated composites.

    NARCIS (Netherlands)

    Schrauwen, B.A.G.; Peijs, A.A.J.M.

    2002-01-01

    This paper describes the results of falling weight impact tests on glass-fibre-reinforced laminates. The test program consisted of (i) falling weight impact tests for the determination of the penetration energy and the influence of laminate construction on damage development and (ii) repeated

  5. Evaluation of fracture toughness and mechanical properties of ternary thiol-ene-methacrylate systems as resin matrix for dental restorative composites.

    Science.gov (United States)

    Beigi, Saeed; Yeganeh, Hamid; Atai, Mohammad

    2013-07-01

    Study and evaluation of fracture toughness, flexural and dynamic mechanical properties, and crosslink density of ternary thiol-ene-methacrylate systems and comparison with corresponding conventional methacrylate system were considered in the present study. Urethane tetra allyl ether monomer (UTAE) was synthesized as ene monomer. Different formulations were prepared based on combination of UTAE, BisGMA/TEGDMA and a tetrathiol monomer (PETMP). The photocuring reaction was conducted under visible light using BD/CQ combination as photoinitiator system. Mechanical properties were evaluated via measuring flexural strength, flexural modulus and fracture toughness. Scanning electron microscopy (SEM) was utilized to study the morphology of the fractured specimen's cross section. Viscoelastic properties of the samples were also determined by dynamic mechanical thermal analysis (DMTA). The same study was performed on a conventional methacrylate system. The data were analyzed and compared by ANOVA and Tukey HSD tests (significance level=0.05). The results showed improvement in fracture toughness of the specimens containing thiol-ene moieties. DMTA revealed a lower glass transition temperature and more homogenous structure for thiol-ene containing specimens in comparison to the system containing merely methacrylate monomer. The flexural modulus and flexural strength of the specimens with higher thiol-ene content were lower than the neat methacrylate system. The SEM micrographs of the fractured surface of specimens with higher methacrylate content were smooth and mirror-like (shiny) which represent brittle fracture. The thiol-ene-methacrylate system can be used as resin matrix of dental composites with enhanced fracture toughness in comparison to the methacrylate analogous. Copyright © 2013 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  6. Microstructural characteristics, mechanical and wear behaviour of aluminium matrix hybrid composites reinforced with alumina, rice husk ash and graphite

    Directory of Open Access Journals (Sweden)

    Kenneth Kanayo Alaneme

    2015-09-01

    Full Text Available The microstructural characteristics, mechanical and wear behaviour of Aluminium matrix hybrid composites reinforced with alumina, rice husk ash (RHA and graphite were investigated. Alumina, RHA and graphite mixed in varied weight ratios were utilized to prepare 10 wt% hybrid reinforced Al-Mg-Si alloy based composites using two-step stir casting. Hardness, tensile properties, scanning electron microscopy, and wear tests were used to characterize the composites produced. The results show that Hardness decreases with increase in the weight ratio of RHA and graphite in the composites; and with RHA content greater than 50%, the effect of graphite on the hardness becomes less significant. The tensile strength for the composites containing o.5wt% graphite and up to 50% RHA was observed to be higher than that of the composites without graphite. The toughness values for the composites containing 0.5wt% graphite were in all cases higher than that of the composites without graphite. The % Elongation for all composites produced was within the range of 10–13% and the values were invariant to the RHA and graphite content. The tensile fracture surface morphology in all the composites produced was identical characterized with the presence of reinforcing particles housed in ductile dimples. The composites without graphite exhibited greater wear susceptibility in comparison to the composite grades containing graphite. However the wear resistance decreased with increase in the graphite content from 0.5 to 1.5 wt%.

  7. New bio-active, antimicrobial and adherent coatings of nanostructured carbon double-reinforced with silver and silicon by Matrix-Assisted Pulsed Laser Evaporation for medical applications

    Science.gov (United States)

    Duta, L.; Ristoscu, C.; Stan, G. E.; Husanu, M. A.; Besleaga, C.; Chifiriuc, M. C.; Lazar, V.; Bleotu, C.; Miculescu, F.; Mihailescu, N.; Axente, E.; Badiceanu, M.; Bociaga, D.; Mihailescu, Ion N.

    2018-05-01

    We report on Matrix-Assisted Pulsed Laser Evaporation (MAPLE) deposition of Carbon thin films, simple or reinforced with intended concentrations of Ag and Si. A KrF∗ (λ = 248 nm, τFWHM ≤ 25 ns, ν = 10 Hz) excimer laser was used for irradiation. The effect of a post-deposition thermal treatment in vacuum was studied. Besides detailed morphological, compositional, structural and pull-out adherence characterizations, the potential of the carbonaceous films for medical applications was investigated in vitro by anti-biofilm and cytocompatibility assays. The microscopic images evidenced no delaminations. Micro-Raman spectroscopy revealed a graphitization tendency depending on preparation conditions, thermal treatment and reinforcing agents' presence. Adherence values improved considerably after thermal treatment. In vitro biological evaluation showed that the films containing ∼1.85 at.% Ag were non-cytotoxic for MG63 cells, while eliciting a limited antimicrobial activity. The increase of Ag content to 3.6 at.% results in a significant enhancement of antimicrobial activity, whilst maintaining the cytotoxic action and adherence characteristics at acceptable levels. We propose a new class of metamaterials based on C reinforced with Ag and Si obtained by MAPLE for medical applications, i.e. the prevention and treatment of various infections associated with biofilms developed on implants and other medical equipments.

  8. Structure evolutions in a Ti–6Al–4V matrix composite reinforced with TiB, characterised using high energy X-ray diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Ropars, Ludovic, E-mail: ludovic.ropars@airbus.com [Airbus Group SAS, Airbus Group Innovations, 12 rue Pasteur, BP-76, 92152 Suresnes Cedex (France); Institut Jean Lamour (IJL), SI2M Dpt., CNRS UMR 7198, Université de Lorraine, Parc de Saurupt, CS 50840, F-54011 Nancy Cedex (France); Dehmas, Moukrane, E-mail: ismoukrane.dehmas@univlorraine.fr [Institut Jean Lamour (IJL), SI2M Dpt., CNRS UMR 7198, Université de Lorraine, Parc de Saurupt, CS 50840, F-54011 Nancy Cedex (France); Laboratory of Excellence for Design of Alloy Metals for Low-mass Structures (‘DAMAS’ Labex), Université de Lorraine (France); Gourdet, Sophie; Delfosse, Jérôme [Airbus Group SAS, Airbus Group Innovations, 12 rue Pasteur, BP-76, 92152 Suresnes Cedex (France); Tricker, David [Materion AMC, RAE Road, Farnborough, Hampshire GU14 6XE (United Kingdom); Aeby-Gautier, Elisabeth [Institut Jean Lamour (IJL), SI2M Dpt., CNRS UMR 7198, Université de Lorraine, Parc de Saurupt, CS 50840, F-54011 Nancy Cedex (France); Laboratory of Excellence for Design of Alloy Metals for Low-mass Structures (‘DAMAS’ Labex), Université de Lorraine (France)

    2015-03-05

    Highlights: • In-situ high energy X-ray diffraction used during different thermal treatments. • Kinetics of phase evolutions characterised for the matrix and for the borides. • Conversion from TiB{sub 2} to TiB-B27 via a metastable structure TiB-B{sub f}. • Strong effect of the process on the matrix phases evolutions and microstructure. - Abstract: A titanium matrix composite reinforced with TiB was produced using powder metallurgy. A Ti–6Al–4V alloy was chosen to be the matrix, and 12 wt.% of TiB{sub 2} was used as the boron source for the solid state formation of TiB. The TiB{sub 2} to TiB conversion reaction was studied using an in situ high energy X-ray diffraction technique while heat treating the composite. The TiB{sub 2} (space group: P6/mmm) converts into TiB-B27 (Pnma), via TiB-B{sub f} (Cmcm). The metastable character of B{sub f} is confirmed here; it is the first phase formed during the conversion and it progressively converts into B27 during elevated temperature heat treatment. A modification of the phase transformation kinetics in the matrix and of the composite β transus temperature (T{sub β} = 1275 °C) was also observed, mainly due to gas contamination and intensive work hardening as a result of the mechanical alloying process used to manufacture the material and to a modification of the matrix equilibria.

  9. A comparative study to check fracture strength of provisional fixed partial dentures made of autopolymerizing polymethylmethacrylate resin reinforced with different materials: An in vitro study

    Directory of Open Access Journals (Sweden)

    Parikshit Gupt

    2017-01-01

    Conclusion: Unidirectional glass fibers showed the maximum strength, which was comparable to mean values of both stainless steel wire groups. Low cost and easy technique of using stainless steel wire make it the material of choice over the unidirectional glass fiber for reinforcement in nonesthetic areas where high strength is required.

  10. Microstructure and wear resistance of a laser clad TiC reinforced nickel aluminides matrix composite coating

    International Nuclear Information System (INIS)

    Chen, Y.; Wang, H.M.

    2004-01-01

    Wear resistant TiC/(NiAl-Ni 3 Al) composite coating was fabricated on a substrate of electrolyzed nickel by laser cladding using Ni-Al-Ti-C alloy powders. The laser clad coating is metallurgically bonded to the substrate and has a homogenous fine microstructure consisting of the flower-like equiaxed TiC dendrite and the dual phase matrix of NiAl and Ni 3 Al. The intermetallic matrix composite coating exhibits excellent wear resistance under both room- and high-temperature sliding wear test conditions due to the high hardness of TiC coupled with the strong atomic bonds of intermetallic matrix

  11. Development of an in-situ multi-component reinforced Al-based metal matrix composite by direct metal laser sintering technique — Optimization of process parameters

    Energy Technology Data Exchange (ETDEWEB)

    Ghosh, Subrata Kumar, E-mail: subratagh82@gmail.com [Department of Mechanical Engineering, National Institute of Technology Agartala, Tripura 799055 (India); Bandyopadhyay, Kaushik; Saha, Partha [Department of Mechanical Engineering, Indian Institute of Technology Kharagpur, Kharagpur 721302 (India)

    2014-07-01

    In the present investigation, an in-situ multi-component reinforced aluminum based metal matrix composite was fabricated by the combination of self-propagating high-temperature synthesis and direct metal laser sintering process. The different mixtures of Al, TiO{sub 2} and B{sub 4}C powders were used to initiate and maintain the self-propagating high-temperature synthesis by laser during the sintering process. It was found from the X-ray diffraction analysis and scanning electron microscopy that the reinforcements like Al{sub 2}O{sub 3}, TiC, and TiB{sub 2} were formed in the composite. The scanning electron microscopy revealed the distribution of the reinforcement phases in the composite and phase identities. The variable parameters such as powder layer thickness, laser power, scanning speed, hatching distance and composition of the powder mixture were optimized for higher density, lower porosity and higher microhardness using Taguchi method. Experimental investigation shows that the density of the specimen mainly depends upon the hatching distance, composition and layer thickness. On the other hand, hatching distance, layer thickness and laser power are the significant parameters which influence the porosity. The composition, laser power and layer thickness are the key influencing parameters for microhardness. - Highlights: • The reinforcements such as Al{sub 2}O{sub 3}, TiC, and TiB{sub 2} were produced in Al-MMC through SHS. • The density is mainly influenced by the material composition and hatching distance. • Hatching distance is the major influencing parameter on porosity. • The material composition is the significant parameter to enhance the microhardness. • The SEM micrographs reveal the distribution of TiC, TiB{sub 2} and Al{sub 2}O{sub 3} in the composite.

  12. Development of an in-situ multi-component reinforced Al-based metal matrix composite by direct metal laser sintering technique — Optimization of process parameters

    International Nuclear Information System (INIS)

    Ghosh, Subrata Kumar; Bandyopadhyay, Kaushik; Saha, Partha

    2014-01-01

    In the present investigation, an in-situ multi-component reinforced aluminum based metal matrix composite was fabricated by the combination of self-propagating high-temperature synthesis and direct metal laser sintering process. The different mixtures of Al, TiO 2 and B 4 C powders were used to initiate and maintain the self-propagating high-temperature synthesis by laser during the sintering process. It was found from the X-ray diffraction analysis and scanning electron microscopy that the reinforcements like Al 2 O 3 , TiC, and TiB 2 were formed in the composite. The scanning electron microscopy revealed the distribution of the reinforcement phases in the composite and phase identities. The variable parameters such as powder layer thickness, laser power, scanning speed, hatching distance and composition of the powder mixture were optimized for higher density, lower porosity and higher microhardness using Taguchi method. Experimental investigation shows that the density of the specimen mainly depends upon the hatching distance, composition and layer thickness. On the other hand, hatching distance, layer thickness and laser power are the significant parameters which influence the porosity. The composition, laser power and layer thickness are the key influencing parameters for microhardness. - Highlights: • The reinforcements such as Al 2 O 3 , TiC, and TiB 2 were produced in Al-MMC through SHS. • The density is mainly influenced by the material composition and hatching distance. • Hatching distance is the major influencing parameter on porosity. • The material composition is the significant parameter to enhance the microhardness. • The SEM micrographs reveal the distribution of TiC, TiB 2 and Al 2 O 3 in the composite

  13. Degradation behaviour of fiber reinforced plastic under electron beam irradiation

    International Nuclear Information System (INIS)

    Sonoda, Katsumi; Yamamoto, Yasushi; Hashimoto, Osamu

    1989-01-01

    Various mechanical properties of four kinds of glass fiber-reinforced plastics irradiated with electron beams were examined at three temperatures; room temperature, 123 K and 77 K. Dynamic viscoelastic properties were measured, and fractography by means of scanning electron microscopy was observed in order to clarify degradation behaviour. A considerable decrease in interlaminar shear strength (ILSS) at room temperature was observed above 60 MGy. On the other hand, the three-point bending strength at 77 K and the ILSS at 123 K decreased with increasing irradiation. Fractography reveals that the degradation of the interface layer between matrix resin and fiber plays an important role in the strength reduction at 123 K and 77 K. These findings suggest that the interface between matrix resin and fiber loses its bondability at 123 K arid 77 K after electron beam irradiation. (author)

  14. The role of the epoxy resin: Curing agent ratio in composite interfacial strength by single fibre microbond test

    DEFF Research Database (Denmark)

    Minty, Ross; Thomason, James L.; Petersen, Helga Nørgaard

    2015-01-01

    This paper focuses on an investigation into the role of the epoxy resin: curing agent ratio in composite interfacial shear strength of glass fibre composites. The procedure involved changing the percentage of curing agent (Triethylenetetramine [TETA]) used in the mixture with several different...... percentages used, ranging from 4% up to 30%, including the stoichiometric ratio. It was found by using the microbond test, that there may exist a relationship between the epoxy resin to curing agent ratio and the level of adhesion between the reinforcing fibre and the polymer matrix of the composite....

  15. In-situ development of carbon nanotubes network and graphitic carbon by catalytic modification of phenolic resin binder in Al2O3–MgO–C refractories

    Directory of Open Access Journals (Sweden)

    Atul V. Maldhure

    2017-09-01

    Full Text Available In-situ formation of cross-linked carbon nanotubes network reinforced the refractory matrix and helps to improve the mechanical properties at elevated temperature. In this paper, the effect of modified phenol-formaldehyde (PF resin binder on the various mechanical properties of alumina–magnesia–carbon (AMC refractories was investigated. Initially, PF resin was modified by adding a different proportion of nickel catalyst. The AMC specimens (with the 7% carbon were prepared by using 5% of modified PF resin. The pressed samples were cured at 180 °C for 24 h and characterized by XRD, Raman spectroscopy, and FE-SEM. The characterisation shows that, in-situ formation of graphitic carbon and carbon nanotubes network in the specimens due to modification of PF resin. In-situ formation of phases leads to enhancement of density and mechanical properties of refractory at elevated temperature due to the reinforcing effect.

  16. An efficient ultrasound assisted approach for the impregnation of room temperature ionic liquid onto Dowex 1 × 8 resin matrix and its application toward the enhanced adsorption of chromium (VI)

    International Nuclear Information System (INIS)

    Kalidhasan, S.; Santhana Krishna Kumar, A.; Vidya Rajesh; Rajesh, N.

    2012-01-01

    Highlights: ► Ultrasound assisted impregnation of an ionic liquid in a Dowex resin matrix is studied through various physicochemical and spectroscopic techniques. ► Chromium is adsorbed with a high adsorption capacity of 230.9 mg g −1 . ► The adsorbent is regenerated using HCl–ascorbic acid mixture. ► Chromium could be effectively detoxified from an industrial effluent and the developed method was validated with the analysis of a certified reference material. - Abstract: The work discussed in this paper is based on the utilization of ultrasound in conjunction with an ionic liquid (Aliquat 336) impregnated Dowex 1 × 8 resin for the effective adsorption of chromium. Ionic liquids are known for their selectivity toward metal extraction and ultrasonic medium offers efficient energy transfer for impregnating the ionic liquid in the resin matrix. The molecular interaction between the ionic liquid impregnated resin and chromium was studied through various physicochemical and spectroscopic techniques. The influence of various analytical parameters on the adsorption of Cr(VI) such as pH, adsorbent dosage, temperature and interference of foreign ions was studied in detail. Chromium (VI) was quantitatively adsorbed in the pH range of 3.5–4, with a high adsorption capacity of 230.9 mg g −1 in conformity with the Langmuir isotherm model. The study of thermodynamic parameters showed that the adsorption process is exothermic and spontaneous. The adsorbent could be regenerated using 1 mol L −1 HCl–0.28 mol L −1 ascorbic acid mixture. Chromium could be effectively detoxified from an industrial effluent and finally the developed method was validated with the analysis of a certified reference material (BCR-715). The obtained results indicated that the ultrasonic assisted impregnation of the room temperature ionic liquid significantly enhances and improves the removal efficiency of Cr(VI).

  17. Young modulus and internal friction of a fiber-reinforced composite

    International Nuclear Information System (INIS)

    Ledbetter, H.M.; Lei, M.; Austin, M.W.

    1986-01-01

    By a kilohertz-frequency resonance method we determined the Young modulus and internal friction of a uniaxially fiber-reinforced composite. The composite comprised glass fibers in an epoxy-resin matrix. We studied three fiber contents: 0, 41, and 49 vol %. The Young modulus fit a linear rule of mixture. The internal friction fit a classical free-damped-oscillator model where one assumes a linear rule of mixture for three quantities: mass, force constant, and mechanical-resistance constant

  18. Tensile properties of in situ synthesized titanium matrix composites reinforced by TiB and Nd2O3 at elevated temperature

    International Nuclear Information System (INIS)

    Geng Ke; Lu Weijie; Zhang Di; Sakata, Taokao; Mori, Hirotaro

    2003-01-01

    Titanium matrix composites reinforced with TiB and Nd 2 O 3 were prepared by a non-consumable arc-melting technology. X-ray diffraction (XRD) was used to identify the phases in the composites. Microstructures of the composites were observed by means of optical microscope (OM). There are three phases: TiB, Nd 2 O 3 and titanium matrix. TiB grows in needle shape, whereas Nd 2 O 3 grows in lath shape. Tensile properties of the composites were tested at 773, 823 and 873 K. Both the fracture surfaces and longitudinal sections of the fractured tensile specimens were comprehensively examined by scanning electron microscope (SEM). The fracture mode and fracture process at different temperatures were analyzed and explained. It shows that the tensile strength of the composites has a significant improvement at elevated temperatures compared to titanium matrix. The ductility of the composites improves with the content of neodymium and the test temperatures. The titanium composite exhibits different fracture modes at different test temperatures

  19. Effect of Zircon Silicate Reinforcements on the Microstructure and Properties of as Cast Al-4.5Cu Matrix Particulate Composites Synthesized via Squeeze Cast Route

    Directory of Open Access Journals (Sweden)

    E. G. Okafor

    2010-06-01

    Full Text Available The as-cast microstructure and properties of Al-4.5Cu/ZrSiO4 particulate composite synthesized via squeezed casting route was studied, varying the percentage ZrSiO4 in the range of 5-25wt%. The result obtained revealed that addition of ZrSiO4 reinforcements, increased the hardness value and apparent porosity by 107.65 and 34.23% respectively and decrease impact energy by 43.16 %. As the weight percent of ZrSiO4 increases in the matrix alloy, the yield and ultimate tensile strength increased by 156.52 and 155.81% up to a maximum of 15% ZrSiO4 addition respectively. The distribution of the brittle ZrSiO4 phase in the ductile matrix alloy led to increase strength and hardness values. These results had shown that, additions of ZrSiO4 particles to Al-4.5Cu matrix alloy improved properties.

  20. Role of the polymeric matrix in the processing and structural properties of composite materials. Proceedings of the Joint U.S.-Italy Symposium on Composite Materials, Capri, Italy, June 15-19, 1981

    International Nuclear Information System (INIS)

    Seferis, J.C.; Nicolais, L.

    1983-01-01

    The interaction between the polymeric matrix and the reinforcing phase and the effect of the matrix on composite performance are discussed under the following headings: chemical and environmental effects, short-fiber reinforcements, interfacial effects, and continuous fiber reinforcements and design. Papers are presented on the factors affecting the development of new matrix resins for advanced composites creep and fracture initiation in fiber-reinforced plastics dimensional stability of reinforced matrices and internal stresses in fiber-reinforced plastics. Other topics discussed include the use of composites in commercial aircraft, design of continuous-fiber composite structures, and delamination in graphite-epoxy. For individual items see A83-46280 to A83-46308