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Sample records for casting impact properties

  1. Enhancements in Magnesium Die Casting Impact Properties

    Energy Technology Data Exchange (ETDEWEB)

    David Schwam; John F. Wallace; Yulong Zhu; Srinath Viswanathan; Shafik Iskander

    2000-06-30

    The need to produce lighter components in transportation equipment is the main driver in the increasing demand for magnesium castings. In many automotive applications, components can be made of magnesium or aluminum. While being lighter, often times the magnesium parts have lower impact and fatigue properties than the aluminum. The main objective of this study was to identify potential improvements in the impact resistance of magnesium alloys. The most common magnesium alloys in automotive applications are AZ91D, AM50 and AM60. Accordingly, these alloys were selected as the main candidates for the study. Experimental quantities of these alloys were melted in an electrical furnace under a protective atmosphere comprising sulfur hexafluoride, carbon dioxide and dry air. The alloys were cast both in a permanent mold and in a UBE 315 Ton squeeze caster. Extensive evaluation of tensile, impact and fatigue properties was conducted at CWRU on permanent mold and squeeze cast test bars of AZ91, AM60 and AM50. Ultimate tensile strength values between 20ksi and 30ksi were obtained. The respective elongations varied between 25 and 115. the Charpy V-notch impact strength varied between 1.6 ft-lb and 5 ft-lb depending on the alloy and processing conditions. Preliminary bending fatigue evaluation indicates a fatigue limit of 11-12 ksi for AM50 and AM60. This is about 0.4 of the UTS, typical for these alloys. The microstructures of the cast specimens were investigated with optical and scanning electron microscopy. Concomitantly, a study of the fracture toughness in AM60 was conducted at ORNL as part of the study. The results are in line with values published in the literature and are representative of current state of the art in casting magnesium alloys. The experimental results confirm the strong relationship between aluminum content of the alloys and the mechanical properties, in particular the impact strength and the elongation. As the aluminum content increases from about 5

  2. Effect of RE Modification and Heat Treatment on Impact Fatigue Property of a Wear Resistant White Cast Iron

    Institute of Scientific and Technical Information of China (English)

    常立民; 刘建华; 张瑞军; 王继东

    2004-01-01

    The morphology of carbides, as well as the generation and propagation of fatigue cracks in a wear resistant white cast iron after impact fatigue test were observed by means of optical microscope and SEM, and the relationship among the content of RE (rare earths) in the wear resistant white cast iron and the heating temperature as well as the length and propagation speed of the fatigue cracks were determined. Based on the obtained results, the effect of RE modification and heat treatment on the impact fatigue property was further studied. Experimental results show that addition of RE can defer the time required for the generation of fatigue cracks, reduce their propagation speed and increase the impact fatigue resistance. The aforesaid effect is more noticeable in case of combined RE modification with heat treatment, which can be attributed to the variation in morphology and the distribution of the eutectic carbide network.

  3. Effects of nonstandard heat treatment temperatures on tensile and Charpy impact properties of carbon-steel casting repair welds

    International Nuclear Information System (INIS)

    This report discusses carbon steel castings which are used for a number of different components in nuclear power plants, including valve bodies and bonnets. Components are often repaired by welding processes, and both welded components and the repair welds are subjected to a variety of postweld heat treatments (PWHT) with temperatures as high as 899 degrees C (1650 degrees F), well above the normal 593 to 677 degrees C (1100 to 1250 degrees F) temperature range. The temperatures noted are above the A1 transformation temperature for the materials used for these components. A test program was conducted to investigate the potential effects of such ''nonstandard'' PWHTs on mechanical properties of carbon steel casting welds. Four weldments were fabricated, two each with the shielded-metal-arc (SMA) and flux-cored-arc (FCA) processes,with a high-carbon and low-carbon filler metal in each case. All four welds were sectioned and given simulated PWHTs at temperatures from 621 to 899 degrees C (1150 to 1650 degrees F) in increments of 56 degrees C (100 degrees F) and for times of 5, 10, 20, and 40 h at each temperature. Hardness, tensile, and Charpy V-notch (CVN) impact tests were conducted for the as-welded and heat-treated conditions

  4. Microstructures and properties of aluminum die casting alloys

    Energy Technology Data Exchange (ETDEWEB)

    M. M. Makhlouf; D. Apelian; L. Wang

    1998-10-01

    This document provides descriptions of the microstructure of different aluminum die casting alloys and to relate the various microstructures to the alloy chemistry. It relates the microstructures of the alloys to their main engineering properties such as ultimate tensile strength, yield strength, elongation, fatigue life, impact resistance, wear resistance, hardness, thermal conductivity and electrical conductivity. Finally, it serves as a reference source for aluminum die casting alloys.

  5. The effect of microstructure of low-alloy spheroidal cast iron on impact strength

    Directory of Open Access Journals (Sweden)

    T. Szykowny

    2010-01-01

    Full Text Available The study presents an evaluation of the effect of microstructure of low-alloy spheroidal cast iron on impact strength within the temperature range from –60 to 100°C. Analyses were conducted on one type of cast iron containing 0.51% Cu and 0.72% Ni. Cast iron was austempered or normalized. Values of KCV and static mechanical properties were determined. Structural and fractographic analyses were based on light and scanning microscopy as well as X-ray diffraction. It was found that thermal processing considerably improves impact strength in relation to cast iron after casting. At the same time static mechanical properties are enhanced.

  6. Fatigue Properties of Cast Magnesium Wheels

    Science.gov (United States)

    Li, Zhenming; Luo, Alan A.; Wang, Qigui; Peng, Liming; Zhang, Peng

    2016-08-01

    This paper investigates the fatigue properties and deformation behavior of a newly developed Mg-2.96Nd-0.21Zn-0.39Zr magnesium alloy wheel in both as-cast and T6 conditions. Compared with the as-cast alloy, the T6-treated alloy shows a significant increase in fatigue strength and cyclic stress amplitude. This is believed to be attributed to the change of defect type from porosity to oxides and the increased matrix strength in the T6 (peak-aged) condition. For the as-cast alloy wheel, fatigue failure mainly originated from the cast defects including porosity, oxide film, and inclusion at or near the sample surface. In the T6-treated alloy, however, oxides and inclusions or slip bands initiate the fatigue cracks. Solution treatment appears to reduce or eliminate the shrinkage porosity because of grain growth and dissolution of as-cast eutectic phases in the grain boundaries. The cyclic stress amplitude of the as-cast alloy increases with increasing the number of cycles, while the T6-treated alloy shows cyclic softening after the stress reaches a maximum value. The Coffin-Manson law and Basquin equation can be used to evaluate the life of low cycle fatigue. The developed long crack model and multi-scale fatigue (MSF) models can be used to predict high-cycle fatigue life of the Mg-2.96Nd-0.21Zn-0.39Zr alloys with or without casting defects.

  7. Fatigue Properties of Cast Magnesium Wheels

    Science.gov (United States)

    Li, Zhenming; Luo, Alan A.; Wang, Qigui; Peng, Liming; Zhang, Peng

    2016-05-01

    This paper investigates the fatigue properties and deformation behavior of a newly developed Mg-2.96Nd-0.21Zn-0.39Zr magnesium alloy wheel in both as-cast and T6 conditions. Compared with the as-cast alloy, the T6-treated alloy shows a significant increase in fatigue strength and cyclic stress amplitude. This is believed to be attributed to the change of defect type from porosity to oxides and the increased matrix strength in the T6 (peak-aged) condition. For the as-cast alloy wheel, fatigue failure mainly originated from the cast defects including porosity, oxide film, and inclusion at or near the sample surface. In the T6-treated alloy, however, oxides and inclusions or slip bands initiate the fatigue cracks. Solution treatment appears to reduce or eliminate the shrinkage porosity because of grain growth and dissolution of as-cast eutectic phases in the grain boundaries. The cyclic stress amplitude of the as-cast alloy increases with increasing the number of cycles, while the T6-treated alloy shows cyclic softening after the stress reaches a maximum value. The Coffin-Manson law and Basquin equation can be used to evaluate the life of low cycle fatigue. The developed long crack model and multi-scale fatigue (MSF) models can be used to predict high-cycle fatigue life of the Mg-2.96Nd-0.21Zn-0.39Zr alloys with or without casting defects.

  8. Effect of annealing on mechanical properties of ledeburitic cast steel

    Directory of Open Access Journals (Sweden)

    E. Rożniata

    2007-01-01

    Full Text Available Purpose: The paper presents evaluation of influence of grain normalization (refinement as a result of repeatedaustenitizing, and the inclination to precipitate the hypereutectoid cementite in Widmannstätten structure inG200CrMoNi4-6-3 cast steel. Four temperatures of heat refining have been applied.Design/methodology/approach: Basic research of G200CrMoNi4-6-3 cast steel included metallographicanalysis, and hardness and impact strength tests. The heat treatment has been planned on the basis of CCTdiagram prepared for that alloy cast steel.Findings: The test material has been G200CrMoNi4-6-3 hypereutectoid cast steel. The evaluation has beencarried out for four annealing temperatures, i.e. 850°C, 900°C, 950°C and 1050°C. At all annealing temperaturesin the structure of cast steel the precipitation of hypereutectoid cementite along grain boundaries of formeraustenite took place. At the temperature of 850°C one may observe the coagulated hypereutectoid cementiteprecipitates inside of primary grains of austenite. Whereas beginning from the temperature of 900°C thecementite in G200CrMoNi4-6-3 cast steel forms distinct „subgrains” inside of primary grains of austenite.Research limitations/implications: Research financed by the Ministry of Scientific Research and InformationTechnology, grant No. 3 T08B 057 29.Practical implications: G200CrMoNi4-6-3 cast steel of ledeburite class is used mainly for rolls production.Any data related to the structure and mechanical properties of that cast steel are precious for the manufacturersand users of the mill rolls.Originality/value: The new heat treatment of G200CrMoNi4-6-3 cast steel

  9. Relationship between tensile and impact properties in Al–Si–Cu–Mg cast alloys and their fracture mechanisms

    International Nuclear Information System (INIS)

    An extensive study related to the investigation of the precipitation behavior of the CuAl2 phase in various 319-type alloys containing strontium (Sr), iron (Fe) and phosphorus (P) alloying elements, and its dissolution during solution heat treatment at 490 °C for times up to 100 h was carried out in the present work. Furthermore, the effect of CuAl2 and other intermetallics on the alloy performance under two different heat treatment conditions (i.e. T5 and T6) was also investigated through an examination of the tensile and impact properties. By comparing the experimental results, conclusions were drawn in terms of the optimum alloying elements, solidification parameters and heat treatment conditions (viz., Sr modification, Fe content, cooling rate and T6 condition). The fracture behaviors of the 319 base alloy and the Sr-modified 319 alloy containing ∼1.2% Fe were also compared through a study of the fracture surfaces of the corresponding alloy samples. The results explicitly reveal that solution heat treatment plays a critical role in the dissolution of the CuAl2 phase. Iron addition leads to an increased precipitation of brittle β-Al5FeSi platelets which act as preferred crack sites and dramatically reduce the impact properties, regardless of the value of dendrite arm spacing. Crack initiation usually occurs through the fragmentation of Si particles and β-Al5FeSi platelets, and the crack propagates through the cleavage of β-Al5FeSi platelets. - Highlights: • The addition of Sr leads to the segregation of the copper phase • The addition of Fe results in the dispersion of the CuAl2 • The CuAl2 phase particles are more or less completely dissolved in the Al matrix after 100 h of solution heat treatment • After T6 heat treatment most of the CuAl2 phase particles are dissolved into the aluminum matrix

  10. Effect of melt treatment on microstructure and impact properties of Al–7Si and Al–7Si–2.5Cu cast alloys

    Indian Academy of Sciences (India)

    K G Basavakumar; P G Mukunda; M Chakraborty

    2007-10-01

    The microstructures and impact toughness of Al–7Si and Al–7Si–2.5Cu cast alloys were studied after various melt treatments like grain refinement and modification. The results indicate that combined grain refined and modified Al–7Si–2.5Cu alloys have microstructures consisting of uniformly distributed -Al grains, interdendritic network of fine eutectic silicon and fine CuAl2 particles in the interdendritic region. These alloys exhibited improved impact toughness in as cast condition when compared to those treated by individual addition of grain refiner or modifier. The improved impact toughness of Al–7Si–2.5Cu alloys are related to breakage of the large aluminum grains and uniform distribution of eutectic silicon and fine CuAl2 particles in the interdendritic region resulting from combined refinement and modification. This paper attempts to investigate the influence of microstructural changes in the Al–7Si and Al–7Si–2.5Cu cast alloys by grain refinement, modification and combined action of both on the impact toughness.

  11. Impact of annealing on the structural and optical properties of methylene green nanostructure films prepared by drop casting

    Science.gov (United States)

    El-Menyawy, E. M.; Darwish, A. A. A.; Zedan, I. T.

    2016-05-01

    The methylene green (MG) powder was found to be polycrystalline with the triclinic system. MG films were deposited by drop coating technique. X-ray diffraction and scanning electron microscopy showed that the MG films have nanostructure nature. It is found that the crystal size is increased by annealing. Optical properties of nanostructured MG films were performed in the spectral range from 200 to 2500 nm to determine the optical constants (n and k). The absorption coefficient of the as-deposited film revealed a two indirect allowed optical band gap with values of 1.90 and 3.11 eV, which increased by annealing to 2 and 3.48 eV, respectively. The dispersion of n was discussed in terms of the single oscillator model. The high frequency dielectric constant and the lattice dielectric constant were estimated and found to decreased by annealing.

  12. Effect of thermal aging on mechanical properties of cast stainless steels

    International Nuclear Information System (INIS)

    A procedure and correlations are presented for predicting mechanical properties of cast stainless steels in service at temperatures <450 degrees C from known material information. The ''saturation'' fracture properties of a cast stainless steel, i.e., the minimum values that would be achieved for the material after long-term service, are estimated from the chemical composition of the steel. Fracture properties as a function of time and temperature of service are estimated from the kinetics of embrittlement, which are also determined from chemical composition. The correlations successfully predict fracture toughness, Charpy-impact, and tensile properties of cast stainless steels from the Shippingport-, Ringhals-, and Gundremmingen-reactor components

  13. Structure and mechanical properties of vermicular cast iron in cylinder head casting

    OpenAIRE

    Guzik, E.; S. Dzik

    2009-01-01

    The paper discusses the problem of grain density and ferrite content in microstructure of vermicular graphite iron cast in bars of different section diameters and cylinder head casting. The experimental results regarding the section effect demonstrate that the nodule count, grain density and ferrite content are all function of the cast bar diameter in this particular case ranging from 0.6 to 8.0 cm and microstructure and mechanical properties in the cylinder head. The nodule count (or grain d...

  14. Properties shaping and repair of selected types of cast iron

    Directory of Open Access Journals (Sweden)

    J. Szajnar

    2007-04-01

    Full Text Available The paper presents research results of twofold use of TIG - Tungsten Inert Gas also known as GTA - Gas Tungsten Arc. First is surfacing by welding on cold and hot-cold to repair chromium cast iron with chromium content about 15%. Second is remelting with electric arc of selected gray (with pearlitic matrix and ductile (with ferritic-pearlitic matrix cast iron. Repair of cast iron elements was realized in order to cut out a casting defects. Defects decrease a usability of castings for constructional application and increase a manufacturing costs. Application of surface heat treatment guarantees mechanical properties i.e. hardness and wear resistance improvement. The result of investigations show possibility of castings repair by put on defects a good quality padding welds, which have comparable properties with base material. Use of electric arc surface heat treatment resulted in increase of hardness and wear resistance, which was measured on the basis of ASTM G 65 - 00 standard.

  15. Aging degradation of cast stainless steels: Effects on mechanical properties

    International Nuclear Information System (INIS)

    A program is being conducted to investigate the significance of in-service embrittlement of cast duplex stainless steels under light-water operating conditions. Mechanical property data are presented from Charpy-impact, tensile, and J-R curve tests for several heats of cast stainless steel aged up to 10,000 h at 450, 400, 350, 320, and 2900C. The results indicate that thermal aging increases the tensile strength and decreases the impact energy, J/sub IC/, and tearing modulus of the steels. Also, the ductile-to-brittle transition curve shifts to higher temperatures. The fracture toughness results are consistent with the Charpy-impact data, i.e., the relative reduction in J/sub IC/ is similar to the relative decrease in impact energy. The ferrite content and concentration of C in the steel have a strong effect on the overall process of low-temperature embrittlement. The low-carbon CF-3 steels are the most resistant and Mo-containing CF-8M steels are most susceptible to embrittlement. Weakening of the ferrite/austenite phase boundaries by carbide precipitates has a significant effect on the kinetics and extent of embrittlement of the high-carbon CF-8 and CF-8M steels, particularly after aging at temperatures ≥4000C. The influence of N content and distribution of ferrite on loss of toughness are discussed. The data also indicate that existing correlations do not accurately represent the embrittlement behavior over the temperature range 280 to 4500C, i.e., extrapolation of high-temperature data to reactor temperatures may not be valid for some compositions of cast stainless steel

  16. Effect of Ablation Casting on Microstructure and Casting Properties of A356 Aluminium Casting Alloy

    Institute of Scientific and Technical Information of China (English)

    V.Bohlooli; M.Shabani Mahalli; S.M.A.Boutorabi

    2013-01-01

    Recently the Ablation Casting Technology was invented as a new casting process to improve foundry products quality.In this study,the effects of processing variables on the porosity content,microstructure and feedability of A356 casting alloy were investigated.Secondary dendrite arm spacing (SDAS) and eutectic silicon morphologies were studied to evaluate the influence of Ablation Casting on the microstructure.Casting density was measured in order to identify porosity content and feedability of ablated and non-ablated specimens.In addition,solidification behavior of the samples was investigated by using thermal analysis technique.The cooling curves and the first derivative curves were plotted and compared with each other.Results showed the ablation process could increase solidification rate significantly.In addition,the microstructural evidences revealed that Ablation Casting process results in more fine and homogeneous structure compared to the nonablated casting.The feedability improved,SDAS reduced to 35% and porosity content decreased to 3.84 vol.% by implementing this process.It concluded the Ablation Casting is an effective process to gain higher quality in aluminum foundry.

  17. Wear Property of Cast Steel Wheel Material in Rail Truck

    Institute of Scientific and Technical Information of China (English)

    MI Guo-fa; LIU Yan-lei; ZHANG Bin; FU Xiu-qin; ZHANG Hong; SONG Guo-xiang

    2009-01-01

    Wear property of material plays a key role in the service time of workpiece.A major objective in the development of new wheel materials is to improve the wear performance.The wear property of B and B+ grade cast steel materials was reported.The results showed that B+ grade cast steel material exhibited better wear property than the B grade material.Carbon content related to the hardness match was the principal factor affecting the wear properties.

  18. SYSTEMATIC AND DYNAMIC PROPER-TIES OF CASTING HOT SPOT

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The variation of casting hot spot with proceeding of solidification and components of casting-mold system is studied by the technique of numerical simulation of solidification.The result shows that the thickest part of casting is not exactly the last part of solidification in the casting, while the last part of solidification is not exactly casting hot spot at the early stage of solidification.The location, size, shape and number of casting hot spot change with geomitric, physical and technological factors of the casting-mold system such as thickness of the casting secondary wall and with the passage of time in the course of the solidification.The former is known as the systematic property of hot spot and the latter, dynamic property.Only when the properties of hot spot are grasped completely and accurately, can it be fed more effectively.By doing so, not only sound castings can be obtained, but also riser efficiency can be improved.

  19. Tensile-property characterization of thermally aged cast stainless steels

    Energy Technology Data Exchange (ETDEWEB)

    Michaud, W.F.; Toben, P.T.; Soppet, W.K.; Chopra, O.K. [Argonne National Lab., IL (United States)

    1994-02-01

    The effect of thermal aging on tensile properties of cast stainless steels during service in light water reactors has been evaluated. Tensile data for several experimental and commercial heats of cast stainless steels are presented. Thermal aging increases the tensile strength of these steels. The high-C Mo-bearing CF-8M steels are more susceptible to thermal aging than the Mo-free CF-3 or CF-8 steels. A procedure and correlations are presented for predicting the change in tensile flow and yield stresses and engineering stress-vs.-strain curve of cast stainless steel as a function of time and temperature of service. The tensile properties of aged cast stainless steel are estimated from known material information, i.e., chemical composition and the initial tensile strength of the steel. The correlations described in this report may be used for assessing thermal embrittlement of cast stainless steel components.

  20. Effect of molybdenum, vanadium, boron on mechanical properties of high chromium white cast iron in as-cast condition

    Science.gov (United States)

    Nurjaman, F.; Sumardi, S.; Shofi, A.; Aryati, M.; Suharno, B.

    2016-02-01

    In this experiment, the effect of the addition carbide forming elements on high chromium white cast iron, such as molybdenum, vanadium and boron on its mechanical properties and microstructure was investigated. The high chromium white cast iron was produced by casting process and formed in 50 mm size of grinding balls with several compositions. Characterization of these grinding balls was conducted by using some testing methods, such as: chemical and microstructure analysis, hardness, and impact test. From the results, the addition of molybdenum, vanadium, and boron on high chromium white cast iron provided a significant improvement on its hardness, but reduced its toughness. Molybdenum induced fully austenitic matrix and Mo2C formation among eutectic M7C3 carbide. Vanadium was dissolved in the matrix and carbide. While boron was played a role to form fine eutectic carbide. Grinding balls with 1.89 C-13.1 Cr-1.32 Mo-1.36 V-0.00051 B in as-cast condition had the highest hardness, which was caused by finer structure of eutectic carbide, needle like structure (upper bainite) matrix, and martensite on its carbide boundary.

  1. Simulation of mechanical properties of forged and casted steel 42CrMo4 specimen

    Directory of Open Access Journals (Sweden)

    B. Smoljan

    2010-12-01

    Full Text Available Purpose: In this paper, the prediction of working stress of quenched and tempered shaft has been done. Prediction was done for two different manufacture processes. In the first manufacture process the shaft was made of steel and in second one the shaft was made of cast steel. The working stress was characterized by yield strength and impact toughness. The method of computer simulation of working stress was applied in workpiece of complex form.Design/methodology/approach: Hardness distribution of quenched and tempered workpiece of complex form was predicted by computer simulation of quenching using a finite volume method. Hardness of quenched and tempered steel can be expressed as function of maximal hardness of actual steel, hardness of steel with 50% of martensite in microstructure, according to the time and temperature of tempering. The algorithm of estimation of yield strength and impact energy was based on hardness, HV. Starting point in studying of the mechanical properties of steel castings can be the fact that the mechanical properties of steel castings are derived from the mechanical properties of ordinary steel metal matrix reduced by the influence of the typical as-cast structure, i.e. casting defects on those properties. Hardness and yield strength will be unaffected by most defects. The only effect will be that due to the reduction in area. Coarse as-cast microstructure of cast steel lowers ductility and toughness. Impact energy of quenched and tempered cast steel was predicted based on pouring temperature, temperature of mould during the pouring and fact that steel castings are not subjected to different metallurgical and mechanical processes of microstructure improvement in so far as wrought steels.Findings: It can be concluded that working stress of quenched and tempered shaft can be successfully predicted by proposed method.Practical implications: Estimation of hardness distribution can be based on time, relevant for structure

  2. Structure and mechanical properties of vermicular cast iron in cylinder head casting

    Directory of Open Access Journals (Sweden)

    E. Guzik

    2009-01-01

    Full Text Available The paper discusses the problem of grain density and ferrite content in microstructure of vermicular graphite iron cast in bars of different section diameters and cylinder head casting. The experimental results regarding the section effect demonstrate that the nodule count, grain density and ferrite content are all function of the cast bar diameter in this particular case ranging from 0.6 to 8.0 cm and microstructure and mechanical properties in the cylinder head. The nodule count (or grain density has been reported to increase, while ferrite content was decreasing with decreasing casting diameter. The density number of the grains Nv has been related (by regression analysis to the undercooling degree

  3. Effect of aging on mechanical properties of austenitic stainless steel castings and welds

    International Nuclear Information System (INIS)

    Study of the influence of long time aging on the properties of the cast austenitic steel and associated welds or cladding in the components of the primary loop of nuclear plants: embrittlement by precipitation of α'(chromium rich) in ferrite islands (mostly for castings); precipitation hardens the ferrite wich breaks by cleavage. The impact energy and Isub(IC) value are lowered by this phenomenon. Low cycle fatigue properties and fatigue crack growth rates are not modified by aging. Study of correlation between KCU impact toughness at the end of the life of a component, chemical composition and ferrite content

  4. Hypereutectoid cementite morphology and mechanical properties of Cr-Ni-Mo cast steel

    Directory of Open Access Journals (Sweden)

    E. Rożniata

    2006-04-01

    Full Text Available Purpose: The paper presents evaluation of the influence of grain normalization (refinement as a result of repeated austenitizing, cooling rate after repeated austenitizing on the morphology of hypereutectoid cementite and fracture toughness of G200CrMoNi4-6-3 cast steel. Moreover, the elimination of hypereutectoid cementite in structure of Widmannstätten type precipitates from the structure of investigated cast steel has been undertaken.Design/methodology/approach: Basic research of G200CrMoNi4-6-3 cast steel included metallographic analysis and fracture toughness research (impact strength, stress intensity factor KIc. The heat treatment has been planned on the basis of CCT diagram prepared for that cast steel.Findings: Heat treatment of investigated cast steel allows to refine the grain and eliminate from it’s structure the hypereutectoid cementite in structure of Widmannstätten type. At very low cooling rate the precipitates of hypereutectoid cementite become partially coagulated. The study of the influence of cooling rate on the mechanical properties of G200CrMoNi4-6-3 cast steel had proven that elimination of hypereutectoid cementite in structure of Widmannstätten type from the investigated cast steel structure to small degree increases it’s fracture toughness.Research limitations/implications: Research financed by the Ministry of Scientific Research and Information Technology, grant No. 3 T08B 057 29.Practical implications: G200CrMoNi4-6-3 cast steel of ledeburite class is used mainly for rolls production. Any data related to the structure and mechanical properties of that cast steel are precious for the manufacturers and users of the mill rolls.Originality/value: The new heat treatment of G200CrMoNi4-6-3 cast steel.

  5. The impact of breaks during foundry work of the pressure casting machine on casting quality

    Directory of Open Access Journals (Sweden)

    S. Borkowski

    2010-10-01

    Full Text Available The result in the appearance of the technical object damage are its failures, which are considered as the most important causes of productivity loss in the technical objects. The article introduces main types of losses resulting from the downtimes of a casting machine. The time impact analysis of the font mould failure and the remaining time of the machine's failures on the castings quality was conducted. The failure time structure of the font mould and other failures of the machine was presented.

  6. TESTING OF ALUMINUM-SILICON ALLOYS MECHANICAL PROPERTIES ON SEPARATELY CASTED SPECIMENS

    OpenAIRE

    Krushenko, G.

    2010-01-01

    The mechanical properties of aluminum alloys before casting into moulds were determined on separately casted control specimens casted in horizontal or vertical forms. A comparison of the mechanical properties (tensile strength t, elongation 8, hardness HB) of 12-mm-diameter individually casted of AK7ch alloy control specimens and its density in the solid state (p) showed that it is necessary to use specimens casted in a horizontal mold for evaluation of castings quality. It was estimated that...

  7. Effect of Bi on graphite morphology and mechanical properties of heavy section ductile cast iron

    Directory of Open Access Journals (Sweden)

    Song Liang

    2014-03-01

    Full Text Available To improve the mechanical properties of heavy section ductile cast iron, bismuth (Bi was introduced into the iron. Five castings with different Bi content from 0 to 0.014 wt.% were prepared; and four positions in the casting from the edge to the center, with different solidification cooling rates, were chosen for microstructure observation and mechanical properties test. The effect of the Bi content on the graphite morphology and mechanical properties of heavy section ductile cast iron were investigated. Results show that the tensile strength, elongation and impact toughness at different positions in the five castings decrease with a decrease in cooling rate. With an increase in Bi content, the graphite morphology and the mechanical properties at the same position are improved, and the improvement of mechanical properties is obvious when the Bi content is no higher than 0.011wt.%. But when the Bi content is further increased to 0.014wt.%, the improvement of mechanical properties is not obvious due to the increase of chunky graphite number and the aggregation of chunky graphite. With an increase in Bi content, the tensile fracture mechanism is changed from brittle to mixture ductile-brittle fracture.

  8. INCREASING OF MECHANICAL PROPERTIES OF CAST GRAPHITIZED STEEL

    Directory of Open Access Journals (Sweden)

    I. V. Akimov

    2015-06-01

    Full Text Available Purpose. Due to the presence of many essential properties (low prime cost, high manufacturability and damping ability, heat conductivity, fluidity and others,the graphitized cast irons are widely applied for parts operating under the conditions of static and cyclic loads, wear at dry friction and aggressive media at elevated temperatures. At the same time because of significant content of the graphite phase in the structure, the cast irons possess relatively low mechanical properties. Thereby the attention is drawn to graphitized steels, the peculiarity of which consists in the presence of graphite inclusions in the structure, which appoints specific cast iron's properties to these materials. But unlike cast irons, the graphite content in them is in 2…3 times lower and it affects positively on mechanical and service properties indices. This work deals with the optimization of the composition of cast graphitized steel, which has high mechanical properties indices. Methodology. The experimental design technique was used in this work. Alloys prototypes were smelted and their mechanical properties were investigated on the basis of these techniques. Findings were exposed to regression processing, and the dependences of the alloys components influence on its properties were obtained. By means of graphical optimization the optimal composition of steel with high mechanical properties indices has been determined. Findings.Ithasbeenestablishedthat carbon and silicon have the most significant influence on the strength and cyclic endurance of graphitized steels. The chemical composition of the cast graphitized steel with high static and cyclic strength indices was suggested in this work. Originality. With the use of mathematical experimental design techniques the dependences describing the influence of carbon, silicon and copper on the static and cyclic strength indices were obtained. They allow optimizing compositions of graphitized steels. Practical

  9. Microstructure and mechanical properties of a new type of austempered boron alloyed high silicon cast steel

    Directory of Open Access Journals (Sweden)

    Chen Xiang

    2013-05-01

    Full Text Available In the present paper, a new type of austempered boron alloyed high silicon cast steel has been developed, and its microstructures and mechanical properties at different temperatures were investigated. The experimental results indicate that the boron alloyed high silicon cast steel comprises a dendritic matrix and interdendritic eutectic borides in as-cast condition. The dendritic matrix is made up of pearlite, ferrite, and the interdendritic eutectic boride is with a chemical formula of M2B (M represents Fe, Cr, Mn or Mo which is much like that of carbide in high chromium white cast iron. Pure ausferrite structure that consists of bainitic ferrite and retained austenite can be obtained in the matrix by austempering treatment to the cast steel. No carbides precipitate in the ausferrite structure and the morphology of borides remains almost unchanged after austempering treatments. Secondary boride particles precipitate during the course of austenitizing. The hardness and tensile strength of the austempered cast steel decrease with the increase of the austempering temperature, from 250 篊 to 400 篊. The impact toughness is 4-11 J昪m-2 at room temperature and the impact fracture fractogragh indicates that the fracture is caused by the brittle fracture of the borides.

  10. Clean Cast Steel Technology: Effect of Micro-porosity on Tensile and Charpy Properties of Four Cast Steels

    Energy Technology Data Exchange (ETDEWEB)

    Griffin, John, A.; Bates, Charles, E.

    2005-09-19

    The effect of these large shrink cavities on mechanical properties could be easily calculated using well established engineering formulas. Over the years, increases in computational and metallurgical resources have allowed the modeler to improve accuracy and increase the complexity of numerical predictors. An accurate prediction of micro-porosity, not observable using conventional radiographic techniques, and an engineering understanding of the effect on mechanical properties would give a designer confidence in using a more efficient casting design and a lower safety factor. This will give castings an additional design advantage. The goal of this project is to provide current and future modelers/designers with a tensile and Charpy property dataset for validation of micro-porosity predictors. The response of ultimate strength, elongation, and reduction in area to micro-porosity was very similar in all four alloys. Ultimate strength was largely unaffected by tensile fracture surface porosity until values of about 25% were reached and decreased linearly with increasing values. Elongation and reduction in area decreased sharply after less than 5% fracture surface porosity. Niyama values of about 0.7 were produced sound material and acceptable tensile properties. Ultrasonic velocities of 0.233 in/usec and higher produced acceptable tensile properties. Metallographic examination revealed a ratio of 4-6 to 1 in fracture surface porosity to metallographic porosity. Charpy impact properties were largely unaffected by the microporosity concentrations examined in this study and did not correlate to either Niyama values, fracture surface porosity, or metallographic porosity.

  11. Basic properties of 3D cast skeleton structures

    Directory of Open Access Journals (Sweden)

    M. Cholewa

    2011-12-01

    Full Text Available Purpose: of this paper is to present recent achievements in field of skeleton structures. The aim of this work is to show results of searching for mechanically and technologically advantageous micro- and macrostructures. Methods of microstructure controlling were described. Most important parameters of the manufacturing process were identified.Design/methodology/approach: The influence of internal topology to stress distribution was described with the use of computer simulations. Simulations of the mold filling processes were also carried out. Real experiments were performed to prove the simulation results. The Qualitative and quantitative metallographic analysis were also carried out.Findings: It was found that the octahedron shape of internal cell causes best stress distribution and that the skeleton castings are a good alternative for cellular materials such as metal foams, lattice structures and sandwich panels. Their structured arranged topology allows precise design of properties.Research limitations/implications: Casting methods used to manufacture materials such as described skeleton castings confirmed their usefulness. Not well known and used yet rheological properties of liquid metals allow obtaining shape complicated structures near to metallic foams but structured arranged.Practical implications: Technological parameters of the skeleton castings manufacturing process were developed. Without use of advanced techniques there is a possibility to manufacture cheap skeleton structures in a typical foundry. With use of advanced technology like 3D printing there are almost unlimited possibilities of the skeleton castings internal topologies.Originality/value: Three dimensional cast skeleton structures with internal topology of octahedron confirmed their usefulness as elements used for energy dissipation. Obtaining the homogenous microstructure in the whole volume of complicated shape castings can be achieved.

  12. Microstructure and properties of cast iron after laser surface hardening

    Directory of Open Access Journals (Sweden)

    Stanislav

    2013-12-01

    Full Text Available Laser surface hardening of cast iron is not trivial due to the material’s heterogeneity and coarse-grained microstructure, particularly in massive castings. Despite that, hardening of heavy moulds for automotive industry is in high demand. The present paper summarises the findings collected over several years of study of materials structure and surface properties. Phase transformations in the vicinity of graphite are described using examples from production of body parts in automotive industry. The description relates to formation of martensite and carbide-based phases, which leads to hardness values above 65 HRC and to excellent abrasion resistance.

  13. Microstructure and Mechanical Properties of Hyper-eutectic Al-Si Alloys Fabricated by Spray Casting

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Microstructure and mechanical properties of hyper-eutectic Al-Si alloy fabricated by spray casting were investigated and then these results were compared with those by squeeze cast. The spray-cast specimen was found to have finer Si particles (~5μm) compared to the squeeze-cast specimen (10-25μm). The tensile strength and elongation of the spray-cast specimen are also higher than those of the squeeze cast one. It was considered that the increased mechanical properties of the spray-cast specimen were mainly due to finer size of the Si particles distributed in Al matrix.

  14. Microstructure and Property of Hypereutectic High Chromium Cast Iron Prepared by Slope Cooling Body-Centrifugal Casting Method

    Institute of Scientific and Technical Information of China (English)

    Zhifu HUANG; Jiandong XING; Anfeng ZHANG

    2006-01-01

    In this paper, the ring-type ingot of hypereutectic high Cr cast iron was obtained by slope cooling bodycentrifugal casting method (SC-CCM), and its microstructure and impact toughness were investigated, respectively. The results indicated that, first, the primary carbides in the microstructure are prominently finer than those in the hypereutectic high Cr cast iron prepared by conventional casting method. Second, in the ring-type ingot, the primary carbides near radial outer field are finer than those near radial inner field; furthermore, there is dividing field in the microstructure. Finally, the impact toughness values of the specimens impacted on the radial outer face and on the radial inner face are improved respectively about 36% and 138%more than that of the hypereutectic high Cr one prepared by conventional casting method.

  15. Effects of Silicon on Mechanical Properties and Fracture Toughness of Heavy-Section Ductile Cast Iron

    Directory of Open Access Journals (Sweden)

    Liang Song

    2015-01-01

    Full Text Available The effects of silicon (Si on the mechanical properties and fracture toughness of heavy-section ductile cast iron were investigated to develop material for spent-nuclear-fuel containers. Two castings with different Si contents of 1.78 wt.% and 2.74 wt.% were prepared. Four positions in the castings from the edge to the center, with different solidification cooling rates, were chosen for microstructure observation and mechanical properties’ testing. Results show that the tensile strength, elongation, impact toughness and fracture toughness at different positions of the two castings decrease with the decrease in cooling rate. With an increase in Si content, the graphite morphology and the mechanical properties at the same position deteriorate. Decreasing cooling rate changes the impact fracture morphology from a mixed ductile-brittle fracture to a brittle fracture. The fracture morphology of fracture toughness is changed from ductile to brittle fracture. When the Si content exceeds 1.78 wt.%, the impact and fracture toughness fracture morphology transforms from ductile to brittle fracture. The in-situ scanning electronic microscope (SEM tensile experiments were first used to observe the dynamic tensile process. The influence of the vermicular and temper graphite on fracture formation of heavy section ductile iron was investigated.

  16. Estimation of mechanical properties of cast stainless steels during thermal aging in LWR systems

    International Nuclear Information System (INIS)

    A procedure and correlations are presented for predicting Charpy- impact energy, tensile flow stress, fracture toughness J-R curve, and JIC of aged cast stainless steels from known material information. The ''saturation'' impact strength and fracture toughness of a specific cast stainless steel, i.e., the minimum value that would be achieved for the material after long-term service, is estimated from the chemical composition of the steel. Mechanical properties as a function of time and temperature of reactor service are estimated from impact energy and flow stress of the unaged material and the kinetics of embrittlement, which are also determined from chemical composition. The JIC values are determined from the estimated J-R curve and flow stress. Examples of estimating mechanical properties of cast stainless steel components during reactor service are presented. A common ''lower-bound'' J-R curve for cast stainless steels of unknown chemical composition is also defined for a given grade of steel, ferrite content, and temperature

  17. Estimation of mechanical properties of cast stainless steels during thermal aging in LWR systems

    International Nuclear Information System (INIS)

    A procedure and correlations are presented for predicting Charpy-impact energy, tensile flow stress, fracture toughness J-R curve, and JIC of aged cast stainless steels from known material information. The ''saturation'' impact strength and fracture toughness of a specific cast stainless steel, i.e., the minimum value that would be achieved for the material after long-term service, is estimated from the chemical composition of the steel. Mechanical properties as a function of time and temperature of reactor service are estimated from impact energy and flow stress of the unaged material and the kinetics of embrittlement, which are also determined from chemical composition. The JIC values are determined from the estimated J-R curve and flow stress. Examples of estimating mechanical properties of cast stainless steel components during reactor service are presented. A common predicted lower-bound J-R curve for cast stainless steels of unknown chemical composition is also defined for a given grade of steel, ferrite content, and temperature

  18. Thermal aging of cast stainless steels in LWR systems: Estimation of mechanical properties

    International Nuclear Information System (INIS)

    A procedure and correlations are presented for predicting Charpy-impact energy, tensile flow stress, fracture toughness J-R curve, and JIC of aged cast stainless steels from known material information. The ''saturation'' impact strength and fracture toughness of a specific cast stainless steel, i.e., the minimum value that would be achieved for the material after long-term service, is estimated from the chemical composition of the steel. Mechanical properties as a function of time and temperature of reactor service are estimated from impact energy and flow stress of the unaged material and the kinetics of embrittlement, which are also determined from chemical composition. The JIC values are determined from the estimated J-R curve and flow stress. Examples of estimating mechanical properties of cast stainless steel components during reactor service are presented. A common ''lower-bound'' J-R curve for cast stainless steels of unknown chemical composition is also defined for a given grade of steel, ferrite content, and temperature

  19. Transport Properties and Transport Phenomena in Casting Nickel Superalloys

    Science.gov (United States)

    Felicelli, S. D.; Sung, P. K.; Poirier, D. R.; Heinrich, J. C.

    1998-11-01

    Nickel superalloys that are used in the high-temperature regions of gas-turbine engines are cast by directional solidification (DS). In the DS processes, the castings are cooled from below, and three zones exist during solidification: (1) an all-solid zone at the bottom, (2) a "mushy zone" that is comprised of solid and liquid material, and (3) an overlying all-liquid zone. Computer simulations can be useful in predicting the complex transport phenomena that occur during solidification, but realistic simulations require accurate values of the transport properties. In addition to transport properties, the thermodynamic equilibria between the solid and liquid during solidification must also be known with reasonable accuracy. The importance of using reasonably accurate estimations of the transport properties is illustrated by two-dimensional simulations of the convection during solidification and the coincidental macrosegregation in the DS castings of multicomponent Ni-base alloys. In these simulations, we examine the sensitivity of the calculated results to measured partition ratios, thermal expansion coefficients, and viscosities that are estimated by regression analyses and correlations of existing property data.

  20. Influence of isothermal quenching of LAMC CrMnSi cast steel on impact toughness

    Institute of Scientific and Technical Information of China (English)

    JIN Bao-shi; HUANG Zhi-qiu; SHEN Da-dong

    2005-01-01

    The influence of isothermal quenching process of low-alloy and medium carbon (LAMC) CrMnSi cast steel on the impact toughness was investigated. The microstructure and mechanical property of LAMC CrMnSi cast steel were analyzed by the laser optical modulator, the scanning electron microscopy, the energy dispersive spectrometer, the hardness and impact tests. The experimental results show that the dual phases of bainite and residual austenite can be obtained by the severity isothermal quenching, the fractographies of specimens change from quasi-cleavage to dimple at 310 ℃ for 60 min, the impact toughness for specimens at the room temperature isothermally achieves 130 J/cm2, meantime and its hardness is more than 45(HRC).

  1. Cast bulk glassy alloys:fabrication,alloy development and properties

    Institute of Scientific and Technical Information of China (English)

    Qingsheng Zhang; Chunling Qin; Akihisa Inoue

    2010-01-01

    Metallic glasses represent an interesting group of materials as they possess outstanding physical, chemical and mechanical properties compared to their crystalline counterparts. Currently, with well designed compositions it is possible to cast liquid alloys into the glassy state at low critical cooling rates from 100 K·s-1 to 1 K·s-1 and in large critical sample sizes up to several centimeters, which significantly enhances the promise for possible applications as advanced engineering materials. This paper reviews the development of(ZrCu)-based bulk metallic glasses with large sizes by copper mold casting and their unique properties. Additionally, the ex-situ and in-situ second phases reinforced BMG composites with large plasticity are also presented.

  2. Prediction of quenched and tempered steel and cast steel properties

    OpenAIRE

    B. Smoljan; D. Iljkić; H. Novak

    2011-01-01

    Purpose: The influence of processing parameters, such as pouring temperature and cooling rate during the casting, as well as application of hot working and pre-heat treatment, on strength and toughness of quenched and tempered steel was investigated.Design/methodology/approach: Strength and toughness were presented by yield strength and Charpy-V notch toughness, respectively. Experimental procedure of material properties optimization was done using the 25-2 factor experiment.Findings: It was ...

  3. Fatigue properties of ductile cast iron containing chunky graphite

    Energy Technology Data Exchange (ETDEWEB)

    Ferro, P., E-mail: ferro@gest.unipd.it [Department of Management and Engineering, University of Padova, Stradella S. Nicola 3, I-36100 Vicenza (Italy); Lazzarin, P.; Berto, F. [Department of Management and Engineering, University of Padova, Stradella S. Nicola 3, I-36100 Vicenza (Italy)

    2012-09-30

    Highlights: Black-Right-Pointing-Pointer Experimental determination of high cycle fatigue properties of EN-GJS-400. Black-Right-Pointing-Pointer Evaluation of the influence of chunky graphite morphology on fatigue life. Black-Right-Pointing-Pointer Metallurgical analysis and microstructural parameters determination. Black-Right-Pointing-Pointer Nodule counting and nodularity rating. - Abstract: This work deals with experimental determination of high cycle fatigue properties of EN-GJS-400 ductile cast iron containing chunky graphite. Constant amplitude axial tests were performed at room temperature under a nominal load ratio R = 0. In order to evaluate the influence of chunky graphite morphology on fatigue life, fatigue tests were carried out also on a second set of specimens without this microstructural defect. All samples were taken from the core of a large casting component. Metallurgical analyses were performed on all the samples and some important microstructural parameters (nodule count and nodularity rating, among others) were measured and compared. It was found that a mean content of 40% of chunky graphite in the microstructure (with respect to total graphite content) does not influence significantly the fatigue strength properties of the analysed cast iron. Such result was attributed to the presence of microporosity detected on the surface fracture of the specimens by means of electron scanning microscope.

  4. Skeleton castings dynamic load resistance

    OpenAIRE

    M. Cholewa; J. Szajnar; T. Szuter

    2013-01-01

    Purpose: The article is to show selected results of research in a field of new type of cast spatial composite reinforcements. This article shows skeleton casting case as a particular approach to continuous, spatial composite reinforcement.Design/methodology/approach: The research is concerning properties of cast spatial microlattice structures called skeleton castings. In this paper results of impact test of skeleton casting with octahedron elementary cell were shown. The selection of interna...

  5. Investigation on Structure and Properties of Brass Casting

    Institute of Scientific and Technical Information of China (English)

    M.M.Haque; A.A.Khan

    2008-01-01

    In this work, alpha (α) brass was poured in green sand mould and metallic chill mould at about 1050℃. Sand casting method and metallic chill casting method are representing the slow and fast cooling rates of the castings, respectively. The slow cooling rate in the sand mould produces larger grains, while the metallic chill mould produces smaller grains in the castings. As the grain size decreases, the strength of the cast brass increases; micro-porosity in the casting decreases and the tendency for the casting to fracture during solidification decreases. Thus, the faster cooling rate casting offers higher strength, density and hardness compared to the slow cooling rate casting.

  6. Effect of titanium on the as-cast microstructure and impact toughness of hypereutectic high-chromium cast iron

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Zhifu; Xing, Jiandong; Gao, Yimin; Zhi, Xiaohui [Xi' an Jiaotong Univ., Xi' an (China). State Key Lab. for Mechanical Behavior of Materials

    2012-05-15

    The effect of titanium on the as-cast microstructure of a hypereutectic high-chromium cast iron was investigated by means of optical microscopy, scanning electron microscopy and energy-dispersive X-ray spectroscopy. The results indicate that the primary M{sub 7}C{sub 3} carbides are refined and spheroidized with the addition of a suitable amount of titanium. TiC is found in the primary carbide by energy dispersive spectroscopy analysis. The mechanism of titanium modification on the microstructure of the alloy is also discussed. In addition, the impact test result indicates that, compared with the hypereutectic high-chromium cast iron without titanium addition, the impact toughness value of hypereutectic high-chromium cast iron with titanium additions is improved and approximately reaches 6.4 J . cm{sup -2}. (orig.)

  7. A study of microstructure and properties of cast Fe-10Cr-1.5B alloy

    Directory of Open Access Journals (Sweden)

    Zhang Haibin

    2014-05-01

    Full Text Available In the present study, the microstructure and mechanical properties of cast Fe-10Cr-1.5B (FCB alloy after different heat treatments were studied. The results showed that the as-cast microstructure of FCB alloy consists of ?Fe, M(M=Cr, Fe, Mn2(B, C and M(M=Cr, Fe, Mn7(C, B3 type borocarbides, and small amounts of pearlite and austenite. After oil quenching treatment, metal matrix transformed into the martensite from the mixture of martensite, pearlite and austenite. There are many M(M=Cr,Fe,Mn23(C,B6 type borocarbide precipitates in the metal matrix, and eutectic borocarbide appears with an apparent disconnection and isolated phenomenon. When the quenching temperature reaches 1,050 oC, the hardness of FCB alloy is the highest, but the change of quenching temperature has no obvious effect on impact toughness of FCB alloy. After tempering, the eutectic microstructure of FCB alloy appears with a "two links" trend. With the increase of tempering temperature, the hardness of FCB alloy decreases gradually and impact toughness increases gradually. Cast FCB alloy oil-quenched from 1,050 oC and tempered from 200 oC has excellent combined properties; its hardness and impact toughness are 61.5 HRC and 8.8 J.m-2 respectively.

  8. Prediction of quenched and tempered steel and cast steel properties

    Directory of Open Access Journals (Sweden)

    B. Smoljan

    2011-12-01

    Full Text Available Purpose: The influence of processing parameters, such as pouring temperature and cooling rate during the casting, as well as application of hot working and pre-heat treatment, on strength and toughness of quenched and tempered steel was investigated.Design/methodology/approach: Strength and toughness were presented by yield strength and Charpy-V notch toughness, respectively. Experimental procedure of material properties optimization was done using the 25-2 factor experiment.Findings: It was found out that yield strength is insensitive on differences between applied manufacturing processes, but by application of hot working and with appropriate pouring temperature the Charpy-V notch toughness is increased. Also, Charpy-V notch toughness is increased by interactive effect of the appropriate cooling rate during the casting and application of hot working.Research limitations/implications: The research was focused mainly on Charpy-V notch toughness of carbon and low alloyed heat treatable steels.Practical implications: The established algorithms can be used for prediction of tensile strength, yield strength and Charpy-V notch toughness in heat treating practice.Originality/value: Original relation for prediction of quenched and tempered steel and cast steel Charpy-V notch toughness are developed.

  9. Solidification, processing and properties of ductile cast iron

    DEFF Research Database (Denmark)

    Tiedje, Niels Skat

    2010-01-01

    Ductile cast iron has been an important engineering material in the past 50 years. In that time, it has evolved from a complicated material that required the foundry metallurgist's highest skill and strict process control to being a commonly used material that can easily be produced with modern...... process technology. Yet, for the skilled metallurgist and foundry engineer, it is a material that can be engineered to meet extreme demands with regard to mechanical properties and geometrical complexity. It is therefore a material that has been in growing use since its discovery. And the results...

  10. Modelling of Filling, Microstructure Formation, Local Mechanical Properties and Stress – Strain Development in High-Pressure Die Cast Aluminium Castings

    DEFF Research Database (Denmark)

    Kotas, Petr; Hattel, Jesper Henri; Thorborg, Jesper;

    2009-01-01

    .e. whether the casting is based on cast iron- or aluminium-alloys. The distribution of local properties in a casting might vary substantially which makes it complex to optimize the casting with good accuracy. Often, mechanical simulations of the load situation are based on the assumption that the cast...... in an aluminium alloy is considered including simulation of the entire casting process with emphasis on microstructure formation related to mechanical properties such as elastic modulus, yield stress, ultimate strength and elongation as well as residual stresses. Subsequently, the casting is subjected to service...... inherently affects the component’s properties depending on design, metallurgy and casting technique. The wall thickness influences the coarseness of the microstructure and the material will have properties depending on the local metallurgical and thermal histories. This is independent on the material, i...

  11. Microstructure, Impact Fatigue Resistance and Impact Wear Resistance of Wear Resistant Low Cr-Si Cast Iron

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A great amount of iron and steel has been consumed in impact wear resistance parts such as grinding balls and lining plates in tube mills. Under this working conditions, the failure of wear resistant white irons is generally caused by fatigue spalling. The martensitic high chromium cast iron (WCr=15 %) has good wear resistance, but its cost is higher. The impact wear resistance of low chromium cast iron sometimes is not good. In the present paper ,a new wear resistant material-low Cr-Si cast iron was introduced. The influence of microstructure of cast iron on impact fatigue resistance and impact wear resistance was discussed. The ball-on-ball impact fatigue test, the high stress impact wear test and the field test of the grinding balls have been carried out. The results showed that the impact fatigue resistance (IFR) and impact wear resistance (IWR) of low Cr-Si cast iron are superior to typical low chromium cast irons and close to the martensitic high chromium cast iron. The main reasons are: ① The as-cast matrix of the low Cr-Si cast iron with stress released is pearlite with better plasticity and toughness; ② The high Si content improves the morphology of eutectic carbide, and has no secondary carbide resulting in less crack sources. All these factors are beneficial to the improvement of impact fatigue spalling resistance and impact wear resistance.

  12. Influence of a matrix on properties of mottled cast iron applied for mill rolls

    Directory of Open Access Journals (Sweden)

    J. Krawczyk

    2010-07-01

    Full Text Available Mill rolls are ones of the most expensive tools applied in plastic working processes and have to satisfy several criteria, which allow them to be used. Cast iron mill rolls, due to their fracture toughness and tribological properties, are the most often applied at hot-rolling in the last rolling stands. This results from the smallest dynamic loads of such rolling stands and the decisive influence of the surface quality of these tools on the surface quality of the rolled product. An improper microstructure of rolls can lead to their premature wearing, e.g. broken flanges, pivots twisting off etc. By means of the heat treatment the matrix microstructure and morphology of carbide precipitationscan be modified and this in-turn can influence cast iron properties.Determination of the influence of microstructure changes, caused by the heat treatment, on the properties of EN-GJN-HV300 low-alloycast iron, after its modification and spheroidization – is the aim of the present paper. Those changes are based on the formation pearlitic or bainitic matrices at the similar morphology of graphite and ledeburitic cementite precipitations. The performed investigations should enable designing the heat treatment of cast iron metallurgical rolls in such a way as to obtain the optimal microstructures for functional parameters of these type of tools. The influence of changing the pearlitic matrix into the bainitic one on such properties as: hardness, impact strength, tensile strength, creep limit, bending strength and a stress intensity factor KIc was investigated in this study. Samples for testing, the listed above mechanical properties, were taken from an industrial casting with care to have pieces of very similar crystallization conditions.

  13. Study on the microstructure and mechanical properties of medium carbon Cr-Si-Mn-Mo-V steel for cast inserted dies

    Directory of Open Access Journals (Sweden)

    HAO Xiao-yan

    2005-11-01

    Full Text Available The microstructure and mechanical properties of cast inserted dies for automobile covering components were studied. The results show that the as-cast microstructures of cast inserted dies are composed of pearlite, martensite,bainite, and austenite; and that the annealed microstructure is granular pearlite. The mechanical properties of cast inserted dies approach that of forged inserted dies. The tensile strength is 855 MPa, the elongation is 16%, the impact toughness is 177 J/cm2, and the hardness after annealing and quenching are HRC 19 and HRC 60-62. In addition, the cast inserted dies have good hardenability. The depth of the hardening zone and the hardness after flame quenching satisfy the operating requirements. The cast inserted dies could completely replace the forged inserted dies for making the dies of automobile covering components.

  14. Life cycle assessment as a method of limitation of a negative environment impact of castings

    Directory of Open Access Journals (Sweden)

    M. Holtzer

    2011-07-01

    Full Text Available Casting production constitutes environmental problems going far beyond the foundry plant area. Applying a notion of the life cycle the input (suppliers side and output factors (clients side can be identified. The foundry plant activities for the environment hazard mitigation can be situated on various stages of the casting life cycle. The environment impact of motorisation castings made of different materials – during the whole life cycle of castings – are discussed in the paper. It starts from the charge material production, then follows via the casting process, car assembly, car exploitation and ends at the car breaking up for scrap.

  15. Artificial intelligence-based control system for the analysis of metal casting properties

    Directory of Open Access Journals (Sweden)

    E. Mares

    2010-06-01

    Full Text Available Purpose: The metal casting process requires testing equipment that along with customized computer software properly supports the analysis of casting component characteristic properties. Due to the fact that this evaluation process involves the control of complex and multi-variable melting, casting and solidification factors, it is necessary to develop dedicated software.Design/methodology/approach: The integration of Statistical Process Control methods and Artificial Intelligence techniques (Case-Based Reasoning into Thermal Analysis Data Acquisition Software (NI LabView was developed to analyze casting component properties. The thermal data was tested in terms of accuracy, reliability and timeliness in order to secure metal casting process effectiveness.Findings: Quantitative values were defined as “Low”, “Medium” and “High” to assess the level of improvement in the metal casting analysis by means of the Artificial Intelligence-Based Control System (AIBCS. The traditional process was used as a reference to measure such improvement. As a result, the accuracy, reliability and timeliness were significantly increased to the “High” level.Research limitations/implications: Presently, the AIBCS predicts a limited number of casting properties. Due to its flexible design more properties could be added.Practical implications: The AIBCS has been successfully used at the Ford/Nemak Windsor Aluminum Plant (WAP to analyze Al casting properties of the engine blocks.Originality/value: The metal casting research community has immensely benefited from these developed information technologies that support the metal casting process.

  16. ON MODELLING OF MICROSTRUCTURE FORMATION, LOCAL MECHANICAL PROPERTIES AND STRESS – STRAIN DEVELOPMENT IN ALUMINIUM CASTINGS

    DEFF Research Database (Denmark)

    Svensson, Ingvar; Seifeddine, Salem; Kotas, Petr;

    2009-01-01

    Today, the industrial demands are to reduce product development time as well as costs of producing prototypes. In this context, virtual prototyping by numerical simulation offers an efficient way of lowering costs and shorten lead time. Castings are produced by a manufacturing method which.......e. whether the casting is based on cast iron- or aluminium-alloys. The distribution of local properties in a casting might vary substantially which makes it difficult to optimize the casting with good accuracy. Often, mechanical simulations of the load situation are based on the assumption that the cast...... product has constant material properties throughout the entire casting. Thus, if the microstructure is determined or predicted at a given point, it gives the possibility to calculate the local material behaviour more realistically. The paper shows modelling and simulation of microstructure formation...

  17. Study of Influence of Heat Treatment on Cyclic Properties of L21HMF Cast Steel

    Science.gov (United States)

    Mroziński, Stanisław; Golański, Grzegorz

    2016-07-01

    This work presents the results of studies of CrMoV cast steel after long-term service and after regenerative heat treatment (RHT). The cast steel was investigated in the conditions of static and changeable load. The tests were carried out at room temperature and 550 °C. The fatigue lifetime curves were determined and described using the Basquin-Manson-Coffin relationship. It has been shown that the cast steel after RHT is characterized by smaller range of plastic strain and bigger range of stress amplitude, with the same value of total strain, compared with the cast steel after service. For the cast steel after RHT, the observed fatigue properties were different in comparison with the cast steel after service at small and large strains. At room temperature (20 °C) and at elevated temperature (550 °C), there is an increase in the life of samples of the cast steel after RHT in comparison with the samples of the cast steel after service only in the area of large strains ( ɛ ac > 1.2%). For small strains ɛ ac life of the cast steel after RHT at the examined temperatures is shorter than that of the cast steel after service. The paper shows that regardless of an explicit improvement in the strength properties (the static and cyclic ones), as a result of the performed RHT, a complete improvement in the fatigue properties of the cast steel does not occur.

  18. Impact Toughness and Heat Treatment for Cast Aluminum

    Science.gov (United States)

    Lee, Jonathan A (Inventor)

    2016-01-01

    A method for transforming a cast component made of modified aluminum alloy by increasing the impact toughness coefficient using minimal heat and energy. The aluminum alloy is modified to contain 0.55%-0.60% magnesium, 0.10%-0.15% titanium or zirconium, less than 0.07% iron, a silicon-tomagnesium product ratio of 4.0, and less than 0.15% total impurities. The shortened heat treatment requires an initial heating at 1,000deg F. for up to I hour followed by a water quench and a second heating at 350deg F. to 390deg F. for up to I hour. An optional short bake paint cycle or powder coating process further increase.

  19. Effect of Heat Treatment on Mechanical Property of High Cr-W Cast Iron

    Institute of Scientific and Technical Information of China (English)

    Liu Jianping; Li Lixia

    2007-01-01

    The microstructure of high Cr-W cast iron after heat treatment were analyzed, and the effect of various heat treatment temperature and time on mechanical properties of high Cr-W cast iron were studied, and the best process parameter of heat treatment was provided in this paper. The results show that the heat treatment can improve the mechanical property of high Cr-W cast iron, and higher synthetic mechanical property of high Cr-W cast iron can be obtained when treated with normalization at 980℃ for 2h and tempered at 400℃ for 2h.

  20. Long-term aging of cast stainless steels: Mechanisms and resulting properties

    International Nuclear Information System (INIS)

    Mechanical property data are presented from Charpy-impact, tensile, and J-R curve tests for several heats of cast stainless steel aged up to 10,000 h at 450, 400, 350, 320 and 290 deg. C. The results indicate that thermal aging increases the tensile strength and decreases the impact energy, JIC, and tearing modules of the steels. Also, the ductile-to-brittle transition curve shifts to higher temperatures. The ferrite content and concentration of carbon in the steel have a strong effect on the overall process of low-temperature embrittlement. The low-carbon CF-3 steels are the most resistant and the molybdenum-containing high-carbon CF-8M steels are the most susceptible to low-temperature embrittlement. Microstructural data indicate that three processes contribute to embrittlement of cast stainless steels, viz., Cr-rich α' and G-phase precipitation in the ferrite, and carbide precipitation on the austenite/ferrite phase boundary. The influence of nitrogen content and ferrite distribution on loss of toughness are discussed. The data also indicate that existing correlations do not accurately represent the embrittlement behavior over the temperature range 280-450 deg. C, i.e., extrapolation of high temperature data to reactor temperatures may not be valid for some compositions of cast stainless steel. (author)

  1. Microstructure and Thermomechanical Properties of Magnesium Alloys Castings

    Directory of Open Access Journals (Sweden)

    P. Lichý

    2012-04-01

    Full Text Available Magnesium alloys thanks to their high specific strength have an extensive potential of the use in a number of industrial applications. The most important of them is the automobile industry in particular. Here it is possible to use this group of materials for great numbers of parts from elements in the car interior (steering wheels, seats, etc., through exterior parts (wheels particularly of sporting models, up to driving (engine blocks and gearbox mechanisms themselves. But the use of these alloys in the engine structure has its limitations as these parts are highly thermally stressed. But the commonly used magnesium alloys show rather fast decrease of strength properties with growing temperature of stressing them. This work is aimed at studying this properties both of alloys commonly used (of the Mg-Al-Zn, Mn type, and of that ones used in industrial manufacture in a limited extent (Mg-Al-Sr. These thermomechanical properties are further on complemented with the microstructure analysis with the aim of checking the metallurgical interventions (an effect of inoculation. From the studied materials the test castings were made from which the test bars for the tensile test were subsequently prepared. This test took place within the temperature range of 20°C – 300°C. Achieved results are summarized in the concluding part of the contribution.

  2. Microstructural evolution and mechanical properties of as-cast and T6-treated AA2195 DC cast alloy

    Energy Technology Data Exchange (ETDEWEB)

    Hekmat-Ardakan, A. [Universite de Sherbrook, Sherbrook, QC, Canada J1K 2R1 (Canada); Elgallad, E.M. [Universite du Quebec a Chicoutimi, Chicoutimi, QC, Canada G7H 2B1 (Canada); Ajersch, F. [Ecole Polytechnique de Montreal, Montreal, QC, Canada H3T 1J4 (Canada); Chen, X.-G., E-mail: xgrant_chen@uqac.ca [Universite du Quebec a Chicoutimi, Chicoutimi, QC, Canada G7H 2B1 (Canada)

    2012-12-15

    The use of direct chill (DC) cast ingot plates of AA2195 alloys has been recently extended for large mold applications in the plastics and automotive industries. The microstructural evolution of the as-cast AA2195 alloy was investigated using the Factsage thermodynamic software under both equilibrium and non-equilibrium conditions, and was compared with the results from differential scanning calorimetry (DSC) analysis and microstructural observations. The as-cast microstructure exhibited the presence of Al{sub 2}CuMg, Al{sub 2}Cu and Al{sub 2}CuLi intermetallic phases formed at the aluminum dendrite boundaries, which can be completely dissolved in the {alpha}-Al matrix during the solution treatment. A significant improvement in the mechanical properties of the AA2195 cast alloy after the T6 heat treatment is attributed to the formation of nano-scale {theta} Prime (Al{sub 2}Cu) and T1 (Al{sub 2}CuLi) precipitates. However, the non-uniform distribution of T1 precipitates together with the large size and low density indicate that the role of {theta} Prime precipitates in strengthening the AA2195 cast alloy is more dominant than that of the T1 precipitates, in contrast with the strengthening mechanism of the pre-deformed AA2195-T8 rolled products.

  3. Effect of Silicon on the casting properties of Al-5.0%Cu alloy

    Institute of Scientific and Technical Information of China (English)

    LI Weijing; CUI Shihai; HAN Jianmin; XU Chao

    2006-01-01

    Poor casting properties restrict the application of high strength casting Al-5.0%Cu alloy.The addition of element can improve the casting properties of this alloy.Effect of Si on the casting properties of Al-5.0%Cu alloy was studied.It has been found that the addition of Si can improve the casting properties of Al-5.0%Cu alloy obviously.With the increase of Si content, the hot cracking tendency of the alloy decreases significantly, and the fluidity of the alloy increases firstly and then decreases slowly.When the content of Si element is higher than 2wt.%, the fluidity of the alloy increases greatly with the increasing of Si content.

  4. The efect of cooling rate on the properties of alloyed cast-iron sizing roll

    Directory of Open Access Journals (Sweden)

    P. Jelić

    2010-01-01

    Full Text Available Directional heat transfer was investigated by temperature measurements in the casting and in the mould using thermocouples. Measurements were performed in operating conditions during pouring, solidification, and cooling of the casting. Total measurement time was 35,5 hours. After cutting, specimens were extracted for metallographic and hardness testing. Test results provided confirmation of directional heat transfer (directional cooling that would ensure acquirement of a desired casting structure and mechanical properties.

  5. Effect of Carbon Properties on Melting Behavior of Mold Fluxes for Continuous Casting of Steels

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    During continuous casting of steel, the properties of mold fluxes strongly affect the casting performance,steel quality and environment of casting operation. The high temperature microscopy technique was used to investigate the melting behaviour of mold fluxes, and drip test method was used to determine their melting rate. The results showed that free carbon is a dominant factor in governing the melting behaviour of fluxes, and the melting rate is increased with increasing carbon reactivity and decreasing carbon content.

  6. Investigate The Effect of Additives on Mechanical Properties During Casting of 6351 Aluminium

    Directory of Open Access Journals (Sweden)

    Kumar Sanjeev

    2016-01-01

    Full Text Available Aluminum is one of the significant and widely used metals in the manufacturing industries. The effectiveness of casting processes depends upon various process parameters like type of sand, moulding process and additive used. However, the additive in the sand plays important roles to make a perfect casting. Hence, in this research work the experiment were performed to investigate the effect of additives like Tamarind Powder, Starch Powder and Coal dust on the Mechanical Properties namely during casting of aluminium alloys.

  7. Microstructure and mechanical properties of a new type of austempered boron alloyed high silicon cast steel

    OpenAIRE

    Chen Xiang; Li Yanxiang

    2013-01-01

    In the present paper, a new type of austempered boron alloyed high silicon cast steel has been developed, and its microstructures and mechanical properties at different temperatures were investigated. The experimental results indicate that the boron alloyed high silicon cast steel comprises a dendritic matrix and interdendritic eutectic borides in as-cast condition. The dendritic matrix is made up of pearlite, ferrite, and the interdendritic eutectic boride is with a chemical formula of M2B (...

  8. The surface layer of austempered ductile iron investment castings properties

    Directory of Open Access Journals (Sweden)

    D. Myszka

    2009-01-01

    Full Text Available The article presents a unique process of carbonnitriding and nitriding the precision casting surfaces of austempered ductile iron. The results of the research are pointing that adequate process parameters allow to obtain multiple increase of wear resistance and a significant increase of corrosion resistance. Also, changes of cast microstructure and hardness are presented.

  9. Effect of Microstructure on Impact Fatigue Resistance and Impact Wear Resistance of Medium Cr-Si Cast Iron

    Institute of Scientific and Technical Information of China (English)

    LI Wei

    2007-01-01

    A great amount of iron grinding balls in tube mills have been consumed. Under this impact abrasive wear working condition, the failure of wear resistant alloying white irons grinding balls is mainly caused by fatigue spalling. The impact wear resistance of martensitic high chromium cast iron (Cr of 15 %) is not high sometimes, but its cost is not low. Thus, medium Cr-Si wear resistant cast iron is recommended. The influence of the iron on impact fatigue resistance and impact wear resistance is pronounced. Ball-on-ball impact fatigue test and high stress impact wear test of the grinding balls have been carried out. The results show that the impact fatigue resistance (IFR) and impact wear resistance (IWR) of medium Cr-Si cast iron are superior to those of martensitic high chromium cast iron (Cr of 15%). The main reasons are that (1) the stress in medium Cr-Si cast iron is released in the as-cast state; (2)the matrix is fine pearlite with better toughness and plasticity; (3) the pearlite is more stable compared with a retained austenite under repeated impact load and less phase transformation can take place; (4) high silicon content improves the morphology of eutectic carbide; (5) there is no secondary carbide which results in less crack sources. All these factors are beneficial to improvement of impact fatigue spalling resistance. The eutectic carbide M7C3 is the main constituent to resist wear.

  10. New crosslinked cast films based on poly(vinyl alcohol: Preparation and physico-chemical properties

    Directory of Open Access Journals (Sweden)

    C. Birck

    2014-12-01

    Full Text Available In this paper, we propose a green route to prepare insoluble poly(vinyl alcohol (PVOH cast films with potential application as antimicrobial packaging. First PVOH films were cast from different aqueous solutions and analyzed by Differential Scanning Calorimetry (DSC and Dynamic Mechanical Analysis (DMA to determine their physical properties under two storage conditions. In order to obtain insoluble films, PVOH was then crosslinked by citric acid (CTR as confirmed by Nuclear Magnetic Resonance (NMR analyses. The crosslinking reaction parameters (curing time, crosslinker content were studied by comparing the characteristics of PVOH/CTR films, such as free COOH content and glass transition temperature (Tg value, as well as the impact of the crosslinking reaction on mechanical properties. It was found that for 40 and 10 wt% CTR contents, 120 and 40 min of crosslinking times were necessary to bind all CTR respectively. Brittle films were obtained for 40 wt% CTR whereas 10 wt% CTR content led to ductile films. Finally, films containing hydroxypropyl-β-cyclodextrin (HPβCD, chosen as a potential vector of antimicrobial agent, were prepared. The obtained results show that the incorporation of HPβCD in the PVOH matrix does not mainly influence the physical and mechanical properties of the films.

  11. Effects of different casting mould cooling rates on microstructure and properties of sand-cast Al-7.5Si-4Cu alloy

    Directory of Open Access Journals (Sweden)

    Liu Guanglei

    2013-11-01

    Full Text Available In this work, Al-7.5Si-4Cu alloy melt modified by Al-10Sr, RE and Al-5Ti-B master alloys was poured into multi-step moulds made from three moulding sands, including quartz, alumina and chromite, to investigate comparatively the effects of different cooling rates of the casting mould on the alloy's microstructures and mechanical properties. The results show that with an increase in wall thickness, the cooling rate decreases, the dendrite arm spacing (DAS increases significantly and the mechanical properties decrease steadily. The elongation is more sensitive to the cooling rate than the tensile strength. No obvious trend of the effect of wall thickness on hardness of the alloy was found. When the cooling rate is at its greatest, the microstructures and mechanical properties are the best when using chromite sand. The improvement of the properties is mainly attributed to the decrease of the DAS, the grain refinement and the metamorphic effect. Each of the three has a strong impact on the microstructures. Furthermore, a series of fitting models was established based on the data of the DAS to predict the mechanical properties of the multivariate sand-cast Al-7.5Si-4Cu alloy.

  12. The Properties of Ammonium Dinitramine (ADN): Part 2: Melt Casting

    Science.gov (United States)

    Hahma, A.; Edvinsson, H.; Östmark, H.

    2010-04-01

    A melt casting technique for ammonium dinitramine (ADN) and ADN/aluminum was developed. ADN proved relatively easy to cast, when 1% of magnesium oxide was used as a stabilizer and crystallization kernels. Densities of ADN/MgO 99/1 were 92 to 97% of theoretical mean density (TMD) and those of ADN/Al/MgO 64/35/1 were between 95 and 99% of TMD. Sedimentation of Al in the melt was prevented and the particle wetting was ensured by selecting a suitable particle size for Al. No gelling agents or other additives were used. The casting process and factors influencing it are discussed.

  13. As cast high silicon ductile irons with optimised mechanical properties and remarkable fatigue properties

    OpenAIRE

    Torre, Urko de la; Loizaga, Aitor; Lacaze, Jacques; Sertucha, Jon

    2014-01-01

    International audience The present work shows a comparative study regarding the mechanical properties of 25 as cast ferritic ductile iron alloys, nine of them with silicon contents higher than 3·00% and carbon contents lower than 3·60%. In a first step, different carbon equivalent values have been used in order to analyse the effect of this parameter on the mechanical properties. After this comparative analysis, the composition ranges C = 3·30–3·40 wt-% and Si = 3·75–3·80 wt-% have been se...

  14. MICROSTRUCTURE AND PROPERTIES OF ZL201 ALLOY OBTAINED BY NEAR-LIQUIDUS ELECTROMAGNETIC CASTING

    Institute of Scientific and Technical Information of China (English)

    P. Wang; L.F. Sh; G.M. Lu; J.Z. Cui

    2005-01-01

    The microstructures of ZL201 alloy slurry prepared by near-liquidus electromagnetic casting(NLEMC), electromagnetic casting(EMC), and near-liquidus casting(NLC) were investigated by means of electron microscopy and image analysis. Mechanical properties of as-cast alloys were determined. The results show that the NLEMC induces a fine, uniform, and equiaxed grain structure with a mean equal-area-circle grain diameter of 32.8μm. The as-cast alloy has a hardness of HV122.8 and a tensile strength of 368MPa. Both of them are better than those of the alloys prepared by EMC and by NLC. The mechanism of grain refinement in the NLEMC alloy slurry was discussed.

  15. Correlation of mechanical properties with the acoustic properties in case of an experimental white cast iron

    Science.gov (United States)

    Gȋrneţ, A.; Stanciu, S.; Chicet, D.; Axinte, M.; Goanţă, V.

    2016-08-01

    The general and traditional opinion regarding the materials used to build bells, musical instruments or sound transmitters is that those materials must be only from the bronze alloyed with tin category. In order to approach this idea from a scientific point of view, the materials with acoustic properties must be analyzed starting from the physical theory and experimental determination that sound travels only through bodies with elastic properties. It has been developed an experimental white cast iron, medium alloyed with Cr and Ni, in order to obtain a material with special acoustic properties. There were determined on specific samples: the vibration damping capacity, the unit energy, the tensile strength and elasticity modulus. These properties were correlated with the properties of other known acoustic materials.

  16. Effect of cerium modification on microstructure and properties of hypereutectic high chromium cast iron

    Energy Technology Data Exchange (ETDEWEB)

    Zhi, Xiaohui, E-mail: mkmkzxh@hotmail.com [School of Mechanical Engineering, Shijiazhuang Tiedao University, Shijiazhuang 050043, Hebei Province (China); Liu, Jinzhi [School of Mechanical Engineering, Shijiazhuang Tiedao University, Shijiazhuang 050043, Hebei Province (China); Xing, Jiandong; Ma, Shengqiang [State Key Laboratory Mechanical Behavior of Materials, School of Materials Science and Engineering, Xi' an Jiaotong University, Xi' an 710049, Shaanxi Province (China)

    2014-05-01

    The effect of cerium modification on the microstructure and properties of hypereutectic high chromium cast iron primarily containing 4.0 wt% C and 20.0 wt% Cr was studied by means of optical microscopy, transmission electron microscope, scanning electron microscope, and energy dispersive X-ray spectrometry. The primary M{sub 7}C{sub 3} carbides were refined obviously when cerium was added in the melt. Ce{sub 2}S{sub 3} was found in the primary M{sub 7}C{sub 3} carbides and acted as the heterogeneous substrate of M{sub 7}C{sub 3} carbides. The impact toughness of the specimen modified with 0.5 wt% cerium increased by 50% compared with the specimen without cerium modification. The hardness of the alloy modified with cerium increased slightly compared with the specimen without cerium modification.

  17. Properties of cast Ti-stabilised stainless steel after long-term ageing

    International Nuclear Information System (INIS)

    Mechanical properties and microstructure are studied and compared for two kinds of specimens of cast Ti-stabilized stainless steel 08Kh18N10T used for manufacturing of valves and pumps in nuclear power plants. One set of specimens represents the main gate valve material after 106000 h (∼ 12 years) operation at 270 deg C. The comparison is made with reference specimens in as-fabricated state. The results of impact tests, hardness measurements and microscopic examination show that 12 year operation gives rise to the shift of ductile-brittle transition temperature to higher values (from - 68 deg C - 103 deg C). The microstructure of both materials is similar. The microhardness of δ-ferrite in the steel after long-term operation is slightly higher

  18. Effects of casting and post casting annealing on xylene isomer transport properties of Torlon® 4000T films

    KAUST Repository

    Chafin, Raymond

    2010-07-01

    Procedures for Torlon® 4000T membrane formation were developed to provide attractive and repeatable xylene separation properties. Torlon® 4000T membrane films cast by our method were investigated in terms of thermally induced imidization, molecular weight enhancement, and solvent removal. After development of the Torlon® 4000T casting procedure, pervaporation of a xylene mixture (i.e. 30% para-xylene, 30% meta-xylene, 30% ortho-xylene, and 10% ethylbenzene) was performed in both Torlon® 4000T and post casting annealed Torlon® 4000T films. The xylene pervaporation in annealed Torlon® 4000T film at 200°C gave a permeability of 0.25 Barrer and a selectivity of 3.1 (para/ortho) and 2.1 (para/meta) respectively. A so-called " permeability collapse" reflecting an accelerated reduction in the free volume is consistent with significant temperature-induced changes in the films observed after thermal annealing at 300°C. This conditioning effect is induced by a combination of heat treatment and the presence of the interacting aromatic penetrants. Optical methods were used to verify that the density of annealed samples exposed to xylene for 5 days eventually increased, suggesting that the membrane is originally swollen upon initial xylene exposure, and then relaxes to a more densified, and more discriminating state. © 2010 Elsevier Ltd.

  19. Long-term aging of cast stainless steels: Mechanisms and resulting properties

    International Nuclear Information System (INIS)

    Mechanical property data are presented from Charpy-impact, tensile, and J-R curve tests for several heats of cast stainless steel aged up to 10,000 h at 450, 400, 350, 320, and 2900C. The results indicate that thermal aging increases the tensile strength and decreases the impactenergy, J/sub IC/ and tearing modulus of the steels. Also, the ductile-to-brittle transition curve shifts to higher temperatures. The low-carbon CF-3 steels were the most resistant and the molybdenum-containing high-carbon CF-8M steels were the most susceptible to low-temperature embrittlement. The influence of nitrogen content and distribution of ferrite on loss of toughness are discussed. Data also indicate that existing correlations do not accurately represent the embrittlement behavior over the temperature range 280 to 4500C, i.e., extrapolation of high-temperature data to reactor temperatures may not be valid for some compositions of cast stainless steels. 13 refs., 13 figs., 2 tabs

  20. Rare earth metals influence on mechanical properties and crack resistance of GP240GH and G17CrMo5-5 cast steels

    Directory of Open Access Journals (Sweden)

    M. Gajewski

    2009-10-01

    Full Text Available This paper presents results of research on modification influence of REM on mechanical properties and crack resistance of GP240GH cast carbon steel and G17CrMo5-5 high-temperature cast steel. The tests have been performed on successive industrial melts. The rare earth metals were put into the ladle during tapping of heat melt from the furnace. Each time ca 2000 kg of liquid metals were modified. Because of this the amount of sulphur in the cast steel was decreased and the non-metallic inclusion morphology was significantly changed. There were tested mechanical properties (Re,Rm, plastic properties (A5,Z and impact strength (KV, and on the basis of the three-point bend test the KJC stress intensity factor was evaluated. It was noticed that the REM modification brings essential increase of impact strength as well as fracture toughness determined by KJC factor.

  1. Effects of cast properties and passage through the earthworm gut on seed germination and seedling growth

    OpenAIRE

    Clause, J.; Barot, Sébastien; Furey, E.

    2015-01-01

    Success of seed germination and seedling establishment is potentially affected by interactions with earthworms. Two of the possible mechanisms that might explain such impact are the selective ingestion of seeds by earthworms that might break seed dormancy, and germination in their nutrient-rich casts. The aim of this study was to disentangle the effect of seed passage through the earthworm gut and the effect of cast alone, as a germination medium, on the germination and growth of four herbace...

  2. Influence of heat treatment on microstructure and properties of GX12CrMoVNbN9-1 cast steel

    Directory of Open Access Journals (Sweden)

    G. Golański

    2010-07-01

    Full Text Available The paper presents results of research on the influence of multistage heat treatment on microstructure and properties of high-chromiummartensitic GX12CrMoVNbN9 – 1 (GP91 steel. The material under investigation were samples taken out from a test coupon. Heattreatment of GP91 cast steel was performed at the parameters of temperature and time typical of treatment for multi-ton steel casts. The research has proved that in the as-received condition (as-cast state GP91 cast steel was characterized by a coarse grain, martensitic microstructure which provided the required standard mechanical properties. The heat treatment of GP91 cast steel contributed to obtainment of a fine grain microstructure of high tempered martensite with numerous precipitations of carbides of diverse size. The GP91 cast steel structure received through heat treatment made it possible to obtain high plastic properties, particularly impact strength, maintaining strength properties on the level of the required minimum.

  3. Effect of inter-critical quenching on mechanical properties of casting low-alloy steel

    OpenAIRE

    Liu Zhongli; Shang Yong

    2013-01-01

    For some casting low-alloy steels, traditional quenching and tempering heat treatments can improve the strength; however, sometimes the ductility is not satisfied. Therefore, some kind of effective heat treatment method seems necessary; one which could improve the ductility, but not seriously affect the strength. In this paper, the effect of inter-critical quenching (IQ) on the mechanical properties of casting low-alloy steel was studied. IQ was added between quenching and tempering heat trea...

  4. Solidification, growth mechanisms, and associated properties of aluminum-silicon and magnesium lightweight casting alloys

    Science.gov (United States)

    Hosch, Timothy Al

    often contain additions of heavier elements, such as zinc, zirconium, and rare earth elements, which significantly improve high temperature performance. However, additions of these elements can lead to macrosegregational effects in castings, which are detectable by radiographic scans. The effect of these flow-line indications on alloy mechanical properties is not well quantified. An examination of these flow-line indications and their effects on mechanical properties in three magnesiumbased casting alloys was performed here in order to determine the best practice for dealing with affected castings. Preliminary results suggest the flow-lines do not measurably impact bulk material properties. Three additional methods of characterizing three-dimensional material structures are also presented: a minimum spanning tree analysis is utilized to quantify local structure in Cu-Zr liquid phase simulations obtained from molecular dynamics; the radial distribution function is applied to directionally solidified Al-Si structures in an attempt to extract local spacing data; and the critical diameter measurement is also defined and applied to irregular eutectic Al-Si structures.

  5. Solidification, growth mechanisms, and associated properties of Al-Si and magnesium lightweight casting alloys

    Energy Technology Data Exchange (ETDEWEB)

    Hosch, Timothy [Iowa State Univ., Ames, IA (United States)

    2010-01-01

    often contain additions of heavier elements, such as zinc, zirconium, and rare earth elements, which significantly improve high temperature performance. However, additions of these elements can lead to macrosegregational effects in castings, which are detectable by radiographic scans. The effect of these flow-line indications on alloy mechanical properties is not well quantified. An examination of these flow-line indications and their effects on mechanical properties in three magnesium-based casting alloys was performed here in order to determine the best practice for dealing with affected castings. Preliminary results suggest the flow-lines do not measurably impact bulk material properties. Three additional methods of characterizing three-dimensional material structures are also presented: a minimum spanning tree analysis is utilized to quantify local structure in Cu-Zr liquid phase simulations obtained from molecular dynamics; the radial distribution function is applied to directionally solidified Al-Si structures in an attempt to extract local spacing data; and the critical diameter measurement is also defined and applied to irregular eutectic Al-Si structures.

  6. Influences of Casting Pressure Conditions on the Quality and Properties of a Magnesium Cylinder Head Cover Die Casting

    Institute of Scientific and Technical Information of China (English)

    Wenhui LIU; Yangai LIU; Shoumei XIONG; Baicheng LIU; Y. Matsumoto; M. Murakami

    2005-01-01

    Casting pressure conditions have great influences on the casting defects, such as gas porosity, shrinkage porosity and gas holes. A Mg cylinder head cover die casting was used to experimentally study the influences of casting pressure,the loading time and the piston position of pressure intensification on the variation of pressure and the quality of casting. The results show that casting pressure, the loading time and the piston position of pressure intensification have great influences on the pressure variations in the mold, the quality and performance of casting. The external quality, the density and the tensile strength of casting were improved with the increase of casting pressure and the piston position of pressure intensification and the decrease of the loading time of pressure intensification.

  7. Microstructures and mechanical properties of AZ91D magnesium alloy processed by low pressure die casting

    Institute of Scientific and Technical Information of China (English)

    JIANG Hai-yan; FU Peng-huai; YU Yan-dong; ZHAI Chun-quan

    2006-01-01

    AZ91D alloy components were cast by low pressure die casting (LPDC) process. The mechanical properties of cast components with different microstructural features (shrinkage and distribution of Mg17Al12 second phase) were investigated under as-cast states. Compared with gravity casting, AZ91D with LPDC has much coarser grain size and second phases(Mg17Al12 and Al8Mn5). The different size and distribution of Mg17Al12 phase and shrinkage correspond to different mechanical properties. The ultimate tensile strengths and elongations are mainly decided by the content and distribution of shrinkage porosity, while the yield strengths are determined by the percentage and distribution of Mg17Al12 phase. The more and finer Mg17Al12 phase in the alloy, the relatively higher the yield strengths are. In the alloy without shrinkage, the mechanical properties are mainly determined by the size and distribution of Mg17Al12 phase. The finer Mg17Al12 phase, the better the mechanical properties are. Under optimal process, the density and mechanical properties of LPDC AZ91D are improved with fine microstructures.

  8. Effect of Nb on Structure and Mechanical Properties of Chilled Cast Iron at Room and Elevated Temperatures

    Institute of Scientific and Technical Information of China (English)

    Qijie ZHAI; Li FU; Huaying ZHAI

    2004-01-01

    Effect of Nb on microstructure and mechanical properties of chilled cast iron at room and elevated temperatures is studied in this research. The results demonstrate that the cast structure and mechanical properties of chilled cast iron at room and elevated temperatures are improved with the addition of trace amount of Nb. However, if Nb was added too much, the cast structure and mechanical properties of chilled cast iron would deteriorate. The suitable content of Nb in chilled cast iron is about 0.05% (mass fraction). Except the dissolution in the matrix of cast iron the excessive Nb will form Nb-rich phases in three morphologies. Those are lumpy NbC, complicated strip-like phase and compound with pearlite structure.

  9. Property enhancement of cast iron used for nuclear casks

    Science.gov (United States)

    Behera, R. K.; Mahto, B. P.; Dubey, J. S.; Mishra, S. C.; Sen, S.

    2016-01-01

    Ductile iron (DI) is a preferred material for use in various structural, automotive, and engineering fields because of its excellent combination of strength, toughness, and ductility. In the current investigation, we elucidate the relationship between the morphological and mechanical properties of DI intended for use in safety applications in the nuclear industry. DI specimens with various alloying elements were subjected to annealing and austempering heat treatment processes. A faster cooling rate appeared to increase the nodule count in austempered specimens, compensating for their nodularity value and subsequently decreasing their ductility and impact strength. The ductility and impact energy values of annealed specimens increased with increasing ferrite area fraction and nodularity, whereas an increase in the amounts of Ni and Cr resulted in an increase of hardness via solid solution strengthening. Austempered specimens were observed to be stronger than annealed specimens and failed in a somewhat brittle manner characterized by a river pattern, whereas the ductile failure mode was characterized by the presence of dimples.

  10. The influence of calcium on technological properties and micropurity of steel castings

    Directory of Open Access Journals (Sweden)

    J. Hampl

    2016-07-01

    Full Text Available The paper analyzes the technological parameters, micro-purity and mechanical properties of castings of steel alloyed with calcium. The effect of calcium on the steel was analyzed on samples taken in the process of casting heavy castings and ingots of the weight of ranging from 40 000 to 60 000 kg. Samples for the determination of the liquidus temperature and the solidus temperature of cast steels were analysed using differential thermal analysis (DTA. The production of low alloyed steel grades was performed on the EAF - ASEA-SKF facilities and the production of highalloyed steels on the EAF - ASEA-SKF - SS-VOD facilities. The purity calcium was added into the steel by the injection of a stuffed profile.

  11. Influence of fabricating process on microstructure and properties of spheroidal cast tungsten carbide powder

    Institute of Scientific and Technical Information of China (English)

    DAI Yu; TAN Xing-long; LI Yu-xi; YANG Jian-gao; HUANG Bai-yun

    2005-01-01

    A super-high temperature furnace was developed to fabricate spheroidal cast tungsten carbide powder with excellent flowability and fine feathery structure in a large scale. Optical microscope and scanning electron microscope were taken to characterize the morphology and microstructure of cast tungsten carbide powder. X-ray diffractometry was used to analyze the phase composition of powders involved. It is found that the carbon potential in the furnace and feeding speed play an important role on the microstructure, morphology and properties of the spheroidal cast tungsten carbide powder. As carbon potential is between 0.3% and 0.9% in the furnace, cast tungsten carbide powder with hardness over 2800(HV0.5 ), flowability over 7. 1 s/50 g and tap density over 10.3 g/cm3 is obtained.

  12. Effect of heat treatment on microstructure, mechanical properties and erosion resistance of cast 23-8-N nitronic steel

    International Nuclear Information System (INIS)

    Effects of heat treatment on microstructure, mechanical properties and erosion behavior of cast 23-8-N nitronic steel were studied. A series of heat treatments were carried out in the temperature range of 1180–1240 °C to observe the effect on microstructure. Optimum heat treatment cycle was obtained at 1220 °C for holding time of 150 min, which leads to dissolution of carbides, formation of equiaxed grains and twins. Heat treatment has shown improvement in tensile strength, toughness, impact strength and work hardening capacity, however at the cost of marginal reduction in hardness and yield strength. This resulted in improvement of erosion resistance of cast 23-8-N nitronic steel. The microstructures, fractured surfaces and phases were studied by optical microscopy, field emission scanning electron microscopy (FESEM) and X-ray diffraction (XRD) analysis respectively

  13. Mechanical properties of stainless steel castings at 4 K

    International Nuclear Information System (INIS)

    Ten heats of cast CF8M stainless steel, which is the casting equivalent of AISI 316, were produced by a commercial vendor. In five of the heats the chromium and nickel contents were varied to obtain different delta-ferritie contents, ranging from 1.1 to 28.5 percent. The other five heats all had approximately 8 percent delta-ferrite and the nitrogen content was varied from 0.02 to 0.20 percent. As was expected from previous data on weldments and wrought materials, an increase in either delta-ferrite or nitrogen content increases the yield strength. In the five heats with varying nitrogen content the increase in strength resulted in a corresponding decrease in fracture toughness. An increase in delta-ferrite content also gave a decrease in fracture toughness up to approximately 15 percent dela-ferrite. Above this level the fracture toughness remained constant with increasing delta-ferrite content. This has been shown, by metallographic and fractographic evidence, to be due to the establishment of a continuous delta-ferrite crack path, at approximately 15 percent delta-ferrite

  14. New Possibilities of Shaping the Surface Properties in Austempered Ductile Iron Castings

    Directory of Open Access Journals (Sweden)

    D. Myszka

    2013-01-01

    Full Text Available The paper presents recent developments concerning the formation of surface layer in austempered ductile iron castings. It was found thatthe traditional methods used to change the properties of the surface layer, i.e. the effect of protective atmosphere during austenitising or shot peening, are not fully satisfactory to meet the demands of commercial applications. Therefore, new ways to shape the surface layer and the surface properties of austempered ductile iron castings are searched for, to mention only detonation spraying, carbonitriding, CVD methods, etc.

  15. Properties of High Basicity Mold Fluxes for Peritectic Steel Slab Casting

    Institute of Scientific and Technical Information of China (English)

    LONG Xiao; HE Sheng-ping; XU Jian-fei; HUO Xu-ling; WANG Qian

    2012-01-01

    In high speed continuous casting of peritectic steel slabs, mold fluxes with high basicity are required for less surface defect product. However, the basicity of remaining liquid slag film tends to decrease in casting process because of the crystallization of 3CaO ·2SiO2 · CaF2. Thus, a way is put forward to improve mold fluxesr properties by raising the original basicity. In order to confirm the possibility of this method, the effect of rising original basicity on the properties of mold fluxes is discussed. Properties of high fluorine based mold fluxes with different basicities and contents of CaF2 , Na2 O, and MgO were measured, respectively. Then, properties of higher basicity mold fluxes were discussed and compared with traditional ones. The results show that increasing the basicity index can improve the melting and flow property of mold fluxes. With the increasing basicity, crystallization rate of mold fluxes increases obviously and crystallization temperature tends to decrease when the basicity exceeds 1.35. The method presen- ted before is proved as a potential way to resolve the contradiction between horizontal heat transfer controlling and solidified shell lubricating for peritectic steel slab casting. But further study on improving the flow property of liquid slag is needed. This work can be used to guide mold fluxes design for high speed continuous casting of peritectic steel slabs.

  16. Modelling the environmental impact of an aluminium pressure die casting plant and options for control

    NARCIS (Netherlands)

    Neto, B.A.F.; Kroeze, C.; Hordijk, L.; Costa, C.

    2008-01-01

    This study describes a model (MIKADO) to analyse options to reduce the environmental impact of aluminium die casting. This model will take a company perspective, so that it can be used as a decision-support tool for the environmental management of a plant. MIKADO can be used to perform scenario anal

  17. Strategies to reduce the environmental impact of an aluminium pressure die casting plant: A scenario analysis

    NARCIS (Netherlands)

    Neto, B.; Kroeze, C.; Hordijk, L.; Costa, C.; Pulles, M.P.J.

    2009-01-01

    This study explores a model (MIKADO) to analyse scenarios for the reduction of the environmental impact of an aluminium die casting plant. Our model calculates the potential to reduce emissions, and the costs associated with implementation of reduction options. In an earlier paper [Neto, B., Kroeze,

  18. EFFECT OF CASTING MOULD ON MECHANICAL PROPERTIES OF 6063 ALUMINUM ALLOY

    Directory of Open Access Journals (Sweden)

    WASIU AJIBOLA AYOOLA

    2012-02-01

    Full Text Available Modern production methods for casting articles include the use of sand- mould, metal-mould, die, and centrifugal castings. Castings produced using sand mould is known to have peculiar microstructures depending on average size, distribution and shape of the moulding sand grains and the chemical composition of the alloy. These affect the surface finish, permeability and refractoriness of all the castings. In this paper, the effect of using CO2 process, metal mould, cement-bonded sand mould and naturally-bonded sand mould on the hardness, tensile and impact strengths of as-cast 6063 Aluminum alloy is presented. The results show that there is significant increase in hardness(33.7 HB of the alloy when naturally-bonded sand mould is used for its production over that of metal, CO2 and cement moulds. The stress-strain curves behaviour of the samples also indicated that sample from naturally bonded sand has highest tensile strength with superior ductility. The alloy shows highest impact strength when metal mould is used for sample preparation in comparison with other moulds.

  19. Effect of Cu and Mn on the Mechanical Properties and Microstructure of Ductile Cast Iron

    Directory of Open Access Journals (Sweden)

    A.M.Omran

    2014-06-01

    Full Text Available This paper described the method used for producing ductile cast iron (SGI. The processing parameters affecting the production of SGI were studied. These parameters include chemical composition, castings thickness, mechanical properties, alloying elements and microstructure. The chemical composition of producing SGI was optimized. The nodularity was increased with increasing the percentages of Mg content and with decreasing the castings thickness. The amount of pearlite and mechanical properties were increased sharply with increasing Cu and Mn contents in the produced SGI. Empirical equations were correlated to indicate the relations among nodularity, Mg content and other parameters. The results shown also as the post inoculation increased the metallurgical quality was improved. The suitability of SGI as automotive engine was tested and different empirical correlations were obtained

  20. Microstructure-Texture-Mechanical Properties in Hot Rolling of a Centrifugal Casting Ring Blank

    Science.gov (United States)

    Qin, Fang-cheng; Li, Yong-tang; Qi, Hui-ping; Ju, Li

    2016-03-01

    Deformation characteristic of centrifugal casting 25Mn steel was investigated by compression tests, and then processing maps were established. According to the deformation parameters identified from the established processing maps and hot ring rolling (HRR) process, the industrial test for the 25Mn ring blank was performed. Optical microscope (OM) and electron backscatter diffraction (EBSD) techniques were used for detecting grain boundary features and textures of deformation structures. The morphologies and mechanisms of tensile and impact fracture were revealed. The results show that softening effect plays a dominant role in higher temperatures of 1050-1150 °C and strain rates lower than 0.1 s-1. The average grain size of the rolled 25Mn ring is about 28 μm, but the grains are more coarse and inhomogeneous on the middle layer than that on rest of the areas. The texture on the outer layer is characterized by strong {110} and weak {112} , followed by {001} and {001} on the inner layer and {110} on the center layer, which is mainly associated with the shear deformation. The rolled ring with precise geometrical dimensions and sound mechanical properties is fabricated by HRR. Tensile fracture is composed of clear river-shaped pattern and a little dimple near the inner layer and outer layer, and the fracture mechanism is mainly quasi-cleavage fracture, accompanied by dimple fracture. The morphologies of impact fracture consist of tear ridge and cleavage platform.

  1. Mechanical property and microstructural change by thermal aging of SCS14A cast duplex stainless steel

    International Nuclear Information System (INIS)

    The aging behavior, especially saturation, of JIS SCS14A cast duplex stainless steels was investigated on the basis of the mechanical properties and microstructural changes during accelerated aging at 350 oC and 400 oC. The aging behavior of the materials mainly proceeds via two stages. During the first stage, the generation and concentration of the iron-rich and chromium-enriched phase in ferrite occurs by phase decomposition. The first stage corresponds to aging times of up to 3000 h at 400 oC. During the first stage, the ferrite hardness achieved is approximately 600 VHN, and the Charpy impact energy is almost saturated. During the second stage, the precipitated chromium-enriched phase aggregates and coarsens, and the G phase precipitation also occurs. The second stage corresponds to the aging times range of 3000-30 000 h at 400 oC. During the second stage, the ferrite hardness achieved is about 800 VHN; however, further hardening exceeding 600 VHN does not influence the Charpy impact energy

  2. Changes of Tempering Microstructure and Properties of Fe-Cr-V-Ni-Mn-C Cast Alloys

    Institute of Scientific and Technical Information of China (English)

    LIU Yan-xia; MA Yong-qing; WANG Yue-hua; ZHANG Zhan-ping; ZHANG Yang

    2004-01-01

    The changes of tempering microstructure and properties of Fe-Cr-V-Ni-Mn-C cast alloys with martensite matrix and much retained austenite are studied. The results showed that when tempering at 200℃ the amount of retained austenite in the alloys is so much that is nearly to as-cast, and a lot of retained austenite decomposes when tempering at 350℃ and the retained austenite decomposes almost until tempering at 560℃. When tempering at 600℃, the retained austenite in the alloys all decomposes. At 560℃ the hardness is highest due to secondary hardening. The effect of nickel and manganese on the microstructure and properties of Fe-Cr-V-C cast alloy were also studied. The results show that the Fe-Cr-V-C cast alloy added nickel and manganese can obtain martensite matrix and much retained austenite microstructure, and nickel can also prevent pearlite transformation. With the increasing content of nickel and manganese, the hardness of as-cast alloy will decreases gradually, so one can improve the hardness of alloy by tempering process. When the content of nickel and manganese is 1.3~1.7%, the hardness of secondary hardening is the highest (HRC64). But when the content of nickel and manganese increase continually, the hardness of secondary hardening is low slightly, and the tempering temperature of secondary hardening rises.

  3. Investigations of Properties of Wax Mixtures Used in the Investment Casting Technology – New Investigation Methods

    Directory of Open Access Journals (Sweden)

    J. Zych

    2012-09-01

    Full Text Available The results of testing of the selected group of wax mixtures used in the investment casting technology, are presented in the paper. Themeasurements of the kinetics of the mixtures shrinkage and changes of viscous-plastic properties as a temperature function wereperformed. The temperature influence on bending strength of wax mixtures was determined.

  4. Skeleton castings dynamic load resistance

    Directory of Open Access Journals (Sweden)

    M. Cholewa

    2013-06-01

    Full Text Available Purpose: The article is to show selected results of research in a field of new type of cast spatial composite reinforcements. This article shows skeleton casting case as a particular approach to continuous, spatial composite reinforcement.Design/methodology/approach: The research is concerning properties of cast spatial microlattice structures called skeleton castings. In this paper results of impact test of skeleton casting with octahedron elementary cell were shown. The selection of internal topology of skeleton casting was based on numerical simulations of stress distribution.Findings: The possibility of manufacturing of geometrically complex skeleton castings without use of advanced techniques was confirmed.Research limitations/implications: With use of computer tomography, analysis of deformation mechanisms was carried out. Different levels of impact energies were usedPractical implications: Spatial skeleton casting with octahedron elementary cell confirmed their usefulness as impact energy absorbers.Originality/value: The overall aim of presented research was to determine the mechanisms of skeleton castings deformation processes. Thanks to CT data next step will be to create accurate numerical model for further simulation and design optimization.

  5. Fractomechanical Properties of As-Cast and Austempered SG Cast Iron Between -40 °C and +20 °C

    Directory of Open Access Journals (Sweden)

    V.E. Fierro

    2002-06-01

    Full Text Available The spheroidal graphite (SG cast iron fractomechanical response varies with the test temperature and with the microstructure parameters. In the present paper, we analyze this variation performing fractomechanical tests in a temperature range from -40°C to +20°C, doing also Charpy and tensile tests for material characterization. The tests were carried out on as-cast samples and heat treated samples to obtain an ADI grade 1. In both cases, we studied samples taken from two well differentiated "Y" block sizes. The results obtained show that, for the chemical composition analyzed, both castings have a fractomechanical response decrease as the temperature diminishes. Besides, the block size enlargement produce a deterioration of the mechanical properties (the fracture toughness, mainly, for both castings.

  6. Economic evaluation of environmental impacts of open cast mining project - an approach

    International Nuclear Information System (INIS)

    Economic valuation of environmental attributes are pragmatic approach to evaluating the impacts and it helps decision makers to arrive at objective decisions on the basis of cost benefit ratio. For determining the physical impact and its quantification, four evaluation methods, namely-market price method, surrogate market price, survey based and cost based approaches are generally used. The present paper reviews the importance of environmental evaluation of impacts of mining and also reviews a few suitable methodologies that could be effectively used for economic evaluation of environmental impacts in open cast mining projects. (author)

  7. Welding and mechanical properties of cast FAPY (Fe-16 at. % Al-based) alloy slabs

    Energy Technology Data Exchange (ETDEWEB)

    Sikka, V.K.; Goodwin, G.M.; Alexander, D.J.; Howell, C.R.

    1995-08-01

    The low-aluminum-content iron-aluminum program deals with the development of a Fe-Al alloy with aluminum content such as a produce the minimum environmental effect at room temperature. The FAPY is an Fe-16 at. % Al-based alloy developed at the Oak Ridge National Laboratory as the highest aluminum-containing alloy with essentially no environmental effect. The chemical composition for FAPY in weight percent is: aluminum = 8.46, chromium = 5.50, zirconium = 0.20, carbon = 0.03, molybdenum = 2.00, yttrium = 0.10, and iron = 83.71. The cast ingots of the alloy can be hot worked by extrusion, forging, and rolling processes. The hot- worked cast structure can be cold worked with intermediate anneals at 800{degrees}C. Typical room-temperature ductility of the fine-grained wrought structure is 20 to 25% for this alloy. In contrast to the wrought structure, the cast ductility at room temperature is approximately 1% with a transition temperature of approximately 100 to 150{degrees}C, above which ductility values exceed 20%. The alloy has been melted and processed into bar, sheet, and foil. The alloy has also been cast into slabs, step-blocks of varying thicknesses, and shapes. The purpose of this section is to describe the welding response of cast slabs of three different thicknesses of FAPY alloy. Tensile, creep, and Charpy-impact data of the welded plates are also presented.

  8. High cycle fatigue properties of die-cast magnesium alloy AZ91D-1%MM

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The high cycle fatigue properties of the die-cast magnesium alloy AZ91D containing 1%mischmetal(mass fraction)at a fatigue ratio of 0.1 were investigated.The difference in the microstructure between the skin and core region of the die-cast magnesium alloy was analyzed by optical microscopy.The mechanical property tests indicate that the values of the tensile strength,elongation and hardness are 185 MPa,1.5%and HBS 70±3 at room temperature,respectively.The p-S-N curve(p=50%)of the die-cast magnesium alloy AZ91D-1%MM is determined and the mean fatigue strength corresponding to 3.8×105cycles is 70 MPa.A linear relation between S and Np in log scale between 103 and 106 cycles is written with a equation.The mechanical properties are influenced by the casting defects.The fatigue life of the samples with minor defects is near to the upper limit of the fatigue life data.The fatigue fracture surface of the samples with minor defects possesses the mixed characteristics of quasi-cleavage,lacerated ridge and dimple and it is briule fracture mode as a whole.

  9. Cast iron - a predictable material

    Directory of Open Access Journals (Sweden)

    Jorg C. Sturm

    2011-02-01

    Full Text Available High strength compacted graphite iron (CGI or alloyed cast iron components are substituting previously used non-ferrous castings in automotive power train applications. The mechanical engineering industry has recognized the value in substituting forged or welded structures with stiff and light-weight cast iron castings. New products such as wind turbines have opened new markets for an entire suite of highly reliable ductile iron cast components. During the last 20 years, casting process simulation has developed from predicting hot spots and solidification to an integral assessment tool for foundries for the entire manufacturing route of castings. The support of the feeding related layout of the casting is still one of the most important duties for casting process simulation. Depending on the alloy poured, different feeding behaviors and self-feeding capabilities need to be considered to provide a defect free casting. Therefore, it is not enough to base the prediction of shrinkage defects solely on hot spots derived from temperature fields. To be able to quantitatively predict these defects, solidification simulation had to be combined with density and mass transport calculations, in order to evaluate the impact of the solidification morphology on the feeding behavior as well as to consider alloy dependent feeding ranges. For cast iron foundries, the use of casting process simulation has become an important instrument to predict the robustness and reliability of their processes, especially since the influence of alloying elements, melting practice and metallurgy need to be considered to quantify the special shrinkage and solidification behavior of cast iron. This allows the prediction of local structures, phases and ultimately the local mechanical properties of cast irons, to asses casting quality in the foundry but also to make use of this quantitative information during design of the casting. Casting quality issues related to thermally driven

  10. SPRAY CASTING

    OpenAIRE

    SALAMCI, Elmas

    2010-01-01

    ABSTRACT This paper is designed to provide a basic review of spray casting. A brief overview of the historical development of spray  casting and the description of plant and equipment have been given. Following metallurgical characteristics of spray formed alloys, process parameters and solidification mechanism of spray deposition have been discussed in detail. Finally, microstructure and mechanical properties of the selected spray cast Al-Zn-Mg-Cu alloys have been presented and compared...

  11. Effects of Ce addition on microstructure, mechanical properties and corrosion resistance of as-cast AZ80 magnesium alloy

    Directory of Open Access Journals (Sweden)

    Wang Wei

    2014-05-01

    Full Text Available In this study, Ce was introduced into the AZ80 alloy and the effects of Ce addition on the microstructure, mechanical properties and corrosion resistance of the as-cast AZ80 magnesium alloy were investigated. The results show that the addition of Ce into the AZ80 alloy can not only refine the microstructure, but also result in the formation of the needle-like Al4Ce phase. These tiny Al4Ce phases are homogeneously distributed at grain boundaries and within grains. An appropriate Ce addition can also change the β-Mg17Al12 phase at the grain boundaries from continuous network to small island-like. At the same time, with the increase of Ce content from 0 to 2.0wt.%, the macro-hardness of the as-cast alloy is enhanced linearly, while impact toughness, tensile strength and elongation all firstly increase and then decrease. The AZ80 alloy containing 1.0wt.% Ce exhibits the optimal properties. Its macro-hardness, impact toughness, tensile strength and elongation are 61.90 HB, 15.50 J·cm-2, 171.80 MPa and 3.35%, increase by 9.95%, 63%, 13.3% and 36.7%, respectively compared with the base alloy. In addition, Ce can enhance the corrosion resistance of the AZ80 magnesium alloy.

  12. Effect of long-term thermal aging on the mechanical properties of casting duplex stainless steels

    International Nuclear Information System (INIS)

    Highlights: ► The micro-hardness change tendency of ferrite and austenite by aging was studied. ► Embrittlement behavior of Z3CN20-09M CDSSs by aging was investigated by SP test. ► The crack propagation energy Wt − Wiu slightly changes with the thermal aging time. ► Spinodal decomposition and spinodally coarsening take place in ferrite by aging. ► Z3CN20-09M CDSSs become embrittlement after long-term thermal aging treatment. - Abstract: Casting duplex stainless steels (CDSSs) used for pressurized water reactor (PWR) pipes are susceptible to thermal aging brittleness during long-term service at its working temperature from 288 °C to 327 °C. In order to investigate its thermal aging behavior, Z3CN20-09M CDSSs have been thermally aged at 400 °C up to 15,000 h. The micro-hardness of austenite and ferrite phases, conventional tensile properties, impact properties and SPT properties at different aging duration have been measured. The results show that the micro-hardness in ferrite gradually increases with increase of long thermal aging time, while the effect of the long aging time on the micro-hardness in austenite is negligible. The tensile strength and yield strength progressively and slightly increase with the long aging time, respectively. The impact property test confirms that there is the same change tendency as the percentage of elongation which decreases with the long aging time. The changes of SPT ultimate strength, SPT yield strength and SPT specific fracture energy by aging individually show that there is an almost same tendency as the tensile strength, the yield strength and the percentage of elongation with the thermal aging time. All above the mechanical properties changes of Z3CN20-09M CDSSs are associated with the changes of the dislocation configurations in austenite, the precipitation of G-phase on the dislocation line and in ferrite phase, the spinodal decomposition and the coarsening of the spinodally decomposed structure in ferrite

  13. Microstructure and mechanical properties of magnesium alloy prepared by lost foam casting

    Institute of Scientific and Technical Information of China (English)

    TIAN Xue-feng; FAN Zi-tian; HUANG Nai-yu; WU He-bao; DONG Xuan-pu

    2005-01-01

    The microstructure and mechanical properties of AZ91 alloy prepared by lost foam casting(LFC) and various heat treatments have been investigated.The microstructure of the AZ91 alloy via LFC consists of dominant α-Mg and β-Mg17Al12 as well as a new phase Al32 Mn25 with size of about 5-50 μm,which has not been detected in AZ91 alloy prepared by other casting processes.The tests demonstrate that the as-cast mechanical properties are higher than those of sand gravity casting because of chilling and cushioning effect of foam pattern during the mould filling.The solution kinetics and the aging processes at different temperatures were also investigated by hardness and electrical resistivity measurements.The kinetics of aging are faster at the high temperature due to enhanced diffusion of atoms in the matrix,so the hardness peak at 380 ℃ occurs after 10 h;while at the lower aging temperature(150 ℃),the peak is not reached in the time(24 h) considered.

  14. Microstructure and mechanical properties of TiAl castings produced by zirconia ceramic mould

    Directory of Open Access Journals (Sweden)

    Tian Jing

    2011-11-01

    Full Text Available Owing to their low density and attractive high-temperature properties, gamma titanium aluminide alloys (TiAl alloys, hereafter have significant potential application in the aerospace and automobile industries, in which these materials may replace the heavier nickel-based superalloys at service temperatures of 600 – 900℃. Investment casting of TiAl alloys has become the most promising cost-effective technique for the manufacturing of TiAl components. Ceramic moulds are fundamental to fabricating the TiAl casting components. In the present work, ceramic mould with a zirconia primary coat was designed and fabricated successfully. Investment casting of TiAl blades and tensile test of specimens was carried out to verify the correctness and feasibility of the proposed method. The tensile test results indicate that, at room temperature, the tensile strength and the elongation are about 450 MPa and 0.8%, respectively. At 700℃, the tensile strength decreases to about 410 MPa and the elongation increases to 2.7%. Microstructure and mechanical properties of investment cast TiAl alloy are discussed.

  15. Properties of Cross-Rolled Low Alloy White Cast Iron Grinding Ball

    Institute of Scientific and Technical Information of China (English)

    CHANG Li-min; LIU Lin; LIU Jian-hua

    2007-01-01

    The low-energy, multi-impact fracture resistance and the abrasiveness of the cross-rolled low alloy white cast iron grinding balls were studied after heat treatments at residual rolling temperature. Moreover, the means by which they are damaged and characters of the wear surface were analyzed. The results show that high resistance to impact fracture and high abrasiveness can be achieved after appropriate heat treatment at residual rolling temperature. This kind of heat treatment technology has several advantages under low impact and hard abrasive. These results are very useful for determining the optimized heat treatment technology at residual rolling temperatures.

  16. Effect of residual Al content on microstructure and mechanical properties of Grade B+Steel for castings for locomotives

    Directory of Open Access Journals (Sweden)

    Wang Kaifeng

    2013-11-01

    Full Text Available The bogie made of Grade B+ steel is one of the most important parts of heavy haul trains. Some accidents were found to be the result of fracture failure of the bogies. It is very important to find the reason why the fracture failure occurred. Because Al was added for the final deoxidation during the smelting process of the Grade B+Steel, residual Al existed to some extent in the castings. High residual Al content in the bogie casting was presumed to be the reason for the fracture. In this work, the influence of residual Al content in the range of 0.015wt.% to 0.3wt.% on the microstructure and mechanical properties of the Grade B+ Steel was studied. The experimental results showed that when the residual Al content is between 0.02wt.% and 0.20wt.%, the mechanical properties of the steel meet the requirements of technical specification for heavy haul train parts, and the fracture is typical plastic fractures. If the residual Al content is less than 0.02wt.%, the microstructures are coarse, and the mechanical properties can not meet the demand of bogie steel castings. When the residual Al content is more than 0.2wt.%, the elongation, reduction of area, and low-temperature impact energy markedly deteriorate. The fracture mode then changes from plastic fracture to cleavage brittle fracture. Therefore, the amount of Al addition for the final deoxidation during the smelting process must be strictly controlled. The optimum addition amount needs to be controlled within the range of 0.02wt.% to 0.20wt.% for the Grade B+Steel.

  17. Effect of microstructure on mechanical properties of a thin-walled cast duplex steel

    Energy Technology Data Exchange (ETDEWEB)

    Petzold, L.; Kreschel, T.; Peisker, D. [TU Bergakademie Freiberg, Institut fuer Eisen- und Stahltechnologie, Freiberg (Germany); Minnich, D. [Evosteel GmbH, Leipzig (Germany)

    2010-06-15

    The paper investigates the microstructure and the resulting mechanical properties of a duplex steel cast in sand dead-moulds. The chemical composition and the cooling rate are the main parameters affecting the properties. The chemical composition influences the thermodynamics of the phase transformation, the cooling rate determines the kinetics of formation of the microstructure. The latter varies with changes in wall thickness (investigated from 2 to 7 mm) and the position of the material within the casting. Through heat treatment, the composition of the microstructural components can be changed selectively afterwards, thereby the properties are improved. The correlation between microstructure and mechanical properties is explained quantitatively. Additionally to the austenite-ferrite ratio, the dispersion of microstructure has a large influence on the mechanical properties. Ranges of chemical composition and heat treatment parameters are identified where third phases, such as carbides and {sigma}-phase tend to occur. These influence the properties very sensitively even in small amounts. Finally, structural parameters are recognized that will lead to optimal combinations of properties. With an appropriate heat treatment technique, in particular the ductility properties are further increased. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

  18. Effect of melting technology on the properties of G17CrMo5-5 steel for cast turbines

    Directory of Open Access Journals (Sweden)

    P. Mańkowski

    2010-10-01

    Full Text Available Two technologies of the G17CrMo 5-5 cast steel melting were compared, i.e. the so far used oxygen-recovery melting technology (electricarc furnace + ladle furnace – EAF + LF and a new recovery melting technology (electric induction furnace + ladle furnace - EIF + LF.The effect of the melting technology on the properties of cast steel for turbine parts was determined. The cast steel was evaluated in term of its metallurgical purity and mechanical properties. During melting of G17CrMo 5-5 steel in induction furnace, lower total content of oxygen in casting was reached, but nitrogen content was higher than it was in the cast steel from arc furnace. Metal refining in LF improved the steel desulphurising degree and contributed to modification of the non-metallic inclusions.

  19. Control of Wear-Resistance Properties in Ti-added Hypereutectic High Chromium Cast Iron

    OpenAIRE

    Liu, Qiang

    2012-01-01

    High chromium cast iron (HCCI) is considered as one of the most useful wear resistance materials and their usage are widely spread in industry. The wear resistance and mechanical properties of HCCI mainly depend on type, size, number, morphology of hard carbides and the matrix structure (γ or α). The Hypereutectic HCCI with large volume fractions of hard carbides is preferred to apply in wear applications. However, the coarser and larger primary M7C3 carbides will be precipitated during the s...

  20. Microstructure Evaluation and Wear-Resistant Properties of Ti-alloyed Hypereutectic High Chromium Cast Iron

    OpenAIRE

    Liu, Qiang

    2013-01-01

    High chromium cast iron (HCCI) is considered as one of the most useful wear resistance materials and their usage are widely spread in industry. The mechanical properties of HCCI mainly depend on type, size, number, morphology of hard carbides and the matrix structure (γ or α). The hypereutectic HCCI with large volume fractions of hard carbides is preferred to apply in wear applications. However, the coarser and larger primary M7C3 carbides will be precipitated during the solidification of the...

  1. Cross-Linked Slurry Cast Composite Modified Double Base Propellants : Mechanical Properties

    Directory of Open Access Journals (Sweden)

    V. K. Bhat

    1987-01-01

    Full Text Available Cross-linking of NC by TDI in slurry cast CMDB propellant enhanced TS by about 100 per cent. Coated AP with resorcinol, phloroglucinol, hexanetriol or silicone oil etc. along with cross-linking of NC raised TS from 18 - 30 kg/cm2. Inclusion of phloroglucinol and silicone oil gave increased burning rates. The probable mechanism of action of cross-linking and improvement of mechanical properties by coating of AP has been discussed.

  2. Microstructure and Tensile Properties of Wrought Al Alloy 5052 Produced by Rheo-Squeeze Casting

    Science.gov (United States)

    Lü, Shulin; Wu, Shusen; Wan, Li; An, Ping

    2013-06-01

    The semisolid slurry of wrought Al alloy 5052 was prepared by the indirect ultrasonic vibration (IUV) method, in which the horn was vibrated under the outside of the metallic cup containing molten alloy, and then shaped by direct squeeze casting (SC). Spherical primary α-Al particles were uniformly dispersed in the matrix and presented a bimodal distribution of grain sizes. The effects of rheo-squeeze casting (RSC) parameters such as squeeze pressure and solid fraction on the microstructure and tensile properties of the semisolid alloy were investigated. The results indicate that average diameters of the primary α-Al particles decreased with the increase of squeeze pressure, while the tensile properties of the alloy increased. With the increase of solid fraction, the tensile strength increased first and then decreased, but the elongation decreased continuously. The best tensile properties were achieved when the slurry with a solid fraction of 0.17 solidified under 100 MPa. Compared to conventional squeeze casting, RSC process can offer the 5052 alloy better tensile strength and elongation, which were improved by 9.7 pct and 42.4 pct, respectively.

  3. Microstructure and mechanical properties of low frequency electromagnetic casting 7075 aluminum alloy

    Institute of Scientific and Technical Information of China (English)

    Gaosong WANG; Zhihao ZHAO; Jianzhong CUI; Qiang GUO

    2012-01-01

    This work explores the microstructure of low frequency electromagnetic casting (LFEC) 7075 aluminum alloys and investigates the effect of heat treatment process on its mechanical properties via the mechanical properties test,X-ray diffraction and transmission electron microscopy.It was found that the grains of LFEC ingot were finer and more evenly distributed than that of the conventional direct chill cast (DC) ingots.The microstructure of LFEC ingot extruded kept their original as-cast structure with small and fine grains.With the same extrusion ratio,the average grain diameters of LFEC and conventional DC extruded were about 10 and 20 μm,respectively.LFEC extruded also had a better aging property,since the regime of T6 treatment peak value aging was at 120 ℃ for 24 h,the tensile strength and hardness (HV) of the LFEC extruded were 673.50 MPa and 194.62,respectively,which were all higher than those of the conventional DC extruded,indicating that the process regime can be applied in the industrial production.

  4. Estimation of integrity of cast-iron cask against impact due to free drop test, (1)

    International Nuclear Information System (INIS)

    Ductile cast iron is examined to use for shipping and storage cask from a economic point of view. However, ductile cast iron is considered to be a brittle material in general. Therefore, it is very important to estimate the integrity of cast iron cask against brittle failure due to impact load at 9 m drop test and 1 m derop test on to pin. So, the F.E.M. analysis which takes nonlinearity of materials into account and the estimation against brittle failure by the method which is proposed in this report were carried out. From the analysis, it is made clear that critical flaw depth (the minimum depth to initiate the brittle failure) is 21.1 mm and 13.1 mm in the case of 9 m drop test and 1 m drop test on to pin respectively. These flaw depth can be detected by ultrasonic test. Then, the cask is assured against brittle failure due to impact load at 9 m drop test and 1 m drop test on to pin. (author)

  5. Properties of ABNT 41xx and 86xx cast steel modified with niobium; evaluation methodology and experimental preliminary results

    International Nuclear Information System (INIS)

    The experimental methodology to evaluate the mechanical properties of ABNT 41xx and 86xx steels modified with NB in the as cast and heat treated conditions and the first preliminary results obtained in a laboratory scale, are presented. (Author)

  6. New developments on optimizing properties of high-Zn aluminium cast alloys

    Science.gov (United States)

    Krajewski, W. K.; Buras, J.; Krajewski, P. K.; Greer, A. L.; Schumacher, P.; Haberl, K.

    2016-07-01

    Foundry alloys with Al-based matrices have a wide range of uses in today's global economy and there is a high demand for castings of Al alloys, including Al-Zn alloys. In this paper, investigations on the grain refinement of high-Zn aluminium cast alloys are presented. Aluminium alloys with relatively high zinc content have a tendency to be coarse-grained, especially in the case of castings with low cooling rates such as are found in sand moulds. The coarse-grained structure degrades the plasticity, specifically the elongation. Therefore, for aluminium alloys of high (10-30 wt.%) zinc content, inoculation is attractive, aiming to break up the primary dendrites of the a-phase solid solution of zinc in aluminium. Such dendrites are the principal microstructural component in these alloys. On the other hand, a finer grain structure usually reduces the damping (e.g. as measured by attenuation of ultrasound) in these alloys. In the present investigations, a binary sand-cast Al-20 wt.% Zn alloy was inoculated with different additions of AlTi3C0.15 (TiCAl) and ZnTi-based master alloys. The sand-cast samples were subjected to mechanical-property measurements (tensile strength and elongation), image analysis to determine grain size, and measurements of the attenuation of 1 MHz ultrasound. It is found that both of the master alloys used cause significant refinement of the a-AlZn primary dendrites and change their morphology from linear-branched to semi-globular, increase the elongation by about 40%, and decrease the attenuation coefficient by about 25% in comparison with the initial alloy without inoculation.

  7. Effect of excitation current intensity on mechanical properties of ZL205A castings solidified under a traveling magnetic field

    OpenAIRE

    Xue-yi Fan; Liang Wang; Zhi-qiang Du

    2015-01-01

    The effect of excitation current intensity on the mechanical properties of ZL205A castings solidified under a traveling magnetic field was studied. The results of the experiment indicate that the excitation current intensity of the traveling magnetic field has a great influence on the mechanical properties of the ZL205A castings. When the excitation current intensity is 15 A, the tensile strength and elongation of ZL205A alloy castings increase 27.2% and 67.7%, respectively, compared with tho...

  8. Effect of eutectic phase on damping and mechanical properties of as-cast Mg-Ni hypoeutectic alloys

    Institute of Scientific and Technical Information of China (English)

    WAN Di-qing; WANG Jin-cheng; WANG Gai-fang; LIN Lin; FENG Zhi-gang; YANG Gen-cang

    2009-01-01

    Dynamic mechanical analysis (DMA) was applied to systematically investigate the low frequency damping properties of as-cast hypoeutectic Mg-Ni alloys. The results show that the as-cast hypoeutectic Mg-Ni alloys exhibit high damping capacities. The strain amplitude dependent damping curve has its own special characteristic, in which the damping is strongly related to the strain amplitude. The effect of the eutectic phase on damping and the mechanical properties of as-cast hypoeutectic Mg-Ni alloys were also discussed in detail.

  9. Morphological and Mechanical Properties of Dispersion-Cast and Extruded Nafion Membranes Subjected to Thermal and Chemical Treatments

    OpenAIRE

    Osborn, Shawn James

    2009-01-01

    The focus of this research project was to investigate morphological and mechanical properties of both extruded and dispersion-cast Nafion® membranes. The project can be divided into three primary objectives; obtaining a fundamental understanding of the glass transition temperature of Nafion®, determining the effect of thermal annealing treatments on the morphology and mechanical properties of dispersion-cast Nafion®, and examination of dispersion-cast Nafion® subjected to an ex-situ, Fen...

  10. Tensile Properties of Al-Cu 206 Cast Alloys with Various Iron Contents

    Science.gov (United States)

    Liu, K.; Cao, X.; Chen, X.-G.

    2014-05-01

    The Al-Cu 206 cast alloys with varying alloy compositions ( i.e., different levels of Fe, Mn, and Si) were investigated to evaluate the effect of the iron-rich intermetallics on the tensile properties. It is found that the tensile strength decreases with increasing iron content, but its overall loss is less than 10 pct over the range of 0.15 to 0.5 pct Fe at 0.3 pct Mn and 0.3 pct Si. At similar iron contents, the tensile properties of the alloys with dominant Chinese script iron-rich intermetallics are generally higher than those with the dominant platelet phase. In the solution and artificial overaging condition (T7), the tensile strength of the 206 cast alloys with more than 0.15 pct Fe is satisfactory, but the elongation does not sufficiently meet the minimum requirement of ductility (>7 pct) for critical automotive applications. However, it was found that both the required ductility and tensile strength can be reached at high Fe levels of 0.3 to 0.5 pct for the alloys with well-controlled alloy chemistry and microstructure in the solution and natural aging condition (T4), reinforcing the motivation for developing recyclable high-iron Al-Cu 206 cast alloys.

  11. Effect of Titanium on the Mechanical Properties and Microstructure of Gray Cast Iron for Automotive Applications

    Science.gov (United States)

    Gelfi, M.; Gorini, D.; Pola, A.; La Vecchia, G. M.

    2016-07-01

    Lamellar gray cast iron, with a mainly pearlitic microstructure, is widely used in the automotive industry, mostly in the manufacturing of brake disks. This work analyzes in depth the effects of small variations of titanium content on the microstructure and mechanical properties of cast iron brake disks. For this purpose, eight different heats of EN-GJL-250 cast iron were selected, with a similar chemical composition but with different titanium contents, varying from 0.013 to 0.031%. The drops in mechanical strength and hardness values measured on the high-Ti samples were correlated to microstructural variations quantitatively observed by means of optical and scanning electron microscope. It was found that titanium combines to form titanium nitrides, suppressing the beneficial microstructural effects of nitrogen at solidification. Residual nitrogen, if present in sufficient quantity, promotes the nucleation of primary austenite from the liquid and the formation of a fine microstructure, with small eutectic cells and lower graphite content. Such a microstructure provides brake disks with better mechanical properties. The interpretation of results was further supported by thermal analysis and thermodynamic calculations.

  12. The evaluation of dynamic cracking resistance of chosen casting alloys in the aspect of the impact bending test

    Directory of Open Access Journals (Sweden)

    J.Sadowski

    2008-10-01

    Full Text Available The increase of quality and durability of produced casting alloys can be evaluated on the base of material tests performed on a high level. One of such modern test methods are tests of the dynamic damage process of materials and the evaluation on the base of obtained courses F(f, F(t of parameters of dynamic cracking resistance KId, JId, performed with the usage of instrumented Charpy pendulums. In the paper there was presented the evaluation of dynamic cracking resistance parameters of casting alloys such as: AK12 aluminum alloy, L20G cast steel and spheroid cast iron. The methodology of the evaluation of that parameters was described and their change as well, for the AK12 alloy with the cold work different level, L20G cast steel cooled from different temperatures in the range +20oC -60oC, and for the spheroid cast iron in different stages of treatment i.e. raw state, after normalization, spheroid annealing and graphitizing annealing.Obtained parameters of dynamic cracking resistance KId, JId of tested casting alloys enabled to define the critical value of the ad defect that can be tolerated by tested castings in different work conditions with impact loadings.

  13. Moving cast shadow resistant for foreground segmentation based on shadow properties analysis

    Science.gov (United States)

    Zhou, Hao; Gao, Yun; Yuan, Guowu; Ji, Rongbin

    2015-12-01

    Moving object detection is the fundamental task in machine vision applications. However, moving cast shadows detection is one of the major concerns for accurate video segmentation. Since detected moving object areas are often contain shadow points, errors in measurements, localization, segmentation, classification and tracking may arise from this. A novel shadow elimination algorithm is proposed in this paper. A set of suspected moving object area are detected by the adaptive Gaussian approach. A model is established based on shadow optical properties analysis. And shadow regions are discriminated from the set of moving pixels by using the properties of brightness, chromaticity and texture in sequence.

  14. Structure changes and mechanical properties of laser alloyed magnesium cast alloys

    OpenAIRE

    W. Kwaśny; T. Tański,; Sz. Malara; J. Domagała; L.A. Dobrzański

    2009-01-01

    Purpose: The aim of this work was to investigate structure and mechanical properties of the MCMgAl12Zn1 casting magnesium alloys after laser treatment. The laser treatment was carried out using a high power diode laser (HPDL).Design/methodology/approach: The laser processing of TiC, WC, SiC particles in MCMgAl12Zn1 and the resulted microstructures and properties are discussed in this paper. The resulting microstructure in the modified surface layer was examined. Phase composition was...

  15. Effect of N on microstructure and mechanical properties of as-cast Ti-6Al alloy

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    In-situ titanium matrix composites with N content of 0. 045-0. 27 wt% have been produced by a casting method. The microstructure and mechanical properties of as-cast materials have been observed and tested.The results show that when N content in Ti-6Al alloy is between 0. 045 wt% and 0. 27 wt%, the reinforcement is a compound of Ti, Al and N, and volume fraction of reinforcements increases with an increase of N content.The hardness, compressive strength and elastic modulus are all higher than that of the matrix alloy. With the increase of N content, the compressive strength, the hardness and the elastic modulus increase. Fracture surface analysis has also shown that the matrix alloy fractures in a ductile model and the composites fracture in a cleavage brittle model with characteristics of dimple and cleavage surface.

  16. Microstructure and mechanical properties of high strength as-cast Ti-15-3 alloy

    Institute of Scientific and Technical Information of China (English)

    丁宏升; 周建中; 贾均; 郭景杰; 苏彦庆; 傅恒志

    2002-01-01

    The effects of heat treatment and solidification cooling rate on the microstructure and mechanical properties of as-cast Ti-15-3 alloy prepared by induction skull melting method were investigated. Results show that the microstructure of as-cast Ti-15-3 alloy changes from the features of simplified and larger size of beta grains to finer grain size with increasing solidification cooling rate. After solution treatment and different ageing treatment, alpha phase precipitates in grains interior as well as in grain boundaries. Due to the modification of the precipitate phase, the tensile strength and elongation of the alloy are improved simultaneously. A good combination of the values of 1.406GPa of σb and 4.5% of δ was obtained, which will be satisfied the use of this kind of alloy in critical areas.

  17. Structure changes and mechanical properties of laser alloyed magnesium cast alloys

    Directory of Open Access Journals (Sweden)

    W. Kwaśny

    2009-02-01

    Full Text Available Purpose: The aim of this work was to investigate structure and mechanical properties of the MCMgAl12Zn1 casting magnesium alloys after laser treatment. The laser treatment was carried out using a high power diode laser (HPDL.Design/methodology/approach: The laser processing of TiC, WC, SiC particles in MCMgAl12Zn1 and the resulted microstructures and properties are discussed in this paper. The resulting microstructure in the modified surface layer was examined. Phase composition was determined by the X-ray diffraction method using XPert device. The measurements of hardness after laser melt injection was also studied.Findings: Structure of the solidyifying material after laser alloying is characteristic with occurrences of areas with the diversified morphology, dependent on solidification rate of the magnesium alloys, is characteristic of structure of the solidified material after laser alloying. The MCMgAl12Zn1 casting magnesium alloys after laser alloying demonstrate similar hardness tests results, in reference to hardness of the alloys before their laser treatment.Research limitations/implications: In this research three powders (titanium carbide, tungsten carbide and silicon carbide were used to reinforcing the surface of the MCMgAl12Zn1 casting magnesium alloys.Practical implications: High power diode laser can be used as an economical substitute for CO2 and Nd:YAG lasers to modify the surface magnesium alloy by feeding the carbide particles.Originality/value: The originality of this work is applying of High Power Diode Laser for laser treatment of cast magnesium alloy consisting in fusion penetration of the hard particles of titanium, tungsten, and silicon carbides into the remelted surface layer of the alloy.

  18. Modeling Mechanical Properties of Aluminum Composite Produced Using Stir Casting Method

    Directory of Open Access Journals (Sweden)

    Muhammad Hayat Jokhio

    2011-01-01

    Full Text Available ANN (Artificial Neural Networks modeling methodology was adopted for predicting mechanical properties of aluminum cast composite materials. For this purpose aluminum alloy were developed using conventional foundry method. The composite materials have complex nature which posses the nonlinear relationship among heat treatment, processing parameters, and composition and affects their mechanical properties. These nonlinear relation ships with properties can more efficiently be modeled by ANNs. Neural networks modeling needs sufficient data base consisting of mechanical properties, chemical composition and processing parameters. Such data base is not available for modeling. Therefore, a large range of experimental work was carried out for the development of aluminum composite materials. Alloys containing Cu, Mg and Zn as matrix were reinforced with 1- 15% Al2O3 particles using stir casting method. Alloys composites were cast in a metal mold. More than eighty standard samples were prepared for tensile tests. Sixty samples were given solution treatments at 580oC for half an hour and tempered at 120oC for 24 hours. The samples were characterized to investigate mechanical properties using Scanning Electron Microscope, X-Ray Spectrometer, Optical Metallurgical Microscope, Vickers Hardness, Universal Testing Machine and Abrasive Wear Testing Machine. A MLP (Multilayer Perceptron feedforward was developed and used for modeling purpose. Training, testing and validation of the model were carried out using back propagation learning algorithm. The modeling results show that an architecture of 14 inputs with 9 hidden neurons and 4 outputs which includes the tensile strength, elongation, hardness and abrasive wear resistance gives reasonably accurate results with an error within the range of 2-7 % in training, testing and validation.

  19. Influence of multi element micro alloying on solidification microstructure and impact wear properties of high chromium cast iron%多元微合金化对高铬铸铁凝固组织及冲击磨损性能的影响

    Institute of Scientific and Technical Information of China (English)

    李秀兰; 周新军; 谢文玲; 马幼平

    2015-01-01

    Titanium,vanadium,niobium and molybdenum were added into 2.85C⁃31Cr high chromium cast iron to prepare multicomponent chromium alloys. The influence of titanium,vanadium,niobium and molybdenum on microsturcture evolvement and impact wear properties was investigated. The results show that carbon in iron liquid together with strong carbides formation elements form the corresponding carbides or alloy carbides. With the increase of addition amount of alloy elements,the microstructure of high chromium cast iron changes from hypereutectic into eutectic and hypoeutectic alloy. The weight losses of the alloy with the same component increase first and then decrease with the increase of impact load(2.0,2.5,3.0,3.5 J),which is related with the hardening behavior of the wearing surface during the impact wear. The more the amount of austenite,the higher the wear weight loss rate. The microstructure with fine size and even distribution can decrease the wear weight loss rate. The wear weight loss for eutectic alloy is the minimum and that for hypoeutectic alloy is the maximum under the same impact load.%通过在2.85C-31Cr合金中加入多元微量合金元素V、Ti、Nb、Mo制备多元铬系合金,研究多元微合金化对高铬铸铁的凝固组织和冲击磨损性能的影响。结果表明:铁液中部分C与强碳化物形成元素结合生成碳化物或合金碳化物;随合金元素加入量的增加,高铬铸铁凝固组织从稍微过共晶转变成共晶、亚共晶组织;相同成分的合金质量损失率随冲击磨损载荷(2.0、2.5、3.0、3.5 J)的增加呈先增加后减小、再增大的变化规律,这与材料在冲击磨损过程中的硬化行为有关;凝固组织中奥氏体数量越多,磨损质量损失率越大,尺寸细小和分布均匀的凝固组织能减小磨损质量损失率;在同一冲击载荷下,共晶成分的合金质量损失率最小,亚共晶成分的质量损失率最大。

  20. Mechanical Properties - Structure Correlation for Commercial Specification of Cast Particulate Metal Matrix Composites

    Energy Technology Data Exchange (ETDEWEB)

    Pradeep Rohatgi

    2002-12-31

    In this research, the effects of casting foundry, testing laboratory, surface conditions, and casting processes on the mechanical properties of A359-SiC composites were identified. To observe the effects, A359-SiC composites with 20 and 305 SiC particles were cast at three different foundries and tested at three different laboratories. The composites were cast in sand and permanent molds and tested as-cast and machined conditions. To identify the effect of the volume fraction and distribution of particles on the properties of the composites, particle distribution was determined using Clemex Image analysis systems, and particle volume fraction was determined using wet chemical analysis and Clemex Image analysis systems. The microstructure and fractured surfaces of the samples were analyzed using SEM, and EDX analysis was done to analyze chemical reaction between the particles and the matrix. The results of the tensile strengths exhibited that the tensile strengths depend on the density and porosity of the composites; in general the higher tensile strength is associated with lower porosity and higher density. In some cases, composites with lower density were higher than these with higher density. In the Al-20% SiC samples, the composites with more inclusions exhibited a lower tensile strength than the ones with fewer inclusions. This suggests that macroscopic casting defects such as micro-porosity, shrinkage porosity and inclusions appear to strongly influence the tensile strength more than the microstructure and particle distribution. The fatigue properties of A359/20 vol.% SiC composites were investigated under strain controlled conditions. Hysteresis loops obtained from strain controlled cyclic loading of 20% SiCp reinforced material did not exhibit any measurable softening or hardening. The fatigue life of Al-20% SiC heat treated alloy at a given total strain showed wide variation in fatigue life, which appeared to be related to factors such as inclusions

  1. Special thermite cast irons

    OpenAIRE

    Yu. Zhiguts; I. Kurytnik

    2008-01-01

    The given paper deals with the problems of the synthesis of cast iron by metallothermy synthesis. On the basis of investigated method of calculations structures of charges have been arranged and cast iron has been synthesized further. Peculiarities metallothermic smelting were found, mechanical properties and structure of received cast iron were investigated and different technologies for cast iron receiving were worked out.

  2. Effect of RE-Al-N on Structures and Properties of M2 Cast High Speed Steel

    Institute of Scientific and Technical Information of China (English)

    符寒光; 杜建铭; 蒋志强; 邢建东

    2003-01-01

    M2 cast high speed steel was inoculated by addition of rare earth(RE)-Al-N, network eutectic carbides were eliminated, matrix microstructures were refined and the segregation of tungsten and molybdenum elements was relieved. In the condition that the hardness does not decrease, impact toughness obviously increases. Quenching at 1180 ℃ and three-times tempering at 560 ℃, the hardness of M2 cast high speed steel is 65~66 HRC, and impact toughness reaches 21.3 J*cm- 2. Modified M2 cast high speed steel has excellent thermal fatigue resistance and high temperature wear resistance. Roller made in modified M2 cast high speed steel has excellent service effect when it is used in slit rolling mill of hot rolling bar mill.

  3. Effect of modifying process on mechanical properties of EN AC-43300 silumin cast into sand moulds

    Directory of Open Access Journals (Sweden)

    J. Pezda

    2009-07-01

    Full Text Available Significance of alloy modification in course of casting process is the most explicitly visible on example of Al-Si alloys. Broad application of these alloys in foundry industry has become possible after invention of a method which changes solidification form of Al-Si eutectic mixture. Such primarily thick, acicular shape of silicon crystals becomes changed into fine and compact structure due to introduction of a small quantity of modifier to liquid alloy. The paper presents an attempt of assessment of melting and modification with strontium effects on mechanical properties of EN AC-43300 alloy cast into sand moulds. Obtained results concern selection of optimal quantity of strontium additive in aspect of obtained mechanical properties (Rm, A5, KCV, HB. Effect of strontium additive on change of mechanical properties of the investigated alloy was presented in graphical form. Further investigations shall be connected with determination of an effect of strontium additive on mechanical properties of the alloy after solution heat treatment and ageing treatment.

  4. Effect of inter-critical quenching on mechanical properties of casting low-alloy steel

    Directory of Open Access Journals (Sweden)

    Liu Zhongli

    2013-07-01

    Full Text Available For some casting low-alloy steels, traditional quenching and tempering heat treatments can improve the strength; however, sometimes the ductility is not satisfied. Therefore, some kind of effective heat treatment method seems necessary; one which could improve the ductility, but not seriously affect the strength. In this paper, the effect of inter-critical quenching (IQ on the mechanical properties of casting low-alloy steel was studied. IQ was added between quenching and tempering heat treatment; and the microstructure and mechanical properties were compared to the same steel with the traditional quenching and tempering treatments. The experimental results show that the microstructure comprises small-size ferrite and martensite when the IQ is adopted; and that different temperatures can control the ferrite quantity and distribution, and, as a result, influence the mechanical properties. In the case of IQ, the tensile strength decreases just a little, but the ductility increases a lot; and the strength-ductility product (its value is the arithmetic product of elongation and tensile strength increases by between 6% and 10%, which means the IQ heat treatment can improve comprehensive mechanical properties.

  5. Microstructures and mechanical properties of cast austenite stainless steels after long-term thermal aging at low temperature

    International Nuclear Information System (INIS)

    Highlights: ► The primary circuit piping materials from Ling Ao Nuclear Power Plant was thermally aged for as long as 20,000 h. ► G-phase precipitation was characterized by HRTEM. ► Hardness in ferrite and austenite, tensile properties and impact behaviors of the long-term aged materials were studied. ► The mechanism of thermal aging embrittlement was proposed. - Abstract: The cast austenite stainless steels were investigate in order to understand the microstructural evolution and mechanical properties in the long-term thermal aging at 400 °C for up to 20,000 h. Spinodal decomposition and G-phase precipitation in ferrite after long-term thermal aging lead to the degradation of mechanical properties. Ferrite hardness increases with aging time, but the austenite hardness does not change. Tensile strength is not strongly affected by aging time, but the plasticity has a significant decrease after long-term aging. Under impact with high strain rate, the ferrite phases deform by the way of deformation twinning. High stress concentration on the phase boundaries cause the phase boundary separating and the austenite’s tearing off

  6. Effects of advanced oxidation on green sand properties via iron casting into green sand molds.

    Science.gov (United States)

    Wang, Yujue; Cannon, Fred S; Voigt, Robert C; Komarneni, Sridhar; Furness, J C

    2006-05-01

    The effects of advanced oxidation (AO) processing on the properties of green sand were studied via pouring cast iron into green sand molds. Upon cooling, the green sand molds were autopsied at various distances from the metal-sand interface. Autopsy green sand samples collected from a mold that incorporated AO water were characterized and compared to controlled samples collected from a similar autopsied mold made with conventional tap water (TAP). It was found that the AO processing removed a coating of coal pyrolysis products from the clay surface that typically accumulated on the clay surface. As a result, the AO-conditioned green sand retained 10-15% more active clay as measured bythe standard ultrasonic methylene blue titration than did the TAP-conditioned green sand. The AO processing also nearly doubled the generation of activated carbon from the normalized amount of coal composition of the green sand during the casting process. The AO-enhanced activated carbon generation and the AO-incurred clay surface cleaning provided the AO-conditioned green sand with higher normalized pore volume, and thus higher normalized m-xylene adsorption capacity, i.e., relative to before-metal-pouring conditions. Furthermore, mathematical analysis indicated that the AO-conditioned green sand better retained its important properties after pouring than did the TAP-conditioned green sand. Effectively, this meant after metal pouring, the AO-conditioned sample offered about the same net properties as the TAP-conditioned sample, even though the AO-conditioned sample contained less clay and coal before metal pouring. These results conformed to the full-scale foundry empirical finding that when AO is used, foundries need less makeup clay and coal addition through each casting cycle, and they release less air emissions. PMID:16719117

  7. Structure and properties of polypropylene cast films: Polymer type and processing effects

    Science.gov (United States)

    Mileva, Daniela; Gahleitner, Markus; Gloger, Dietrich

    2016-05-01

    The influence of processing parameters in a cast film extrusion process of thin films of isotactic polypropylene homopolymer and random propylene-ethylene copolymer was analyzed. Variation of the chill roll temperature allowed changing the supercooling of the melt and thus the generation of different crystal polymorphs of iPP. Additional focus was placed on the effect of flow induced crystallization via changing the output rate of the line. The crystal structure and morphology of the materials were evaluated and correlated to selected optical and mechanical properties.

  8. Effect of graphite degradation on the LCF properties of nodular cast iron

    Directory of Open Access Journals (Sweden)

    Denk Josef

    2014-06-01

    Full Text Available The effect of degraded microstructure on the tensile and LCF properties was studied on a casing of a turbocharger, which exhibited locally irregular graphite formation. The tensile tests showed that the ductility values of the zone with degraded graphite decreased strongly compared to the zone with normal graphite, while the strength values decreased only slightly. Based on these results and a LCF reference curve for nodular cast iron with normal graphite structure, a synthetic LCF curve was generated for the material condition with degraded graphite structure. LCF tests on specimens with irregular graphite structure confirmed the predicted LCF behaviour quite good.

  9. Quantitative characterization of processing-microstructure-properties relationships in pressure die-cast magnesium alloys

    Science.gov (United States)

    Lee, Soon Gi

    The central goal of this research is to quantitatively characterize the relationships between processing, microstructure, and mechanical properties of important high-pressure die-cast (HPDC) Mg-alloys. For this purpose, a new digital image processing technique for automatic detection and segmentation of gas and shrinkage pores in the cast microstructure is developed and it is applied to quantitatively characterize the effects of HPDC process parameters on the size distribution and spatial arrangement of porosity. To get better insights into detailed geometry and distribution of porosity and other microstructural features, an efficient and unbiased montage based serial sectioning technique is applied for reconstruction of three-dimensional microstructures. The quantitative microstructural data have been correlated to the HPDC process parameters and the mechanical properties. The analysis has led to hypothesis of formation of new type of shrinkage porosity called, "gas induced shrinkage porosity" that has been substantiated via simple heat transfer simulations. The presence of inverse surface macrosegregation has been also shown for the first time in the HPDC Mg-alloys. An image analysis based technique has been proposed for simulations of realistic virtual microstructures that have realistic complex pore morphologies. These virtual microstructures can be implemented in the object oriented finite elements framework to model the variability in the fracture sensitive mechanical properties of the HPDC alloys.

  10. Effect of two-step aging on the mechanical properties of AA2219 DC cast alloy

    Energy Technology Data Exchange (ETDEWEB)

    Elgallad, E.M., E-mail: eelgalla@uqac.ca; Zhang, Z.; Chen, X.-G.

    2015-02-11

    With its combination of high specific strength, good machinability and excellent weldability, AA2219 direct chill (DC) cast alloy has become a new category of materials for manufacturing large molds for the plastics and automotive industries. The effect of two-step aging on the microstructural evolution and mechanical properties of AA2219 DC cast alloy was investigated. The precipitate microstructure was characterized under different heat treatment conditions using differential scanning calorimetry (DSC) and transmission electron microscopy (TEM). The poor mechanical properties of the air-quenched alloy were attributed to the presence of quench-induced coarse θ′ and θ precipitates, which had very limited contribution to the precipitation hardening during the aging treatment. The two-step aging treatment of the air-quenched AA2219 alloy involved the precipitation of GP zones in the first step followed by their transformation into fine θ″ strengthening precipitates in the second step, which considerably improved the mechanical properties. After undergoing 120 °C/36 h+190 °C/8 h two-step aging, the hardness, YS and UTS of the air-quenched alloy were increased by 27%, 46% and 15%, respectively, compared with 190 °C/8 h one-step aging.

  11. MICROSTRUCTURE AND TENSILE PROPERTY OF AN AS-CAST DUPLEX STAINLESS STEEL

    Institute of Scientific and Technical Information of China (English)

    P.L.Mao; K.Yang; G.Y.Su

    2001-01-01

    The effect of high temperature solution heat treatment on the microstructure and ten-sile property of as-cast 0Cr17Mn14Mo2N duplex stainless steel was investigated.Itwas found that the morphology ofδ-ferrite in the dual phases microstructures changedgradually from dendritic to lamellar and then to spheroidal,and its distribution be-came more uniform under appropriate treatment.When the treat temperature waslower than 1250C,the spheroidial ratio and the homogeneous distribution o fδ-ferriteincrease with increasing temperature,which corresponds to a better tensile property.In addition,when the treat temperature reached 1250~C and above,the microstructureconsists of coarse equiaxial δ-ferrite grains with the needle austenite at its boundaries,which results in a decrease of the tensile properties of the steel.

  12. Microstructure and properties of Ti–Nb–V–Mo-alloyed high chromium cast iron

    Indian Academy of Sciences (India)

    Youping Ma; Xiulan Li; Yugao Liu; Shuyi Zhou; Xiaoming Dang

    2013-10-01

    The correlations of microstructure, hardness and fracture toughness of high chromium cast iron with the addition of alloys (titanium, vanadium, niobium and molybdenum) were investigated. The results indicated that the as-cast microstructure changed from hypereutectic, eutectic to hypoeutectic with the increase of alloy contents. Mo dissolved in austenite and increased the hardness by solid solution strengthening. TiC and NbC mainly existed in austenite and impeded the austenite dendrite development. V existed in multicomponent systems in forms of V alloy compounds (VCrFe8 and VCr2C2).With the increase of alloy additions, carbides size changed gradually from refinement to coarseness, hardness and impact toughness were increased and then decreased. Compared with the fracture toughness (6 J/cm2) and hardness (50.8HRC) without any alloy addition, the toughness and hardness at 0.60 V–0.60Ti–0.60Nb–0.35Mo (wt%) additions were improved and achieved to 11 J/cm2 and 58.9HRC, respectively. The synergistic roles of Ti, Nb, V and Mo influenced the solidification behaviour of alloy. The refinement of microstructure and improvement of carbides morphologies, size and distribution improved the impact toughness.

  13. Novel strip-cast Mg/Al clad sheets with excellent tensile and interfacial bonding properties

    Science.gov (United States)

    Kim, Jung-Su; Lee, Dong Ho; Jung, Seung-Pill; Lee, Kwang Seok; Kim, Ki Jong; Kim, Hyoung Seop; Lee, Byeong-Joo; Chang, Young Won; Yuh, Junhan; Lee, Sunghak

    2016-06-01

    In order to broaden industrial applications of Mg alloys, as lightest-weight metal alloys in practical uses, many efforts have been dedicated to manufacture various clad sheets which can complement inherent shortcomings of Mg alloys. Here, we present a new fabrication method of Mg/Al clad sheets by bonding thin Al alloy sheet on to Mg alloy melt during strip casting. In the as-strip-cast Mg/Al clad sheet, homogeneously distributed equi-axed dendrites existed in the Mg alloy side, and two types of thin reaction layers, i.e., γ (Mg17Al12) and β (Mg2Al3) phases, were formed along the Mg/Al interface. After post-treatments (homogenization, warm rolling, and annealing), the interfacial layers were deformed in a sawtooth shape by forming deformation bands in the Mg alloy and interfacial layers, which favorably led to dramatic improvement in tensile and interfacial bonding properties. This work presents new applications to multi-functional lightweight alloy sheets requiring excellent formability, surface quality, and corrosion resistance as well as tensile and interfacial bonding properties.

  14. Characterization of Jatropha curcas L. Protein Cast Films with respect to Packaging Relevant Properties

    Directory of Open Access Journals (Sweden)

    Gabriele Gofferje

    2015-01-01

    Full Text Available There is increasing research ongoing towards the substitution of petrochemical based plastics by more sustainable raw materials, especially in the field of bioplastics. Proteins of different types such as whey, casein, gelatine, or zein show potential beyond the food and feed industry as, for instance, the application in packaging. Protein based coatings provide different packaging relevant properties such as barrier against permanent gases, certain water vapour barrier, and mechanical resistance. The aim of this study was to explore the potential for packaging applications of proteins from Jatropha curcas L. and to compare the performance with literature data on cast films from whey protein isolate. As a by-product from oil extraction, high amounts of Jatropha meal are obtained requiring a concept for its sustainable utilization. Jatropha seed cake includes up to 40% (w/w of protein which is currently not utilized. The present study provides new data on the potential of Jatropha protein for packaging applications. It was shown that Jatropha protein cast films show suitable barrier and mechanical properties depending on the extraction and purification method as well as on the plasticiser content. Based on these findings Jatropha proteins own potential to be utilized as coating material for food packaging applications.

  15. Influence of waxes remelting used in investment casting on their thermal properties and linear shrinkage

    Directory of Open Access Journals (Sweden)

    K. Grzeskowiak

    2015-04-01

    Full Text Available This paper presents the results of thermal properties and linear shrinkage of jewelry waxes utilized in investment casting. Three types of jewelry waxes were cyclically processed (by heating, holding in a molten state and coolingin the temperature range between 25 and 90 °C for about 7 hours. The samples were tested after 5th, 10th and 15thcycle. The remelting was designed to simulate the process of waxes reusability for production of patterns. Changes in thermal properties of waxes were determined using differential scanning calorimetry (DSC and linear shrinkage values were specified. The conducted examinations allowed to establish the way of multiple utilization of waxes in producing precise models.

  16. Influence of niobium addition on the high temperature mechanical properties of a centrifugally cast HP alloy

    International Nuclear Information System (INIS)

    The influence of niobium addition on the mechanical properties at high temperature of HP alloy has been investigated. Two HP alloys were centrifugally cast with a similar chemical composition differing only in the niobium content. Low strain rate high temperature tensile tests and creep-rupture tests were performed in the range of 900–1100 °C, and the results compared between the alloys. According to the results, the high temperature mechanical behavior of both alloys is controlled by several factors like solid solution, network of eutectic carbides, intradendritic precipitation and dendrite spacing. A significant increase in the mechanical properties for the HP alloy with niobium addition was found within the temperature range of 900–1050 °C. Beyond this temperature the mechanical behavior of both alloys is basically the same

  17. Influence of niobium addition on the high temperature mechanical properties of a centrifugally cast HP alloy

    Energy Technology Data Exchange (ETDEWEB)

    Andrade, A.R., E-mail: arandrade@gmail.com [Department of Materials Engineering, Federal University of São Carlos, Rod. Washington Luiz, km 235, São Carlos, SP (Brazil); Department of Research and Development, ENGEMASA – Engineering and Materials Ltda., Rua Ernesto Cadinalli, 303, São Carlos, SP (Brazil); Bolfarini, C. [Department of Materials Engineering, Federal University of São Carlos, Rod. Washington Luiz, km 235, São Carlos, SP (Brazil); Ferreira, L.A.M.; Vilar, A.A.A. [Department of Research and Development, ENGEMASA – Engineering and Materials Ltda., Rua Ernesto Cadinalli, 303, São Carlos, SP (Brazil); Souza Filho, C.D.; Bonazzi, L.H.C. [Department of Research and Development, ENGEMASA – Engineering and Materials Ltda., Rua Ernesto Cadinalli, 303, São Carlos, SP (Brazil); Department of Materials, Aeronautical and Automotive Engineering, University of São Paulo, Av. Trabalhador Sancarlense, 400, São Carlos, SP (Brazil)

    2015-03-25

    The influence of niobium addition on the mechanical properties at high temperature of HP alloy has been investigated. Two HP alloys were centrifugally cast with a similar chemical composition differing only in the niobium content. Low strain rate high temperature tensile tests and creep-rupture tests were performed in the range of 900–1100 °C, and the results compared between the alloys. According to the results, the high temperature mechanical behavior of both alloys is controlled by several factors like solid solution, network of eutectic carbides, intradendritic precipitation and dendrite spacing. A significant increase in the mechanical properties for the HP alloy with niobium addition was found within the temperature range of 900–1050 °C. Beyond this temperature the mechanical behavior of both alloys is basically the same.

  18. Properties of casting solutions and ultrafiltration membranes based on fullerene-polyamide nanocomposites

    Directory of Open Access Journals (Sweden)

    N. N. Sudareva

    2012-03-01

    Full Text Available Poly(phenylene isophtalamide (PA was modified by fullerene C60 using solid-phase method. Novel ultrafiltration membranes based on nanocomposites containing up to 10 wt% of fullerene and carbon black were prepared. Properties of PA/C60 composites in solutions were studied by light scattering and rheological methods. The relationship between characteristics of casting solutions and properties of nanocomposite membranes was studied. Scanning electron microscopy was used for structural characterization of the membranes. It was found that increase in fullerene content in nanocomposite enhances the membrane rigidity. All nanocomposite membranes were tested in dynamic (ultrafiltration and static sorption experiments using a solution of protein mixture, with the purpose of studying protein sorption. The membranes modified by fullerene demonstrate the best values of flux reduced recovery after contact with protein solution. It was found that addition of fullerene C60 to the polymer improves technological parameters of the obtained composite membranes.

  19. Evaluation of material properties considering thermal embrittlement for accelerated aged CF-8M and CF-8A cast austenitic stainless steel

    International Nuclear Information System (INIS)

    Cast austenitic stainless steel have been widely used for primary coolant piping in light water reactors. This material is subject to thermal embrittlement at reactor operating temperature. CF-8M and CF-8A cast austenitic stainless steel is used for several components, such as primary coolant piping, elbow, pump casing, and valve bodies in light water reactors. Thermal embrittlement results in spinodal decomposition of delta-ferrite leading to decreased fracture toughness. In this study, the specimens were prepared using an accelerated aging method. The measurement of ferrite content, Charpy impact test and J-R test were performed to verify the predicting equation for aged material properties. In case of above 25% ferrite content, predicted result of J-R curve might be non-conservative

  20. Heat treatment of investment cast PH 13-8 Mo stainless steel: Part I. Mechanical properties and microstructure

    Science.gov (United States)

    Hochanadel, P. W.; Edwards, G. R.; Robino, C. V.; Cieslak, M. J.

    1994-04-01

    The microstructure of investment cast PH 13-8 Mo stainless steel heat-treated to various conditions was studied using light and electron microscopy, electron probe microanalysis, and Mössbauer spectroscopy. The mechanical properties were investigated by using uniaxial tensile testing, hardness testing, and Charpy impact testing. The Β-NiAl strengthening precipitates, though detectable by electron diffraction, were difficult to resolve by transmission electron microscopy (TEM) in specimens aged at low temperatures (566 °C and below). A high dislocation density was observed in the lath martensitic structure. The higher strength and lower ductility observed at low aging temperatures was attributed to both the high dislocation density and the precipitation of Β-NiAl. When samples were aged at high temperatures (> 566 °C), a lower dislocation density and a reverted austenite fraction on the order of 15 pct were observed. Spherical Β-NiAl precipitates were observed in the overaged condition. The decrease in strength and corresponding increase in ductility observed in samples aged at temperatures above 566 °C were attributed to the reverted austenite and recovery. Mechanical properties were improved when the homogenizing temperature and time were increased. Electron probe microanalysis quantified the increased homogeneity realized by increasing homogenizing temperature and time. Elimination of the refrigeration step, which normally follows the solution treatment, did not degrade the mechanical properties. Mössbauer spectroscopy showed only minor decreases in the fraction of retained austenite when refrigeration followed the solution treatment.

  1. Structure and mechanical properties of as-cast Ti–5Sn–xCr alloys

    Energy Technology Data Exchange (ETDEWEB)

    Hsu, Hsueh-Chuan; Wu, Shih-Ching; Hsu, Shih-Kuang [Department of Dental Technology and Materials Science, Central Taiwan University of Science and Technology, Taiwan, ROC (China); Institute of Biomedical Engineering and Materials Science, Central Taiwan University of Science and Technology, Taiwan, ROC (China); Chen, Chien-Yu [Advanced Materials and BioMaterials Laboratory, Department of Materials Science and Engineering, Da-Yeh University, 168 University Road, Dacun, Changhua 51591, Taiwan, ROC (China); Ho, Wen-Fu, E-mail: fujii@mail.dyu.edu.tw [Advanced Materials and BioMaterials Laboratory, Department of Materials Science and Engineering, Da-Yeh University, 168 University Road, Dacun, Changhua 51591, Taiwan, ROC (China)

    2014-06-01

    In this study, the effects of chromium (Cr) on the structure and mechanical properties of a Ti–5Sn-based system were examined, with an emphasis on improving the strength/modulus ratio. Commercially pure titanium (c.p. Ti) was used as a control. As-cast Ti–5Sn and a series of Ti–5Sn–xCr (x=1, 3, 5, 7, 9, 11 and 13 wt%) alloys prepared by using a commercial arc-melting vacuum-pressure casting system were investigated. X-ray diffraction (XRD) for phase analysis was conducted using a diffractometer. Three-point bending tests were performed on all specimens to evaluate their mechanical properties. The experimental results indicate that the structure and mechanical properties of these alloys changed with the addition of various amounts of Cr. The as-cast Ti–5Sn has a hexagonal α' phase. When 1 wt% Cr was introduced into the Ti–5Sn alloy, the structure essentially stayed the same. When the Cr content was at 3 wt%, retention of the metastable β phase began. When the Cr content was increased to 5 wt% or greater, the β phase was entirely retained. The ω phase was detected in Ti–5Sn–3Cr and Ti–5Sn–5Cr. Ti–5Sn–5Cr, which had the largest quantity of the ω phase, exhibited the highest microhardness value due to the hardening effect of the ω phase. Among all Ti–5Sn-based alloys, the β-phase Ti–5Sn–7Cr alloy had the lowest elastic modulus. It also exhibited higher bending strength/modulus ratios, which at 26.8 were higher than that of c.p. Ti (8.5) and that of Ti–6Al–4V (17.4). Furthermore, the elastically recoverable angle of this alloy (31.0°) was much greater than that of c.p. Ti (2.7°). In the search for better implant materials, the low modulus, ductile property, excellent elastic recovery capability and high strength/modulus ratio of β-phase Ti–5Sn–7Cr make this alloy a promising candidate.

  2. Microstructure, tensile properties and fracture behavior of high temperature Al–Si–Mg–Cu cast alloys

    International Nuclear Information System (INIS)

    The high temperature tensile behavior of 354 aluminum cast alloy was investigated in the presence of Zr and Ni. The cast alloys were given a solutionizing treatment followed by artificial aging at 190 °C for 2 h. High temperature tensile tests were conducted at various temperatures from 25 °C to 300 °C. Optical microscopy and electron probe micro-analyzer were used to study the microstructure of different intermetallic phases formed. The fractographic observations of fracture surface were analyzed by scanning electron microscopy to understand the fracture mechanism. The results revealed that the intermetallics phases of (Al, Si)3(Zr, Ti), Al3CuNi and Al9NiFe are the main feature in the microstructures of alloys with Zr and Ni additions. The results also indicated that the tensile strength of alloy decreases with an increase in temperature. The combined addition of 0.2 wt% Zr and 0.2 wt% Ni leads to a 30% increase in the tensile properties at 300 °C compared to the base alloy. Zr and Ni bearing phases played a vital role in the fracture mechanism of the alloys studied

  3. Microstructure, tensile properties and fracture behavior of high temperature Al–Si–Mg–Cu cast alloys

    Energy Technology Data Exchange (ETDEWEB)

    Mohamed, A.M.A., E-mail: madel@uqac.ca [Center for Advanced Materials, Qatar University, Doha (Qatar); Department of Metallurgical and Materials Engineering, Faculty of Petroleum and Mining Engineering, Suez Canal University, Box 43721, Suez (Egypt); Samuel, F.H. [Université du Québec à Chicoutimi, Chicoutimi, QC, Canada G7H 2B1 (Canada); Al Kahtani, Saleh [Industrial Engineering Program, Mechanical Engineering Department, College of Engineering, Salman bin Abdulaziz University, Al Kharj (Saudi Arabia)

    2013-08-10

    The high temperature tensile behavior of 354 aluminum cast alloy was investigated in the presence of Zr and Ni. The cast alloys were given a solutionizing treatment followed by artificial aging at 190 °C for 2 h. High temperature tensile tests were conducted at various temperatures from 25 °C to 300 °C. Optical microscopy and electron probe micro-analyzer were used to study the microstructure of different intermetallic phases formed. The fractographic observations of fracture surface were analyzed by scanning electron microscopy to understand the fracture mechanism. The results revealed that the intermetallics phases of (Al, Si){sub 3}(Zr, Ti), Al{sub 3}CuNi and Al{sub 9}NiFe are the main feature in the microstructures of alloys with Zr and Ni additions. The results also indicated that the tensile strength of alloy decreases with an increase in temperature. The combined addition of 0.2 wt% Zr and 0.2 wt% Ni leads to a 30% increase in the tensile properties at 300 °C compared to the base alloy. Zr and Ni bearing phases played a vital role in the fracture mechanism of the alloys studied.

  4. Effects of different casting mould cooling rates on microstructure and properties of sand-cast Al-7.5Si-4Cu alloy

    OpenAIRE

    Liu Guanglei; Si Naichao; Sun Shaochun

    2013-01-01

    In this work, Al-7.5Si-4Cu alloy melt modified by Al-10Sr, RE and Al-5Ti-B master alloys was poured into multi-step moulds made from three moulding sands, including quartz, alumina and chromite, to investigate comparatively the effects of different cooling rates of the casting mould on the alloy's microstructures and mechanical properties. The results show that with an increase in wall thickness, the cooling rate decreases, the dendrite arm spacing (DAS) increases significantly and the mecha...

  5. Thermal cooling effects in the microstructure and properties of cast cobalt-base biomedical alloys

    Science.gov (United States)

    Vega Valer, Vladimir

    Joint replacement prosthesis is widely used in the biomedical field to provide a solution for dysfunctional human body joints. The demand for orthopedic knee and hip implants motivate scientists and manufacturers to develop novel materials or to increase the life of service and efficiency of current materials. Cobalt-base alloys have been investigated by various researchers for biomedical implantations. When these alloys contain Chromium, Molybdenum, and Carbon, they exhibit good tribological and mechanical properties, as well as excellent biocompatibility and corrosion resistance. In this study, the microstructure of cast Co-Cr-Mo-C alloy is purposely modified by inducing rapid solidification through fusion welding processes and solution annealing heat treatment (quenched in water at room temperature. In particular the effect of high cooling rates on the athermal phase transformation FCC(gamma)↔HCP(epsilon) on the alloy hardness and corrosion resistance is investigated. The Co-alloy microstructures were characterized using metallography and microscopy techniques. It was found that the as cast sample typically dendritic with dendritic grain sizes of approximately 150 microm and containing Cr-rich coarse carbide precipitates along the interdendritic boundaries. Solution annealing gives rise to a refined microstructure with grain size of 30 microm, common among Co-Cr-Mo alloys after heat treating. Alternatively, an ultrafine grain structure (between 2 and 10 microm) was developed in the fusion zone for specimens melted using Laser and TIG welding methods. When laser surface modification treatments were implemented, the developed solidification microstructure shifted from dendritic to a fine cellular morphology, with possible nanoscale carbide precipitates along the cellular boundaries. In turn, the solidified regions exhibited high hardness values (461.5HV), which exceeds by almost 110 points from the alloy in the as-cast condition. The amount of developed athermal

  6. Effect of austempering parameters on microstructure and mechanical properties of horizontal continuous casting ductile iron dense bars

    Directory of Open Access Journals (Sweden)

    Chun-jie Xu

    2015-03-01

    Full Text Available In the present research, the orthogonal experiment was carried out to investigate the influence of different austempering process parameters (i.e. austenitizing temperature and time, and austempering temperature and time on microstructure and mechanical properties of LZQT500-7 ductile iron dense bars with 172 mm in diameter which were produced by horizontal continuous casting (HCC. The results show that the major factors influencing the hardness of austempered ductile iron (ADI are austenitizing temperature and austempering temperature. The fraction of retained austenite increases as the austenitizing and austempering temperatures increase. When austenitizing temperature is low, acicular ferrite and retained austenite can be efficiently obtained by appropriately extending the austenitizing time. The proper austmepering time could ensure enough stability of retained austenite and prevent high carbon austenite decomposition. The optimal mechanical properties of ADI can be achieved with the following process parameters: austenitizing temperature and time are 866 °C and 135 min, and austempering temperature and time are 279 °C and 135 min, respectively. The microstructure of ADI under the optimal austempering process consists of fine acicular ferrite and a small amount of retained austenite, and the hardness, tensile strength, yield strength, elongation and impact toughness of the bars are HBW 476, 1670 MPa, 1428 MPa, 2.93% and 25.7 J, respectively.

  7. Property evaluations of dry-cast reconstituted bacterial cellulose/tamarind xyloglucan biocomposites.

    Science.gov (United States)

    de Souza, Clayton F; Lucyszyn, Neoli; Woehl, Marco A; Riegel-Vidotti, Izabel C; Borsali, Redouane; Sierakowski, Maria Rita

    2013-03-01

    We describe the mechanical defibrillation of bacterial cellulose (BC) followed by the dry-cast generation of reconstituted BC films (RBC). Xyloglucan (XGT), extracted from tamarind seeds, was incorporated into the defibrillated cellulose at various compositions, and new films were created using the same process. Microscopy and contact angle analyses of films revealed an increase in the microfibre adhesion, a reduced polydispersity in the diameters of the microfibrils and increased hydrophobic behaviour as a function of %XGT. X-ray diffraction analysis revealed changes to the crystallographic planes of the RBC and the biocomposite films with preferential orientation along the (110) plane. Compared with BC, RBC/XGT biocomposite with 10% XGT exhibited improvement in its thermal properties and in Young's modulus. These results indicated a reorganisation of the microfibres with mechanical treatment, which when combined with hydrocolloids, can create cellulose-based materials that could be applied as scaffolding for tissue engineering and drug release.

  8. Evaluation of Physical Properties of Wax Mixtures Obtained From Recycling of Patterns Used in Precision Casting

    Directory of Open Access Journals (Sweden)

    Biernacki R.

    2015-04-01

    Full Text Available The study investigated the properties of selected certified mixtures used to make wax patterns for the production of precision castings for the aerospace industry. In addition, an assessment of the recycled mixtures consisting of certified wax materials recovered during autoclaving was carried out. Hardness was tested via a proposed method based on penetration, creep related deformation, bending strength and linear contraction. The hardness was studied on laboratory specimens and patterns made with the use of injection molding equipment. For these patterns, linear contraction was estimated at variable pressure and for different temperature injection parameters. Deformations connected with creep and resistance were evaluated on cylindrical specimens. Differences in creep resistance in relation to the hardness were observed depending on the type of pattern mixtures. Recycled mixture has a greater resistance and smaller linear contraction than certified mixtures used for making sprue, raisers and other parts of filler system.

  9. Mechanical and microstructural properties of a nickel-chromium alloy after casting process

    Directory of Open Access Journals (Sweden)

    Mauro Sayão de Miranda

    2012-01-01

    Full Text Available Introduction: There is a growing concern on the development of adequate materials to interact with the human body. Several researches have been conducted on the development of biomaterials for dental applications. Objective: This study aimed to determine the microstructural and mechanical properties of a nickel- based alloy, after the casting process. Material and methods: The alloy was melted through lost wax technique and centrifugation, by using blowtorch with liquefied petroleum gas. To evaluate the mechanical properties, tensile bond strength and microhardness tests were performed. The microstructural characterization was performed using scanning electron microscopy (SEM and energy dispersive spectroscopy (EDS. Statistical analyses were performed on microhardness results, through Student t test. A program for digital image processing was used to determine the percentage of the existing phases. Results and conclusion: The tensile strength was higher than that reported by the manufacturer, 559.39±25.63MPa versus 306 MPa, respectively. However, the yield strength was slightly lower, 218.71±29.75 MPa versus 258 MPa, reported by the manufacturer. The microhardness tests showed about 70 HV, far above the value informed by the manufacturer (21 HV. It can be affirmed with 95% confidence interval that the casting process did not alter the material’s hardness. The alloy’s microstructure is formed by a matrix with dendritic aspect and gray color and a second white interdendritic phase with equally distributed precipitates as well as porosities. EDS tests showed that the matrix is rich in nickel and chromium, the interdendritic second phase is rich in molybdenum and the precipitates in titanium or silicon. The matrix represents 86% of the area and the second phase 12%.

  10. Microstructure and Mechanical Properties of Electromagnetic Centrifugal Cast 1Cr25Ni20Si2 Tube Blank

    Institute of Scientific and Technical Information of China (English)

    QIU Yi-qing; JIA Guang-lin; LIU Xiang-hua; WANG Guo-dong

    2006-01-01

    1Cr25Ni20Si2 tube blank centrifugally cast in a steady magnetic field was investigated. The results indicated that the solidification structure and the mechanical properties of the blank can be improved remarkably by electromagnetic stirring, and seamless tube can be manufactured from such blanks.

  11. Synthesis and Properties of Some polyurethane/ Partially Aromatic Polyester Casting Samples

    International Nuclear Information System (INIS)

    A series of partially aromatic terephthalate polyesters were synthesized by melt transesterification of dimethyl terephthalate with various types of aliphatic diol compounds in 1:1.1 molar ratio. Ethylene-, di-, tri-, tetra ethylene glycol and polyethylene glycol with different molecular weights 1000, 4000, 6000 as well as the prepared dihydroxy natural rubber were used. Another series of partially aromatic adipate and sebacate polyesters based on the prepared bisphenol A and its tetrabromo derivative were also synthesized by direct polycondensation esterification with adipic and sebacic acid. Polyurethane with NCO/OH ratio equal 4 was prepared from the reaction of 2,4 toluene diisocyanate with polyethylene glycol 1000. The prepared polyurethane was mixed with different weight percentages (2, 4, 6, 8, 10 or 12 % w/w) of the prepared partially aromatic polyesters to give polyurethane/polyester compositions. Mechanical and electrical properties as well as water and chemical resistance of the prepared film samples with thickness 3-4 mm were determined and compared with those of polyurethane film sample without polyester. The data indicate that 10 % w/w of the added partially aromatic polyester increases polyurethane tensile strength, improves its insulation properties and hydrolytic stability as well as its chemical resistance. Film samples based on bisphenol A impart excellent properties as compared with those based on aliphatic glycol species and dihydroxy natural rubber. Keywords: Partially aromatic polyesters, Dimethyl terephthalate, Glycols, Bisphenol A, Tetrabromo bisphenol A, Natural rubber, Adipic acid, Sebacic acid, Polyurethane, Casting

  12. High Pressure Die Casting of Aluminium and Magnesium Alloys : Grain Structure and Segregation Characteristics

    OpenAIRE

    Laukli, Hans Ivar

    2004-01-01

    Cold chamber high pressure die casting, (HPDC), is an important commercial process for the production of complex near net shape aluminium and magnesium alloy castings. The work presented in the thesis was aimed at investigating the microstructure formation in this type of casting. The solidification characteristics related to the process and the alloys control the formation of grains and defects. This again has a significant impact on the mechanical properties of the castings.The investigatio...

  13. Special thermite cast irons

    Directory of Open Access Journals (Sweden)

    Yu. Zhiguts

    2008-07-01

    Full Text Available The given paper deals with the problems of the synthesis of cast iron by metallothermy synthesis. On the basis of investigated method of calculations structures of charges have been arranged and cast iron has been synthesized further. Peculiarities metallothermic smelting were found, mechanical properties and structure of received cast iron were investigated and different technologies for cast iron receiving were worked out.

  14. Effects of Na2CO3 on properties of low fluoride content mould flux for thin slab continuous casting.

    Science.gov (United States)

    Lu, Yanqing; Zhang, Guodong; Jiang, Maofa; Liu, Haixiao; Li, Ting

    2011-06-01

    To reduce fluorine pollution, partial fluoride could be replaced by Na2C03 in mould flux for continuous casting. The properties including melting temperature, viscosity fluidity, surface tension and A1203 inclusion adsorption of low fluoride content mould flux with addition of Na2C03 for thin slab casting were studied. The results showed that with the increase in Na2C03 content, melting temperature, viscosity and viscous activation energy of mould flux decreased obviously, fluidity increased, surface tension changed little, and A1203 inclusion adsorption of mould flux increased. The Na2C03 could play effective role when its content was less than 9%. The results would play a guiding role in designing of low fluoride content mould flux for thin slab continuous casting. PMID:25084585

  15. Effect of melt conditioning on heat treatment and mechanical properties of AZ31 alloy strips produced by twin roll casting

    International Nuclear Information System (INIS)

    In the present investigation, magnesium strips were produced by twin roll casting (TRC) and melt conditioned twin roll casting (MC-TRC) processes. Detailed optical microscopy studies were carried out on as-cast and homogenized TRC and MC-TRC strips. The results showed uniform, fine and equiaxed grain structure was observed for MC-TRC samples in as-cast condition. Whereas, coarse columnar grains with centreline segregation were observed in the case of as-cast TRC samples. The solidification mechanisms for TRC and MC-TRC have been found completely divergent. The homogenized TRC and MC-TRC samples were subjected to tensile test at elevated temperature (250–400 °C). At 250 °C, MC-TRC sample showed significant improvement in strength and ductility. However, at higher temperatures the tensile properties were almost comparable, despite of TRC samples having larger grains compared to MC-TRC samples. The mechanism of deformation has been explained by detailed fractures surface and sub-surface analysis carried out by scanning electron and optical microscopy. Homogenized MC-TRC samples were formed (hot stamping) into engineering component without any trace of crack on its surface. Whereas, TRC samples cracked in several places during hot stamping process

  16. Structure and properties of gray iron casted in the electromagnetic field

    Directory of Open Access Journals (Sweden)

    J. Szajnar

    2009-07-01

    Full Text Available In the national [1] and foreign [2] literature the methods of improving the homogeneity of the structure of castings using forced convection of the solidifying metal in the casting mould or the crystallizer are presented. This article presents the influence of chosen parameters of the rotating electromagnetic filed that is forcing the movement of melted metal in the mould on the morphology of graphite and the abrasive wear of the grey cast iron. The effect of this examination is the obtained modification of the flake graphite divisions morphology and a alteration of the abrasive wear resistance of the castings manufactured this way.

  17. Utilization of En Ac-42100 Cast Aluminum Alloy for Casting of Critical Components. I. Preparation and Mechanical Properties

    Directory of Open Access Journals (Sweden)

    Vanko Branislav

    2014-12-01

    Full Text Available Requirement on the minimum value of elongation for critical components is about 15 %. The research deals with the possibility of replacing the dendritic morphology of primary solid solution and brittle eutectic silicon plates with finer particles with a more suitable morphology and size, and the possibility of increasing the mechanical properties. Introduced first part is focused on the process of preparation of experimental material and mechanical properties.

  18. Influence of New Sol-gel Refractory Coating on the Casting Properties of Cold Box and Furan Cores for Grey Cast iron

    DEFF Research Database (Denmark)

    Nwaogu, Ugochukwu Chibuzoh; Poulsen, T.; Bischoff, C;

    2010-01-01

    New Sol-Gel coated sand cores made from coldbox and furan binder systems were investigated. The idea of the coating was to improve the surface quality of castings. Grey iron was cast on the cores in a sand casting process. The effect of the high temperature of the melt on the cores was assessed...

  19. Properties of cast films from hemp (Cannabis sativa L.) and soy protein isolates. A comparative study.

    Science.gov (United States)

    Yin, Shou-Wei; Tang, Chuan-He; Wen, Qi-Biao; Yang, Xiao-Quan

    2007-09-01

    The properties of cast films from hemp protein isolate (HPI) including moisture content (MC) and total soluble mass (TSM), tensile strength (TS) and elongation at the break (EAB), and surface hydrophobicity were investigated and compared to those from soy protein isolate (SPI). The plasticizer (glycerol) level effect on these properties and the interactive force pattern for the film network formation were also evaluated. At some specific glycerol levels, HPI films had similar MC, much less TSM and EAB, and higher TS and surface hydrophobicity (support matrix side), as compared to SPI films. The TS of HPI and SPI films as a function of plasticizer level (in the range of 0.3-0.6 g/g of protein) were well fitted with the exponential equation with coefficient factors of 0.991 and 0.969, respectively. Unexpectedly, the surface hydrophobicity of HPI films (including air and support matrix sides) increased with increasing the glycerol level (from 0.3 to 0.6 g/g of protein). The analyses of protein solubility of film in various solvents and free sulfydryl group content showed that the disulfide bonds are the prominent interactive force in the HPI film network formation, while in the SPI case, besides the disulfide bonds, hydrogen bonds and hydrophobic interactions are also to a similar extent involved. The results suggest that hemp protein isolates have good potential to be applied to prepare protein film with some superior characteristics, e.g., low solubility and high surface hydrophobicity.

  20. Regularization Method to the Parameter Identification of Interfacial Heat Transfer Coefficient and Properties during Casting Solidification

    Institute of Scientific and Technical Information of China (English)

    SUI Da-shan; CUI Zhen-shan

    2007-01-01

    The accurate material physical properties, initial and boundary conditions are indispensable to the numerical simulation in the casting process, and they are related to the simulation accuracy directly.The inverse heat conduction method can be used to identify the mentioned above parameters based on the temperature measurement data.This paper presented a new inverse method according to Tikhonov regularization theory.A regularization functional was established and the regularization parameter was deduced, the Newton-Raphson iteration method was used to solve the equations.One detailed case was solved to identify the thermal conductivity and specific heat of sand mold and interfacial heat transfer coefficient (IHTC) at the meantime.This indicates that the regularization method is very efficient in decreasing the sensitivity to the temperature measurement data, overcoming the illposedness of the inverse heat conduction problem (IHCP) and improving the stability and accuracy of the results.As a general inverse method, it can be used to identify not only the material physical properties but also the initial and boundary conditions' parameters.

  1. Displaying structural property and inheritance of cast iron surfacing on steel base

    Science.gov (United States)

    Shveev, I. A.

    2016-06-01

    Graphite inclusions heredity in deposited layer from remelted special cast iron billets was established. The possibility of controlling the structural state and the quality of the deposited layer due to technological parameters of welding and heat treatment of parts is shown. Ways of improving cast iron wear resistance durability are proposed.

  2. Study of rare earth element effect on microstructures and mechanical properties of an Al-Cu-Mg-Si cast alloy

    Institute of Scientific and Technical Information of China (English)

    WAN Weiwei; HAN Jianmin; LI Weijing; WANG Jinhua

    2006-01-01

    The improvements of microstructures and properties of a high strength aluminum cast alloy were studied.The effects of rare earth elements on the microstructures and mechanical properties of the high strength cast alloy Al-Cu-Mg-Si were investigated.The result shows that the addition of rare earth elements can change the microstructures in refining the grain size of the alloy and making the needle-like and laminar eutectic Si to a granular Si.With the increase of the rare earth, the tensile strength and elongation of the alloy increase first and then fall down.The mechanical properties of the alloy will reach the highest value when the content of rare earth elements is about 0.7%.

  3. Metal particle compaction during drop-substrate impact for inkjet printing and drop-casting processes

    Science.gov (United States)

    Clancy, I.; Amarandei, G.; Nash, C.; Glowacki, B. A.

    2016-02-01

    Direct coating methods using metal particles from aqueous solutions or solvent-based inks become central in the roll-to-roll fabrication processes as these methods can lead to continuous or pre-defined conductive layers on a large variety of substrates. For good electrical conductivity, the metal particles have to be brought into contact, and traditionally, additional sintering treatments are required. Such treatments can degrade the sensitive substrates as paper or polymer films. In this study, the possibility of obtaining conductive layers at room temperature is investigated for direct coating methods with an emphasis on drop-casting and inkjet printing. Thus, it is shown that electrical conductive layers can be achieved if the metal particles can compact during the drop-substrate impact interaction. It is theoretically shown that the compaction process is directly related to the particle and ink drop size, the initial fractional particle loading of the ink, solvent viscosity, and drop velocity. The theoretical predictions on compaction are experimentally validated, and the particle compaction's influence on changes in the electrical conductivity of the resulting layers is demonstrated.

  4. Microstructure characteristics and effect of aging process on the mechanical properties of squeeze-cast AZ91 alloy

    International Nuclear Information System (INIS)

    Highlights: • Characterization of three-dimensional morphologies of precipitates using AFM. • Quantitative microstructure of aged squeeze-cast AZ91 alloy. • The non-uniform continuous precipitation during aging of squeeze-cast AZ91 alloy. • The relationship between microstructure and property of aged squeeze-cast AZ91 alloy. - Abstract: Quantitative microstructure information is critical to modeling and prediction of mechanical properties of structural components. In this study, the microstructure characteristics of aged squeeze-cast AZ91 alloy were investigated using scanning electron microscopy (SEM), transmission electron microscopy (TEM), and atomic force microscopy (AFM) analyses. Particularly, a study of the three-dimensional morphology of continuous precipitation during heat treatment was carried out using a combination of TEM and AFM. The results showed that a typical precipitate consisted of three kinds of faces, namely, broad, side, and end faces. The precipitate also presented a lath-shaped morphology with lozenge ends. Combined SEM and TEM analyses revealed quantitative information on the sizes and area number densities of precipitates after aging at different temperatures with different times. In general, the length and width of precipitates increased more rapidly than thickness during aging. The area number density initially increased and then slowly decreased because of coarsening. Furthermore, a special microstructure characteristic of the non-uniform continuous precipitation during aging was investigated using electron probe microanalysis (EPMA). The relationship between hardness response and yield strength was established

  5. Microstructure and mechanical properties of NZ30K alloy by semi-continuous direct chill and sand mould casting processes

    Directory of Open Access Journals (Sweden)

    Zheng Xingwei

    2011-02-01

    Full Text Available The Mg-3.0Nd-0.2Zn-0.4Zr (NZ30K alloys were prepared by direct-chill casting (DCC and sand mould casting (SMC processes, respectively and their microstructures and mechanical properties were investigated. The results indicate that casting method plays a remarkable influence on the microstructure and mechanical properties of as-cast NZ30K alloy. The grain size increases from 35-40 μm in the billets made by the DCC to about 100-120 μm in the billets by the SMC. The aggregation of Mg12Nd usually found at the triple joints of grain boundaries in the billets prepared by SMC while is not observable from the billets by DCC. The tensile strengths and elongations of the billets are 195.2 MPa and 15.5% by DCC, and 162.5 MPa and 3.2% by SMC, respectively. The tensile strength of the alloy by DCC is remarkably enhanced by T6 heat treatment, which reached 308.5 MPa. Fracture surfaces of NZ30K alloy have been characterized as intergranular fracture by SMC and quasi-cleavage fracture by DCC, respectively.

  6. Microstructure And Mechanical Properties Of An Al-Zn-Mg-Cu Alloy Produced By Gravity Casting Process

    Directory of Open Access Journals (Sweden)

    Saikawa S.

    2015-06-01

    Full Text Available High-strength aluminum alloy are widely used for structural components in aerospace, transportation and racing car applications. The objective of this study is to enhance the strength of the Al-Zn-Mg-Cu alloy used for gravity casting process. All alloys cast into stepped-form sand mold (Sand-mold Casting; SC and Y-block shaped metal mold(Permanent mold Casting; PC C and then two –step aged at 398-423 K after solution treated at 743 K for 36 ks. The tensile strength and total elongation of the two-step aged SC alloys were 353-387 MPa and about 0.4% respectively. This low tensile properties of the SC alloys might be caused by remaining of undissolved crystallized phase such as Al2CuM, MgZn2 and Al-Fe-Cu system compounds. However, good tensile properties were obtained from PC alloys, tensile strength and 0.2% proof stress and elongation were 503-537 MPa, 474-519 MPa and 1.3-3.3%.

  7. Wear Properties of Thixoformed and High Pressure Die Cast Aluminium Alloys for Connecting Rod Applications in Compressors

    Science.gov (United States)

    Birol, Yücel; Birol, Feriha

    2007-04-01

    Hypereutectic aluminium casting alloys are attractive candidates for connecting rod applications in compressors. The wear properties of these alloys are largely controlled by their microstructural features which in turn are affected by the processing route. Several hypo- and hypereutectic Al-Si alloys were produced by high pressure die casting and thixoforming in the present work. The former route produced a very fine microstructure while relatively coarser, globular α-Al matrix dominated in thixoformed grades. A modified Falex Block on Ring equipment was employed to investigate the wear properties of these alloys. Wear tests were carried out under service conditions in the lubricated state at 75°C. The superior wear properties of hypereutectic alloys produced by high pressure die casting with respect to the thixoformed variety is accounted for by the very fine microstructure with a fine dispersion of primary Si particles in the former. Of the two production routes employed, thixoforming had a favorable effect on wear properties at equal Si levels.

  8. Thermal analysis, structure and mechanical properties of the MC MgAl3Zn1 cast alloy

    Directory of Open Access Journals (Sweden)

    L.A. Dobrzański

    2010-06-01

    Full Text Available Purpose: This work presents effect of cooling rate on the mechanical and structural properties and thermal characteristic results of MC MgAl3Zn1 cast alloy.Design/methodology/approach: The experiments were performed using the novel Universal Metallurgical Simulator and Analyzer Platform. Material used in this experiment is experimental magnesium alloy made as-cast.Findings: The research show that the thermal analysis carried out on UMSA Technology Platform is an efficient tool for collect and calculate thermal parameters. The formation temperatures of various thermal parameters, mechanical properties (hardness and ultimate compressive strength and grain size are shifting with an increasing cooling rate.Research limitations/implications: This paper presents results for one alloy - MC MgAl3Zn1 only, cooled with three different solidifications rate i.e. 0.6, 1.2 and 2.4°C/s, for assessment for the liquidus and solidus temperatures and its influence on the mechanical properties and structure.Practical implications: The parameters described can be applied in metal casting industry for selecting magnesium ingot preheating temperature for semi solid processing to achieve requirements properties.Originality/value: The paper contributes to better understanding and recognition an influence of different solidification condition on non-equilibrium thermal parameters of magnesium alloys.

  9. Effect of laser treatment on micro-structure and properties of cast magnesium alloys

    Directory of Open Access Journals (Sweden)

    L.A. Dobrzański

    2009-11-01

    Full Text Available Purpose: The goal of this paper is to present the structure and properties of the cast magnesium alloy after laser treatment.Design/methodology/approach: The laser treatment of magnesium alloys with TiC, WC powders was carried out using a high power diode laser (HDPL. The resulting microstructure in the modified surface layer was examined using optical microscopy, scanning electron microscopy and transmission electron microscope. Phase composition was determined by the X-ray diffraction method using the XPert device. The measurements of hardness and wear resistance of the modified surface layer were also studied.Findings: The region after laser treatment has a fine microstructure with hard carbide particles. Hardness of laser surface layer with both TiC and WC particles was improved as compared to alloy without laser treatment.Research limitations/implications: In this research two powders (WC and TiC were used with the particle size over 5 μm. This investigation presents different laser power by one process speed rates.Practical implications: The results obtained in this investigation were promising towards compared other conventional processes. High Power Diode Laser can be used as an economical substitute of Nd:YAG and CO2 to improve the surface magnesium alloy by feeding the carbide particles.Originality/value: The originality of this work is applying of High Power Diode Laser for alloying of magnesium alloy using hard particles like tungsten and titanium carbides.

  10. The Kinetics and Dry-Sliding Wear Properties of Boronized Gray Cast Iron

    Directory of Open Access Journals (Sweden)

    Dong Mu

    2013-01-01

    Full Text Available Some properties of boride formed on gray cast iron (GCI have been investigated. GCI was boronized by powder-pack method using Commercial LSB-II powders at 1123, 1173, and 1223 K for 2, 4, 6, and 8 h, respectively. Scanning electron microscopy showed that boride formed on the surface of boronized GCI had tooth-shaped morphology. The hardness of boride formed on surfaces of GCI ranged from 1619 to 1343 HV0.025, and quenched and tempered GCI ranged from 400 to 610 HV0.025. The boride formed in the coating layer confirmed by X-ray diffraction analysis was Fe2B single phase. Depending on boronizing time and temperature, the thickness of coating layers on boronized GCI ranged from 26 to 105 μm. The activation energy was 209 kJ/mol for boronized GCI. Moreover, the possibility of predicting the iso-thickness of boride layers variation was studied. Dry-sliding wear tests showed that the wear resistance of boronized sample was greater than that of quenched and tempered sample.

  11. Microstructure and property of zinc phosphate coating on die-casting magnesium alloy AZ91D

    Institute of Scientific and Technical Information of China (English)

    LI Guang-yu; LIAN Jian-she; NIU Li-yuan; JIANG Zhong-hao

    2006-01-01

    A surface treatment method was described, which can form a uniform and dense phosphate conversion coating on the die -casting magnesium alloy AZ91D in a non-chromate and non-nitrite bath. The coating consists of Zn3(PO4)2-4H2O, Zn, AlPO4 and MgZn2(PO4)2 analyzed by XRD. The SEM results show that the microstructure of the zinc phosphate coating transfers from flower-like to slab-like crystals with the increase of immersion time of magnesium alloy samples in the phosphating bath. The zinc phosphate coating formed in the bath with immersion time of 1 min is denser because metallic Zn and insoluble phosphate crystals co-deposit on the magnesium alloy surface and the growth of the crystals are restricted by each others. The zinc phosphate coating on the magnesium alloy is used as the base layer for further cataphoric and powder paintings. The cataphoric painting on AZ91D alloy based on phosphate coating has similar adhesion and corrosion-resistance to that based on the chromate conversion coating. But for powder painting, the former exhibits better adhesion property than the latter, due to the uneven microstructure and the enough thickness of the phosphate coating.

  12. Mechanical Properties of Carbon Fiber-Reinforced Aluminum Manufactured by High-Pressure Die Casting

    Science.gov (United States)

    Kachold, Franziska; Singer, Robert

    2016-03-01

    Carbon fiber reinforced aluminum was produced by a specially adapted high-pressure die casting process. The MMC has a fiber volume fraction of 27%. Complete infiltration was achieved by preheating the bidirectional, PAN-based carbon fiber body with IR-emitters to temperatures of around 750 °C. The degradation of the fibers, due to attack of atmospheric oxygen at temperatures above 600 °C, was limited by heating them in argon-rich atmosphere. Additionally, the optimization of heating time and temperature prevented fiber degradation. Only the strength of the outer fibers is reduced by 40% at the most. The fibers in core of fiber body are nearly undamaged. In spite of successful manufacturing, the tensile strength of the MMC is below strength of the matrix material. Also unidirectional MMCs with a fiber volume fraction of 8% produced under the same conditions, lack of the reinforcing effect. Two main reasons for the unsatisfactory mechanical properties were identified: First, the fiber-free matrix, which covers the reinforced core, prevents effective load transfer from the matrix to the fibers. And second, the residual stresses in the fiber-free zones are as high as 100 MPa. This causes premature failure in the matrix. From this, it follows that the local reinforcement of an actual part is limited. The stress distribution caused by residual stresses and by loading needs to be known. In this way, the reinforcing phase can be placed and aligned accordingly. Otherwise delamination and premature failure might occur.

  13. Microstructure and mechanical properties of the pressure die cast magnesium alloy AZ91D after long-term thermal exposure

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The thermal resistance of the pressure die cast magnesium alloy AZ91D is yet not investigated sufficiently. In order to assess the effect of a thermal exposure on the microstructural stability and the mechanical properties, the alloy AZ91D is subjected to a long-term annealing for 1 000 h at 80 ℃, 100 ℃, 120 ℃, 150 ℃, 180 ℃ and 200 ℃. After the annealing, the microstructural appearance of the material is investigated by light and scanning electron microscopy and compared with the as-cast condition. Furthermore, tensile tests, hardness measurements and fracture toughness tests are carried out and the measured values are discussed on the basis of the microstructural changes. The results reveal the distinct correlation between the microstructural changes, especially the precipitation of discontinuous and continuous β-particles (Mg17Al12), and the mechanical properties.

  14. Effect of austempering parameters on microstructure and mechanical properties of horizontal continuous casting ductile iron dense bars

    OpenAIRE

    Chun-jie Xu; Pan Dai; Zheng-yang Zhang

    2015-01-01

    In the present research, the orthogonal experiment was carried out to investigate the influence of different austempering process parameters (i.e. austenitizing temperature and time, and austempering temperature and time) on microstructure and mechanical properties of LZQT500-7 ductile iron dense bars with 172 mm in diameter which were produced by horizontal continuous casting (HCC). The results show that the major factors influencing the hardness of austempered ductile iron (ADI) are austeni...

  15. Examination of Cast Iron Material Properties by Means of the Nanoindentation Method

    Directory of Open Access Journals (Sweden)

    A. Trytek

    2012-12-01

    Full Text Available The paper presents results of examination of material parameters of cast iron with structure obtained under rapid resolidification conditions carried out by means of the nanoindentation method.

  16. Low temperature impact toughness and fracture mechanism of cast QT400-18L ductile iron with different Ni additions

    OpenAIRE

    Zhang Xinning; Qu Yingdong; Yang Hongwang

    2013-01-01

    Different contents of Ni (0.3wt.% to 1.2wt.%) were added to the QT400-18L ductile iron to investigate the effect of Ni addition on the impact toughness of cast ductile irons at low temperatures. The impact toughnesses of the samples at room and low temperatures were tested. The microstructures and fractographs were observed. Results show that with the increase of Ni addition there is a general trend of refinement of the ferrite matrix while the nodule density shows no obvious change. When the...

  17. Phase-inversion tape casting and oxygen permeation properties of supported ceramic membranes

    NARCIS (Netherlands)

    He, Wei; Huang, Hua; Gao, Jianfeng; Winnubst, A.J.A.; Chen, Chusheng

    2014-01-01

    A variant of tape casting, involving phase inversion, was explored for the preparation of supported ceramic oxygen separation membranes in one step. A slurry of Zr0.84Y0.16O1.92 (YSZ) andLa0.8Sr0.2MnO3 δ (LSM) powders in a N-methyl-2-pyrrolidone solution of polyethersulfone was tape cast, and immers

  18. Thermo-mechanical properties and cracking during solidification of thin slab cast steel

    OpenAIRE

    Santillana, M.B.

    2013-01-01

    Nowadays a vast majority of the steel produced worldwide is via the continuous casting process route because this is the most low-cost, efficient and high quality method to mass produce metal products in a variety of sizes and shapes. Most of the continuous casters are the initial manufacturing step of a product which is very close to the final shape, reducing the need for further finishing. During continuous casting the liquid steel is solidified under controlled conditions of heat extractio...

  19. Mechanical properties and microstructure of large IN713LC nickel superalloy castings

    OpenAIRE

    Zýka Jiří; Málek Jaroslav; Hrbáček Karel

    2014-01-01

    When approving large castings for use, mechanical values are measured by room temperature tensile test on test bodies made from the centres of the castings. These test bodies often exhibit lower values than required, in particular ultimate tensile strength and elongation. The presence of fragile niobium carbides in the structure of the alloy was identified as the main cause of this situation, which originated as a result of the slow speed cooling. Because of large grain size compared to gauge...

  20. Properties of Cast Films Made from Different Ratios of Whey Protein Isolate, Hydrolysed Whey Protein Isolate and Glycerol

    Directory of Open Access Journals (Sweden)

    Markus Schmid

    2013-08-01

    Full Text Available Whey protein isolate (WPI-based cast films are very brittle, due to several chain interactions caused by a large amount of different functional groups. In order to overcome film brittleness, plasticizers, like glycerol, are commonly used. As a result of adding plasticizers, the free volume between the polymer chains increases, leading to higher permeability values. The objective of this study was to investigate the effect of partially substituting glycerol by hydrolysed whey protein isolate (h-WPI in WPI-based cast films on their mechanical, optical and barrier properties. As recently published by the author, it is proven that increasing the h-WPI content in WPI-based films at constant glycerol concentrations significantly increases film flexibility, while maintaining the barrier properties. The present study considered these facts in order to increase the barrier performance, while maintaining film flexibility. Therefore glycerol was partially replaced by h-WPI in WPI-based cast films. The results clearly indicate that partially replacing glycerol by h-WPI reduces the oxygen permeability and the water vapor transmission rate, while the mechanical properties did not change significantly. Thus, film flexibility was maintained, even though the plasticizer concentration was decreased.

  1. Effect of excitation current intensity on mechanical properties of ZL205A castings solidified under a traveling magnetic field

    Directory of Open Access Journals (Sweden)

    Xue-yi Fan

    2015-05-01

    Full Text Available The effect of excitation current intensity on the mechanical properties of ZL205A castings solidified under a traveling magnetic field was studied. The results of the experiment indicate that the excitation current intensity of the traveling magnetic field has a great influence on the mechanical properties of the ZL205A castings. When the excitation current intensity is 15 A, the tensile strength and elongation of ZL205A alloy castings increase 27.2% and 67.7%, respectively, compared with those of the same alloy solidified under gravity. The improvement of mechanical properties is attributed to the decrease of micro-porosity in the alloy. Under the traveling magnetic field, the feeding pressure in the alloy melt before solidification can be enhanced due to the electromagnetic force. Moreover, the melt flow induced by the traveling magnetic field can decrease the temperature gradient. The feeding resistance will be increased because the temperature gradient decrease. So traveling magnetic field has an optimum effect on feeding.

  2. Effect of rare earth element on microstructure formation and mechanical properties of thin wall ductile iron castings

    International Nuclear Information System (INIS)

    Ductile iron castings with 2, 3, 4, 6, 8, and 25 mm thickness and various amount of rare earth elements (RE) (from 0 to 0.04%), were cast in sand molds to identify the effects of sample thickness and the content of RE% on microstructural formation and selected mechanical properties. The effects of RE content and sample thickness on microstructural formation, including on graphite nodule count, graphite nodule shape, spherodization, and ferrite amount, were observed. The yield strength of the samples with RE within the range investigated were lower than those of the specimens without RE. The elongation was improved with the addition of RE up to 0.03% in ductile iron castings. The additions of 0.02% RE caused a smaller graphite nodule size and a higher number of graphite nodules than those in the specimen without RE at all levels of RE addition; the nodule count decreased with increase in section size. The chill zones were observed in the 2 mm thick samples, but were absent in the samples from castings which were thicker than 2 mm, irrespective of the addition of RE. The nodularity of graphite nodules improved due to the addition of 0.02-0.04% RE. The specimens with RE content up to 0.03% had a lower tensile strength and hardness, higher elongation than that of the specimens without RE. The ferrite content in all castings increased with additions of 0.02% RE. The tensile strengths of the 2 and 3 mm thick samples were also estimated using the relationship between strength and hardness, obtained from the data on the tensile strength and hardness of the 25 mm thick samples

  3. Tensile properties of strip casting 6.5 wt% Si steel at elevated temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Li, Hao-Ze, E-mail: lhzqq83@163.com; Liu, Zhen-Yu, E-mail: zyliu@mail.neu.edu.cn

    2015-07-15

    Tensile behaviors of strip casting 6.5 wt% Si steel are tested at elevated temperatures ranging from 300 °C to 800 °C. A detailed study of the morphology of the fracture surface and the ordered phase at each deforming temperature is carried out by a scanning electron microscope and a transmission electron microscope. The results show that the deforming temperature rather than the ordered degree determines the tensile properties. As the deforming temperature increases, the stress level in the whole deforming stage continually decreases, whereas the elongation gradually increases. The ductile–brittle transition occurs around 350 °C. The elongation of 2% at 300 °C rapidly increases up to 16.4% at 350 °C and the corresponding fracture mode transforms from the complete cleavage fracture to the mixture of the very limited cleavage fracture, intergranular dimple fracture and the dimple fracture. Serrated flow is observed at 350 °C and 400 °C probably due to the occurrence of dynamic strain aging. Due to the gradually weakened grain boundary cohesion with the deforming temperature increasing, intergranular dimple pattern dominates the fracture surface at 600 °C and the elongation slowly increases from 16.4% at 350 °C to 22.8% at 600 °C. At 700 °C and 800 °C, the much more enhanced dynamic recovery, the substantially decreased stress levels which contribute to the inhibition of the intergranular dimple fracture, the much lower content of the B2 ordered phase at 700 °C, and the completely disordered state at 800 °C give rise to the dramatically improved elongations of 88.8% and 130.8%, respectively.

  4. Impact properties of shear thickening fluid impregnated foams

    Science.gov (United States)

    Soutrenon, M.; Michaud, V.

    2014-03-01

    Concentrated colloidal suspensions of silica particles in polyethylene glycol exhibit a shear thickening behavior: above a critical shear rate in a confined environment, they show a steep increase of viscosity. This reversible transition from a low to a high viscosity state is associated with a large energy absorption that could be harnessed for impact protection. As these suspensions are liquid at rest, however, shear thickening fluids (STFs) are difficult to use in practical applications. Furthermore, their specific rheological properties exist within a narrow range of concentration, so they tend to disappear when the material is in contact with air and humidity. In this work, a soft foam scaffold was impregnated with STF to provide a three-dimensional shape to the assembly at rest, while a silicone was cast around it to serve as a physical barrier to the external environment. A method to quickly impregnate the foam was proposed. Impact tests were carried out on the STF/foam/silicone composite pads using a free fall impact tower. Compared to rubber or pure silicone, larger energy absorptions, up to 85%, were observed, which could be repeated for multiple impacts. The transmitted shock waves were also reduced, showing the potential of this system for impact protection of structures.

  5. Impact properties of shear thickening fluid impregnated foams

    International Nuclear Information System (INIS)

    Concentrated colloidal suspensions of silica particles in polyethylene glycol exhibit a shear thickening behavior: above a critical shear rate in a confined environment, they show a steep increase of viscosity. This reversible transition from a low to a high viscosity state is associated with a large energy absorption that could be harnessed for impact protection. As these suspensions are liquid at rest, however, shear thickening fluids (STFs) are difficult to use in practical applications. Furthermore, their specific rheological properties exist within a narrow range of concentration, so they tend to disappear when the material is in contact with air and humidity. In this work, a soft foam scaffold was impregnated with STF to provide a three-dimensional shape to the assembly at rest, while a silicone was cast around it to serve as a physical barrier to the external environment. A method to quickly impregnate the foam was proposed. Impact tests were carried out on the STF/foam/silicone composite pads using a free fall impact tower. Compared to rubber or pure silicone, larger energy absorptions, up to 85%, were observed, which could be repeated for multiple impacts. The transmitted shock waves were also reduced, showing the potential of this system for impact protection of structures. (paper)

  6. MICROSTRUCTURE ANALYSIS AND MECHANICAL PROPERTIES OF Zn-Al ALLOY ROD PRODUCED BY HEATED MOLD CONTINUOUS CASTING

    Institute of Scientific and Technical Information of China (English)

    Y. Ma; Y. Hao; F.Y. Yan; H.J.Liu

    2003-01-01

    The new technology of continuous casting by heated mold was used to produce dtirectional solidification ZA alloy lines to eliminate the inter defects of these lines and increase their mechanical properties. The results are as follows: (1) The microstructure of the ZA alloy lines is the parallel directional dendritic columnar crystal. Every dendritic crystal of eutectic alloy ZA5 was composed of many layer eutectic β and η phases. The microstructure of hypereutectic ZA alloys is primary dendritic crystal and interdendritic eutectic structure. The primary phase of ZA8 and ZA12 isβ,among them, but the primary phase of ZA22 and ZA27 is α. (2) Through the test to the as-cast ZA alloy lines made in continuous casting by heated mold, it is found that the tensile strength and hardness increase greatly, but the elongation decreases. With the increase of aluminum amount from ZA 5 to ZA 12, ZA22 and ZA27, the tensile strength increases gradually. ZA27 has the best comprehensive mechanical properties in these four kinds of ZA alloys. (3) Heat treatment can decrease the dendritic segregation and improve the elongation of ZA alloy, but make their strength decrease slightly.

  7. Structure and Properties of Cast Near-Congruent Copper-Manganese Alloys

    Science.gov (United States)

    Chaput, Kevin; Trumble, Kevin P.

    2014-10-01

    Microstructure development in the casting of copper-manganese alloys based on the congruent point at 34.6 wt pct Mn and 1146 K (873 °C) has been studied. The alloys were prepared by induction melting of electrolytic Cu and Mn in clay-graphite crucibles in open air. Under conventional casting conditions, the alloys exhibit fine cellular (non-dendritic) solidification morphology with a distinct absence of solidification shrinkage microporosity, and they maintain these attributes over a composition range of approximately 3 wt pct Mn about the congruent point. The high Mn concentration in the alloy admits carbon into solution in the melt, resulting in formation of manganese carbide Mn7C3 particles having two different forms (globular and angular) in the cast microstructure. The Mn carbide was eliminated or controlled to low levels by melting in an alumina or a silicon carbide crucible, or in a clay-graphite crucible at lower temperatures. Microstructure development in casting the alloy was analyzed in terms of the available phase diagrams and thermochemical data. Hardness and tensile testing indicated a potent solid solution strengthening effect of Mn and high ductility in the as-cast condition, with additional hardness (strength) when the alloy contains the Mn carbide phase.

  8. Effect of Ni Contents on the Microstructure and Mechanical Properties of Martensitic Stainless Steel Guide Roll by Centrifugal Casting

    Institute of Scientific and Technical Information of China (English)

    Villando Thursdiyanto; Eun-Jae Bae; Eung-Ryul Baek

    2008-01-01

    A novel process based on centrifugal casting was developed to produce martensitic stainless steel for guideroll materials. Centrifugal casting provides a lower production cost and less of the thermal cracking defects which normally occur in the overlaid welding process. In this study, the effects of Ni on the microstructure and mechanical properties of martensitic stainless steel were investigated. The results show that the addition of Ni resulted in a decrease in the volume fraction of delta ferrite and an increase in the volume fraction of the retained austenite, respectively. Moreover, a tensile strength of 1600 MPa with an elongation of 4% were obtained after tempering at 500℃ for 2 h. These values were higher than those obtained by using the conventional overlaid process.

  9. Development of low-temperature high-strength integral steel castings for offshore construction by casting process engineering

    Science.gov (United States)

    Lim, Sang-Sub; Mun, Jae-Chul; Kim, Tae-Won; Kang, Chung-Gil

    2014-12-01

    In casting steels for offshore construction, manufacturing integral casted structures to prevent fatigue cracks in the stress raisers is superior to using welded structures. Here, mold design and casting analysis were conducted for integral casting steel. The laminar flow of molten metal was analyzed and distributions of hot spots and porosities were studied. A prototype was subsequently produced, and air vents were designed to improve the surface defects caused by the release of gas. A radiographic test revealed no internal defects inside the casted steel. Evaluating the chemical and mechanical properties of specimens sampled from the product revealed that target values were quantitatively satisfied. To assess weldability in consideration of repair welding, the product was machined with grooves and welded, after which the mechanical properties of hardness as well as tensile, impact, and bending strengths were evaluated. No substantive differences were found in the mechanical properties before and after welding.

  10. Influence of stress relief annealing on the microstructure and properties of GX12CrMoVNbN9-1(GP91 cast steel

    Directory of Open Access Journals (Sweden)

    G. Golański

    2011-04-01

    Full Text Available The paper presents an effect of stress relief annealing, applied to casts after the repair by welding, on the microstructure and mechanical properties of quenched and tempered martensitic GX12CrMoVNbN9 – 1 cast steel (called GP91. The test pieces being the subject of research were taken out from a test coupon. Heat treatment of GP91 cast steel was carried out at the parameters of temperature and time appropriate for the treatment of multi-ton steel casts, while stress relief annealing was performed at the temperatures of 730 and 750oC.After quenching and tempering GP91 cast steel was characterized by the microstructure of high-tempered martensite with numerousprecipitations of carbides of diverse size. Mechanical properties of the investigated cast steel after heat treatment fulfilled the standard requirements. Stress relief annealing contributes to the processes of recovery and recrystallization of the matrix as well as the privileged precipitation of M23C6 carbides on grain boundaries. Changes in the microstructure of the examined cast steel cause deterioration in mechanical properties – the higher the temperature of stress relief annealing, the greater the deterioration.

  11. EFFECT OF LOW-FREQUENCY ELECTROMAGNETIC FIELD ON THE AS-CASTING MICROSTRUCTURES AND MECHANICAL PROPERTIES OF HDC 2024 ALUMINUM ALLOY

    Institute of Scientific and Technical Information of China (English)

    Q.F.Zhu; Z.H.Zhao; J.Z.Cui; Y.B.Zuo; F.Qu

    2008-01-01

    The influences of the low frequency electromagnetic field on the horizontal direct chill casting process were investigated experimentally. Ingots of 2024 aluminum alloy with a cross size of 40 mm×200 mm were produced by the conventional horizontal chill casting process and low frequency electromagnetic horizontal chill casting processrespectively. The as-cast structures and the mechanical property of the ingots were examined. The results showed that the low frequency electromagnetic field could substantially refine the microstructures and pronouncedly reduce the macrosegregation in the horizontal direct chill casting process. Moreover, the surface quality of the ingot was prominently improved by the low frequency electromagnetic field. The fracture strength and elongation percentage of the ingot was increased with the low frequency electromagnetic field.

  12. Influence of formwork surface on the orientation of steel fibres within self-compacting concrete and on the mechanical properties of cast structural elements

    DEFF Research Database (Denmark)

    Svec, Oldrich; Zirgulis, Giedrius; Bolander, John E.;

    2014-01-01

    tomography, indicate that fibres tend to orient according to the flow patterns during casting, but such tendencies are suppressed near rough formwork surfaces. Fibre orientation, in turn, affects the mechanical properties of the concrete as demonstrated by the load testing of beams extracted from the cast......The influences of formwork surface on the final orientation of steel fibres immersed in self-compacting concrete and on the resulting mechanical response of the cast structural elements are investigated. Experimental observations of fibre orientation within cast slabs, obtained via computed...... slabs. These processes and results are simulated using a computational fluid dynamics model of the casting process, in tandem with a lattice model of the fracture of the beam specimens. The computational fluid dynamics model determines the coordinates of each fibre within the concrete, which serve...

  13. The Effect of Casting Solvent on the Electrical Property of Polyaniline/Polyacrylonitrile

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Blends of dodecylbenzene sulfonic acid doped polyaniline (PANI-DBSA) and polyacrylonitrile (PAN) dissolved in either CHCl3/DMF or CHCl3/DMSO mixture were solution cast. The conductivity of the blends with various compositions was measured and the doped cxtent of PANIDBSA in different casting solvent systems was studied.Solution blends prepared from CHCl3/DMSO displayed higher conductivity than those obtained via CHCl3/DMF.The dedoping reaction of PANI-DBSA in CHCl3/DMF identified by UV-Vis and FTIR analysis contributed to the lower conductivity of PANI-DBSA/PAN blend.

  14. A Comparative Study on Wear Properties of As Cast, Cast Aged and Forge Aged A356 Alloy with Addition of Grain Refiner and/or Modifier

    Directory of Open Access Journals (Sweden)

    D.G. Mallapur

    2015-03-01

    Full Text Available In the present work, a comparative wear behavior study of three categories of materials viz, as cast, cast aged (casting followed by T6 and forge aged (forging followed by T6 has been investigated. Neither melt treatment nor solid state processing (like aging and forging seems to be altering the wear behavior of the materials drastically. Cast aged A356 materials exhibit higher wear resistance compared to as cast and forge aged A356 materials. Further, it was observed that cast aged samples register lower coefficient of friction compared to other samples. It is also noted that the difference in wear behavior is revealed only at conditions of higher load, higher speed and longer sliding distance of testing. At lower regimes the difference is marginal. Among cast aged samples, ones treated with combined addition exhibit better wear resistance compared to other materials. Samples treated with combined addition register lowest coefficient of friction followed by samples treated with Sr, those with B, those with Ti and untreated ones. Abrasive wear mechanism is found to be operative in the regime of higher loading and higher velocity of sliding. Adhesive wear mechanism seems to be dominating the wear process at the lower regime of load and velocity of sliding.

  15. Microstructure and Mechanical Properties of MWCNTs Reinforced A356 Aluminum Alloys Cast Nanocomposites Fabricated by Using a Combination of Rheocasting and Squeeze Casting Techniques

    Directory of Open Access Journals (Sweden)

    Abou Bakr Elshalakany

    2014-01-01

    Full Text Available A356 hypoeutectic aluminum-silicon alloys matrix composites reinforced by different contents of multiwalled carbon nanotubes (MWCNTs were fabricated using a combination of rheocasting and squeeze casting techniques. A novel approach by adding MWCNTs into A356 aluminum alloy matrix with CNTs has been performed. This method is significant in debundling and preventing flotation of the CNTs within the molten alloy. The microstructures of nanocomposites and the interface between the aluminum alloy matrix and the MWCNTs were examined by using an optical microscopy (OM and scanning electron microscopy (SEM equipped with an energy dispersive X-ray analysis (EDX. This method remarkably facilitated a uniform dispersion of nanotubes within A356 aluminum alloy matrix as well as a refinement of grain size. In addition, the effects of weight fraction (0.5, 1.0, 1.5, 2.0, and 2.5 wt% of the CNT-blended matrix on mechanical properties were evaluated. The results have indicated that a significant improvement in ultimate tensile strength and elongation percentage of nanocomposite occurred at the optimal amount of 1.5 wt% MWCNTs which represents an increase in their values by a ratio of about 50% and 280%, respectively, compared to their corresponding values of monolithic alloy. Hardness of the samples was also significantly increased by the addition of CNTs.

  16. Impact of arbitrary and mean transfer of dental casts to the articulator on centric occlusal errors.

    Science.gov (United States)

    Morneburg, Thomas R; Pröschel, Peter A

    2011-06-01

    When fabricating dental restorations, casts are usually transferred to the articulator based on arbitrary hinge axes or mean values instead of true hinge axis points. Using arbitrary hinge axis points or mean values can lead to occlusal errors if the vertical relation is changed in the articulator (e.g., when a centric record is used). This study predicted the probability of occlusal errors occurring in a group of subjects when casts are mounted based on arbitrary hinge axis points or mean values. In 57 healthy volunteers, true hinge axis points, arbitrary hinge axis points, right infraorbital point, maxillary incisal point, and the palatal cusps of the second molars were determined. Mean hinge axis points were established based on Balkwill angles between 17° and 25°. Occlusal errors evoked by cast mounting in relation to arbitrary or mean axes compared to true hinge axes were calculated. Errors were determined for vertical relation settings of 2 and 4 mm. With 2 mm vertical relation, occlusal errors ≥340 µm occurred with a 10% probability with arbitrary hinge axis mounting. At the same probability level, the error increased moderately to ≥440 µm with mean value mounting and a Balkwill angle of 17°. With a Balkwill angle of 25° occlusal errors ≥1,120 µm occurred with 10% probability. Occlusal errors increased considerably with a vertical relation setting of 4 mm. If vertical relation shall be altered, a transfer of the casts according to arbitrary hinge axes is recommended. If casts are transferred according to mean values, errors are bigger depending on the articulator used.

  17. The effect of coiling temperature on the microstructure and mechanical properties of a niobium–titanium microalloyed steel processed via thin slab casting

    Energy Technology Data Exchange (ETDEWEB)

    Challa, V.S.A.; Zhou, W.H. [Laboratory for Excellence in Advanced Steel Research, Center for Structural and Functional Materials, Institute for Material Research and Innovation, University of Louisiana at Lafayette, P.O. Box 44130, Lafayette, LA 70503 (United States); Misra, R.D.K., E-mail: dmisra@louisiana.edu [Laboratory for Excellence in Advanced Steel Research, Center for Structural and Functional Materials, Institute for Material Research and Innovation, University of Louisiana at Lafayette, P.O. Box 44130, Lafayette, LA 70503 (United States); O' Malley, R. [Nucor Decatur Sheet Mill, 4301 Iverson Blvd., Trinity, AL 35673 (United States); Jansto, S.G. [CBMM North America, 1000 Old Pond Road, Bridgeville, PA 15017 (United States)

    2014-02-10

    We describe here the influence of coiling temperature on the microstructure and mechanical properties, especially toughness, in a low carbon niobium microalloyed steel processed via thin slab casting. The objective is to elucidate the impact of coiling temperature on the nature and distribution of microstructural constituents (including different phases, precipitates, and dislocations) that contribute to variation in the strength–toughness relationship of these steels. In general, the microstructure primarily consisted of fine lath-type bainite and polygonal ferrite, and NbC, TiC and (Nb, Ti)C precipitates of size ∼2–10 nm in the matrix and at dislocations. However, the dominance of bainite and distribution of precipitates was a function of coiling temperature. The lower coiling temperature provided superior strength–toughness combination and is attributed to predominantly bainitic microstructure and uniform precipitation of NbC, TiC, and (Nb, Ti)C during the coiling process, consistent with continuous cooling transformation diagrams.

  18. Effects of heat treatment on mechanical properties and microstructure of tungsten fiber reinforced grey cast iron matrix composites

    Institute of Scientific and Technical Information of China (English)

    Niu Libin; Xu Yunhua; Peng jianHong; Wu Hong

    2009-01-01

    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 flexural strength and modulus than that of cast iron without reinforcement, and the flexural 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 flakes in the matrix seemingly becomes lower; and some hard carbide particles are formed around the residual tungsten fibers. 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.

  19. 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.

  20. Thermo-mechanical properties and cracking during solidification of thin slab cast steel

    NARCIS (Netherlands)

    Santillana, M.B.

    2013-01-01

    Nowadays a vast majority of the steel produced worldwide is via the continuous casting process route because this is the most low-cost, efficient and high quality method to mass produce metal products in a variety of sizes and shapes. Most of the continuous casters are the initial manufacturing step

  1. Impact Strength of Austenitic and Ferritic-Austenitic Cr-Ni Stainless Cast Steel in -40 and +20°C Temperature

    Directory of Open Access Journals (Sweden)

    Kalandyk B.

    2014-10-01

    Full Text Available Studies described in this paper relate to common grades of cast corrosion resistant Cr-Ni steel with different matrix. The test materials were subjected to heat treatment, which consisted in the solution annealing at 1060°C followed by cooling in water. The conducted investigations, besides the microstructural characteristics of selected cast steel grades, included the evaluation of hardness, toughness (at a temperature of -40 and +20oC and type of fracture obtained after breaking the specimens on a Charpy impact testing machine. Based on the results of the measured volume fraction of ferrite, it has been found that the content of this phase in cast austenitic steel is 1.9%, while in the two-phase ferritic-austenitic grades it ranges from 50 to 58%. It has been demonstrated that within the scope of conducted studies, the cast steel of an austenitic structure is characterised by higher impact strength than the two-phase ferritic-austenitic (F-A grade. The changing appearance of the fractures of the specimens reflected the impact strength values obtained in the tested materials. Fractures of the cast austenitic Cr-Ni steel obtained in these studies were of a ductile character, while fractures of the cast ferritic-austenitic grade were mostly of a mixed character with the predominance of brittle phase and well visible cleavage planes.

  2. The effect of water-soluble polymers on the microstructure and properties of freeze-cast alumina ceramics

    Science.gov (United States)

    Pekor, Christopher Michael

    Porous ceramics can be divided into three separate classes based on their pore size: microporous ceramics with pores less than 2 nm, mesoporous ceramics with pores in the range of 2--50 nm and macroporous ceramics with pores that are greater than 50 nm. In particular, macroporous ceramics are used in a variety of applications such as refractories, molten metal filtration, diesel particulate filters, heterogeneous catalyst supports and biomedical scaffolds. Freeze casting is a novel method used to create macroporous ceramics. In this method growing ice crystals act as a template for the pores and are solidified, often directionally, through a ceramic dispersion and removed from the green body through a freeze drying procedure. This method has attracted some attention over the past few years due to its relative simplicity, flexibility and environmental friendliness. On top of this freeze casting is capable of producing materials with high pore volume fractions, which is an advantage over processing by packing and necking of particles, where the pore volume fraction is typically less than 50%. Many of the basic processing variables that affect the freeze cast microstructure, such as the temperature gradient, interfacial velocity and solid loading of the dispersion have been well established in the literature. On the other hand, areas such as the effect of additives on the microstructure and mechanical properties have not been covered in great detail. In this study the concept of constitutional supercooling from basic solidification theory is used to explain the effects of two water-soluble polymers, polyethylene glycol and polyvinyl alcohol, on the microstructure of freeze cast alumina ceramics. In addition, changes in the observed microstructure will be related to experimentally determined values of permeability and compressive strength.

  3. Influence of gelling additives in the green properties of Al{sub 2}O{sub 3} bodies obtained by aqueous gel casting

    Energy Technology Data Exchange (ETDEWEB)

    Millan, A.J. [IUT, Caracas (Venezuela). Dept. Materiales; Baudin, C.; Moreno, R.; Nieto, M.I. [Consejo Nacional de Investigaciones Cientificas, Madrid (Spain). Ist. de Ceramica y Vidrio

    2002-07-01

    The use of gelling additives, as polysaccharides, in colloidal processing provides adequate mechanical properties to the green bodies to be handled. In this work, Al{sub 2}O{sub 3} gel casting is studied by using agar, agarose and carrageenan as gelling additives. The rheological behaviour of the gel casting slurries on cooling is studied. The green characteristics of the gel cast bodies prepared at different conditions are characterised in terms of density, microstructure and mechanical behaviour (bend strength, elastic modulus) at room temperature. A correlation between the obtained results is established and the best compositions and processing conditions are discussed. (orig.)

  4. Effects of cooling method after intercritical heat treatment on microstructural characteristics and mechanical properties of as-cast high-strength low-alloy steel

    International Nuclear Information System (INIS)

    Highlights: • The effect of cooling method after intercritical heat treatment on microstructure evolution was investigated. • Fracture mechanism of tensile and impact after different intercritical heat treatment has been analyzed. • The crack initiation and propagation after different intercritical heat treatment was compared in details. - Abstract: The effect of cooling method after intercritical heat treatment on the microstructures and mechanical properties of as-cast steel produced by electroslag casting was investigated. The microstructure characteristics were analyzed by optical microscope (OM), scanning electron microscope (SEM), transmission electron microscopy (TEM) and electron back scatter diffraction (EBSD). The mechanical performance was evaluated by tensile testing at ambient temperature and Charp V-notch impact tests at various temperatures (−40 °C, −20 °C, 20 °C). The tensile and impact fracture micromechanisms were discussed in details. The results of microstructure investigation indicated that water cooling after intercritical heat treatment led to a mixed microstructure of ferrite and tempered martensite, while a composite microstructure of ferrite and tempered bainite was obtained after air cooling. The carbides of Cr, Mo and Nb in matrix after water quenching were finer than the ones after air cooling. Compared with water cooling, a good balance of strength and toughness was obtained after air cooling. The crack propagation path in the steel after water cooling can propagate along the long axis direction of ferrite bands, directly across the intersecting banded ferrite and martensite as well as along the interfaces between ferrite and martensite. However, the crack propagation path in the steel after air cooling depends on the shape, size and distribution of M/A islands

  5. High integrity automotive castings

    Energy Technology Data Exchange (ETDEWEB)

    Weiss, D. [Eck Industries Inc., St. Manitowoc, WI (United States)

    2007-07-01

    This paper described the High Integrity Magnesium Automotive Casting (HI-MAC) program, which was developed to ensure the widespread adoption of magnesium in structural castings. The program will encourage the use of low pressure permanent molds, squeeze casting, and electromagnetic pumping of magnesium into dies. The HI-MAC program is currently investigating new heat treatment methods, and is in the process of creating improved fluid flow and solidification modelling to produce high volume automotive components. In order to address key technology barriers, the program has been divided into 8 tasks: (1) squeeze casting process development; (2) low pressure casting technology; (3) thermal treatment; (4) microstructure control; (5) computer modelling and properties; (6) controlled molten metal transfer and filling; (7) emerging casting technologies; and (8) technology transfer throughout the automotive value chain. Technical challenges were outlined for each of the tasks. 1 ref., 3 tabs., 5 figs.

  6. Structure of Water Mist Stream and its Impact on Cooling Efficiency of Casting Die

    Directory of Open Access Journals (Sweden)

    R. Władysiak

    2012-04-01

    Full Text Available The work is a continuation of research on the use water mist cooling in order to increase efficiency of die-casting aluminum alloys. The paper presents results of research and analysis process, spraying water and generated a stream of water mist, the effect of the type of nozzle, the nozzle size and shape of the emitting of the water mist on the wall surface of casting die on the microstructure and geometry of water mist stream and cooling efficiency. Tests were used to perform high-speed camera to record video in the visible and infrared camera. Results were used to develop a computerized image analysis and statistical analysis. The study showed that there are statistical relationships between water and air flow and geometry of the nozzle and nozzle emitting a stream of microstructure parameters of water mist and heat the incoming stream. These relationships are described mathematical models that allow you to control the generating of adequate stream of water mist and a further consequence, the cooling efficiency of casting die.

  7. Influence of heat treatment on microstructure and tensile properties of a cast Al-Cu-Si-Mn alloy

    Directory of Open Access Journals (Sweden)

    Liu Zhixue

    2013-11-01

    Full Text Available Solution and aging treatments are important approaches to improve mechanical properties and microstructure of aluminum-base alloys. In this research, a new type high strength Al-Cu-Si-Mn cast alloy was prepared. The effect of different solution and aging treatment temperatures on microstructure and mechanical properties of the Al-Cu-Si-Mn cast alloy were studied by means of microstructure observation and mechanical properties testing. Results showed that after solution treated at different temperatures for 12 h and aged at 175 ℃ for 12 h, with the increase of the solution temperature, both the tensile strength and the elongation of the alloy firstly increase and then decrease, and reach their peak values at 530 ℃. When the solution temperature is below 530 ℃, the microstructure of the alloy consists of α phase, undissolved θ phase and T phase; while when it exceeds 530 ℃, the microstructure only consists of α phase and T phase. After solution treated at 530 ℃ for 12 h and aged at different temperatures for 12 h, both the tensile strength and the elongation of the alloy firstly increase and then decrease with the increasing of temperature, and reach their peak values at 175 ℃. Therefore, the optimal heat treatment process for the alloy in this study is 12 h solution at 530 ℃ and 12 h aging at 175 ℃, and the corresponding tensile strength is 417 MPa, elongation is 4.0%.

  8. PHYSICOCHEMICAL AND ANTIBACTERIAL PROPERTIES OF PLA-CHITOSAN BLENDS OBTAINED BY CASTING WITH POTENTIAL USE AS AGRICULTURAL MULCH FILMS

    Directory of Open Access Journals (Sweden)

    Danila Merino

    2016-03-01

    Full Text Available PLA-Chitosan films compatibilized with hexamethylenediisocyanate (HDI were obtained by casting and subsequent hot pressing. The films were prepared with different contents of chitosan (CS and then its physicochemical properties were studied by Fourier Transform infrared spectroscopy (FTIR, thermogravimetric analysis (TGA, differential scanning calorimetry (DSC, optical microscopy (OM and X-ray diffraction (XRD. It was found that the compatibilizing agent reacts completely and that chitosan affects the thermal properties of the films decreasing their decomposition temperatures, glass transition temperature (Tg and melting (Tm and increase its crystallinity. From the functional standpoint, antimicrobial properties of each blend were tested against Pseudomonas syringae pv tomato DC-3000. The increase in chitosan content was proportional to the antimicrobial effect allowing project its potential application in the agronomic field.

  9. Effect of Gas Pores on Mechanical Properties of High-Pressure Die-Casting AM50 Magnesium Alloy.

    Science.gov (United States)

    Jiang, Wei; Cao, Zhanyi; Liu, Liping; Jiang, Bo

    2016-08-01

    High-pressure die-casting (HPDC) AM50 tensile specimens were used to investigate characteristics of gas pores and its effect on mechanical properties of HPDC AM50 magnesium alloy. Combining microstructure morphology gained from optical microscopy, scanning electron microscopy (SEM), and three-dimensional (3D) reconstruction with the experimental data from uniaxial tensile testing, we pursued the relationship between gas pores and the mechanical properties of HPDC AM50 Mg alloy. Results indicate that comparing with 3D reconstruction models, 2D images like optical metallography images and SEM images have one-sidedness. Furthermore, the size and maximum areal fraction of gas pores have negative effects on the mechanical properties of HPDC AM50 Mg alloy. With increase of the maximum size of gas pores in the specimen, the ultimate tensile strength (UTS) and elongation decrease. In addition, with the maximum areal fraction becoming larger, both the UTS and elongation decrease linearly.

  10. The influence of aluminosilicate fibre in moulding material for investment casting technology on its mechanical properties

    OpenAIRE

    Nadolski M.; Konopka Z.; Łągiewka M.; Zyska A.

    2008-01-01

    An incrcnsc of mcchnnicol propcrtics of thin-walled ccramic moulds far the invcstrncnt casting tcchnology has hccn thc main pupscOF thc undcrlakcn rcscnrch work. Partial rcplaccmcnt of grain silica rnatcrials with alrrminasilicatc materials in thc [ibrous rorm is ancsscncc nf a ncw cnnccpt of slruct~~mchla ngc of ~hmc oulding matcrial. Thcrc havc hcen prcparcd inntcrials ol various librc fractioncon~aincdin thc matrix and thcir mcchnnical propcrtics havc bccn cxamincd, narncly thcir bcndiiig ...

  11. Materials for Advanced Ultrasupercritical Steam Turbines Task 4: Cast Superalloy Development

    Energy Technology Data Exchange (ETDEWEB)

    Thangirala, Mani

    2015-09-30

    The Steam Turbine critical stationary structural components are high integrity Large Shell and Valve Casing heavy section Castings, containing high temperature steam under high pressures. Hence to support the development of advanced materials technology for use in an AUSC steam turbine capable of operating with steam conditions of 760°C (1400°F) and 35 Mpa (5000 psia), Casting alloy selection and evaluation of mechanical, metallurgical properties and castability with robust manufacturing methods are mandated. Alloy down select from Phase 1 based on producability criteria and creep rupture properties tested by NETL-Albany and ORNL directed the consortium to investigate cast properties of Haynes 282 and Haynes 263. The goals of Task 4 in Phase 2 are to understand a broader range of mechanical properties, the impact of manufacturing variables on those properties. Scale up the size of heats to production levels to facilitate the understanding of the impact of heat and component weight, on metallurgical and mechanical behavior. GE Power & Water Materials and Processes Engineering for the Phase 2, Task 4.0 Castings work, systematically designed and executed casting material property evaluation, multiple test programs. Starting from 15 lbs. cylinder castings to world’s first 17,000 lbs. poured weight, heavy section large steam turbine partial valve Haynes 282 super alloy casting. This has demonstrated scalability of the material for steam Turbine applications. Activities under Task 4.0, Investigated and characterized various mechanical properties of Cast Haynes 282 and Cast Nimonic 263. The development stages involved were: 1) Small Cast Evaluation: 4 inch diam. Haynes 282 and Nimonic 263 Cylinders. This provided effects of liquidus super heat range and first baseline mechanical data on cast versions of conventional vacuum re-melted and forged Ni based super alloys. 2) Step block castings of 300 lbs. and 600 lbs. Haynes 282 from 2 foundry heats were evaluated which

  12. Improvement of Structure and Properties of Cast Ferrite-Pearlite Steels for Freight Railway Cars

    Directory of Open Access Journals (Sweden)

    A. Rabinovich

    2008-03-01

    Full Text Available As it i s known For increasing of propcnics (YTS 2 380 MPa of cast stcds i t is c f k ~ i v tco incrcasc conlcnt o f alhsti~uiionaal lloyingclcrncnts, (Si, Mn, Cr, Ni. 1 lowevcr it lcads to rising in pricc olstccl ton. lncrcasing of Si and Mn conrcnl only is limitcd hy decreasing o lductility and weld nhility. As a rule silicon contcnt at ~hcsca ccls is not highcr than 0.4-0.67'0 and Si:Mn ratio is not highcr khan 1:2. Nowfor grain rcfincmcnt ~wc sin oculation of stcct by nitrogcn and clcincnrs with high chcmical affinity to nltmgcn. Mostly vanadium i s usd.howcvcr niobium sornctime is uscd. Dissldvantagcs of this arc high cost of alloying clcmcnrs and low thcrrnodynamic stability OFvanadium and niobium nitridcs. Parlicles of V(C,N and Nh(C.N dissolvc during hcating fnr licnt trcatmcnt or during wclding. It [cads lodccrcasing of grain refinement elfcc!.Adaptat ion or this microalloying stratcgy Tor casts producing For rrcight mil way cars let cstirnatc possibility of application thcsc casts in ancw gcnerazion freight railway cars.

  13. The structure and mechanical properties of pearlitic-ferritic vermicular cast iron

    Directory of Open Access Journals (Sweden)

    E. Guzik

    2012-01-01

    Full Text Available The results of studies on the use of magnesium alloy in modern Tundish + Cored Wire injection method for production of vermicular graphite cast irons were described. The injection of Mg Cored Wire length is a treatment method which can be used to process iron melted in an electric induction furnace. This paper describes the results of using a high-magnesium ferrosilicon alloy in cored wire for the production of vermicular graphite cast irons at the; Tundish + Cored Wire to be injected methods (PE for pearlitic-ferritic matrix GJV with about 25 %ferrite content. The results of calculations and experiments have indicated the length of the Cored Wire to be injected basing on the initial sulfur content and weight of the treated melt. The paper presents a microstructure matrix and vermicular graphite in standard sample and different walled castings. The results of numerous trials have shown that the magnesium Tundish + PE Method process can produce high quality vermicular graphite irons under the specific industrial conditions of the above mentioned foundries.

  14. Influence of additives on the microstructure and tensile properties of near-eutectic Al-10.8%Si cast alloy

    International Nuclear Information System (INIS)

    The continuing quest for aluminum castings with enhanced mechanical properties for applications in the automotive industries has intensified the interest in aluminum-silicon alloys. In Al-Si alloys, the properties are influenced by the shape and distribution of the eutectic silicon particles in the matrix, as also by the iron intermetallics and copper phases that occur upon solidification. The detailed microstructure and tensile properties of as-cast and heat-treated new experimental alloy belonging to cast Al-Si near-eutectic alloys have been investigated as a function of Fe, Mn, Cu, and Mg content. Microstructural examination was carried out using optical microscopy, image analysis, and electron probe microanalysis (EPMA), wavelength dispersive spectroscopic (WDS) analysis facilities. Tensile properties upon artificial aging in the temperature range of 155-240 oC for 5 h were also investigated. The results show that the volume fraction of Fe-intermetallics increases as the iron or manganese contents increase. Compact polygonal or star-like particles form when the sludge factor is greater than 2.1. The Al2Cu phase was observed to dissolve almost completely during solution heat treatment of all the alloys studied, especially those containing high levels of Mg and Fe, while Al5Cu2Mg8Si6, sludge, and α-Fe phases were found to persist after solution heat treatment. The β-Al5(Fe,Mn)Si phase dissolved partially in Sr-modified alloys, and its dissolution became more pronounced after solution heat treatment. At 0.5% Mn, the β-Fe phase forms when the Fe content is above 0.75%, causing the tensile properties to decrease drastically. The same results are obtained when the levels of both Fe and Mn are increased beyond 0.75%, because of sludge formation. On the other hand, the tensile properties of the Cu-containing alloys are affected slightly at high levels of Mg as a result of the formation of Al5Cu2Mg8Si6 which decreases the amount of free Mg available to form the Al2Cu

  15. Effect of double quenching and tempering heat treatment on the microstructure and mechanical properties of a novel 5Cr steel processed by electro-slag casting

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Jian, E-mail: healygo@163.com; Yu, Hao, E-mail: yuhao@ustb.edu.cn; Zhou, Tao, E-mail: zhoutao130984@163.com; Song, Chenghao, E-mail: songchenghao28@126.com; Zhang, Kai, E-mail: zhangkai8901@126.com

    2014-12-01

    The effect of double quenching and tempering (DQT) treatment as well as conventional high temperature quenching and tempering (CQT) treatment on the microstructures and mechanical properties of low carbon 5Cr martensitic as cast steel produced by electroslag casting was investigated. The microstructure changes were characterized by optical microscope (OM), scanning electron microscope (SEM), electron back scatter diffraction (EBSD) and transmission electron microscopy (TEM). The characteristics of carbides precipitated during tempering were analyzed on both carbon extraction replica and thin foil samples by TEM. The mechanical performance was evaluated by Vickers hardness test, tensile test, and Charpy V-notch impact test at ambient temperature. The results of microstructure study indicated that DQT treatment led to a finer microstructure than that of CQT. The carbides of the tempered samples were identified as M{sub 7}C{sub 3}. The carbides along the prior austenite grain boundaries nucleated directly while those within the laths should be transformed from cementite which formed at the early tempering stage. Compared with CQT condition, yield strength slightly increased after DQT treatment, and impact toughness improved a lot. The strengthening mechanisms were analyzed and it was found that grain refining and precipitation strengthening were mainly responsible for the increase of strength. The superior toughness of DQT condition was attributed to the finer microstructure resulting in more frequent deflections of the cleavage crack and the smaller size of carbides along the prior austenite boundaries. EBSD analysis showed that both martensitic block and packet of low carbon 5Cr tempered martensitic steel could hinder crack propagation, while the latter was more effective.

  16. Effect of double quenching and tempering heat treatment on the microstructure and mechanical properties of a novel 5Cr steel processed by electro-slag casting

    International Nuclear Information System (INIS)

    The effect of double quenching and tempering (DQT) treatment as well as conventional high temperature quenching and tempering (CQT) treatment on the microstructures and mechanical properties of low carbon 5Cr martensitic as cast steel produced by electroslag casting was investigated. The microstructure changes were characterized by optical microscope (OM), scanning electron microscope (SEM), electron back scatter diffraction (EBSD) and transmission electron microscopy (TEM). The characteristics of carbides precipitated during tempering were analyzed on both carbon extraction replica and thin foil samples by TEM. The mechanical performance was evaluated by Vickers hardness test, tensile test, and Charpy V-notch impact test at ambient temperature. The results of microstructure study indicated that DQT treatment led to a finer microstructure than that of CQT. The carbides of the tempered samples were identified as M7C3. The carbides along the prior austenite grain boundaries nucleated directly while those within the laths should be transformed from cementite which formed at the early tempering stage. Compared with CQT condition, yield strength slightly increased after DQT treatment, and impact toughness improved a lot. The strengthening mechanisms were analyzed and it was found that grain refining and precipitation strengthening were mainly responsible for the increase of strength. The superior toughness of DQT condition was attributed to the finer microstructure resulting in more frequent deflections of the cleavage crack and the smaller size of carbides along the prior austenite boundaries. EBSD analysis showed that both martensitic block and packet of low carbon 5Cr tempered martensitic steel could hinder crack propagation, while the latter was more effective

  17. Behavior of surface residual stress in explosion hardened high manganese austenitic cast steel due to repeated impact loads

    International Nuclear Information System (INIS)

    Explosion hardened high manganese austenitic cast steel is being tried for rail crossing recently. From the previous studies, it became clear that high tensile residual stress was generated in the hardened surface layer by explosion and microcracks were observed. In this study, therefore, the behavior of surface residual stress in explosion hardened steel due to repeated impact loads was examined and compared with those of the original and shot peened steels. The results obtained are summarized as follows: (1) In the initial stage of the repetition of impact, high tensile surface residual stress in explosion hardened steel decreased rapidly with the repetition of impact, while those of the original and shot peened steels increased rapidly. This difference was attributed to the difference in depth of the work hardened layer in three testing materials. (2) Beyond 20 impacts the residual stress of three test specimens decreased gradually, and at more than 2000 impacts the compressive stress of about 500 MPa was produced regardless of the histories of working of testing materials. (3) The linear law in the second stage of residual stress fading was applicable to this case, and the range of the linear relationship was related to the depth of the work hardened layer of testing material. (4) From the changes in half-value breadth and peak intensity of diffraction X-ray, it was supposed that a peculiar microscopic strain exists in explosion hardened steel. (author)

  18. Low temperature impact toughness and fracture mechanism of cast QT400-18L ductile iron with different Ni additions

    Directory of Open Access Journals (Sweden)

    Zhang Xinning

    2013-09-01

    Full Text Available Different contents of Ni (0.3wt.% to 1.2wt.% were added to the QT400-18L ductile iron to investigate the effect of Ni addition on the impact toughness of cast ductile irons at low temperatures. The impact toughnesses of the samples at room and low temperatures were tested. The microstructures and fractographs were observed. Results show that with the increase of Ni addition there is a general trend of refinement of the ferrite matrix while the nodule density shows no obvious change. When the Ni content is 0.7wt.%, the matrix structure is the refined ferrite with a very small fraction (about 2% of pearlite near the eutectic cell boundaries. When the Ni content is further increased, the fraction of pearlite increases significantly and reaches more than 5% when 1.2wt.% Ni is added. The impact toughness at room temperature increases as the content of Ni increases from 0.3 wt.% to 0.7 wt.%, but decreases as the Ni content further increases to 1.2wt.% due to the increase of pearlite fraction. The maximum value of the impact work is 18.5 J at room temperature with 0.7wt.% Ni addition. The average value of the impact work is still more than 13 J even at -30 ℃. In addition, the fracture mechanism changes from ductile manner to brittleness as the testing temperature decreases from 20 ℃ to -60 ℃.

  19. Modeling and Analysis of Mechanical Properties of Aluminium Alloy (A413 Processed through Squeeze Casting Route Using Artificial Neural Network Model and Statistical Technique

    Directory of Open Access Journals (Sweden)

    R. Soundararajan

    2015-01-01

    Full Text Available Artificial Neural Network (ANN approach was used for predicting and analyzing the mechanical properties of A413 aluminum alloy produced by squeeze casting route. The experiments are carried out with different controlled input variables such as squeeze pressure, die preheating temperature, and melt temperature as per Full Factorial Design (FFD. The accounted absolute process variables produce a casting with pore-free and ideal fine grain dendritic structure resulting in good mechanical properties such as hardness, ultimate tensile strength, and yield strength. As a primary objective, a feed forward back propagation ANN model has been developed with different architectures for ensuring the definiteness of the values. The developed model along with its predicted data was in good agreement with the experimental data, inferring the valuable performance of the optimal model. From the work it was ascertained that, for castings produced by squeeze casting route, the ANN is an alternative method for predicting the mechanical properties and appropriate results can be estimated rather than measured, thereby reducing the testing time and cost. As a secondary objective, quantitative and statistical analysis was performed in order to evaluate the effect of process parameters on the mechanical properties of the castings.

  20. Crystallization and mechanical properties of biodegradable poly(p-dioxanone)/octamethyl-polyhedral oligomeric silsesquioxanes nanocomposites via simple solution casting method

    Indian Academy of Sciences (India)

    Zhecun Wang; Chengdong Xiong; Qing Li

    2015-10-01

    In this study, biodegradable poly(p-dioxanone) (PPDO)/octamethyl-polyhedral oligomeric silsesquioxanes (ome-POSS) nanocomposites were fabricated by the simple solution casting method with various ome-POSS loadings. Scanning electron microscopic observations indicate that ome-POSS is well dispersed in the PPDO matrix. Effect of ome-POSS on the isothermal melt crystallization and dynamic mechanical properties of PPDO in the nanocomposites were studied in detail. It shows that the overall crystallization rates are faster in the nanocomposites than in neat PPDO and increase with the increase in ome-POSS loadings; however, X-ray diffraction patterns, POM and the Avrami exponent suggest that the crystal structure and the crystallization mechanism do not change despite the presence of ome-POSS. The mechanical property of PPDO/ome-POSS nanocomposites was enhanced with respect to neat PPDO.

  1. Embrittlement of cast stainless steels in LWR systems

    International Nuclear Information System (INIS)

    Mechanical property data from Charpy-impact and J-R curve tests are presented for several experimental and commercial heats, as well as reactor-aged material of CF-3, CF-8, and CF-8M grades of cast stainless steel. The effects of material variables on the embrittlement of cast stainless steels are evaluated. The chemical composition and ferrite morphology have a strong effect on the extent and kinetics of embrittlement. The data are analyzed to establish the mechanisms of embrittlement. The procedure and correlations for predicting the impact strength and fracture toughness of cast components during reactor service are described. The lower bound values of impact strength and fracture toughness for low-temperature aged cast stainless steel are defined. 13 refs., 13 figs., 3 tabs

  2. Mechanical properties of phase constituents in selected grades of cast steel

    OpenAIRE

    M. Garbiak; Zubko, P.

    2011-01-01

    The nanoindentation measurements performed on three cast steels of 0.3C-30Ni-18Cr type with various content of niobium and titanium were carried out.Mechanical propertiesofthe main phaseconstituents of the alloys, such as austenite, MC and M23C6 type carbides, were determined and analysed. The values of hardness (H) and Young modulus (E) for the austenite matrix were similar within the tested alloys. Essential differences (H=12 ÷ 24 GPa; E = 250 ÷ 400 GPa) were found between the carbide phase...

  3. New Approaches to Aluminum Integral Foam Production with Casting Methods

    OpenAIRE

    Ahmet Güner; Mustafa Merih Arıkan; Mehmet Nebioglu

    2015-01-01

    Integral foam has been used in the production of polymer materials for a long time. Metal integral foam casting systems are obtained by transferring and adapting polymer injection technology. Metal integral foam produced by casting has a solid skin at the surface and a foam core. Producing near-net shape reduces production expenses. Insurance companies nowadays want the automotive industry to use metallic foam parts because of their higher impact energy absorption properties. In this paper, m...

  4. Microstructure and Mechanical Properties After Shock Wave Loading of Cast CrMnNi TRIP Steel

    Science.gov (United States)

    Eckner, Ralf; Krüger, L.; Ullrich, C.; Rafaja, D.; Schlothauer, T.; Heide, G.

    2016-10-01

    The mechanical response of shock wave-prestrained high-alloy Cr16-Mn7-Ni6 TRIP steel was investigated under compressive and tensile loading at room temperature. Previous shock wave loading was carried out using a flyer-plate assembly with different amounts of explosives in order to achieve shock pressures of 0.3, 0.6, 0.9, and 1.2 Mbar. A significant increase in hardness and strength was observed as compared with the initial as-cast condition. In contrast, a slight decrease in strain hardening rates was measured together with a decrease in fracture elongation in the tensile test. Microstructural analyses of the shock-loaded samples were performed by light optical and scanning electron microscopy. The microstructure revealed a high density of deformation bands consisting of separated stacking faults, ɛ-martensite, or twins. Significant amounts of deformation-induced α'-martensite were only present at the highest shock pressure of 1.2 Mbar. The thickness of the deformation bands and the number of martensite nuclei at their intersections increased with increasing shock pressure. In all shock-loaded specimens, pronounced phase transformation occurred during subsequent mechanical testing. Consequently, the amount of the deformation-induced α'-martensite in the shock-loaded specimens was higher than in the unshocked as-cast samples.

  5. Properties of polylactide inks for solvent-cast printing of three-dimensional freeform microstructures.

    Science.gov (United States)

    Guo, Shuang-Zhuang; Heuzey, Marie-Claude; Therriault, Daniel

    2014-02-01

    Solvent-cast printing is a highly versatile microfabrication technique that can be used to construct various geometries such as filaments, towers, scaffolds, and freeform circular spirals by the robotic deposition of a polymer solution ink onto a moving stage. In this work, we have performed a comprehensive characterization of the solvent-cast printing process using polylactide (PLA) solutions by analyzing the flow behavior of the solutions, the solvent evaporation kinetics, and the effect of process-related parameters on the crystallization of the extruded filaments. Rotational rheometry at low to moderate shear rates showed a nearly Newtonian behavior of the PLA solutions, while capillary flow analysis based on process-related data indicated shear thinning at high shear rates. Solvent vaporization tests suggested that the internal diffusion of the solvent through the filaments controlled the solvent removal of the extrudates. Different kinds of three-dimensional (3D) structures including a layer-by-layer tower, nine-layer scaffold, and freeform spiral were fabricated, and a processing map was given to show the proper ranges of process-related parameters (i.e., polymer content, applied pressure, nozzle diameter, and robot velocity) for the different geometries. The results of differential scanning calorimetry revealed that slow solvent evaporation could increase the ability of PLA to complete its crystallization process during the filament drying stage. The method developed here offers a new perspective for manufacturing complex structures from polymer solutions and provides guidelines to optimize the various parameters for 3D geometry fabrication.

  6. Mechanical properties and microstructure of large IN713LC nickel superalloy castings

    Directory of Open Access Journals (Sweden)

    Zýka Jiří

    2014-01-01

    Full Text Available When approving large castings for use, mechanical values are measured by room temperature tensile test on test bodies made from the centres of the castings. These test bodies often exhibit lower values than required, in particular ultimate tensile strength and elongation. The presence of fragile niobium carbides in the structure of the alloy was identified as the main cause of this situation, which originated as a result of the slow speed cooling. Because of large grain size compared to gauge length diameter, crystal orientation of individual grains also plays an important role. Interdendritic carbides are oriented parallel with dendrites thus parallel with directions in Ni superalloy crystal lattice. Grain oriented with axis parallel to tensile direction has platelet carbides oriented perpendicular to the tensile axis. In that position carbides crack easily at low grain deformation. Longitudinal metallographic cuts of selected tested specimen gauge lengths were prepared and grain orientation of individual grains was investigated by EBSD, Specimens, where grain oriented with axis parallel to tensile direction were found, performed poor elongation values 3%, compared to 7% where no such oriented grains were found.

  7. Inoculation of chromium white cast iron

    Directory of Open Access Journals (Sweden)

    D. Kopyciński

    2009-01-01

    Full Text Available It has been proved that an addition of boron carbide introduced as an inoculant to the chromium white cast iron changes the structureof castings. Castings after inoculation revealed a different structure with numerous grains. Primary precipitates of chromium carbide also appeared, reducing the mechanical properties of as-cast parts. Properly established heat treatment regime makes chromium iron castings regain their, originally high, mechanical properties.

  8. Simulation of Heat Flow in Computational Method and Its Verification on the Structure and Property of Gray Cast Iron

    Directory of Open Access Journals (Sweden)

    S. K. Shaha

    2010-01-01

    Full Text Available Problem statement: The solidification of materials depends on the cooling rate of the materials which is governed by heat flow in the mould and alloy composition. Solidification rate also affects the structure and properties of the materials. Approach: In the present study, the heat flow of cold set resin bonded sand mould was simulated using JL Analyzer FEM analysis software. To verify the model, the gray cast iron was melted at 1350°C temperature and poured into a resin bonded sand mould at 1300°C. Results: It showed that most of the heat-reserve at the junction of the mould which was nearer to the source of liquid metal and the lowest heat-reserve at the end of the mould. So, the solidification rate was very high at the end of the mould wall whereas it was comparatively low near the sprue of the mould. Conclusion: Finally, depending on the heat-flow through the mould, the solidification rate changed the microstructure from chill, mottled and gray cast iron and hardness changed from 95.1 HRB-78.78 HRB.

  9. Mechanical properties and constitutive behaviors of as-cast 7050 aluminum alloy from room temperature to above the solidus temperature

    Science.gov (United States)

    Bai, Qing-ling; Li, Hong-xiang; Du, Qiang; Zhang, Ji-shan; Zhuang, Lin-zhong

    2016-08-01

    The mechanical properties and constitutive behaviors of as-cast AA7050 in both the solid and semi-solid states were determined using the on-cooling and in situ solidification approaches, respectively. The results show that the strength in the solid state tends to increase with decreasing temperature. The strain rate plays an important role in the stress-strain behaviors at higher temperatures, whereas the influence becomes less pronounced and irregular when the temperature is less than 250°C. The experimental data were fitted to the extended Ludwik equation, which is suitable to describe the mechanical behavior of the materials in the as-cast state. In the semi-solid state, both the strength and ductility of the alloy are high near the solidus temperature and decrease drastically with decreasing solid fraction. As the solid fraction is less than 0.97, the maximum strength only slightly decreases, whereas the post-peak ductility begins to increase. The experimental data were fitted to the modified creep law, which is used to describe the mechanical behavior of semi-solid materials, to determine the equivalent parameter f GBWL, i.e., the fraction of grain boundaries covered by liquid phase.

  10. Effect of rolling deformation and solution treatment on microstructure and mechanical properties of a cast duplex stainless steel

    Indian Academy of Sciences (India)

    S K Ghosh; D Mahata; R Roychaudhuri; R Mondal

    2012-10-01

    The present study deals with the effect of rolling deformation and solution treatment on the microstructure and mechanical properties of a cast duplex stainless steel. Cast steel reveals acicular/Widmanstätten morphology as well as island of austenite within the -ferrite matrix. Hot rolled samples exhibit the presence of lower volume percent of elongated band of -ferrite (∼40%) and austenite phase which convert into finer and fragmented microstructural constituents after 30% cold deformation. By the solution treatment, the elongated and broken crystalline grains recrystallize which leads to the formation of finer grains (<10 m) of austenite. X-ray diffraction analysis has corroborated well with the above-mentioned microstructural investigation. Enhancement in hardness, yield strength and tensile strength values as well as drop in percent elongation with cold deformation increases its suitability for use in thinner sections. 30% cold rolled and solution treated sample reveals attractive combination of strength and ductility (25.22 GPa%). The examination of fracture surface also substantiates the tensile results. The sub-surface micrographs provide the potential sites for initiation of microvoids.

  11. Effect of Friction Stir Processing on Microstructure and Mechanical Properties of AZ91C Magnesium Cast Alloy Weld Zone

    Science.gov (United States)

    Hassani, Behzad; Karimzadeh, Fathallah; Enayati, Mohammad Hossein; Sabooni, Soheil; Vallant, Rudolf

    2016-07-01

    In this study, friction stir processing (FSP) was applied to the GTAW (TIG)-welded AZ91C cast alloy to refine the microstructure and optimize the mechanical properties of the weld zone. Microstructural investigation of the samples was performed by optical microscopy and the phases in the microstructure were determined by x-ray diffraction (XRD). The microstructural evaluations showed that FSP destroys the coarse dendritic microstructure. Furthermore, it dissolves the secondary hard and brittle β-Mg17Al12 phase existing at grain boundaries of the TIG weld zone. The closure and decrease in amount of porosities along with the elimination of the cracks in the microstructure were observed. These changes were followed by a significant grain refinement to an average value of 11 µm. The results showed that the hardness values increased to the mean ones, respectively, for as-cast (63 Hv), TIG weld zone (67 Hv), and stir zone (79 Hv). The yield and ultimate strength were significantly enhanced after FSP. The fractography evaluations, by scanning electron microscopy (SEM), indicated to a transition from brittle to ductile fracture surface after applying FSP to the TIG weld zone.

  12. New Approaches to Aluminum Integral Foam Production with Casting Methods

    Directory of Open Access Journals (Sweden)

    Ahmet Güner

    2015-08-01

    Full Text Available Integral foam has been used in the production of polymer materials for a long time. Metal integral foam casting systems are obtained by transferring and adapting polymer injection technology. Metal integral foam produced by casting has a solid skin at the surface and a foam core. Producing near-net shape reduces production expenses. Insurance companies nowadays want the automotive industry to use metallic foam parts because of their higher impact energy absorption properties. In this paper, manufacturing processes of aluminum integral foam with casting methods will be discussed.

  13. Impact of environmental chemicals on key transcription regulators and correlation to toxicity end points within EPA's ToxCast program.

    Science.gov (United States)

    Martin, Matthew T; Dix, David J; Judson, Richard S; Kavlock, Robert J; Reif, David M; Richard, Ann M; Rotroff, Daniel M; Romanov, Sergei; Medvedev, Alexander; Poltoratskaya, Natalia; Gambarian, Maria; Moeser, Matt; Makarov, Sergei S; Houck, Keith A

    2010-03-15

    Exposure to environmental chemicals adds to the burden of disease in humans and wildlife to a degree that is difficult to estimate and, thus, mitigate. The ability to assess the impact of existing chemicals for which little to no toxicity data are available or to foresee such effects during early stages of chemical development and use, and before potential exposure occurs, is a pressing need. However, the capacity of the current toxicity evaluation approaches to meet this demand is limited by low throughput and high costs. In the context of EPA's ToxCast project, we have evaluated a novel cellular biosensor system (Factorial (1) ) that enables rapid, high-content assessment of a compound's impact on gene regulatory networks. The Factorial biosensors combined libraries of cis- and trans-regulated transcription factor reporter constructs with a highly homogeneous method of detection enabling simultaneous evaluation of multiplexed transcription factor activities. Here, we demonstrate the application of the technology toward determining bioactivity profiles by quantitatively evaluating the effects of 309 environmental chemicals on 25 nuclear receptors and 48 transcription factor response elements. We demonstrate coherent transcription factor activity across nuclear receptors and their response elements and that Nrf2 activity, a marker of oxidative stress, is highly correlated to the overall promiscuity of a chemical. Additionally, as part of the ToxCast program, we identify molecular targets that associate with in vivo end points and represent modes of action that can serve as potential toxicity pathway biomarkers and inputs for predictive modeling of in vivo toxicity. PMID:20143881

  14. Clean Metal Casting

    Energy Technology Data Exchange (ETDEWEB)

    Makhlouf M. Makhlouf; Diran Apelian

    2002-02-05

    The objective of this project is to develop a technology for clean metal processing that is capable of consistently providing a metal cleanliness level that is fit for a given application. The program has five tasks: Development of melt cleanliness assessment technology, development of melt contamination avoidance technology, development of high temperature phase separation technology, establishment of a correlation between the level of melt cleanliness and as cast mechanical properties, and transfer of technology to the industrial sector. Within the context of the first task, WPI has developed a standardized Reduced Pressure Test that has been endorsed by AFS as a recommended practice. In addition, within the context of task1, WPI has developed a melt cleanliness sensor based on the principles of electromagnetic separation. An industrial partner is commercializing the sensor. Within the context of the second task, WPI has developed environmentally friendly fluxes that do not contain fluorine. Within the context of the third task, WPI modeled the process of rotary degassing and verified the model predictions with experimental data. This model may be used to optimize the performance of industrial rotary degassers. Within the context of the fourth task, WPI has correlated the level of melt cleanliness at various foundries, including a sand casting foundry, a permanent mold casting foundry, and a die casting foundry, to the casting process and the resultant mechanical properties. This is useful in tailoring the melt cleansing operations at foundries to the particular casting process and the desired properties of cast components.

  15. THE IMPACT OF STRUCTURAL, PETROGRAPHIC AND CLIMATIC FACTORS ON THE SLOPE STABILITY IN THE OPEN CAST MINE OF GRADNA

    Directory of Open Access Journals (Sweden)

    Ivan Tomašić

    1992-12-01

    Full Text Available This paper presents an analysis of a complexity of interrelated structural, petrologic and climatic factors that considerably affect the instabilities in the open cast mine of Gradna, near Samobor. The instabilities provoke the slope failures such as slides and slumps of rock material. During the protracted periodical investigations, the relationship among the factors of regional geology, tectonics, structural geology, petrography, engineering geology, rock mechanics and the rock mining technology was observed in the area. The local control of hydrogeologic properties, as well as climatic fluctuations of temperature and precipitation on the slope stability, was also recognized. It turned out that the structural relationships, characteristic of the manifold cataclased dolomite, stimulated the development of local instabilities, particularly during the period of low temperatures affecting the process of ground-water accumulation. When the temperatures are worm, the ground-water circulation is slow, exerting only the small-scale influence on the local instabilities (the paper is published in Croatian.

  16. Role of Titanium in Thin Wall Vermicular Graphite Iron Castings Production

    Directory of Open Access Journals (Sweden)

    M. Górny

    2013-04-01

    Full Text Available In this paper the effects of titanium addition in an amount up to 0.13 wt.% have been investigated to determine their effect on the microstructure and mechanical properties of Thin Wall Vermicular Graphite Iron Castings (TWVGI. The study was performed for thinwalled iron castings with 3-5 mm wall thickness and for the reference casting with 13 mm. Microstructural changes were evaluated by analyzing quantitative data sets obtained by image analyzer and also using scanning electron microscope (SEM. Metallographic examinations show that in thin-walled castings there is a significant impact of titanium addition to vermicular graphite formation. Thinwalled castings with vermicular graphite have a homogeneous structure, free of chills, and good mechanical properties. It may predispose them as a potential use as substitutes for aluminum alloy castings in diverse applications.

  17. The influence of aluminosilicate fibre in moulding material for investment casting technology on its mechanical properties

    Directory of Open Access Journals (Sweden)

    Nadolski M.

    2008-03-01

    Full Text Available An incrcnsc of mcchnnicol propcrtics of thin-walled ccramic moulds far the invcstrncnt casting tcchnology has hccn thc main pupscOF thc undcrlakcn rcscnrch work. Partial rcplaccmcnt of grain silica rnatcrials with alrrminasilicatc materials in thc [ibrous rorm is ancsscncc nf a ncw cnnccpt of slruct~~mchla ngc of ~hmc oulding matcrial. Thcrc havc hcen prcparcd inntcrials ol various librc fractioncon~aincdin thc matrix and thcir mcchnnical propcrtics havc bccn cxamincd, narncly thcir bcndiiig srrcngth MORE, work of frncrurc FI.and thc deflcclionl;,,,, An addit ion of ccminic fibrc [a thc rnatcrial matrix rcst~ltsin t hc inctcasc of a!l thc mechanical propcrtics. Thc fihrcfraction ranging horn 25 10 SO wt-% is oplirnal as far as mhanical propcrtics and rhc spraying icctlnology or huilrling lhc thin-wallcdmould arc conccmcd.

  18. Effect of Welding Parameters on Microstructure and Mechanical Properties of Cast Fe-40Al Alloy

    Directory of Open Access Journals (Sweden)

    Osman Torun

    2016-09-01

    Full Text Available Friction welding of cast Fe-40Al alloy was carried out at 1000 rmp for various friction times, friction pressures, and forging pressures. The microstructures of the interface of welded samples were analyzed by optical and scanning electron microscopy (SEM. Micrographs demonstrated that excellent welding formed continuously along the interface, except for samples welded for 3 s. Chemical compositions of the interface of the friction welded samples and of the fractured surface of all the specimens were determined using energy dispersive spectroscopy (EDS. After the welding process, shear tests were applied to the welded samples to determine the shear strength of joints. Test results indicated that the maximum shear strength was 469.5 MPa.

  19. Preparation and mechanical properties of SiC/2024 composite by semisolid casting

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A SiC/2024 composite was made by semisolid casting. The wetting between SiC and Al matrix is improved by treating SiC particles at a high temperature, coating K2ZrF6, and adding Mg to the Al melt. An effective way to remove the gas around SiC particles was also found. Microsturctures were observed under optical microscope (OM) and scanning electron microscopy (SEM). The results show that SiC particles and Al matrix are well bonded and no gaps or cavities around the particles are observed. SiC particles distribute homogeneously in the Al matrix. The existence of SiC particles results in the increase of wear resistance and strength.

  20. Mechanical properties of phase constituents in selected grades of cast steel

    Directory of Open Access Journals (Sweden)

    M. Garbiak

    2011-07-01

    Full Text Available The nanoindentation measurements performed on three cast steels of 0.3C-30Ni-18Cr type with various content of niobium and titanium were carried out.Mechanical propertiesofthe main phaseconstituents of the alloys, such as austenite, MC and M23C6 type carbides, were determined and analysed. The values of hardness (H and Young modulus (E for the austenite matrix were similar within the tested alloys. Essential differences (H=12 ÷ 24 GPa; E = 250 ÷ 400 GPa were found between the carbide phases present in tested alloys. The nanoindentation measurement on small particles is affected by different effects. One of these effects was excluded using numerical simulation of impressing the phase constituent into the matrix during indentation. The values of H and E obtained from simulation were: 30/450 GPa for NbC; 50/580 GPa for TiC; and 19/320 GPa for Cr23C6 respectively

  1. Effects of selected casting methods on mechanical behaviour of Al-Mg-Si alloy

    Directory of Open Access Journals (Sweden)

    Henry Kayode TALABI

    2014-11-01

    Full Text Available This study investigated the effects of selected casting methods on mechanical behaviour of Al-Mg-Si alloy. The casting methods used was spin, sand and die casting, these were done with a view to determine which of the casting methods will produce the best properties. The pure aluminium scrap, magnesium and silicon were subjected to chemical analysis using spectrometric analyzer, thereafter the charge calculation to determine the amount needed to be charged into the furnace was properly worked out and charged into the crucible furnace from which as-cast aluminium was obtained. The mechanical properties of the casting produced were assessed by hardness and impact toughness test. The optical microscopy and experimental density and porosity were also investigated. From the results it was observed that magnesium and silicon were well dispersed in aluminium matrix of the spin casting. It was observed from visual examination after machining that there were minimal defects. It was also observed that out of the three casting methods, spin casting possesses the best mechanical properties (hardness and impact toughness.

  2. Final Technical Report Quantification and Standardization of Pattern Properties for the Control of the Lost Foam Casting Process

    Energy Technology Data Exchange (ETDEWEB)

    Ronald Michaels

    2005-09-30

    This project takes a fresh look at the ''white side'' of the lost foam casting process. We have developed the gel front hypothesis for foam pyrolysis behavior and the magnetic metal pump method for controlling lost foam casting metal fill event. The subject of this report is work done in the improvement of the Lost Foam Casting Process. The original objective of this project was to improve the control of metal fill by understanding the influence of foam pattern and coating properties on the metal fill event. Relevant pattern properties could then be controlled, providing control of the metal fill event. One of the original premises of this project was that the process of metal fill was relatively well understood. Considerable previous work had been done to develop fluid mechanical and heat transfer models of the process. If we could just incorporate measured pattern properties into these models we would be able predict accurately the metal fill event. As we began to study the pyrolysis behavior of EPS during the metal fill event, we discovered that the chemical nature of this event had been completely overlooked in previous research. Styrene is the most prevalent breakdown product of EPS pyrolysis and it is a solvent for polystyrene. Much of the styrene generated by foam pyrolysis diffuses into intact foam, producing a molten gel of mechanically entangled polystyrene molecules. Much of the work of our project has centered on validation of this concept and producing a qualitative model of the behavior of EPS foam undergoing pyrolysis in a confined environment. A conclusion of this report is that styrene dissolution in EPS is a key phenomenon in the pyrolysis process and deserves considerable further study. While it is possible to continue to model the metal fill event parametrically using empirical data, we recommend that work be undertaken by qualified researchers to directly characterize and quantify this phenomenon for the benefit of modelers

  3. Effects of Nd on microstructure and mechanical properties of as-cast Mg-8Li-3Al alloy

    Institute of Scientific and Technical Information of China (English)

    LI Ming; HAO Hai; ZHANG Aimin; SONG Yingde; ZHANG Xingguo

    2012-01-01

    Effects of Nd on microstructure and mechanical properties of as-cast Mg-8Li-3Al alloy were investigated by OM,X-ray diffraction (XRD),EPMA,scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS).The results showed that the dendrites sizes of α phase were decreased by the Nd addition.When the amount of addition Nd was 1.6 wt.%,the alloy with the smallest α phase was obtained.The refining mechanism mainly owed to the increasing constitutional supercooling at the solidification front.Furthermore,the compound Al2Nd generated by the reaction of Al and Nd,which distributed at the phase boundary and inside β phase,could also restrain the growth of α phase.Nd could improve the tensile strength and elongation of Mg-8Li-3Al alloy,however,excessive Al2Nd might also become crack source and decrease the elongation.

  4. Preparation and thermomechanical properties of stir cast Al–2Mg–11TiO2 (rutile) composite

    Indian Academy of Sciences (India)

    S K Chaudhury; A K Singh; C S S Sivaramakrishnan; S C Panigrahi

    2004-12-01

    Al–2Mg–11TiO2 composite was successfully prepared by the conventional vortex method. The macrostructural observation revealed columnar structure with rutile particles being distributed throughout the matrix in the form of agglomerates. Microstructural observation showed the presence of micro voids in the particle-enriched zone. Electrical resistivity measurement showed a phase transformation at 360°C, which was consistent during DSC studies due to the precipitation of TiAl3 phase. As-cast composite was both hot rolled and cold rolled successfully to 50 and 40% reduction, respectively. The mechanical properties of the thermomechanically-worked composite were studied. From fractographic analysis, it was clear that the crack had nucleated at the particle/matrix interface and propagated through the matrix by microvoid coalescence. Ultimate tensile strength of cold worked composite was found to be better than the hot worked material.

  5. Effect of particle size on thermo-physical properties of SiCp/Cu composites fabricated by squeeze casting

    Institute of Scientific and Technical Information of China (English)

    WU Gao-hui; CHEN Guo-qin; ZHU De-zhi; ZHANG Qiang; JIANG Long-tao

    2005-01-01

    For the electronic packaging applications, copper matrix composites reinforced with different sized SiC particles (10 μm, 20 μm and 63 μm) were fabricated by squeeze casting technology. And the effect of particle size on their thermo-physical properties was discussed. The composites are free of porosity and the SiC particles are distributed uniformly in the composites. It is found that the mean linear thermal expansion coefficients(20 - 100 ℃ ) of SiCp/Cu composites are in the range of (8.4 - 9.2) × 10-6/℃, and smaller expansion coefficient can be obtained for the composites with finer SiC particles because of the larger restriction in expansion through interfaces. Their thermal conductivities are reduced with the decrease of SiC sizes. This is attributed to the fact that the negative effect of interfacial thermal resistance becomes increasingly dominant as the particles becomes smaller.

  6. Preparation and properties of multi-wall carbon nanotube/SiC composites by aqueous tape casting

    Institute of Scientific and Technical Information of China (English)

    L(U) ZhiHui; JIANG DongLiang; ZHANG JingXian; LIN QingLing

    2009-01-01

    MWCNTS/SiC composites were fabricated by aqueous tape casting. High solid content (50 vol%) SiC slurries with sintering additives and multi-wall carbon nanotubes (MWCNTs) as reinforcements were prepared using Tetramethylammonium hydroxide as the dispersant. The stability of MWCNTs/SiC slur-ries was studied and characterized in terms of zeta potential and rheology measurements. The relative density of the composite was about 98% after hot-pressing at 1850℃ (at 25 MPa in Ar for 30 min). The hardness of the composites decreased with the increase in MWCNTs content, The flexural strength and was 0,25 wt%. Further increase in MWCNTs content to 0.50 wt% did not lead to the increase in me-chanical properties. Most of MWCNTs were found to be located at SiC grain boundaries and the pull out of the MWCNTs was observed.

  7. Property Characteristics of a TiB2P/AI Composite Fabricated by Squeeze Casting Technology

    Institute of Scientific and Technical Information of China (English)

    Min ZHAO; Gaohui WU; Zuoyong DOU; Longtao JIANG

    2006-01-01

    TiB2P/Al composite was successfully fabricated by squeeze casting technology. Its mechanical and tribological properties were evaluated. The elimination of Ti-Al intermetallic compound was confirmed by X-ray diffraction (XRD) studies. At 45% volume fraction, the bending strength at ambient temperature was 934 MPa. And the fracture modes included ductile failure of Al matrix and brittle fracture of TiB2 particles. In dry sliding wear mode, severe plastic deformation and adhesive wear were found on the worn surfaces of the SiCP/Alcomposite. But no obvious characteristics of adhesion or abrasion wear were observed on that of the TiB2P/Al composites. At the steady stage, the friction coefficient of the SiCP/Al composite was about 0.6. While that of TiB2P/Al composite was only about 0.16~0.17.

  8. Influence of yttrium on microstructure and mechanical properties of as-cast Mg-5Li-3Al-2Zn alloy

    International Nuclear Information System (INIS)

    Highlights: → The effects of Y additions (0-2.0 wt.%) on the microstructure and mechanical properties of Mg-5Li-3Al-2Zn alloy have been studied. → The new phase generated after Y addition has been identified, the change of grain size due to Y addition has also been discussed. → The mechanisms of the improvement of the mechanical properties due to Y addition have been investigated. - Abstract: The influence of Y on microstructure and mechanical properties of as-cast Mg-5Li-3Al-2Zn alloy was investigated. The results show that the phase compositions of Mg-5Li-3Al-2Zn consist of α-Mg and AlLi phases. Adding Y to the alloy results in the formation of Al2Y compound and facilitates grain refinement. The addition of 0.8 wt.% Y produces the smallest grain size. The tensile tests performed at room temperature show that the additions of Y can improve the mechanical properties of the alloy; the tensile strength and ductility reach peak values when the Y additions are 0.8 wt.% and 1.2 wt.%, respectively. The mechanisms of improvement are related to grain refinement and compound strengthening effects.

  9. Colour Metallography of Cast Iron

    Institute of Scientific and Technical Information of China (English)

    Zhou Jiyang; Liu Jincheng

    2010-01-01

    @@ Chapter 3 Spheroidal Graphite Cast Iron(I) Spheroidal Graphite Cast Iron, SG iron in short, refers to the cast iron in which graphite precipitates as spheroidal shape during solidification of liquid iron. The graphite in common commercial cast iron can only be changed from flake to spheroidal shape by spheroidising treatment. Since spheroidal graphite reduces the cutting effect of stress concentration, the metal matrix strength of SG iron can be applied around 70%-90%, thus the mechanical property of SG iron is significantly superior to other cast irons;even the tensile strength of SG iron is higher than that carbon steel.

  10. Assessment of thermal embrittlement of cast stainless steels

    International Nuclear Information System (INIS)

    A procedure and correlations are presented for assessing thermal embrittlement and predicting Charpy-impact energy and fracture toughness J-R curve of cast stainless steel components under Light Water Reactor operating conditions from known material information. The ''saturation'' impact strength and fracture toughness of a specific cast stainless steel, i.e., the minimum value that would be achieved for the material after long-term service, is estimated from the chemical composition of the steel. Fracture properties as a function of time and temperature of reactor service are estimated from the kinetics of embrittlement, which are also determined from chemical composition. A common ''predicted lower-bound'' J-R curve for cast stainless steels of unknown chemical composition is also defined for a given grade of steel, ferrite content, and temperature. Examples of estimating fracture toughness of cast stainless steel components during reactor service are presented

  11. Energy Saving Melting and Revert Reduction (E-SMARRT): Optimization of Heat Treatments on Stainless Steel Castings for Improved Corrosion Resistance and Mechanical Properties

    Energy Technology Data Exchange (ETDEWEB)

    John N. DuPont; Jeffrey D. Farren; Andrew W. Stockdale; Brett M. Leister

    2012-06-30

    It is commonly believed that high alloy steel castings have inferior corrosion resistance to their wrought counterparts as a result of the increased amount of microsegregation remaining in the as-cast structure. Homogenization and dissolution heat treatments are often utilized to reduce or eliminate the residual microsegregation and dissolve the secondary phases. Detailed electron probe microanalysis (EPMA) and light optical microscopy (LOM) were utilized to correlate the amount of homogenization and dissolution present after various thermal treatments with calculated values and with the resultant corrosion resistance of the alloys.The influence of heat treatment time and temperature on the homogenization and dissolution kinetics were investigated using stainless steel alloys CN3MN and CK3MCuN. The influence of heat treatment time and temperature on the impact toughness and corrosion reistance of cast stainless steel alloys CF-3, CF-3M, CF-8, and CF-8M was also investigated.

  12. Effect of Cd and Sn Addition on the Microstructure and Mechanical Properties of Al-Si-Cu-Mg Cast Alloy

    Institute of Scientific and Technical Information of China (English)

    LI Rong-de; LI Run-xia; YU Li; HU Zhuang-qi

    2004-01-01

    The present work has investigated the effect of trace elements Cd and Sn on the microstructure and mechanical properties of Al-Si-Cu-Mg cast alloy. With the increase of Cd addition the strength of alloy rises at first and then drops. The optimal amount of Cd and Sn addition for Al-Si-Cu-Mg alloy is about 0.27% and 0.1% respectively. Due to the formation of some coarse Cd-rich phases and pure Cd particles the mechanical properties of alloy decrease when Cd amount exceeds0.27%. When more than 0.1% Sn added, some Sn atoms form low-melting eutectic compound at grain boundary, and then cause over-burning in alloy when solution treated, which may deteriorate properties of alloy, especially ductility of alloy.On the other hand, the addition of Cd and Sn remarkably increases the peak hardness and reduces the time to reach aging peak in Al-Si-Cu-Mg alloy. The action of Cd/Sn in quaternary Al-Si-Cu-Mg alloy is effectively the same as that occur in binary Al-Cu alloy that the enhanced hardening associated with Cd / Sn addition is due to the promotion of the θ' phase.

  13. Effect of Ce-rich misch metal addition on squeeze cast microstructure and mechanical properties of AZ81 alloy

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The effect of cerium-rich misch metal addition on the microstructure and properties of squeeze cast magnesium alloys AZ81 was empirically investigated. The results indicate that the addition of cerium-rich misch metal modifies the microstructure gradually. With the increase of the RE addition, the amount of Mg17Al12 decreases while that of Al11(RE)3 increases, accompanied by grain refinement. When the addition reaches 1.5%, the grain refinement becomes obvious. However, when the addition exceeds 2.0%,Al11(RE)3 phase coarsens into rod shape and the grain size increases. The tensile properties of the AZ81 at both room temperature and 150℃ increase with the addition, and reach their optimal values with the addition of 1.5%. Further increase of the addition to above 2.0% decreases the tensile properties considerably. The tensile fracture of the alloy is characterized by the cleavage of the brittle second phases and ductile dimples of the matrix.

  14. Study on Properties of LSGM Electrolyte Made by Tape Casting Method and Applications in SOFC

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Solid oxide fuel cell is attracting more attention in recent years for its lower pollution emission and high energy convert efficiency. La0.9Sr0.1Ga0.8Mg0.2O3-δ is a new kind of electrolyte for intermediate temperature SOFC. In this paper, La0.9Sr0.1Ga0.8Mg0.2O3-δ (LSGM) was prepared by solid state reaction method and formed by tape casting process to make a planar electrolyte. The appropriate amount of the dispersive was obtained by viscosity test. The densities of sintered samples increase with the increasing sintering temperature. It was found that the relative density of electrolyte can approach the value of 95% by the isostatic pressing treatment of the green tape. The average thermal expansion coefficient of the LSGM is 11.4×10-6/℃ at temperature range (200~1200 ℃). Measurements of the current-voltage and power-current characteristics of the H2-Air cell show that the open-circuit voltage is 1.067 V at 800 ℃, peak current density is 0.56 A·cm-2 and the maximum power output is 0.147 W·cm-2.

  15. Microstructure and Tribological Properties of Plasma Nitriding Cast CoCrMo Alloy

    Institute of Scientific and Technical Information of China (English)

    Qingliang Wang; Chuanhui Huan; Lei Zhang

    2012-01-01

    A medical cast CoCrMo alloy was coated by plasma nitriding process to enhance the wear resistance. The microstructures, phases and micro-hardness of nitrided layers were investigated by atomic force microscopy (AFM), scanning electron microscopy (SEM), X-ray diffraction (XRD) and micro-hardness. Tribological prop- erties were investigated on a pin-on-disc wear tester under 25% bovine serum solutions. The experimental results showed that plasma nitriding was a promising process to produce thick, hard and wear resistant layers on the surface of CoCrMo alloy. The harder CrN and Cr2N phases formed on the plasma nitrided layer with the compact nano-crystalline structure. Compared with the untreated sample, all nitrided samples showed the lower wear rates and higher wear resistance at different applied loads and nitriding temperatures. It was concluded that the improvement of wear resistance could be ascribed to the formation of thicker and harder nitrided layers with the specific microstructures on nitrided surfaces.

  16. The effect of repeated immersion of gypsum cast in sodium hypochlorite and glutaraldehyde on its physical properties: An in vitro study

    Directory of Open Access Journals (Sweden)

    Rachuri Narendra Kumar

    2012-01-01

    Full Text Available Background: One method used to disinfect a dental cast is immersion in a disinfecting solution. Repeated immersion of a cast in disinfectant may affect its physical properties. Purpose: The purpose of this study was to evaluate the changes in dimensional accuracy and hardness of the dental casts as a result of repeated disinfection in 0.525% sodium hypochlorite and 2% glutaraldehyde solutions. Materials and Methods: Sixty specimens were made of type III dental stone. Twenty specimens were immersed in slurry, a supernatant solution of calcium sulfate in distilled water (control casts, 20 specimens in 0.525% sodium hypochlorite, and 20 specimens in 2% glutaraldehyde solutions for 30 min and air dried for 24 h. This process was repeated for 7 times for testing. Linear dimensional change and hardness were determined according to American National Standards Institute/American Dental Association (ANSI/ADA standards. The data were analyzed using two-way analysis of variance. Results: For specimens prepared with type III stones, treatment was by immersion in slurry (group I - control casts, and by immersion in 0.525% sodium hypochlorite (group II - test group 1 and in 2% glutaraldehyde solution (group III - test group 2. The specimens treated with sodium hypochlorite and glutaraldehyde showed more linear dimensional change compared to the specimens treated in slurry. However, the difference between test casts and control casts was significant. But the difference between the two test groups was not significant. Both the test groups showed decrease in hardness of the specimens compared to that specimens in control group. But the difference between two test groups was not significant in hardness.However,the values remained close to ANSI/ADA standards. Conclusion: The results demonstrated that repeated immersion of type III dental stone specimens in slurry with distilled water, 0.525% sodium hypochlorite and 2% glutaraldehyde, along with drying in air

  17. Rheo-Cast Microstructure and Mechanical Properties of AM60 Alloy Produced by Self-Inoculation Rheo-Diecasting Process

    Directory of Open Access Journals (Sweden)

    Bo Xing

    2016-03-01

    Full Text Available Rheo-forming is becoming the choice for production of high quality parts with diminished defects and fine integrity. In this paper, the novel self-inoculation rheo-diecasting (SIRD process, in which semisolid slurry is produced by mixing two precursory solid and liquid alloys and subsequently pouring them through a multi-stream fluid director, has been proposed. Microstructural characteristics of AM60 alloy slurry and the microstructure and mechanical properties of rheo-diecasting AM60 samples were investigated. Quenching experiments reveal that the slurry microstructure of AM60 was well refined to irregular α-Mg particles with the average size of approximately 20–40 μm after pouring with the self-inoculation process, and these particles were evolved to globular and coarse morphology while continuously keeping in semisolid state. After rheo-diecasting, the microstructure of the sample was dominated by fine primary α-Mg globules accompanied with tiny secondary α-Mg particles while the sample from conventional liquid die casting was characterized by developed dendrite and porosity. Microscopic analysis indicates that there are three stages of remaining liquid solidification in die cavity in SIRD: α-Mg nucleation and growth on primary α-Mg surface, α-Mg nucleated independently in liquid, and, finally, formation of skeleton devoiced eutectic. Due to diminished porosity and hot tearing, tensile strength and elongation of SIRD samples were increased by 12.9% and 35.3%, respectively, compared to a conventional liquid die casting sample.

  18. Hot extrusion and its effect on microstructure and properties of squeeze casting SiCp/Al composites with lower volume fraction of reinforcement

    Energy Technology Data Exchange (ETDEWEB)

    Geng, L.; Qu, S.J.; Lei, T.Q. [School of Material Science and Engineering, Harbin Inst. of Tech. (China)

    2003-07-01

    Deformable SiCp/Al composites with lower volume fractions (15%, 20%, 25%) of the SiC particle reinforcement were fabricated by a squeeze casting technique. The volume fraction of the SiC particle was controlled by adding aluminum powder into the preform. The deformability of the SiCp/Al composites was studied by hot extrusion and the effect of the hot extrusion on microstructure and properties of the composites was investigated. The results show that the SiCp/Al composites fabricated by the modified squeeze casting method used here could be extruded successfully by the extrusion ratios of 9:1, 16:1, 25:1, 36:1, respectively. The strength, modulus and tensile elongation of the composites were improved by the hot extrusion. The resulting microstructure of the composites in both as cast and extrusion states was observed and analyzed by using SEM and TEM. (orig.)

  19. Research on the squeeze cast technology of the castings with large ratio of height to thickness

    Institute of Scientific and Technical Information of China (English)

    LI Chen-xi; SAN Jing-chao; XU Na; CAO Liang; BAI Yan-hua; LI Rong-de

    2005-01-01

    The squeeze cast technology is only applicable, at present, to the castings with a ratio of height to thickness less than 3.5. Researching the squeeze cast technology for castings with a large ratio of height to thickness will broaden the applicable range of the advanced casting technology. This paper describes a study of the temperature distribution during solidification for castings with a ratio of height to thickness of 7 by the methods of experiment and computer simulation. The shrinkage porosity distribution in the castings and the mechanical properties of the castings were also researched. The experimental and simulated results show that increasing squeeze force, or enhancing mold temperature,cannot reduce the shrinkage porosities in the castings. When castings solidify in a sequential manner and the squeeze force effectively acts on the surface of the liquid metal, the shrinkage porosities in the castings are eliminated and mechanical properties are clearly improved.

  20. Investigation of weldability and property changes of high pressure heat-resistant cast stainless steel tubes used in pyrolysis furnaces after a five-year service

    International Nuclear Information System (INIS)

    Highlights: → To investigate the weldability and property changes of high pressure heat-resistant cast stainless steel (HP) tubes. → Welding was done by gas-tungsten arc welding (GTAW) process. → Composition of precipitates was characterized by means of SEM and EDS analyses. → The solution treatment was used to recover the properties of tubes. → To investigate mechanical strength of specimens, tensile tests were carried out at room temperature. -- Abstract: High pressure heat-resistant cast stainless steel (HP steel) tubes produced by centrifugal casting are used in petrochemical industries for pyrolysis furnaces. They have appropriate ductility and weldability in as-cast conditions. These steels lose their ductility and weldability after being used in service and, hence, require repair. In the present study, the effect of metallurgical changes on weldability and ductility was investigated. The life span of the studied tubes was 5 years. Using electrodes with a chemical composition close to the base metal analysis, welding was done by gas-tungsten arc welding (GTAW) process. Solution treatment was used to recover the properties of tubes which can be useful, depending on metallurgical changes.

  1. Improved material properties of solution-cast starch films: effect of varying amylopectin structure and amylose content of starch from genetically modified potatoes

    OpenAIRE

    Menzel, Carolin; Andersson, Mariette; Andersson, Roger; Vázquez Gutiérrez, José Luis; Daniel, Geoffrey; Langton, Maud; Gällstedt, Mikael; Koch, Kristine

    2015-01-01

    High-amylose potato starches were produced through genetic modification resulting in changed granule morphology and composition, with higher amylose content and increased chain length of amylopectin. The increased amylose content and structural changes in amylopectin enhanced film-forming behavior and improved barrier and tensile properties in starch films. The molecular structure in these starches was related to film-forming properties. Solution-cast films of high-amylose starch revealed a h...

  2. Properties of Cross-Impact Balance Analysis

    CERN Document Server

    Weimer-Jehle, Wolfgang

    2009-01-01

    CIB matrices are N x N hypermatrices, the elements of which are m x n matrices. They are used in Cross-Impact Balance Analysis, a concept applied in social sciences, management sciences, scenario analysis and technology foresight to identify plausible configurations of qualitatively defined impact networks. Cross-Impact Balance Analysis (CIB) offers an opportunity for qualitative systems analysis without complex mathematics. Although CIB doesn't confront its user with too much mathematics, the background of the method and its algorithm can be scrutinized by mathematical means, thus revealing an extensive set of useful properties which are described and proved in this article. Among them are four laws of invariance, a treatise on several special cases of CIB matrices, and the proof that CIB analysis is equivalent to a universal computer (a Turing machine).

  3. Impact of sea-level rise in a Mediteranean delta: The Ebro delta cast

    NARCIS (Netherlands)

    Sánchez-Arcilla, A.; Stive, M.D.F.; Jiménez, J.A.; García, M.A.

    1993-01-01

    In anticipation of a comprehensive, multidisciplinary study on the impact of climatic change on the Ebro Delta preliminary results are here presented of the response of the outer delta coast to present and future relative sea-level rise. Due to the absence of observations and predictions of regional

  4. The effect of palm kernel shell ash on the mechanical properties of as-cast aluminium alloy matrix composites

    Directory of Open Access Journals (Sweden)

    Isiaka Oluwole OLADELE

    2016-06-01

    Full Text Available The present work describes the effect of palm kernel shell ash (PKSA as reinforcement on the mechanical properties of As-cast aluminium alloy. Recycled aluminium alloy from cylinder of an automotive engine block was degreased by using premium motor spirit (PMS also known as petrol, washed thoroughly with soap and water and sun dried for 5 days. The palm kernel shell was screened of dirt and other unwanted foreign materials before being roasted in furnace. The ash was further pulverized by laboratory ball mill machine followed by sieving to obtain particle sizes of 106 µm and divided into two parts. One portion was treated with NaOH solution while the other part was left as untreated before they are used to reinforced molten aluminium alloy in predetermined proportions. The newly developed composites were characterized with respect to their mechanical properties in response to the tests that were carried out on them. The results indicate that palm kernel shell ash can be used as potential reinforcing material for automobile applications.

  5. Processing and mechanical properties of SiC particulate reinforced AZ91 composites fabricated by stir casting

    Institute of Scientific and Technical Information of China (English)

    WANG Xiao-jun; WU Kun; PENG De-lin; ZHANG Hai-feng; ZHENG Ming-yi; HUANG Wen-xian

    2006-01-01

    The influence of stirring parameters (stirring temperature, stirring speed and stirring time) on the particle distribution of 10%(volume fraction) SiC particulate reinforced AZ91 composites (SiCp/AZ91) was studied. It is found that it is necessary for 10 μm SiC particulate reinforced AZ91 composites to stir the molten composites in semi-solid condition with vortex formation, or else the cluster of the reinforcements would not be eliminated. Compared with the monolithic alloy, the SiCp/AZ91 composite has higher strength, especially for yield strength, but the elongation is reduced. For the as-cast composite, the particles often segregate within the grain boundary regions. Extrusion can effectively reduce the segregation of SiC particles and improve the mechanical properties of the composite. The extrusion-induced reduction in particle size varies with extrusion temperatures and extrusion ratios. The effect of extrusion-induced reduction in particle size on the mechanical properties of the composites is not always beneficial.

  6. Properties of PP/MWCNT-COOH /PP composites made by melt mixing versus solution cast /melt mixing methods

    Science.gov (United States)

    Reinholds, I.; Roja, Z.; Zicans, J.; Merijs Meri, R.; Bitenieks, J.

    2015-03-01

    An approach on improvement of the properties of polypropylene / carbon nanotube (PP/CNT) composites is reported. PP blend compositions with carboxylic acid functionalized multi-walled carbon nanotubes (MWCNT-COOH) at filler content 1.0 wt.% were researched. One part of the composites was manufactured by direct thermoplastic mixing PP with the filler, but the other one was made from solution casted masterbatch with the following thermoplastic mixing. An increase of mechanical properties (Young's modulus, storage modulus and tensile strength), compared to an increase of glass transition temperature indicated a reinforcement effect of CNTs on PP matrix, determined from the tensile tests and differential mechanical analysis (DMA), while the elongation was reduced, compared to PP matrix. By differential scanning calorimetry (DSC) analysis, the effect of nanofiller on the reorganization of PP crystallites was observed. A noticeable enhanced effect on increase of the crystallization temperature was indicated for masterbatch manufactured composite. An increase of thermal stability was also observed, compared to pristine PP and the composite made by direct thermoplastic mixing PP with the filler.

  7. Impact Property of Ultra Fine Grain Copper

    Directory of Open Access Journals (Sweden)

    Fahad Al-Mufadi

    2014-06-01

    Full Text Available Ultrafine Grained (UFG and Nano-Structured (NS materials have experienced a rapid development during the last decade and made profound impact on every field of materials science and engineering. The present study has been undertaken to develop ultrafine grained pure copper by severe plastic deformation method and to examine the impact property by different characterizing tools. For this aim, equal channel angular pressing die with the channel angle, outer corner angle and channel diameter of 90°, 17° and 20 mm, respectively had been designed and manufactured. Commercial pure copper billets were ECAPed up to four passes by route BC at the ambient temperature. The results indicated that there is a great improvement at the hardness measurement, yield strength and ultimate tensile strength after ECAP process. It is found that the magnitudes of HV reach 136 from 52 HV after the final pass. Also, about 285 and 125% enhancement at the YS and UTS values have been obtained after the fourth pass as compared to the as-received conditions, respectively. On the other hand, the elongation to failure and impact energy have been reduced by imposing ECAP process and pass numbers. It is needed to say that about 56% reductions in the impact energy have been attained for the samples as contrasted to annealed specimens. Furthermore, the grain size of the final pass is 800 nm for Cu sample. Finally, fracture surfaces of billets after impact test have been investigated using Scanning Electron Microscope (SEM.

  8. Addition of Oils to Polylactide Casting Solutions as a Tool to Tune Film Morphology and Mechanical Properties

    NARCIS (Netherlands)

    Sawalha, H.I.M.; Schroën, C.G.P.H.; Boom, R.M.

    2010-01-01

    Poly(L-lactide) (PLLA) films exhibit toughening by the addition of oils to the polymer casting. This was investigated by casting films from solution and evaporation in air; the investigated oils were linear alkanes, cyclic alkanes, and two terpenes (limonene and eugenol). The addition of the oils gr

  9. Study on the Mechanical Properties of Cast 6063 Al Alloy Using a Mixture of Aluminum Dross and Green Sand as Mold

    Science.gov (United States)

    Adeosun, S. O.; Sekunowo, O. I.; Balogun, S. A.; Obembe, O. O.

    2012-08-01

    The mechanical characteristics of 6063 aluminum alloy cast in a mixture of aluminum dross and silica sand as mold have been examined. The amount of dross in the green silica sand was varied in the range of 0-80% with bentonite as binder. In all, 40 samples were cast, and 8 of these were left in the as-cast condition for control while 32 were first homogenized at 470°C for 6 h and then rolled in a two-high mill at ambient temperature to 10% reduction in one pass. The rolled samples were solution heat treated at 515°C for 8 h followed by normalizing, annealing, and quench tempering, respectively. The samples were then simulated and tensile behavior coupled with the evaluation of microhardness and microstructures developed. The results obtained demonstrate significant improvement in mechanical properties from 50% to 80% dross in the mold. Tensile strength increased to 177 MPa and 15% elongation compared with conventional 6063-T5 aluminum alloy with 145 MPa tensile strength and 8% elongation. The improvement in mechanical properties by the quench-tempered samples can be attributed to the inducement of fine and coherent Mg2Si crystals within the matrix. Furthermore, the overall analysis of the proportion of dross to the size of cast show that about 64% of dross generated can be utilized as mold material.

  10. Mechanical and structural properties of solution-cast high-amylose maize starch films.

    Science.gov (United States)

    Koch, Kristine; Gillgren, Thomas; Stading, Mats; Andersson, Roger

    2010-01-01

    Environmental issues have forced the introduction of sustainable solutions such as annually renewable resources being used as a raw material for packaging and disposables. This paper examined the effects of time and temperature during manufacturing and plasticiser content on the molecular structure of high-amylose maize starch films. It also analysed how manufacturing conditions, plasticiser content and molecular structure of the films affected their material properties. It was found that increased time or temperature increased the degradation of amylose and of amylopectin, which in turn negatively affected film cohesiveness. However, neither time nor temperature had any effect on tensile properties. PMID:19828118

  11. Fabrication and ageing of cast austenitic steels

    International Nuclear Information System (INIS)

    An investigation has been undertaken to determine the magnitude of any reduction in properties which may occur in cast duplex stainless steels and weldments during long term exposure to reactor operating conditions. Test panels were fabricated in CF3 stainless steel by a manual metal arc (MMA) process using 19.9.L (Type 308L) consumables. The mechanical properties and intergranular corrosion resistance of parent material and weldments were measured following accelerated ageing at 3750 and 4000C for up to 10,000 hours. Both the impact energy and J/sub R/ fracture toughness properties of the cast austenitic/ferritic stainless steel were reduced following aging at 4000C for 10,000 hours, whereas austenitic stainless steel MMA weld metals exhibited a reduction in J/sub R/ fracture toughness but no change in impact energy. Even in the unaged state, MMA weld metals were shown to have a much lower resistance to stable crack growth than the parent cast steel, and, following aging, there is a further reduction in the ductile tearing resistance of such weld metals. Therefore, in any assessment of the structural integrity of the reactor coolant pump bowl for a pressurized water reactor (PWR), the weld metal fracture properties during service are likely to be of considerable importance

  12. Effect of sigma phase precipitation on the mechanical and wear properties of Z3CN20.09M cast duplex stainless steel

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Y.Q.; Han, J.; Wu, H.C. [State Key Laboratory for Advanced Metals and Materials, University of Science and Technology, Beijing (China); Yang, B., E-mail: byang@ustb.edu.cn [State Key Laboratory for Advanced Metals and Materials, University of Science and Technology, Beijing (China); Wang, X.T. [State Key Laboratory for Advanced Metals and Materials, University of Science and Technology, Beijing (China)

    2013-06-15

    Highlights: ► The σ phase in the steel precipitated at a temperature range of 600–900 °C. ► The decomposition of α-ferrite into γ{sub 2} and σ phase in aged specimens is suggested. ► The tensile and yield strengths decreased first and then increased with aging time. ► The impact energy decreased slightly first but then drastically with aging time. ► The hardness and wear rates are not sensitive parameters to aged specimens. -- Abstract: The effect of sigma phase on the mechanical and wear properties of a Z3CN20.09M cast duplex stainless steel (CDSS) used in primary coolant pipe of nuclear power plants has been investigated. The experimental results showed that the sigma phase precipitated from ferrite at a temperature range of 600–900 °C. The tensile and yield strengths of the specimens aged at 700 °C decreased first and then increased with the increase of aging time. With increasing aging time, the impact energy of specimens decreased slightly before 4 h and then dropped drastically when aged a longer time more than 10 h. Fracture surface analysis showed that the hard and brittle sigma phase degraded the toughness of the aged steel. The hardness and wear resistance of the specimens aged for 1–4 h were lower than those of un-aged ones. However, the higher values of hardness and wear resistance were got in the specimens aged more than 10 h.

  13. Methanol-Sensing Property Improvement of Meso structured Zinc Oxide Prepared by the Nano casting Strategy

    International Nuclear Information System (INIS)

    The specific structure and morphology often play a critical role in governing the excellent intrinsic properties of the compound semiconductor. Herein, meso structured ZnO with excellent methanol-sensing properties was prepared by a structure replication procedure through the incipient wetness technique. The investigation on the crystal structure and morphology of the resultant material shows that the product consists of hexagonally arranged meso pores and crystalline walls, and its structure is an ideal replication of CMK-3 template. Consequently, meso structured ZnO was fabricated as a gas sensor for methanol. The excellent methanol-sensing performance was achieved at a relatively low operating temperature of 120°C. In comparison with the non porous ZnO prepared through conventional coprecipitation approach, meso structured ZnO material shows the higher sensitivity and stability. Furthermore, it shows the discrimination between methanol and ethanol sensitivity, which makes it a good candidate in fabricating selective methanol sensor in practice

  14. Structural and mechanical properties of 7075 alloy strips fabricated by roll-casting in a static magnetic field

    Institute of Scientific and Technical Information of China (English)

    Xin Su; Guang-ming Xu; Jiu-wen Jiang

    2014-01-01

    The influences of a 0.2 T static magnetic field on the microstructure of 7075 aluminum alloys sheets produced with a twin-roll continuous caster at 675°C were investigated in this paper. Under a uniform magnetic field, the primary dendrites were refined and tended to be equiaxed. The microstructure consisted of an intermediate case between dendritic and equiaxed grains. Moreover, the use of an external static field in the twin-roll casting process can reduce heat discharge, resulting in a decrease in undercooling, and may also account for the abatement of segregation bands. In addition, the static magnetic field effectively improved the solute mixing capacity, and the added atoms more easily diffused from precipitates to theα-Al matrix, which resulted in an increase in the mechanical properties of the rolled sheets. Specimens prepared both in the presence of a static magnetic field and in the absence of a static magnetic field exhibited brittle-fracture characteristics.

  15. Effect of medium on friction and wear properties of compacted graphite cast iron processed by biomimetic coupling laser remelting process

    International Nuclear Information System (INIS)

    Stimulated by the cuticles of soil animals, an attempt to improve the wear resistance of compact graphite cast iron (CGI) with biomimetic units on the surface was made by using a biomimetic coupled laser remelting process in air and various thicknesses water film, respectively. The microstructures of biomimetic units were examined by scanning electron microscope and X-ray diffraction was used to describe the microstructure and identify the phases in the melted zone. Microhardness was measured and the wear behaviors of biomimetic specimens as functions of different mediums as well as various water film thicknesses were investigated under dry sliding condition, respectively. The results indicated that the microstructure zones in the biomimetic specimens processed with water film are refined compared with that processed in air and had better wear resistance increased by 60%, the microhardness of biomimetic units has been improved significantly. The application of water film provided finer microstructures and much more regular grain shape in biomimetic units, which played a key role in improving the friction properties and wear resistance of CGI.

  16. Joint properties of cast Fe-Pt magnetic alloy laser-welded to Co-Cr alloy.

    Science.gov (United States)

    Baba, Naoki; Watanabe, Ikuya; Tanaka, Yasuhiro; Hisatsune, Kunihiro; Atsuta, Mitsuru

    2005-12-01

    This study investigated the joint properties of Fe-Pt alloy laser-welded to Co-Cr alloy. Cast plates (0.5 x 3.0 x 10 mm) were prepared with Fe-Pt and Co-Cr alloys. Fe-Pt plates were butted against Co-Cr plates and laser-welded using Nd:YAG laser. Control and homogeneously welded specimens were also prepared. Laser welding was performed with and without argon shielding. Tensile testing was conducted, and both fracture force (Ff: N) and elongation (El: %) were recorded. There were no differences in the Ff value between the specimens with and without argon shielding for the welded Fe-Pt/Co-Cr. Lower Ff value of the welded specimen was obtained in the order of Fe-Pt alloy welded to Co-Cr had Ff values between the values of homogeneously welded Fe-Pt and Co-Cr alloys. Argon shielding, on the other hand, had no effect on the weld strength between Fe-Pt and Co-Cr alloys. PMID:16445017

  17. Preparation and properties of multi-wall carbon nanotube/SiC composites by aqueous tape casting

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    MWCNTS/SiC composites were fabricated by aqueous tape casting. High solid content (50 vol%) SiC slurries with sintering additives and multi-wall carbon nanotubes (MWCNTs) as reinforcements were prepared using Tetramethylammonium hydroxide as the dispersant. The stability of MWCNTs/SiC slur-ries was studied and characterized in terms of zeta potential and rheology measurements. The relative density of the composite was about 98% after hot-pressing at 1850℃ (at 25 MPa in Ar for 30 min). The hardness of the composites decreased with the increase in MWCNTs content. The flexural strength and the fracture toughness were 742.17 MPa and 4.63 MPa·m1/2, respectively when the MWCNTs content was 0.25 wt%. Further increase in MWCNTs content to 0.50 wt% did not lead to the increase in mechanical properties. Most of MWCNTs were found to be located at SiC grain boundaries and the pull out of the MWCNTs was observed.

  18. Effect of Rolling Route on Microstructure and Tensile Properties of Twin-Roll Casting AZ31 Mg Alloy Sheets

    Directory of Open Access Journals (Sweden)

    Dan Luo

    2016-06-01

    Full Text Available Twin-roll casting AZ31 Mg alloy sheets have been fabricated by normal unidirectional-rolling, head-to-tail rolling, and clock-rolling, respectively. It has been demonstrated that head-to-tail rolling is the most effective to refine the microstructure and weaken the basal texture among the three rolling routes. Excellent integrated tensile properties can be obtained by the head-to-tail rolling. The yield strength, ultimate tensile strength, and plastic elongation are 196 MPa, 301 MPa, and 28.9%, respectively. The strength can benefit from the fine grains (average value of 4.0 μm of the AZ31 alloy processed by the head-to-tail rolling route, while the excellent plastic elongation is achieved owing to the weakened basal texture besides the fine grains. Results obtained here can be used as a basis for further study of some simple rolling methods, which is critical to the development of Mg alloys with high strength and plasticity.

  19. Melting and casting of FeAl-based cast alloy

    Energy Technology Data Exchange (ETDEWEB)

    Sikka, V.K. [Oak Ridge National Lab., TN (United States); Wilkening, D. [Columbia Falls Aluminum Co., Columbia Falls, MT (United States); Liebetrau, J.; Mackey, B. [AFFCO, L.L.C., Anaconda, MT (United States)

    1998-11-01

    The FeAl-based intermetallic alloys are of great interest because of their low density, low raw material cost, and excellent resistance to high-temperature oxidation, sulfidation, carburization, and molten salts. The applications based on these unique properties of FeAl require methods to melt and cast these alloys into complex-shaped castings and centrifugal cast tubes. This paper addresses the melting-related issues and the effect of chemistry on the microstructure and hardness of castings. It is concluded that the use of the Exo-Melt{trademark} process for melting and the proper selection of the aluminum melt stock can result in porosity-free castings. The FeAl alloys can be melted and cast from the virgin and revert stock. A large variation in carbon content of the alloys is possible before the precipitation of graphite flakes occurs. Titanium is a very potent addition to refine the grain size of castings. A range of complex sand castings and two different sizes of centrifugal cast tubes of the alloy have already been cast.

  20. Melting and casting of FeAl-based cast alloy

    Energy Technology Data Exchange (ETDEWEB)

    Sikka, V.K. [Oak Ridge National Lab., TN (United States). Metals and Ceramics Div.; Wilkening, D. [Columbia Falls Aluminum Co., 2000 Aluminum Dr., Columbia Falls, MT 59912 (United States); Liebetrau, J.; Mackey, B. [AFFCO, L.L.C., P.O. Box 1071, Anaconda, MT 59711 (United States)

    1998-12-31

    The FeAl-based intermetallic alloys are of great interest because of their low density, low raw material cost, and excellent resistance to high-temperature oxidation, sulfidation, carburization, and molten salts. The applications based on these unique properties of FeAl require methods to melt and cast these alloys into complex-shaped castings and centrifugal cast tubes. This paper addresses the melting-related issues and the effect of chemistry on the microstructure and hardness of castings. It is concluded that the use of the Exo-Melt{sup TM} process for melting and the proper selection of the aluminum melt stock can result in porosity-free castings. The FeAl alloys can be melted and cast from the virgin and revert stock. A large variation in carbon content of the alloys is possible before the precipitation of graphite flakes occurs. Titanium is a very potent addition to refine the grain size of castings. A range of complex sand castings and two different sizes of centrifugal cast tubes of the alloy have already been cast. (orig.) 18 refs.

  1. Materials for Advanced Ultrasupercritical Steam Turbines Task 4: Cast Superalloy Development

    Energy Technology Data Exchange (ETDEWEB)

    Thangirala, Mani

    2015-09-30

    The Steam Turbine critical stationary structural components are high integrity Large Shell and Valve Casing heavy section Castings, containing high temperature steam under high pressures. Hence to support the development of advanced materials technology for use in an AUSC steam turbine capable of operating with steam conditions of 760°C (1400°F) and 35 Mpa (5000 psia), Casting alloy selection and evaluation of mechanical, metallurgical properties and castability with robust manufacturing methods are mandated. Alloy down select from Phase 1 based on producability criteria and creep rupture properties tested by NETL-Albany and ORNL directed the consortium to investigate cast properties of Haynes 282 and Haynes 263. The goals of Task 4 in Phase 2 are to understand a broader range of mechanical properties, the impact of manufacturing variables on those properties. Scale up the size of heats to production levels to facilitate the understanding of the impact of heat and component weight, on metallurgical and mechanical behavior. GE Power & Water Materials and Processes Engineering for the Phase 2, Task 4.0 Castings work, systematically designed and executed casting material property evaluation, multiple test programs. Starting from 15 lbs. cylinder castings to world’s first 17,000 lbs. poured weight, heavy section large steam turbine partial valve Haynes 282 super alloy casting. This has demonstrated scalability of the material for steam Turbine applications. Activities under Task 4.0, Investigated and characterized various mechanical properties of Cast Haynes 282 and Cast Nimonic 263. The development stages involved were: 1) Small Cast Evaluation: 4 inch diam. Haynes 282 and Nimonic 263 Cylinders. This provided effects of liquidus super heat range and first baseline mechanical data on cast versions of conventional vacuum re-melted and forged Ni based super alloys. 2) Step block castings of 300 lbs. and 600 lbs. Haynes 282 from 2 foundry heats were evaluated which

  2. Inlfuence of carbon content on microstructure and mechanical properties of Mn13Cr2 and Mn18Cr2 cast steels

    Institute of Scientific and Technical Information of China (English)

    Lu Dingshan; Liu Zhongyi; Li Wei

    2014-01-01

    In this paper, a comparison study was carried out to investigate the inlfuence of carbon content on the microstructure, hardness, and impact toughness of water-quenched Mn13Cr2 and Mn18Cr2 cast steels. The study results indicate that both steels' water-quenched microstructures are composed of austenite and a smal amount of carbide. The study also found that, when the carbon contents are the same, there is less carbide in Mn18Cr2 steel than in Mn13Cr2 steel. Therefore, the hardness of Mn18Cr2 steel is lower than that of Mn13Cr2 steel but the impact toughness of Mn18Cr2 steel is higher than that of Mn13Cr2 steel. With increasing the carbon content, the hardness increases and the impact toughness decreases in these two kinds of steels, and the impact toughness of Mn18Cr2 steel substantialy exceeds that of Mn13Cr2 steel. Therefore, the water-quenched Mn18Cr2 steel with high carbon content could be applied to relatively high impact abrasive working conditions, while the as-cast Mn18Cr2 steel could be only used under working conditions of relatively low impact abrasive load due to lower impact toughness.

  3. Effect of Ca addition on the as-cast microstructure and creep properties of Mg-5Zn-5Sn magnesium alloy

    Institute of Scientific and Technical Information of China (English)

    YANG Mingbo; CHENG Liang; SHEN Jia; PAN Fusheng

    2009-01-01

    The effect of Ca addition on the as-cast microstructure and creep properties of Mg-5Zn-5Sn magnesium alloy was investigated. The results indicate that adding 1.0 wt.% Ca to Mg-5Zn-5Sn alloy can effectively refine the as-cast microstructure of the alloy, and the CaMgSn phase with high thermal stability is formed in the alloy. In addition, adding 1.0 wt.% Ca to Mg-5Zn-5Sn alloy can also improve the creep properties of the alloy. After adding 1.0 wt.% Ca to Mg-5Zn-5Sn alloy, the second creep rate of the alloy at 150℃ and 50 MPa for 100 h decreases from 4.67×10~(-8) to 1.43×10~(-8) s~(-1). The strengthening mechanism is mainly attributed to the microstructural refinement and the formation of CaMgSn phase.

  4. Tensile and impact properties of the steel MANET-II and their optimization

    International Nuclear Information System (INIS)

    The report describes the investigations concerning tensile and impact bending properties done in the IMF-II of the KfK. The tensile tests include the investigation of the parameters test temperature, deformation rate, specimen site, cast, dimensions of the semi finished products and other parameters. The material has an adequate strength (e.g. Rp0,2 (500 C) = 465 MPa), a sufficient ductility (e.g. A > 10%) and a good homogenity of this properties. The impact bending properties of some heats of the MANET-II grade steel had been investigated using instrumented V-notch impact bending tests, and it has been compared with other steels. The strength of the MANET-II grade steel, measured by the maximum load and the stress intensity factor, is very high. The ductility, measured by the specimen bending up to the cleavage fracture, is sufficient. The toughness of the material, measured by the upper shelf energy of the impact strength, by the energy up to the maximum load and by the J-integral, is adequate. Only the transition temperature of the impact energy (DBTT = 0 C) and the FATT (T = +4 C) are too high. The limiting temperature of the first or last appearance of cleavage fracture is too high, too. For that reason an optimization of the thermal treatment of the steel had been attempted. That leads to a higher yield strength at elevated temperature and to a lower DBTT = -30 C. (orig.)

  5. Microstructure and mechanical properties of in situ casting TiC/Ti6Al4V composites through adding multi-walled carbon nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Ya, Bin; Zhou, Bingwen; Yang, Hongshuo; Huang, Bingkun; Jia, Fei; Zhang, Xingguo, E-mail: zxgwj@dlut.edu.cn

    2015-07-15

    Highlights: • Adding MWCNTs in situ casting fabricating TiC/Ti6Al4V composites is first reported. • The solidification process of in situ casting TiC/Ti6Al4V composites is discussed. • Microstructure shows remarkable correlations with adding MWCNTS. • Strength and plasticity show remarkable correlations with adding MWCNTs. - Abstract: In this study, multi-walled carbon nanotubes (MWCNTs) were added as carbon sources to fabricate in situ casting TiC/Ti6Al4V (TC4) composites. The effects of MWCNTs on the microstructure and mechanical properties are studied. The composites are analyzed by X-ray diffraction, field-emission scanning electron microscope and electron probe microanalysis. The fracture behavior of TiC/TC4 composites are also studied. Smaller size of TiC particles and grain compared with TC4-graphite composites can be observed. The tensile strength of TC4-MWCNTs composites is about 1110.1 MPa, which is higher than that of TC4-graphite composites, about 1003.6 MPa. Fracture behavior also was changed by adding MWCNTs in situ casting TiC/TC4 composites.

  6. Structure and mechanical properties of as-cast (ZrTi){sub 100−x}B{sub x} alloys

    Energy Technology Data Exchange (ETDEWEB)

    Xia, C.Q.; Jiang, X.J.; Wang, X.Y.; Zhou, Y.K.; Feng, Z.H. [State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004 (China); Tan, C.L. [Beijing Institute of Spacecraft System Engineering, Beijing 100094 (China); Ma, M.Z. [State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004 (China); Liu, R.P., E-mail: riping@ysu.edu.cn [State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004 (China)

    2015-07-15

    Highlights: • Trace boron additions result in significant grain refinement. • Large numbers of stacking faults are observed in ZrB{sub 2} and TiB intermetallics. • The tensile strength is enhanced by increasing the amount of B. • Intermetallics microcracking causes the failure of the alloys. - Abstract: The microstructure, mechanical properties, and fracture characteristics of (Zr{sub 50}Ti{sub 50}){sub 100−x}B{sub x} alloys (x = 0, 0.5, 1, 2 at.%) obtained by casting were investigated. Trace additions of boron (B) to the Zr{sub 50}Ti{sub 50} alloys induced significant microstructural changes. Changes included the promotion of dendritic growth and refinement in prior-β grain and α′-lath size. Large numbers of stacking faults were also observed in ZrB{sub 2} and TiB intermetallics. The location of B atoms and the lattice mismatch energy between intermetallics and matrix were responsible for the stacking faults. (ZrTi)B alloys demonstrated higher tensile strength than matrix material. Both the intermetallics with high strength and modulus and the grain refinement played important roles in improving the mechanical properties of alloys. This result could be explained in terms of a shear-lag model based on the load transfer concept and Hall–Petch mechanism. The elongation-to-failure of (ZrTi)B alloys decreased with increased B concentration. The reduction in elongation-to-failure of (ZrTi)B alloys could be attributed to the presence of ZrB{sub 2} and TiB intermetallics and refinement of α′-laths.

  7. Fracture Mechanisms in Steel Castings

    Directory of Open Access Journals (Sweden)

    Z. Stradomski

    2013-07-01

    Full Text Available The investigations were inspired with the problem of cracking of steel castings during the production process. A single mechanism of decohesion - the intergranular one - occurs in the case of hot cracking, while a variety of structural factors is decisive for hot cracking initiation, depending on chemical composition of the cast steel. The low-carbon and low-alloyed steel castings crack due to the presence of the type II sulphides, the cause of cracking of the high-carbon tool cast steels is the net of secondary cementite and/or ledeburite precipitated along the boundaries of solidified grains. Also the brittle phosphor and carbide eutectics precipitated in the final stage solidification are responsible for cracking of castings made of Hadfield steel. The examination of mechanical properties at 1050°C revealed low or very low strength of high-carbon cast steels.

  8. Mechanical properties of a squeeze cast Mg–Al–Sr alloy

    Directory of Open Access Journals (Sweden)

    Z. Trojanová

    2008-02-01

    Full Text Available Purpose: The aim of the present work is to study the influence of temperature on tensile properties of the magnesium alloy AJ50, and to discuss possible hardening and softening mechanisms and thermally activated processes.Design/methodology/approach: Deformation behaviour of a Mg-Al-Sr magnesium alloy has been studied in tension as well as compression in the temperature interval from room temperature up to 300°C. Stress relaxation tests were performed with the aim to find applied stress components (internal stress and effective stress and parameters of the thermally activated process/-es.Findings: The yield stress as well as the maximum stress of the alloy are very sensitive to the testing temperature. The work hardening coefficient Θ=dσ/dε decreases with increasing stress and temperature. Performed analysis of the -! plots determined the hardening and softening mechanisms operating during the deformation. The internal stress decreses with increasin temperature, while the effective stress component increases.Practical implications: Estimated values of the activation volume as well as the activation energy indicate that the main thermally activated process is connected with the rapid decrease of the internal stress.Originality/value: An analysis showed that the main hardening process is the storage of dislocations at impenetrable obstacles. The activation volume values indicate that the main thermally activated process is connected with recovery process.

  9. Microstructure, texture evolution and magnetic properties of strip-casting non-oriented 6.5 wt.% Si electrical steel doped with cerium

    Energy Technology Data Exchange (ETDEWEB)

    Li, Hao-Ze, E-mail: lhzqq83@163.com; Liu, Hai-Tao; Liu, Zhen-Yu, E-mail: zyliu@mail.neu.edu.cn; Wang, Guo-Dong

    2015-05-15

    A 0.3 mm thick non-oriented 6.5 wt.% Si electrical steel sheet doped with cerium is produced by twin-roll strip casting, hot rolling, warm rolling and annealing. A detailed study of the cerium precipitates in the as-cast strip, microstructure and texture evolution at different processing stages is carried out by electron probe micro-analysis, optical microscopy, X-ray diffraction and electron backscattered diffraction analysis. Grain interior distributing precipitates identified as Ce-oxides, Ce-oxysulfides and Ce-phosphides, and boundary distributing Ce-oxides and Ce-phosphides are observed in the as-cast strip. The initial as-cast strip is characterized by a much finer solidification microstructure and dominated by obvious < 001 >//ND texture through the strip thickness. After hot and warm rolling, inhomogeneous microstructure containing large amounts of in-grain shear bands is characterized by mixed < 110 >//RD and < 111 >//ND textures. The texture of the annealed sheet with a relatively large average grain size is far more optimized by the domination of the beneficial cube, rotated cube, (001)< 120 > to (001)< 130 > and Goss texture components, and the elimination of the detrimental γ-fiber texture, leading to a superior magnetic induction and improved iron loss. - Highlights: • An Fe–6.5 wt.% Si as-cast strip doped with cerium was produced. • A thin warm rolled sheet with limited edge cracks was obtained. • Microstructure and texture evolution at each stage were investigated. • Strong λ-fiber and Goss recrystallization textures were formed. • The magnetic properties of the annealed sheet were significantly improved.

  10. Microstructure, texture evolution and magnetic properties of strip-casting non-oriented 6.5 wt.% Si electrical steel doped with cerium

    International Nuclear Information System (INIS)

    A 0.3 mm thick non-oriented 6.5 wt.% Si electrical steel sheet doped with cerium is produced by twin-roll strip casting, hot rolling, warm rolling and annealing. A detailed study of the cerium precipitates in the as-cast strip, microstructure and texture evolution at different processing stages is carried out by electron probe micro-analysis, optical microscopy, X-ray diffraction and electron backscattered diffraction analysis. Grain interior distributing precipitates identified as Ce-oxides, Ce-oxysulfides and Ce-phosphides, and boundary distributing Ce-oxides and Ce-phosphides are observed in the as-cast strip. The initial as-cast strip is characterized by a much finer solidification microstructure and dominated by obvious < 001 >//ND texture through the strip thickness. After hot and warm rolling, inhomogeneous microstructure containing large amounts of in-grain shear bands is characterized by mixed < 110 >//RD and < 111 >//ND textures. The texture of the annealed sheet with a relatively large average grain size is far more optimized by the domination of the beneficial cube, rotated cube, (001)< 120 > to (001)< 130 > and Goss texture components, and the elimination of the detrimental γ-fiber texture, leading to a superior magnetic induction and improved iron loss. - Highlights: • An Fe–6.5 wt.% Si as-cast strip doped with cerium was produced. • A thin warm rolled sheet with limited edge cracks was obtained. • Microstructure and texture evolution at each stage were investigated. • Strong λ-fiber and Goss recrystallization textures were formed. • The magnetic properties of the annealed sheet were significantly improved

  11. Developing technological process of obtaining giality casts

    Directory of Open Access Journals (Sweden)

    A. Issagulov

    2014-10-01

    Full Text Available The article considers the process of manufacturing castings using sand-resin forms and alloying furnace. Were the optimal technological parameters of manufacturing shell molds for the manufacture of castings of heating equipment. Using the same upon receipt of castings by casting in shell molds furnace alloying and deoxidation of the metal will provide consumers with quality products and have a positive impact on the economy in general engineering.

  12. Application of Integrated Database to the Casting Design

    Institute of Scientific and Technical Information of China (English)

    In-Sung Cho; Seung-Mok Yoo; Chae-Ho Lim; Jeong-Kil Choi

    2008-01-01

    Construction of integrated database including casting shapes with their casting design, technical knowledge, and thermophysical properties of the casting alloys were introduced in the present study. Recognition tech- nique for casting design by industrial computer tomography was used for the construction of shape database. Technical knowledge of the casting processes such as ferrous and non-ferrous alloys and their manufacturing process of the castings were accumulated and the search engine for the knowledge was developed. Database of thermophysical properties of the casting alloys were obtained via the experimental study, and the properties were used for .the in-house computer simulation of casting process. The databases were linked with intelligent casting expert system developed in center for e-design, KITECH. It is expected that the databases can help non casting experts to devise the casting and its process. Various examples of the application by using the databases were shown in the present study.

  13. Preparation and properties of gradient Al2O3-ZrO2 ceramic foam by centrifugal slip casting method

    Directory of Open Access Journals (Sweden)

    Li Qiang

    2012-11-01

    Full Text Available The aim of the present research is to provide a novel technique for preparing gradient Al2O3-ZrO2 ceramic foams. This technique used epispastic polystyrene spheres to array templates and centrifugal slip casting to obtain cell struts with gradient distribution of Al2O3 and ZrO2 particles and high packing density. Aqueous Al2O3-20vol.% ZrO2 slurries with 20vol.% solid contents were prepared and the dispersion and rheological characteristics of the slurries were investigated. The settling velocity and mass segregation of Al2O3 and ZrO2 particles at different centrifugal accelerations were calculated and studied. The drying behavior, macrostructure, microstructure, compressive property and resistance to thermal shock of the sintered products were also investigated. The results show that the difference of settling velocity of Al2O3 and ZrO2 particles increases and mass segregation becomes acute with an increase in centrifugal acceleration. The cell struts prepared at a centrifugal acceleration of 1,690 g have high sintered density (99.0% TD and continuous gradient distribution of Al2O3 and ZrO2 particles. When sintered at 1,550 oC for 2 h, the cell size of gradient Al2O3-ZrO2 foam is approximately uniform, about 1.1 mm. With the porosity of gradient Al2O3-ZrO2 ceramic foams increasing from 75.3% to 83.0%, the compressive strength decreases from 4.4 to 2.4 MPa, and the ceramic foams can resist 8-11 repeated thermal shock from 1,100 oC to room temperature.

  14. Solidification and casting

    CERN Document Server

    Cantor, Brian

    2002-01-01

    INDUSTRIAL PERSPECTIVEDirect chillcasting of aluminium alloysContinuous casting of aluminium alloysContinuous casting of steelsCastings in the automotive industryCast aluminium-silicon piston alloysMODELLING AND SIMULATIONModelling direct chill castingMold filling simulation of die castingThe ten casting rulesGrain selection in single crystal superalloy castingsDefects in aluminium shape castingPattern formation during solidificationPeritectic solidificationSTRUCTURE AND DEFECTSHetergeneous nucleation in aluminium alloysCo

  15. Microstructural and mechanical properties of gravity-die-cast A356 alloy inoculated with yttrium and Al-Ti-B grain refiner simultaneously

    Directory of Open Access Journals (Sweden)

    Y.P. Lim

    2011-10-01

    Full Text Available In the present work, the effect of inoculating yttrium and Al-5Ti-1B simultaneously on A356 aluminum alloy has been studied. Gravity die casting process is used to cast the ASTM tensile test specimens for analysis. In each experiment, the Ti and B contents were maintained constantly at 0.1 and 0.02 wt% respectively. The addition of yttrium was manipulated at the amount of 0, 0.1, 0.2, 0.3, 0.4 and 0.5 wt%. Microstructural characterization of the as-cast A356 alloy was investigated by means of optical microscope and its phases are detected by XRD. The mechanical properties tested are tensile strength and hardness. The inoculation of yttrium was found to enhance the grain refinement effect of Al-5Ti-1B grain refiner and improve the mechanical properties. The optimal weight percentage of yttrium was found to be 0.3. The grain refining efficiency of combining yttrium and Al-5Ti-1B on A356 aluminum alloy was mainly attributed to the heterogeneous nucleation of TiB2 and TiAl3 particles which were dispersed more evenly in the presence of yttrium and the grain growth restriction effected by the accumulation of Al-Y compound at grain boundaries.

  16. Tribology properties of composite layer of CrMoCu alloy cast iron by combined treatment of ion nitrocarburizing and sulphurizing

    Institute of Scientific and Technical Information of China (English)

    MA Shi-ning; HU Chun-hua; LI Xin; QIU Ji

    2004-01-01

    Composite layer with nitrocarbonide and sulfide was made on the surface of CrMoCu alloy cast iron by combined treatment of ion nitrocarburizing and sulphurizing. The composite layer is composed of sulfide layer, nitrocarbonide hypo-surface layer and its diffusing layer, the size of sulfide globular grains distributing equably on the surface is in nano-micron-scale, and the phase structure of the composite layer is composed of FeS, FeS1-x, Fe2C and Fe3N. Under oil lubrication, sulphurized surface shows good scuffing-resistance only under low velocity, and nitrocarburized and sulphurized surface greatly improves the scuffing-resistance and wear-resistance of CrMoCu alloy cast iron, its integrated friction and wear properties are better than those of the plain and sulphurized surfaces under all the velocities.

  17. Characterisation of the fatigue properties of cast irons used in the water industry and the effect on pipe strength and performance

    International Nuclear Information System (INIS)

    As part of an on going programme to characterise the residual properties and understand the failure mechanisms of in-service grey cast iron water pipes, the fatigue crack propagation behaviour of grey cast iron samples has been studied. Specimens were sourced from three ex-service pipes. For each pipe the microstructure and composition were characterised and the fracture toughness was determined. The fatigue behaviour was investigated in terms of the crack growth rate (da/dN) as a function of the applied stress intensity factor range. Clear differences in the fatigue behaviour of the samples from different pipes were observed. The result from these investigations, which indicate that microstructural differences play a role in mechanical behaviour, will support the development of asset management tools for use in the water industry.

  18. Residual Stress, Structure and Other Properties Formation by Combined Thermo-Hardening Processing of Surface Layer of Gray Cast Iron Parts

    Science.gov (United States)

    Rakhimyanov, Kh M.; Nikitin, Yu V.; Semenova, Yu S.; Eremina, A. S.

    2016-04-01

    The proposed combined thermo-hardening processing of gray cast iron enables to control the surface layer structure and mechanical properties formation. The processing includes high-speed heating by low-temperature plasma source and ultrasonic surface plastic deformation. The algorithm of calculation the stress-strain state of a surface layer at combined processing of gray cast iron is developed. This algorithm is based on method of sections. The ultrasonic surface deformation contribution is determined during formation of residual stresses. It is established that the combination of the thermal and deformation effects on the material provides an additional increment of microhardness and increase of surface layer thickness. Experimental results shows that the features of structural and phase transformations in a surface layer are revealed without a surface melting by energy of low-temperature plasma. The top of a layer does not contain inclusions of graphite that testifies to change of structural transformations in conditions of combined processing.

  19. The influence of the graphite mechanical properties on the constitutive response of a ferritic ductile cast iron – A micromechanical FE analysis

    DEFF Research Database (Denmark)

    Andriollo, Tito; Thorborg, Jesper; Hattel, Jesper Henri

    2015-01-01

    In the present paper a micro-mechanical approach is used to investigate the influence of the graphite mechanical properties on the loading response in the early deformation range of ductile cast iron. A periodic unit cell composed by a single graphite nodule embedded in a uniform ferritic matrix...... is considered and elasto-plastic behavior of both constituents is assumed; damage evolution in the ductile matrix is taken into account via Lemaitre’s isotropic model. Full 3D and 2D plane-stress finite element analyses are performed to simulate the loading conditions experienced by nodules located in the bulk...... as well as on the material surface. The effects of residual stresses arising during the manufacturing process are also accounted for. It is shown that the constitutive response of the equivalent composite medium can match ductile cast iron only if the graphite Young’s modulus value lies within a certain...

  20. Thermal aging evaluation of casting stainless steel under BWR environment

    International Nuclear Information System (INIS)

    Effect of thermal aging under BWR condition on material properties of casting stainless steel were evaluated by such as Charpy impact test, using replaced BWR component material. Solution heat treatment was performed to the same material and the material properties were obtained. Comparing each material test results, impact value of thermal aging material was lower than solution heat treatment material. By the results, thermal aging effect on material properties under BWR condition was confirmed. The material properties were compared with model equation using PLM evaluation and conservativeness of model equation was confirmed. (author)

  1. The heat treatment of Fermanal cast steel

    OpenAIRE

    F. Binczyk; A. Smoliński; J. Szymszal

    2007-01-01

    The study discloses the results of microstructural examinations, testing of magnetic properties and hardness measurements as cast and after heat treatment conducted on the Fermanal cast steel. A characteristic feature of this cast steel is its density lower by about 10% than the density of carbon cast steel [4]. It has been proved that the factor deciding about the composition of microstructure (fraction of ferrite and austenite) is the content of aluminium. The matrix totally austenitic is p...

  2. Extended Leach Testing of Simulated LAW Cast Stone Monoliths

    Energy Technology Data Exchange (ETDEWEB)

    Serne, R. Jeffrey [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Westsik, Joseph H. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Williams, Benjamin D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Jung, H. B. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Wang, Guohui [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-07-09

    This report describes the results from long-term laboratory leach tests performed at Pacific Northwest National Laboratory (PNNL) for Washington River Protection Solutions (WRPS) to evaluate the release of key constituents from monoliths of Cast Stone prepared with four simulated low-activity waste (LAW) liquid waste streams. Specific objectives of the Cast Stone long-term leach tests described in this report focused on four activities: 1. Extending the leaching times for selected ongoing EPA-1315 tests on monoliths made with LAW simulants beyond the conventional 63-day time period up to 609 days reported herein (with some tests continuing that will be documented later) in an effort to evaluate long-term leaching properties of Cast Stone to support future performance assessment activities. 2. Starting new EPA-1315 leach tests on archived Cast Stone monoliths made with four LAW simulants using two leachants (deionized water [DIW] and simulated Hanford Integrated Disposal Facility (IDF) Site vadose zone pore water [VZP]). 3. Evaluating the impacts of varying the iodide loading (starting iodide concentrations) in one LAW simulant (7.8 M Na Hanford Tank Waste Operations Simulator (HTWOS) Average) by manufacturing new Cast Stone monoliths and repeating the EPA-1315 leach tests using DIW and the VZP leachants. 4. Evaluating the impacts of using a non-pertechnetate form of Tc that is present in some Hanford tanks. In this activity one LAW simulant (7.8 M Na HTWOS Average) was spiked with a Tc(I)-tricarbonyl gluconate species and then solidified into Cast Stone monoliths. Cured monoliths were leached using the EPA-1315 leach protocol with DIW and VZP. The leach results for the Tc-Gluconate Cast Stone monoliths were compared to Cast Stone monoliths pertechnetate.

  3. Properties of pre-cast terrazzo tiles and recommended specifications Propriedades de telhas de terrazzo pré-moldadas e especificações recomendadas

    Directory of Open Access Journals (Sweden)

    G. Karam

    2009-03-01

    Full Text Available A targeted experimental program was carried out to establish basic reference physical and mechanical properties of commercially available pre-cast marble chip terrazzo tiles and to investigate the effects of varying manufacturing process parameters on those properties. The transverse strength, density, water absorption, and abrasion resistance were measured as a function of casting pressure and residence time in the casting mold for a standard mix design. A simple surface abrasion index test was developed and applied comparing pre-cast terrazzo tiles with reference natural tiling stones. Recommendations for improving existing specifications and developing quality control measures are presented.Foi feito um programa experimental direcionado para estabelecer propriedades físicas e mecânicas como referências básicas de telhas de terrazzo de peças de mármore pré-moldadas disponíveis comercialmente e para investigar os efeitos de vários parâmetros de processo de fabricação nessas propriedades. A resistência transversal, a densidade, a absorção de água e a resistência ao desgaste foram medidas em função da pressão de moldagem e do tempo de residência do molde de um projeto de mistura padrão. Um teste simples de índice de desgaste de superfície foi desenvolvido e aplicado na comparação de telhas de terrazzo pré-moldadas com pedras de telhas naturais de referência. As recomendações para a melhoria das especificações existentes e o desenvolvimento de medidas para controle de qualidade são apresentadas.

  4. The effects of novel surface treatments on the wear and fatigue properties of steel and chilled cast iron

    Science.gov (United States)

    Carroll, Jason William

    Contact fatigue driven wear is a principal design concern for gear and camshaft engineering of power systems. To better understand how to engineer contact fatigue resistant surfaces, the effects of electroless nickel and hydrogenated diamond-like-carbon (DLC) coatings on the fatigue life at 108 cycles of SAE 52100 steel were studied using ultrasonic fatigue methods. The addition of DLC and electroless nickel coatings to SAE 52100 bearing steel had no effect on the fatigue life. Different inclusion types were found to affect the stress intensity value beyond just the inclusion size, as theorized by Murakami. The difference in stress intensity values necessary to propagate a crack for Ti (C,N) and alumina inclusions was due to the higher driving force for crack extension at the Ti (C,N) inclusions and was attributed to differences in the shape of the inclusion: rhombohedral for the Ti (C,N) versus spherical for the oxides. A correction factor was added to the Murakami equation to account for inclusion type. The wear properties of DLC coated SAE 52100 and chilled cast iron were studied using pin-on-disk tribometry and very high cycle ultrasonic tribometry. A wear model that includes sliding thermal effects as well as thermodynamics consistent with the wear mechanism for DLCs was developed based on empirical results from ultrasonic wear testing to 108 cycles. The model fit both ultrasonic and classic tribometer data for wear of DLCs. Finally, the wear properties of laser hardened steels - SAE 8620, 4140, and 52100 - were studied at high contact pressures and low numbers of cycles. A design of experiments was conducted to understand how the laser processing parameters of power, speed, and beam size, as well as carbon content of the steel, affected surface hardness. A hardness maximum was found at approximately 0.7 wt% carbon most likely resulting from increased amounts of retained austenite. The ratcheting contact fatigue model of Kapoor was found to be useful in

  5. Colour Metallography of Cast Iron

    Institute of Scientific and Technical Information of China (English)

    Zhou Jiyang

    2009-01-01

    @@ Preface Cast iron, as a traditional metal material, has advantages of low total cost, good castability and machinability, good wear resistance and low notch sensitivity, and is still facing tough challenge in quality, property and variety of types etc.

  6. MECHANICAL PROPERTIES OF AS-CAST ZA-27/Gr/SiCp HYBRID COMPOSITE FOR THE APPLICATION OF JOURNAL BEARING

    OpenAIRE

    T. S. KIRAN; M. PRASANNA KUMAR; S. Basavarajappa; VISHWANATHA, B. M.

    2013-01-01

    The mechanical behavior of as-cast ZA-27 alloy and hybrid composite reinforced with graphite (Gr) of constant 3% by weight and silicon carbide particle (SiCp) varying from 0-9% by weight in steps of 3% was carried out. Vortex method of production was employed in which thoroughly mixed Gr and SiC particles were poured into the vortex created by means of mechanical stirrer. The melt was cast using a pre-heated permanent mold box. Microstructure showed fine distribution of the reinforcements in ...

  7. A fracture mechanics safety concept to assess the impact behavior of ductile cast iron containers for shipping and storage of radioactive materials

    International Nuclear Information System (INIS)

    Within the scope of the German licensing procedures for shipping and storage containers for radioactive materials made of ductile cast iron, BAM performs approval design tests including material tests to ensure the main safety goals of shielding, leaktightness and subcriticality under ''Type B accident conditions''. So far the safety assessment concept of BAM is based essentially on the experimental proof of container strength by prototype testing under most damaging test conditions in connection with complete approval design tests, and has been developed especially for cylindrical casks like CASTOR- and TN-design. In connection with the development of new container constructions such as ''cubic cast containers'', and the fast developments in the area of numerical calculation methods, there is a need for a more flexible safety concept especially considering fracture mechanics aspects.This paper presents the state of work at BAM for such an extended safety concept for ductile cast iron containers, based on a detailed brittle fracture safe design proof. The requirements on stress analysis (experimental or numerical), material properties, material qualification, quality assurance provisions and fracture mechanics safety assessment, including well defined and justified factors of safety, are described. ((orig.))

  8. Spring Cleaning: Rural Water Impacts, Valuation and Property Rights Institutions

    OpenAIRE

    Michael Kremer; Jessica Leino; Edward Miguel; Alix Peterson Zwane

    2009-01-01

    In many societies, social norms create common property rights in natural resources, limiting incentives for private investment. This paper uses a randomized evaluation in Kenya to measure the health impacts of investments to improve source water quality through spring protection, estimate the value that households place on spring protection, and simulate the welfare impacts of alternative water property rights norms and institutions, including common property, freehold private property, and a...

  9. RESEARCH AND APPLICATION OF AS-CAST WEAR RESISTANCE HIGH CHROMIUM CAST IRON

    Institute of Scientific and Technical Information of China (English)

    1998-01-01

    The influence of alloy elements, such as boron and silicon, on the microstructure and properties of as-cast high chromium cast iron is studied. The results show that boron and silicon have a great effect on the mechanical properties and the wear resistance. Through proper addition of boron and silicon, the properties of as-cast high chromium cast iron can be improved effectively. Through analyzing the distribution of elements by scanning electron microscope, it has been shown that the addition of boron and silicon lowers the mass fraction of chromium saturated in as-cast austenite, and makes it unstable and liable to be transformed into martensite. The as-cast high chromium cast iron with proper content of boron and silicon is suitable for the manufacture of lining for asphalt concrete mixer and its wear resistance is 14 times that of lining made of low alloy white cast iron.

  10. Characterization of microstructure, texture and magnetic properties in twin-roll casting high silicon non-oriented electrical steel

    Energy Technology Data Exchange (ETDEWEB)

    Li, Hao-Ze; Liu, Hai-Tao, E-mail: liuht@ral.neu.edu.cn; Liu, Zhen-Yu, E-mail: zyliu@mail.neu.edu.cn; Lu, Hui-Hu; Song, Hong-Yu; Wang, Guo-Dong

    2014-02-15

    An Fe-6.5 wt.% Si-0.3 wt.% Al as-cast sheet was produced by twin-roll strip casting process, then treated with hot rolling, warm rolling and annealing. A detailed study of the microstructure and texture evolution at different processing stages was carried out by optical microscopy, X-ray diffraction and electron backscattered diffraction analysis. The initial as-cast strip showed strong columnar grains and pronounced < 001 >//ND texture. The hot rolled and warm rolled sheets were characterized by large amounts of shear bands distributed through the thickness together with strong < 110 >//RD texture and weak < 111 >//ND texture. After annealing, detrimental < 111 >//ND texture almost disappeared while beneficial (001)<210 >, (001)<010 >, (115)<5 − 10 1 > and (410) < 001 > recrystallization textures were formed, thus the magnetic induction of the annealed sheet was significantly improved. The recrystallization texture in the present study could be explained by preferred nucleation and grain growth mechanism. - Highlights: • A high silicon as-cast strip with columnar structure was produced. • A thin warm rolled sheet without large edge cracks was obtained. • Microstructure and texture evolution at each stage were investigated. • Beneficial (001)<210 >, (001)<010 >, (410)<001 > recrystallization textures were formed. • The magnetic induction of annealed sheet was significantly improved.

  11. Grey water impact on soil physical properties

    Directory of Open Access Journals (Sweden)

    Miguel L. Murcia-Sarmiento

    2014-01-01

    Full Text Available Due to the increasing demand for food produced by the increase in population, water as an indispensable element in the growth cycle of plants every day becomes a fundamental aspect of production. The demand for the use of this resource is necessary to search for alternatives that should be evaluated to avoid potential negative impacts. In this paper, the changes in some physical properties of soil irrigated with synthetic gray water were evaluated. The experimental design involved: one factor: home water and two treatments; without treated water (T1 and treated water (T2. The variables to consider in the soil were: electrical conductivity (EC, exchangeable sodium percentage (ESP, average weighted diameter (MWD and soil moisture retention (RHS. The water used in drip irrigation high frequency was monitored by tensiometer for producing a bean crop (Phaseolous vulgaris L. As filtration system used was employed a unit composed of a sand filter (FLA and a subsurface flow wetland artificial (HFSS. The treatments showed significant differences in the PSI and the RHS. The FLA+HFSS system is an alternative to the gray water treatment due to increased sodium retention.

  12. Mechanical and Tribological Properties of HVOF-Sprayed (Cr3C2-NiCr+Ni) Composite Coating on Ductile Cast Iron

    Science.gov (United States)

    Ksiazek, Marzanna; Boron, Lukasz; Radecka, Marta; Richert, Maria; Tchorz, Adam

    2016-07-01

    The aim of the investigations was to compare the microstructure, mechanical, and wear properties of Cr3C2-NiCr+Ni and Cr3C2-NiCr coatings deposited by HVOF technique (the high-velocity oxygen fuel spray process) on ductile cast iron. The effect of nickel particles added to the chromium carbide coating on mechanical and wear behavior in the system of Cr 3 C 2 -NiCr+Ni/ductile cast iron was analyzed in order to improve the lifetime of coated materials. The structure with particular emphasis of characteristic of the interface in the system of composite coating (Cr 3 C 2 -NiCr+Ni)/ductile cast iron was studied using the optical, scanning, and transmission electron microscopes, as well as the analysis of chemical and phase composition in microareas. Experimental results show that HVOF-sprayed Cr3C2-NiCr+Ni composite coating exhibits low porosity, high hardness, dense structure with large, partially molten Ni particles and very fine Cr3C2 and Cr7C3 particles embedded in NiCr alloy matrix, coming to the size of nanocrystalline. The results were discussed in reference to examination of bending strength considering cracking and delamination in the system of composite coating (Cr 3 C 2 -NiCr+Ni)/ductile cast iron as well as hardness and wear resistance of the coating. The composite structure of the coating provides the relatively good plasticity of the coating, which in turn has a positive effect on the adhesion of coating to the substrate and cohesion of the composite coating (Cr3C2-NiCr+Ni) in wear conditions.

  13. Cradle-to-Gate Impact Assessment of a High-Pressure Die-Casting Safety-Relevant Automotive Component

    Science.gov (United States)

    Cecchel, Silvia; Cornacchia, Giovanna; Panvini, Andrea

    2016-09-01

    The mass of automotive components has a direct influence on several aspects of vehicle performance, including both fuel consumption and tailpipe emissions, but the real environmental benefit has to be evaluated considering the entire life of the products with a proper life cycle assessment. In this context, the present paper analyzes the environmental burden connected to the production of a safety-relevant aluminum high-pressure die-casting component for commercial vehicles (a suspension cross-beam) considering all the phases connected to its manufacture. The focus on aluminum high-pressure die casting reflects the current trend of the industry and its high energy consumption. This work shows a new method that deeply analyzes every single step of the component's production through the implementation of a wide database of primary data collected thanks to collaborations of some automotive supplier companies. This energy analysis shows significant environmental benefits of aluminum recycling.

  14. Cradle-to-Gate Impact Assessment of a High-Pressure Die-Casting Safety-Relevant Automotive Component

    Science.gov (United States)

    Cecchel, Silvia; Cornacchia, Giovanna; Panvini, Andrea

    2016-08-01

    The mass of automotive components has a direct influence on several aspects of vehicle performance, including both fuel consumption and tailpipe emissions, but the real environmental benefit has to be evaluated considering the entire life of the products with a proper life cycle assessment. In this context, the present paper analyzes the environmental burden connected to the production of a safety-relevant aluminum high-pressure die-casting component for commercial vehicles (a suspension cross-beam) considering all the phases connected to its manufacture. The focus on aluminum high-pressure die casting reflects the current trend of the industry and its high energy consumption. This work shows a new method that deeply analyzes every single step of the component's production through the implementation of a wide database of primary data collected thanks to collaborations of some automotive supplier companies. This energy analysis shows significant environmental benefits of aluminum recycling.

  15. Impact of Intermetallic Precipitates on the Tribological and/or Corrosion Performance of Cast Aluminium Alloys: a Short Review

    OpenAIRE

    Culliton, David; Betts, Tony; Kennedy, David

    2013-01-01

    The role of various intermetallic precipitates (IMP), or secondary phase particles, in governing the wear and corrosion performance characteristics of cast aluminium alloys is outlined in this brief review. Such alloys are especially important in transport applications where their low weight, low cost and recyclability make them very attractive. However alloy wear and/or corrosion behaviour often limit their industrial application and more work needs to done to extend their use into other are...

  16. Impact of a Core Ferrule Design on Fracture Resistance of Teeth Restored with Cast Post and Core.

    Science.gov (United States)

    Shamseddine, Loubna; Chaaban, Farid

    2016-01-01

    Objectives. To investigate the influence of a contra bevel on the fracture resistance of teeth restored with cast post and core. Materials and Methods. Sixty plastic analogues of an upper incisor were endodontically treated and prepared with 6° internal taper and 2 mm of ferrule in order to receive a cast post and core. The prepared samples were divided into two groups (n = 30); the first group serves as control while the second group was prepared with an external 30° bevel on the buccal and lingual walls. All samples crowned were exposed to a compressive load at 130° to their long axis until fractures occurred. Fracture resistance loads were recorded and failure modes were also observed. Mann-Whitney test was carried out to compare the two groups. Results. Mean failure loads for the groups were, respectively, 1038.69 N (SD ±243.52 N) and 1078.89 N (SD ±352.21 N). Statistically, there was no significant difference between the two groups (P = 0.7675 > 0.05). Conclusion. In the presence of a ferrule and a crown in the anterior teeth, adding a secondary ferrule to the cast post and core will not increase the resistance to fracture. PMID:27419202

  17. Impact of a Core Ferrule Design on Fracture Resistance of Teeth Restored with Cast Post and Core

    Directory of Open Access Journals (Sweden)

    Loubna Shamseddine

    2016-01-01

    Full Text Available Objectives. To investigate the influence of a contra bevel on the fracture resistance of teeth restored with cast post and core. Materials and Methods. Sixty plastic analogues of an upper incisor were endodontically treated and prepared with 6° internal taper and 2 mm of ferrule in order to receive a cast post and core. The prepared samples were divided into two groups (n=30; the first group serves as control while the second group was prepared with an external 30° bevel on the buccal and lingual walls. All samples crowned were exposed to a compressive load at 130° to their long axis until fractures occurred. Fracture resistance loads were recorded and failure modes were also observed. Mann-Whitney test was carried out to compare the two groups. Results. Mean failure loads for the groups were, respectively, 1038.69 N (SD ±243.52 N and 1078.89 N (SD ±352.21 N. Statistically, there was no significant difference between the two groups (P=0.7675>0.05. Conclusion. In the presence of a ferrule and a crown in the anterior teeth, adding a secondary ferrule to the cast post and core will not increase the resistance to fracture.

  18. Influence of Sn content on microstructural and mechanical properties of centrifugal cast Ti-Nb-Sn biomedical alloys

    International Nuclear Information System (INIS)

    The arc voltaic centrifugal casting is an interesting alternative in terms of economic and technological development in the production of components based on materials with high reactivity and high melting point, such as titanium alloys. In this work, Ti-30Nb (wt. %) with additions of Sn (2, 4, 6, 8 and 10 wt. %) were formed by casting process. Characterization of the samples included optical microscopy, scanning electron microscopy, X-ray diffraction, Vickers hardness and elastic modulus measures by acoustic techniques. It was observed that the microstructure of the samples investigated is composed by dendritic structures, with clear segregation of alloying elements. The Vickers hardness and the elastic modulus decreased with the addition of Sn. The results show that the mechanical behavior of Ti-Nb alloys can be controlled within certain limits, by adding Sn. (author)

  19. MECHANICAL PROPERTIES OF AS-CAST ZA-27/Gr/SiCp HYBRID COMPOSITE FOR THE APPLICATION OF JOURNAL BEARING

    Directory of Open Access Journals (Sweden)

    KIRAN, T. S.

    2013-10-01

    Full Text Available The mechanical behavior of as-cast ZA-27 alloy and hybrid composite reinforced with graphite (Gr of constant 3% by weight and silicon carbide particle (SiCp varying from 0-9% by weight in steps of 3% was carried out. Vortex method of production was employed in which thoroughly mixed Gr and SiC particles were poured into the vortex created by means of mechanical stirrer. The melt was cast using a pre-heated permanent mold box. Microstructure showed fine distribution of the reinforcements in the specimen. Tensile and hardness tests were carried out as per ASTM standards. The results reveal that, as the percentage of SiCp was increased, UTS and hardness increased with reduction in ductility.

  20. Properties of Cast Films Made from Different Ratios of Whey Protein Isolate, Hydrolysed Whey Protein Isolate and Glycerol

    OpenAIRE

    Markus Schmid

    2013-01-01

    Whey protein isolate (WPI)-based cast films are very brittle, due to several chain interactions caused by a large amount of different functional groups. In order to overcome film brittleness, plasticizers, like glycerol, are commonly used. As a result of adding plasticizers, the free volume between the polymer chains increases, leading to higher permeability values. The objective of this study was to investigate the effect of partially substituting glycerol by hydrolysed whey protein isolate ...

  1. Effect of the concentrated heat flow treatment on the structure and the antiwear properties of cast iron

    Directory of Open Access Journals (Sweden)

    W. Orlowicz

    2009-04-01

    Full Text Available The influence of modes of surface fusion by electric arc plasma (GTAW method on the hardness and wear-resistance of plain cast ironwas studied. A possible mechanism of structural rearrangement in the processed material during the friction was analyzed. This mechanismis determined by specific behaviour of hardened martensitic structure under dynamic load. This martensitic structure forms a metalbasis of cementite eutectic under conditions of fast crystallisation.

  2. Properties and application spectrum of cast porous implants made of Ti-6Al-7Nb in coated and uncoated conditions

    OpenAIRE

    Guillén Girón, Teodolito

    2012-01-01

    This thesis presents the development, the characterization and the application of cast Ti-6Al-7Nb porous implants with respect to repair defects in cancellous bone. In the framework of this project, it was aimed at fabricating a porous implant with high mechanical strength to resist the applied load, a relatively low Young's modulus to prevent stress shielding phenomena, controlled cell dimensions to stimulate both mineral and collagen osseointegration, high porosity to guarantee intercon...

  3. Creep Properties of the As-Cast Al-A319 Alloy: T4 and T7 Heat Treatment Effects

    Science.gov (United States)

    Erfanian-Naziftoosi, Hamid R.; Rincón, Ernesto J.; López, Hugo F.

    2016-08-01

    In this work, the creep behavior of a commercial Al-A319 alloy was investigated in the temperature range of 413 K to 533 K (140 °C to 260 °C). Tensile creep specimens in the as-cast condition and after heat treating by solid solution (T4) and by aging (T7) were tested in a stress range varying from 60 to 170 MPa. It was found that steady-state creep strain rate was significantly low in the T7 condition when compared with either the T4 or as-cast alloy conditions. As a result, the time to failure behavior considerably increased. The experimentally determined creep exponents measured from the stress-strain curves were 4 for the as-cast alloy, 7.5 in the solid solution, and 9.5 after aging. In particular, after solid solution a grain substructure was found to develop which indicated that creep in a constant subgrain structure was active, thus accounting for the n exponent of 7.5. In the aged condition, a stress threshold is considered to account for the power law creep exponent n of 9.5. Moreover, It was found that the creep activation energy values were rather similar for the alloys in the as-cast (134 kJ/mol) and T4 (146 kJ/mol) conditions. These values are close to the one corresponding to pure Al self-diffusion (143 kJ/mol). In the aged alloy, the apparent creep activation energy (202 kJ/mol) exceeded that corresponding to Al self-diffusion. This deviation in activation energy is attributed to the effect of temperature on the alloy elastic modulus. Microstructural observations using transmission electron microscopy provided further support for the various dislocation-microstructure interactions exhibited by the alloy under the investigated creep conditions and implemented heat treatments.

  4. Effect of Ti, Nb, Cr and B on Structure and Mechanical Properties of High Aluminium Cast Iron

    Directory of Open Access Journals (Sweden)

    D. Kopyciński

    2013-01-01

    Full Text Available In this work, a method was investigated to eliminate the presence of undesirable Al4C3 phases in a high-aluminium alloys, and thusimprove the production process. The melting conditions employed in this work enabled the formation of a Fe-Al-C liquid solution.Moreover, titanium additions into the liquid allowed the precipitation of TiC. According to this reaction, the extent of carbon removal from the melt is strongly influenced by the amount of Ti additions. Hence, proper titanium levels can result in total removal of carbon from the liquid. Notice from this figure that Ti additions above 4.5%, totally eliminate the undesirable Al4C3 precipitates. Making Cr, Ti, B additions reduces size of FeAl alloys grains. In addition, this work indicates that the high-aluminium cast iron posses high oxidation resistance, exceeding that of high-chromium cast iron and chromium cast steels. Finally, the alloy ductility can be enhanced by additions of dopants such as B and Cr. Hence, additions of 0.03% B and 0.03%B-5% Cr combined with a heat treatment were implemented. As a result, the alloy ductility was significantly improved, where the strain of up to 5.3%, (B alone or 15% (B-Cr were obtained.

  5. A study on the structure and mechanical properties of vermicular cast iron with pearlitic-ferritic matrix

    Directory of Open Access Journals (Sweden)

    E. Guzik

    2009-07-01

    Full Text Available The results of studies on the use of magnesium alloy in modern cored wire injection method for production of vermicular graphite cast irons were described. The injection of Mg cored wire length is a treatment method which can be used to process iron melted in an electric induction furnace. This paper describes the results of using a high-magnesium ferrosilicon alloy in cored wire (Mg recovery 45% for the production of vermicular graphite cast irons at Giesserei Heunisch GmbH Foundry with the pearlite matrix with about 20%ferrite content. The results of calculations and experiments have indicated the length of the cored wire to be injected basing on the initial sulfur content and weight of the treated melt. The paper presents a microstructure matrix and vermicular graphite in standard sample and different walled castings. The results of numerous trials have shown that the magnesium cored wire process can produce high quality vermicular graphite irons under the specific industrial conditions of the above mentioned foundries.

  6. Evaluation of porosity in Al alloy die castings

    Directory of Open Access Journals (Sweden)

    M. Říhová

    2012-01-01

    Full Text Available Mechanical properties of an Al-alloy die casting depend significantly on its structural properties. Porosity in Al-alloy castings is one of the most frequent causes of waste castings. Gas pores are responsible for impaired mechanical-technological properties of cast materials. On the basis of a complex evaluation of experiments conducted on AlSi9Cu3 alloy samples taken from the upper engine block which was die- cast with and without local squeeze casting it can be said that castings manufactured without squeeze casting exhibit maximum porosity in the longitudinal section. The area without local squeeze casting exhibits a certain reduction in mechanical properties and porosity increased to as much as 5%. However, this still meets the norms set by SKODA AUTO a.s.

  7. Influence of regenerative heat treatment on structure and properties of G20CrMo2 - 5 (L20HM cast steel

    Directory of Open Access Journals (Sweden)

    G. Golański

    2008-03-01

    Full Text Available Thc papcr prcscnts rcsuSts or rcscarch on thc influence of rcgcncratic hcat treatment on thc structurc and propcrtics [hardncss. impactcncrgy or L2O11M cnst stccl. Invcstipatcd material was taken from outer fmmc of a turbinc which was scrviccd for t 67 424 hours a! thctcmpcrauirc or 535 "C and prcssurc or 12.75 MPa. In psi-operating condition ~hicnv cstigntcd cast steel was cl~aracteri~cbdy low impactcncrpy of II I ant1 hart3ncss of 139HV30. Analysis uF the irlflue~~uuel ;lustcniriz;~ti on pariimctcrs (tcrnpcr;lturc and lime has rcvealcd rhntat thc tcinpcr;~turcr angc o f 895 + 955 "C (i-e. h3 - +I IO + 70 "C.fo r both 3 and 5 hours of holtl timc. rhc ohtaincd grain sizc amounls to 20+ 2511m. I has hccn pmved that tempcred bainitic-rcrri~ica nd remit ic-hainiric-pearlit ic stn~cturco f thc invcstigatcd cast stccl msurcs highimpact cncrgy, i.c. KV > 1001. as well a5 hardncss. i.e. 11Y30. just at thc tcrnpcmturc of OXl "C. 'I'crnpcmliirc or 7110 "C causcs i'~tnhcrincrclrsc of impact cncrgy along with a slight dccrcasc of hardncss. Morcovcr. it has hccn concludd that nppl ying oS under-annealinginstcad or tcmpcring. nflcr standardizalion. guarantees scquircd impact cncrgy of KY r 271.

  8. Final Report, Volume 1, Metallurgical Evaluation of Cast Duplex Stainless Steels and their Weldments

    Energy Technology Data Exchange (ETDEWEB)

    Wen, Songqing; Lundin, Carl, W.; Batten, Greg, W.

    2005-09-30

    Duplex stainless steels (DSS) are being specified for chloride containing environments due to their enhanced pitting and stress corrosion cracking resistance. They exhibit improved corrosion performance over the austenitic stainless steels. Duplex stainless steels also offer improved strength properties and are available in various wrought and cast forms. Selected grades of duplex stainless steel castings and their welds, in comparison with their wrought counterparts, were evaluated, regarding corrosion performance and mechanical properties and weldability. Multiple heats of cast duplex stainless steel were evaluated in the as-cast, solution annealed (SA) static cast and SA centrifugal cast conditions, while their wrought counterparts were characterized in the SA condition and in the form of as-rolled plate. Welding, including extensive assessment of autogenous welds and a preliminary study of composite welds (shielded metal arc weld (SMAW)), was performed. The evaluations included critical pitting temperature (CPT) testing, intergranular corrosion (IGC) testing, ASTM A923 (Methods A, B and C), Charpy impact testing, weldability testing (ASTM A494), ferrite measurement and microstructural evaluations. In the study, the corrosion performances of DSS castings were characterized and assessed, including the wrought counterparts for comparison. The evaluation filled the pore of lack of data for cast duplex stainless steels compared to wrought materials. A database of the pitting corrosion and IGC behavior of cast and wrought materials was generated for a greater depth of understanding for the behavior of cast duplex stainless steel. In addition, improved evaluation methods for DSS castings were developed according to ASTM A923, A262, G48 and A494. The study revealed that when properly heat treated according to the specification, (1) DSS castings have equal or better pitting and intergranular corrosion resistance than their wrought counterparts; (2) Welding reduces the

  9. Final Report, Volume 1, Metallurgical Evaluation of Cast Duplex Stainless Steels and their Weldments

    Energy Technology Data Exchange (ETDEWEB)

    Wen, Songqing; Lundin, Carl, W.; Batten, Greg, W.

    2005-09-30

    Duplex stainless steels (DSS) are being specified for chloride containing environments due to their enhanced pitting and stress corrosion cracking resistance. They exhibit improved corrosion performance over the austenitic stainless steels. Duplex stainless steels also offer improved strength properties and are available in various wrought and cast forms. Selected grades of duplex stainless steel castings and their welds, in comparison with their wrought counterparts, were evaluated, regarding corrosion performance and mechanical properties and weldability. Multiple heats of cast duplex stainless steel were evaluated in the as-cast, solution annealed (SA) static cast and SA centrifugal cast conditions, while their wrought counterparts were characterized in the SA condition and in the form of as-rolled plate. Welding, including extensive assessment of autogenous welds and a preliminary study of composite welds (shielded metal arc weld (SMAW)), was performed. The evaluations included critical pitting temperature (CPT) testing, intergranular corrosion (IGC) testing, ASTM A923 (Methods A, B and C), Charpy impact testing, weldability testing (ASTM A494), ferrite measurement and microstructural evaluations. In the study, the corrosion performances of DSS castings were characterized and assessed, including the wrought counterparts for comparison. The evaluation filled the pore of lack of data for cast duplex stainless steels compared to wrought materials. A database of the pitting corrosion and IGC behavior of cast and wrought materials was generated for a greater depth of understanding for the behavior of cast duplex stainless steel. In addition, improved evaluation methods for DSS castings were developed according to ASTM A923, A262, G48 and A494. The study revealed that when properly heat treated according to the specification, (1) DSS castings have equal or better pitting and intergranular corrosion resistance than their wrought counterparts; (2) Welding reduces the

  10. Process on cold crucible electromagnetic casting for titanium alloy

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The parameters and factors that influence the surface quality and macrostructure of titanium alloy with reactive properties under liquid state were studied experimentally using a cold crucible electromagnetic casting method. The variations in the process parameters have great impact on the surface quality and macrostructure of cast billets. Billets with crack free and smooth surfaces as well as directional solidified primary structures were obtained after the selection of optimized process parameters. The formation mechanisms of defects such as cracks and non-directional structural morphology were interpreted briefly. Finally, the casting of billets with good outer qualities and inner column grains has been attained successfully, which in turn gives a solid foundation for further development of the technology.

  11. Process on cold crucible electromagnetic casting for titanium alloy

    Directory of Open Access Journals (Sweden)

    CHEN Rui-run

    2007-08-01

    Full Text Available The parameters and factors that influence the surface quality and macrostructure of titanium alloy with reactive properties under liquid state were studied experimentally using a cold crucible electromagnetic casting method. The variations in the process parameters have great impact on the surface quality and macrostructure of cast billets. Billets with crack free and smooth surfaces as well as directional solidified primary structures were obtained after the selection of optimized process parameters. The formation mechanisms of defects such as cracks and non-directional structural morphology were interpreted briefly. Finally, the casting of billets with good outer qualities and inner column grains has been attained successfully, which in turn gives a solid foundation for further development of the technology.

  12. Prediction of Part Distortion in Die Casting

    Energy Technology Data Exchange (ETDEWEB)

    R. Allen Miller

    2005-03-30

    The die casting process is one of the net shape manufacturing techniques and is widely used to produce high production castings with tight tolerances for many industries. An understanding of the stress distribution and the deformation pattern of parts produced by die casting will result in less deviation from the part design specification, a better die design and eventually more productivity and cost savings. This report presents methods that can be used to simulate the die casting process in order to predict the deformation and stresses in the produced part and assesses the degree to which distortion modeling is practical for die casting at the current time. A coupled thermal-mechanical finite elements model was used to simulate the die casting process. The simulation models the effect of thermal and mechanical interaction between the casting and the die. It also includes the temperature dependant material properties of the casting. Based on a designed experiment, a sensitivity analysis was conducted on the model to investigate the effect of key factors. These factors include the casting material model, material properties and thermal interaction between casting and dies. To verify the casting distortion predictions, it was compared against the measured dimensions of produced parts. The comparison included dimensions along and across the parting plane and the flatness of one surface.

  13. Effects of little Ce addition on as-cast microstructure and creep properties of Mg-3Sn-2Ca magnesium alloy

    Institute of Scientific and Technical Information of China (English)

    YANG Ming-bo; MA Yan-long; PAN Fu-sheng

    2009-01-01

    The effects of little Ce addition on the as-cast microstructure and creep properties of Mg-3Sn-2Ca magnesium alloy were investigated. The results indicate that adding 0.5% (mass fraction) Ce to Mg-3Sn-2Ca alloy does not cause the formation of any new phase in the alloy. However, an interesting microstructural change in the as-cast Mg-3Sn-2Ca alloy added with 0.5%Ce is observed. After adding 0.5%Ce to Mg-3Sn-2Ca alloy, not only the volume fraction of CaMgSn phase in the alloy is decreased but also the CaMgSn phases in the alloy are refined. In addition, adding 0.5%Ce to Mg-3Sn-2Ca alloy can also improve the creep-resistant properties of the alloy. After adding 0.5%Ce to Mg-3Sn-2Ca alloy, the second creep rate of the alloy at 150 ℃ and 70 Mpa for 100 h changes from 3.28×10~(-8) to 1.81×10~(-8) s~(-1).

  14. Influence of Niobium on Thermal Fatigue Properties of Gray Cast Irons%Nb对灰铸铁热疲劳性能的影响

    Institute of Scientific and Technical Information of China (English)

    朱洪波; 闫永生; 孙小亮; 华勤; 翟启杰

    2011-01-01

    采用Uddeholm热疲劳方法测定了Nb对灰铸铁热疲劳性能的影响,试验结果表明:(1)Nb的加入能够提高灰铸铁的抗热疲劳性能,随着w(Nb)的增加,试样最大裂纹深度和宽度都逐渐减小;(2)由于Nb细化石墨使裂纹源减少和裂纹扩展途径变细,Nb元素能够改善材料表面经热疲劳处理后恶化的性能.%By adopting Uddeholm thermal fatiguing method , the influence of niobium on the thermal fatigue properties of the gray cast irons was tested. The results showed: ( 1)Niobium addition could improve the thermal fatigue resistance of the gray cast irons. Both the maximum cracking depth and width gradually reduced with increase of the niobium adding amount; (2)Since the niobium could make the graphite finer, reduce the number of cracking sources and make the crack extending tracks narrower, therefore it could reduce the properties worsening of the material after having been thermally fatiguing treated.

  15. Effect of Substrate Movement Speed by Synchronous Rolling-casting Freeform Manufacturing for Metal on Microstructure and Mechanical Property of ZLl04 Aluminum Alloy Slurry

    Institute of Scientific and Technical Information of China (English)

    LUO Xiaoqiang; LI Zhengyang; CHEN Guangnan; XU Wanli; YAN Qingzhi

    2015-01-01

    Synchronous rolling-casting freeform manufacturing for Metal (SRCFMM) means that the refined liquid metal is continuously pressed out from the bottom of crucible. There is a horizontal movable plate beneath the outlet. The clearance between the outlet and the plate is about several hundred micrometers. SRCFMM, similar to additive manufacturing, implies layer by layer shaping and consolidation of feedstock to arbitrary conifgurations, normally using a computer controlled movable plate. The primary dendritic crystal is easily crushed by movement of substrate in the rolling-casting area. ZL104 was used as the test materials, determi-ning the control temperature by differential scanning thermal analysis (DSC), preparing a kind of samples by SR CFMM, then analyzing microstructures and mechanical property of the samples. Characteristics and distribution of the primary particles were assessed by optical microscopy (OM), scanning electron microscopy (SEM), energy dispersive spectrum (EDS) and image analysis software. Mechanical property of the samples was assessed by vickers hardness. The results show that the samples fabricated by SRCFMM have uniform structures and good performances with the velocity of the substrate controlled about 10 cm/s and temperature at about 580℃.

  16. Influence of Technological Parameters of Furane Mixtures on Shrinkage Creation in Ductile Cast Iron Castings

    Directory of Open Access Journals (Sweden)

    Vasková I.

    2014-10-01

    Full Text Available Ductile cast iron (GS has noticed great development in last decades and its boom has no analogue in history humankind. Ductile iron has broaden the use of castings from cast iron into areas, which where exclusively domains for steel castings. Mainly by castings, which weight is very high, is the propensity to shrinkage creation even higher. Shrinkage creation influences mainly material, construction of casting, gating system and mould. Therefore, the main realized experiment was to ascertain the influence of technological parameters of furane mixture on shrinkage creation in castings from ductile iron. Together was poured 12 testing items in 3 moulds forto determine and compare the impact of various technological parameters forms the propensity for shrinkage in the casting of LGG.

  17. Microstructure of CrMnNi Cast Steel After Explosive-Driven Flyer-Plate Impact at Room Temperature and Below

    Science.gov (United States)

    Eckner, R.; Reichel, B.; Savinykh, A. S.; Krüger, L.; Razorenov, S. V.; Garkushin, G. V.

    2016-01-01

    A low-carbon metastable austenitic CrMnNi cast steel was investigated under shock conditions in a flyer-plate impact test. The samples were impacted by aluminum flyer-plates with impact velocities of 620 ± 30 m/s. Depending on deformation temperature and strain rate, the material exhibited different deformation mechanisms (dislocation glide, martensitic transformation, and mechanical twinning), which determined the microstructural evolution and mechanical behavior. Flyer-plate impact tests were carried out at 213 K and 293 K (-60 °C and +20 °C). A soft recovered sample revealed microstructural changes directly after impact. The subsequent microstructural investigations via light-optical microscopy and scanning electron microscopy revealed that transformation-induced plasticity (TRIP effect) was the primary deformation mechanism. Moreover, it was possible to quantify the martensite volume fraction by different methods and to identify the hcp ɛ-martensite phase as an intermediate transformation stage. A decrease in temperature also increased the driving force for the martensitic transformation.

  18. Mechanical properties and microstructures of dental cast Ti-6Nb-4Cu, Ti-18Nb-2Cu, and Ti-24Nb-1Cu alloys.

    Science.gov (United States)

    Takahashi, Masatoshi; Kikuchi, Masafumi; Takada, Yukyo

    2016-01-01

    The mechanical properties -tensile strength, yield strength, elongation after fracture, and Vickers hardness- and alloy phases of the dental cast alloys Ti-6%Nb-4%Cu, Ti-18%Nb-2%Cu, and Ti-24%Nb-1%Cu were investigated. Ti-6%Nb-4%Cu consisted of a single α-phase, while Ti-18%Nb-2%Cu and Ti-24%Nb-1%Cu consisted of α- and β-phases. The tensile strengths, yield strengths, and hardnesses of these alloys were higher than those of Ti-5%Cu and Ti-30%Nb; however, their breaking elongations were smaller. These differences in the mechanical properties are attributable to solid-solution strengthening or to precipitation strengthening by the dual-phase (α+β) structure. Thus, Ti-Nb-Cu alloys are suitable for use in high-strength dental prostheses, such as implantretained superstructures and narrow-diameter implants. PMID:27477221

  19. Mechanical properties dependency on chemical composition of spheroidal graphite cast iron; Dependencia de las propiedades mecanicas y de la composicion quimica en la fundicion de grafito esferoidal

    Energy Technology Data Exchange (ETDEWEB)

    Gonzaga-Cinco, R.; Fernandez-Carrasquilla, J.

    2006-07-01

    With this work, we try to study the chemical composition of four specimens in form of stair of ductile cast iron to determine the influence of the chemical composition of different alloying elements on microstructure and on mechanical properties. The dimensions of each specimens are 200 x 100 x 50 mm. Cooling rate has been considered to be different for each one of the four stairs when determining the mechanical properties, therefore, grain size varies in each case. In this analysis, the different microstructures of the stairs have been considered. Influence of the thickness on hardness of each specimen has been taken into account. Heat treatments are not used. Yield and tensile strength are determined. Charpy tests have been done. Rockwell and Brinell hardness are determined. (Author)

  20. The effect of nano-TiO2 addition on the properties of mullite-zirconia composites prepared by slip casting

    Directory of Open Access Journals (Sweden)

    Badiee S.H.

    2012-01-01

    Full Text Available The mullite-zirconia composites were prepared by reaction-sintering of alumina and zircon powder. Besides, the slip casting method was employed for fabrication of these composites. Then, the effect of nano-TiO2 addition on the properties of these composites was investigated and the results were compared with micro-sized TiO2. Hence, the physical properties, phase composition, flexural strength and microstructure of these composites after firing at 1600°C were studied. The results showed that the flexural strength of composite tends to increase with the addition of 0.5 wt.% nano-TiO2. It is attributed to the formation of larger size rod-like ZrO2 and enhanced ceramic bonding between them.

  1. Effect of inoculation on high temperature plastic properties of the centrifugally cast Cr-Ni-Nb steel

    Directory of Open Access Journals (Sweden)

    G. Tęcza

    2008-12-01

    Full Text Available From the centrifugally cast sleeve segments, in direction parallel to the axis, the specimens for mechanical tests were cut out in a way such as to get in one batch of the specimens a structure composed of columnar crystals and in another batch of the specimens a structure composed of equiaxial crystals. The specimens were subjected to a tensile test at the temperature of 820°C. It has been observed that the two zones of crystals differ quite considerably in the values of elongation, while preserving similar tensile strength levels.

  2. Effect of inoculation on high temperature plastic properties of the centrifugally cast Cr-Ni-Nb steel

    OpenAIRE

    G. Tęcza; Głownia, J.

    2008-01-01

    From the centrifugally cast sleeve segments, in direction parallel to the axis, the specimens for mechanical tests were cut out in a way such as to get in one batch of the specimens a structure composed of columnar crystals and in another batch of the specimens a structure composed of equiaxial crystals. The specimens were subjected to a tensile test at the temperature of 820°C. It has been observed that the two zones of crystals differ quite considerably in the values of elongation, while pr...

  3. Estimation of sediment properties during benthic impact experiments

    Digital Repository Service at National Institute of Oceanography (India)

    Yamazaki, T.; Sharma, R.

    Sediment properties, such as water content and density, have been used to estimate the dry and wet weights, as well as the volume of sediment recovered and discharged, during benthic impact experiments conducted in the Pacific and Indian Oceans...

  4. Properties of Dispersion Casting of Y2O3 Particles in Hypo, Hyper and Eutectic Binary Al-Cu Alloys

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    In the present work, the dispersion casting of Y2O3 particles in aluminum-copper alloy was investigated in terms of microstructural changes with respect to Cu contents of 20 (hypo), 33 (eutectic) and 40 (hyper)wt pct by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). For the fabrication of Al-Cu alloy dispersed Y2O3 ceramic particles, stir casting method was employed. In case of Al-20 wt pct Cu alloy (hypoeutectic), SEM images revealed that primary Al was grown up in the beginning. After that, eutectic phase with well dispersed ceramic particles was formed. In case of eutectic composition, Y2O3 particles were uniformly dispersed in the matrix. When the Cu is added into Al up to 40 wt pct (hypereutectic), primary θ phase was grown up without any Y2O3 ceramic particles in the early stage of solidification. Thereafter,eutectic phase was formed with well dispersed ceramic particles. It can be concluded that Y2O3 ceramic particles is mostly dispersed in case of eutectic composition in Al-Cu alloy.

  5. Evaluation of impact and fatigue properties on austempered ductile iron

    OpenAIRE

    Arias Fernández, Sergio

    2009-01-01

    Austempered Ductile Iron (ADI) proved to be an excellent material as it possesses attractive properties: high strength, ductility and toughness are combined with good wear resistance and machinability. In this work impact and the fatigue properties have been evaluated for low alloyed Austempered Ductile Iron. To do this, Charpy-type impact test for austempered ductile iron was performed by the standard ASTM A 327M and Fatigue Crack Growth Rates (FCGR) were measured by the stand...

  6. Electron impact phenomena and the properties of gaseous ions

    CERN Document Server

    Field, F H; Massey, H S W; Brueckner, Keith A

    1970-01-01

    Electron Impact Phenomena and the Properties of Gaseous Ions, Revised Edition deals with data pertaining to electron impact and to molecular gaseous ionic phenomena. This book discusses electron impact phenomena in gases at low pressure that involve low-energy electrons, which result in ion formation. The text also describes the use of mass spectrometers in electron impact studies and the degree of accuracy obtained when measuring electron impact energies. This book also reviews relatively low speed electrons and the transitions that result in the ionization of the atomic system. This text the

  7. Effects of scandium and zirconium combination alloying on as-cast microstructure and mechanical properties of Al-4Cu-1.5Mg alloy

    Directory of Open Access Journals (Sweden)

    Xiang Qingchun

    2011-02-01

    Full Text Available The influences of minor scandium and zirconium combination alloying on the as-cast microstructure and mechanical properties of Al-4Cu-1.5Mg alloy have been experimentally investigated. The experimental results show that when the minor elements of scandium and zirconium are simultaneously added into the Al-4Cu-1.5Mg alloy, the as-cast microstructure of the alloy is effectively modified and the grains of the alloy are greatly refined. The coarse dendrites in the microstructure of the alloy without Sc and Zr additions are refined to the uniform and fine equiaxed grains. As the additions of Sc and Zr are 0.4% and 0.2%, respectively, the tensile strength, yield strength and elongation of the alloy are relatively better, which are 275.0 MPa, 176.0 MPa and 8.0% respectively. The tensile strength is increased by 55.3%, and the elongation is nearly raised three times, compared with those of the alloy without Sc and Zr additions.

  8. Tensile properties of cast titanium alloys: Titanium-6Al-4V ELI and Titanium-5Al-2.5Sn ELI

    Science.gov (United States)

    Billinghurst, E. E., Jr.

    1992-01-01

    This work was performed to determine the tensile properties of cast, hot isostatic pressed (HIP'ed), and annealed titanium alloys, Ti-6Al-4V ELI and Ti-5Al-2.5Sn ELI, that are candidate materials for the space transportation main engine (STME) liquid hydrogen turbopump impeller. Samples of the cast alloys were HIP'ed, annealed, and machined into tensile specimens. The specimens were tested in air at ambient temperature (70 F) and also at -423 F in liquid hydrogen. The Ti-6Al-4V alloy had an average ultimate strength of 129.1 ksi at 70 F and 212.2 ksi at -423 F. The Ti-5Al-2.5Sn alloy had an average ultimate strength of 108.4 ksi at 70 degrees F and 185.0 ksi at -423 F. The ductility, as measured by reduction of area, for the Ti-6Al-4V averaged 15.2 percent at 70 F and 8.7 percent at -423 F, whereas for the Ti-5Al-2.5Sn alloy average reduction of area was 24.6 percent at 70 F and 11.7 percent at -423 F.

  9. HA/nylon 6,6 porous scaffolds fabricated by salt-leaching/solvent casting technique: effect of nano-sized filler content on scaffold properties

    Directory of Open Access Journals (Sweden)

    Mehrabanian M

    2011-08-01

    Full Text Available Mehran Mehrabanian1, Mojtaba Nasr-Esfahani21Member of Young Researchers Club, Najafabad Branch, Islamic Azad University, Isfahan, Iran; 2Department of Materials Science and Engineering, Najafabad Branch, Islamic Azad University, Isfahan, IranAbstract: Nanohydroxyapatite (n-HA/nylon 6,6 composite scaffolds were produced by means of the salt-leaching/solvent casting technique. NaCl with a distinct range size was used with the aim of optimizing the pore network. Composite powders with different n-HA contents (40%, 60% for scaffold fabrication were synthesized and tested. The composite scaffolds thus obtained were characterized for their microstructure, mechanical stability and strength, and bioactivity. The microstructure of the composite scaffolds possessed a well-developed interconnected porosity with approximate optimal pore size ranging from 200 to 500 µm, ideal for bone regeneration and vascularization. The mechanical properties of the composite scaffolds were evaluated by compressive strength and modulus tests, and the results confirmed their similarity to cortical bone. To characterize bioactivity, the composite scaffolds were immersed in simulated body fluid for different lengths of time and results monitored by scanning electron microscopy and energy dispersive X-ray microanalysis to determine formation of an apatite layer on the scaffold surface.Keywords: scaffold, nanohydroxyapatite, nylon 6,6, salt-leaching/solvent casting, bioactivity

  10. Predicting the impact of biochar additions on soil hydraulic properties

    Science.gov (United States)

    Different physical and chemical properties of biochar, which is made out of a variety of biomass materials, can impact water movement through amended soil. The objective of this research was to develop a decision support tool predicting the impact of biochar additions on soil saturated hydraulic con...

  11. Effects of warm temper rolling on microstructure, texture and magnetic properties of strip-casting 6.5 wt% Si electrical steel

    Energy Technology Data Exchange (ETDEWEB)

    Li, Hao-Ze [State Key Laboratory of Rolling and Automation, Northeastern University, Shenyang 110819 (China); Liu, Hai-Tao, E-mail: liuht@ral.neu.edu.cn [State Key Laboratory of Rolling and Automation, Northeastern University, Shenyang 110819 (China); Liu, Yi [State Key Laboratory of Rolling and Automation, Northeastern University, Shenyang 110819 (China); Liu, Zhen-Yu, E-mail: zyliu@mail.neu.edu.cn [State Key Laboratory of Rolling and Automation, Northeastern University, Shenyang 110819 (China); Cao, Guang-Ming [State Key Laboratory of Rolling and Automation, Northeastern University, Shenyang 110819 (China); Luo, Zhong-Han; Zhang, Feng-Quan; Chen, Sheng-Lin; Lyu, Li [National Engineering Research Center for Silicon Steel, Wuhan Iron and Steel (Group) Corp, Wuhan 430083 (China); Wang, Guo-Dong [State Key Laboratory of Rolling and Automation, Northeastern University, Shenyang 110819 (China)

    2014-12-15

    6.5 wt% Si electrical steel thin sheets were produced by a processing route including strip casting, hot rolling, warm rolling, intermediate annealing, warm temper rolling and final annealing, in which the warm temper rolling reduction varied from 2.7% to 14.4%. A detailed study of the microstructural and textural evolutions through the whole processing route was carried out by optical microscopy, X-ray diffraction and electron backscattered diffraction analysis. The findings revealed that the final recrystallization microstructure, texture and magnetic properties relied heavily on the warm temper rolling reduction. As the warm temper rolling reduction increased from 2.7% to 14.4%, the finally recrystallized microstructures were more homogeneous and the average grain size was decreased. At the warm temper rolling reduction lower than 7.0%, the occurrence of the exaggeratedly large annealing grains which dominated the whole sheet thickness resulted in strong 〈001〉//ND fiber, parallel α-fiber, 〈111〉//ND fiber and many other strong hard-magnetization texture components. By contrast, at the warm temper rolling reduction higher than 7.0%, the recrystallization textures were characterized by weak 〈001〉//ND fiber, parallel α-fiber, 〈111〉//ND texture, together with fewer and weak hard-magnetization texture components. The mechanism responsible for the finally microstructural and textural changes was explained by strain induced boundary migration. As warm temper rolling reduction increased, the magnetic properties at high frequency were gradually improved due to smaller grain sizes and more desirable textures. The highest magnetic inductions of 1.383 T (B{sub 8}), 1.484 T (B{sub 25}) and 1.571 T (B{sub 50}) in combination with the lowest iron losses at high frequencies of 19.11 W/Kg (W{sub 10/400}) and 3.824 W/Kg (W{sub 2/1000}) were obtained at 14.4% warm temper rolling reduction under the applied condition. - Highlights: • 6.5 wt% Si electrical steel

  12. How property title impacts urban consolidation

    DEFF Research Database (Denmark)

    Easthope, Hazel; Warnken, Jan; Sherry, Cathy;

    2014-01-01

    tensions inherent in multi-title developments: i) tensions between individual and collective property rights, ii) tensions between the needs and responsibilities of different stakeholders, and iii) tensions inherent in the concurrent role of multi-title developments as governmental, market and civil...

  13. The UK Casting Industry

    Institute of Scientific and Technical Information of China (English)

    Jincheng Liu

    2006-01-01

    The casting production in the UK in 2004 is presented and analysed. The UK casting industry has played an important role in world casting and manufacturing production. However recent years the rapid development of some developing countries has been shifting the casting production from the western industrialized countries including the UK. The UK casting industry and associated research and technology organizations, universities have been working together very hard to face the serious competition to make the UK casting industry have a sustainable future. The UK casting industry remains strong and plays an important role in world casting and manufacturing production.

  14. Effect of delta-ferrite on the mechanical properties of CF8M stainless steel castings at 4 K

    International Nuclear Information System (INIS)

    A series of five CF8M stainless steel castings, with varying delta-ferrite contents, has been tensile and fracture toughness tested at 4 K. Tensile tests were conducted in the low strain region to establish the initial strain hardening behavior for comparison with two phase deformation theory. It was found that the tensile behavior of the duplex austenite/delta-ferrite structure fits very well with the two phase deformation theory proposed by Ashby. The initial strain hardening rate is determined by the mean-free-path between delta-ferrite particles. Fracture toughness results at 4 K show a decrease in fracture toughness with increasing delta-ferrite content up to approximately 15%; at this point a continuous delta-ferrite crack path is established, and the fracture toughness remains constant with increasing delta-ferrite

  15. Fabrication of ZnO Nanowires Arrays by Anodization and High-Vacuum Die Casting Technique, and Their Piezoelectric Properties.

    Science.gov (United States)

    Kuo, Chin-Guo; Chang, Ho; Wang, Jian-Hao

    2016-01-01

    In this investigation, anodic aluminum oxide (AAO) with arrayed and regularly arranged nanopores is used as a template in the high-vacuum die casting of molten zinc metal (Zn) into the nanopores. The proposed technique yields arrayed Zn nanowires with an aspect ratio of over 600. After annealing, arrayed zinc oxide (ZnO) nanowires are obtained. Varying the anodizing time yields AAO templates with thicknesses of approximately 50 μm, 60 μm, and 70 μm that can be used in the fabrication of nanowires of three lengths with high aspect ratios. Experimental results reveal that a longer nanowire generates a greater measured piezoelectric current. The ZnO nanowires that are fabricated using an alumina template are anodized for 7 h and produce higher piezoelectric current of up to 69 pA.

  16. CA Investment Casting Process of Complex Castings

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    CA (Computer aided) investment casting technique used in superalloy castings of aerospace engine parts was presented. CA investment casting integrated computer application, RP (Rapid Prototyping) process, solidification simulation and investment casting process. It broke the bottle neck of making metal die. Solid model of complex parts were produced by UGII or other software, then translated into STL(Stereolithography) file, after RP process of SLS(Selective Laser Sintering), wax pattern used in investment ...

  17. A Conceptual Framework of Green Certification Impact On Property Price

    Directory of Open Access Journals (Sweden)

    Abdullah Lizawati

    2016-01-01

    Full Text Available Green building is one of the sustainability dimensions in built environment. The issues of green building and its impact to the society have been increasingly discussed. Green certification is one of the components in measuring sustainable development and plays an important role as an assessment system to an individual building’s performance. The question arises whether the market understand and recognized the green certification. The objectives of this research are to discuss the issue pertaining to green value and the relationship between green certification and property price. The research emphasized on the understanding of property attributes focusing on green certification and the impact to the property price. Among the attributes identified are structural characteristics, location and neighborhood, and time attributes. Thus, this paper will discusses the review of literature on green development and the significance impact on property market in term of price and value. The green building development across the country could be classified as another sector in property markets that give significant impact to the real estate industry. As a result, a conceptual framework in assessing the impact of green certification is suggested to provide a significant input in developing the model of hedonic pricing for green building. This research may contribute to extend the body of knowledge in the area of green development and a suggested significant input will give much emphasize on the new valuation technique in valuing green building properties.

  18. Changes of Structure and Magnetic Properties during Crystallization in Cast Nd60Fe20Al8Co10B2 Alloy

    Institute of Scientific and Technical Information of China (English)

    谭晓华; 徐晖; 王庆; 戚楠楠; 董远达

    2004-01-01

    The Nd60Fe20Al8Co10B2 alloy was prepared by suction casting of the molten alloy into a copper mold under argon atmosphere.The micro-structural and magnetic property changes in the Nd60Fe20Al8Co10B2 alloy during crystallization were investigated by X-ray diffraction(XRD),differential scanning calorimetry(DSC),scanning electron microscope(SEM)and the vibrating sample magnetometer(VSM).The precipitation and Nd-rich and Fe-rich phases have no significant effect on the intrinsic coercitity for Nd60Fe20Al8Co10B2 alloy annealed below 723 K.However,the growth of Fe-rich phase decreases the saturate magnetization and remanence of the alloy.The hard magnetic behavior is disappeared when the alloy is fully crystallized.

  19. Estimation of fracture toughness of cast stainless steels in LWR systems

    International Nuclear Information System (INIS)

    A program is being conducted to investigate the low-temperature embrittlement of cast duplex stainless steels under light water reactor (LWR) operating conditions and to evaluate possible remedies for the embrittlement problem in existing and future plants. The scope of the investigation includes the following goals: develop a methodology and correlations for predicting the toughness loss suffered by cast stainless steel components during normal and extended life of LWRs, validate the simulation of in-reactor degradation by accelerated aging, and establish the effects of key compositional and metallurgical variables on the kinetics and extent of embrittlement. Microstructural and mechanical property data are being obtained on 25 experimental heats (static-cast keel blocks and slabs) and 6 commercial heats (centrifugally cast pipes and a static-cast pump impeller and pump casing ring), as well as on reactor-aged material of CF-3, CF-8, and CF-8M grades of cast stainless steel. The ferrite content of the cast materials ranges from 3 to 30%. Charpy-impact, tensile, and J-R curve tests have been conducted on several experimental and commercial heats of cast stainless steel that were aged up to 30,000 h at temperatures of 290 to 400 degrees C. The results indicate that thermal aging at these temperatures increases the tensile strength and decreases the impact energy and fracture toughness of the steels. In general, the low-carbon CF-3 steels are the most resistant to embrittlement, and the molybdenum-containing high-carbon CF-8M steels are the least resistant. Ferrite morphology has a strong effect on the degree or extent of embrittlement, and the kinetics of embrittlement can vary significantly with small changes in the constituent elements of the cast material

  20. Soft magnetic properties and thermal stability of bulk Fe{sub 83}B{sub 17} alloy prepared by undercooling and Cu-mold casting methods

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Changlin, E-mail: ycl@nwpu.edu.cn; Zhang, Jun; Huang, Huili; Sheng, Gang; Liu, Feng

    2015-06-15

    The thermal stability and soft magnetic properties of bulk Fe{sub 83}B{sub 17} rods with nano-lamellar eutectic structures and metastable Fe{sub 3}B phases were investigated by annealing at 973–1273 K for 1.5 h. Samples with a diameter of 3 mm were prepared by undercooling solidification combined with Cu-mold casting. The decomposition of Fe{sub 3}B and the transformation of nano-lamellar eutectic structures were finished after annealing at 1173 K for 1.5 h. Increasing annealing temperature showed that the soft magnetic properties of the sample were kept relatively stable. The saturation magnetization and retentivity were decreased only slightly, while the coercivity was decreased significantly. - Highlights: • Thermal stability of the nano-lamellar eutectic structure was obtained. • Thermal stability of the metastable Fe{sub 3}B phase was obtained. • The soft magnetic properties of the sample remain stability by annealing. • Nano-lamellar eutectic structures enhance the soft magnetic properties.

  1. Letter Report: LAW Simulant Development for Cast Stone Screening Test

    Energy Technology Data Exchange (ETDEWEB)

    Russell, Renee L.; Westsik, Joseph H.; Swanberg, David J.; Eibling, Russell E.; Cozzi, Alex; Lindberg, Michael J.; Josephson, Gary B.; Rinehart, Donald E.

    2013-03-27

    More than 56 million gallons of radioactive and hazardous waste are stored in 177 underground storage tanks at the U.S. Department of Energy’s (DOE’s) Hanford Site in southeastern Washington State. The Hanford Tank Waste Treatment and Immobilization Plant (WTP) is being constructed to treat the wastes and immobilize them in a glass waste form. The WTP includes a pretreatment facility to separate the wastes into a small volume of high-level waste (HLW) containing most of the radioactivity and a larger volume of low-activity waste (LAW) containing most of the nonradioactive chemicals. The HLW will be converted to glass in the HLW vitrification facility for ultimate disposal at an offsite federal repository. At least a portion (~35%) of the LAW will be converted to glass in the LAW vitrification facility and will be disposed of onsite at the Integrated Disposal Facility (IDF). The pretreatment and HLW vitrification facilities will have the capacity to treat and immobilize the wastes destined for each facility. However, a second facility will be needed for the expected volume of additional LAW requiring immobilization. A cementitious waste form known as Cast Stone is being considered to provide the required additional LAW immobilization capacity. The Cast Stone waste form must be acceptable for disposal in the IDF. The Cast Stone waste form and immobilization process must be tested to demonstrate that the final Cast Stone waste form can comply with waste acceptance criteria for the IDF disposal facility and that the immobilization processes can be controlled to consistently provide an acceptable waste form product. Further, the waste form must be tested to provide the technical basis for understanding the long term performance of the waste form in the IDF disposal environment. These waste form performance data are needed to support risk assessment and performance assessment (PA) analyses of the long-term environmental impact of the waste disposal in the IDF. A

  2. Light metal compound casting

    Institute of Scientific and Technical Information of China (English)

    Konrad J.M.PAPIS; Joerg F.LOEFFLER; Peter J.UGGOWITZER

    2009-01-01

    'Compound casting'simplifies joining processes by directly casting a metallic melt onto a solid metal substrate. A continuously metallurgic transition is very important for industrial applications, such as joint structures of spaceframe constructions in transport industry. In this project, 'compound casting' of light metals is investigated, aiming at weight-saving. The substrate used is a wrought aluminium alloy of type AA5xxx, containing magnesium as main alloying element. The melts are aluminium alloys, containing various alloying elements (Cu, Si, Zn), and magnesium. By replacing the natural oxygen layer with a zinc layer, the inherent wetting difficulties were avoided, and compounds with flawless interfaces were successfully produced (no contraction defects, cracks or oxides). Electron microscopy and EDX investigations as well as optical micrographs of the interfacial areas revealed their continu-ously metallic constitution. Diffusion of alloying elements leads to heat-treatable microstructures in the vicinity of the joining interfaces in Al-Al couples. This permits significant variability of mechanical properties. Without significantly cutting down on wettability, the formation of low-melting intermetallic phases (Al3Mg2 and AI12Mg17 IMPs) at the interface of Al-Mg couples was avoided by applying a protec-tive coating to the substrate.

  3. Impact of foundation properties on seismic response

    International Nuclear Information System (INIS)

    Seismic response of the NPP structures depends on the foundation properties twice. First, “free-field excitation” depends on soil/rock layering; second, soil-structure interaction also depends on soil/rock profile. Extreme cases of soil foundation profile are homogeneous half-space and soil layer resting on rigid rock. These two site profiles are principally different in behavior. Each particular site is usually somewhere in between. It is important to know the type of site in order to predict seismic response of NPP structures. (author)

  4. As-Cast Acicular Ductile Aluminum Cast Iron

    Institute of Scientific and Technical Information of China (English)

    S M Mostafavi Kashani; S M A Boutorabi

    2009-01-01

    The effects of nickel (2.2%)and molybdenum (0.6%)additions on the kinetics, microstructure, and me-chanical properties of ductile aluminum cast iron were studied under the as-cast and tempered conditions. Test bars machined from cast to size samples were used for mechanical and metallurgical studies. The results showed that adding nickel and molybdenum to the base iron produced an upper bainitic structure, resulting in an increase in strength and hardness. The same trend was shown when the test bars were tempered at 300 ℃ in the range of 300℃ to 400 ℃. The elongation increased with increasing the temperature from 300 ℃ to 400 ℃. The carbon content of the retained austenite also increased with increasing the temperature. The results also showed that the kinetics, mi-crostructure, and mechanical properties of this iron were similar to those of Ni-Mo alloyed silicon ductile iron.

  5. Stress ratio effects in fatigue of lost foam cast aluminum alloy 356

    Science.gov (United States)

    Palmer, David E.

    Lost foam casting is a highly versatile metalcasting process that offers significant benefits in terms of design flexibility, energy consumption, and environmental impact. In the present work, the fatigue behavior of lost foam cast aluminum alloy 356, in conditions T6 and T7, was investigated, under both zero and non-zero mean stress conditions, with either as-cast or machined surface finish. Scanning electron microscopy was used to identify and measure the defect from which fatigue fracture initiated. Based on the results, the applicability of nine different fatigue mean stress equations was compared. The widely-used Goodman equation was found to be highly non-conservative, while the Stulen, Topper-Sandor, and Walker equations performed reasonably well. Each of these three equations includes a material-dependent term for stress ratio sensitivity. The stress ratio sensitivity was found to be affected by heat treatment, with the T6 condition having greater sensitivity than the T7 condition. The surface condition (as-cast vs. machined) did not significantly affect the stress ratio sensitivity. The fatigue life of as-cast specimens was found to be approximately 60--70% lower than that of machined specimens at the same equivalent stress. This reduction could not be attributed to pore size alone, and is suspected to be due to the greater concentration of pyrolysis products at the as-cast surface. Directions for future work, including improved testing methods and some possible methods of improving the properties of lost foam castings, are discussed.

  6. Estimation of fracture toughness of cast stainless steels during thermal aging in LWR systems-revision 1

    International Nuclear Information System (INIS)

    This report presents a revision of the procedure and correlations presented earlier in NUREG/CR-4513, ANL-90/42 (June 1991) for predicting the change in mechanical properties of cast stainless steel components due to thermal aging during service in light water reactors at 280-330 degrees C (535-625 degrees F). The correlations presented in this report are based on an expanded data base and have been optimized with mechanical-property data on cast stainless steels aged up to ∼58,000 h at 290-350 degrees C (554-633 degrees F). The fracture toughness J-R curve, tensile stress, and Charpy-impact energy of aged cast stainless steels are estimated from known material information. Mechanical properties of a specific cast stainless steel are estimated from the extent and kinetics of thermal embrittlement. Embrittlement of cast stainless steels is characterized in terms of room-temperature Charpy-impact energy. Charpy-impact energy as a function of time and temperature of reactor service is estimated from the kinetics of thermal embrittlement, which are also determined from the chemical composition. The initial impact energy of the unaged steel is required for these estimations. Initial tensile flow stress is needed for estimating the flow stress of the aged material. The fracture toughness J-R curve for the material is then obtained by correlating room-temperature Charpy-impact energy with fracture toughness parameters. The values of JIC are determined from the estimated J-R curve and flow stress. A common open-quotes predicted lower-boundclose quotes J-R curve for cast stainless steels of unknown chemical composition is also defined for a given grade of steel, range of ferrite content, and temperature. Examples of estimating mechanical properties of cast stainless steel components during reactor service are presented

  7. The ancient Chinese casting techniques

    OpenAIRE

    Tan Derui; Lian Haiping

    2011-01-01

    In the course of Chinese civilization, which lasted more than 5,000 years, casting production has made a huge contribution. In this paper, some representative metal castings were presented. According to their forming techniques, they can be grouped into stone mould casting, clay mould casting, ablation casting, lost wax casting, stack casting, permanent mould casting, sand casting, etc. According to their materials, they can be categorized into tin bronze, bimetallic bronze, malleable cast ir...

  8. Long-term embrittlement of cast duplex stainless steels in LWR systems

    International Nuclear Information System (INIS)

    This progress report summarizes work performed by Argonne National Laboratory on longterm thermal embrittlement of cast duplex stainless steels in LWR systems during the six months from April--September 1992. A procedure and correlations are presented for predicting Charpy-impact energy, tensile flow stress, fracture toughness J-R curve, tearing modulus, and JIC of aged cast stainless steels from known material information. The ''saturation'' impact strength and fracture toughness of a specific cast stainless steel, i.e., the minimum value that would be achieved for the material after long-term service, is estimated from the chemical composition of the steel. Mechanical properties as a function of time and temperature of reactor service are estimated from impact energy and flow stress of the unaged material and the kinetics of embrittlement, which are also determined from chemical composition. The JIC values are determined from the estimated J-R curve and flow stress. Examples of estimating mechanical properties of cast stainless steel components during reactor service are presented. A common ''lower-bound'' J-R curve for cast stainless steels of unknown chemical composition is also defined for a given grade of steel, ferrite content, and temperature

  9. The heat treatment of Fermanal cast steel

    Directory of Open Access Journals (Sweden)

    F. Binczyk

    2007-12-01

    Full Text Available The study discloses the results of microstructural examinations, testing of magnetic properties and hardness measurements as cast and after heat treatment conducted on the Fermanal cast steel. A characteristic feature of this cast steel is its density lower by about 10% than the density of carbon cast steel [4]. It has been proved that the factor deciding about the composition of microstructure (fraction of ferrite and austenite is the content of aluminium. The matrix totally austenitic is present in cast steel containing from 0,8 to 0,9% C, from 22 to 24% Mn, and from 4,5 to 5,5% Al. The magnetic properties examined on samples of the Fermanal cast steel were determined by spectroscopy of the Mössbauer effect with isotope 57Fe. The magnetic properties represented by a mean value of the hyperfine magnetic field Bhf and relative magnetic permeability were determined. It has been stated that the level of magnetic properties of the Fermanal cast steel depends on the content of ferrite. The effect of the parameters of solutioning and ageing on the cast steel microstructure and hardness after modification with additions of B, Ti and Nb was investigated.

  10. Homogenity of Die Casting and Returning Material

    Directory of Open Access Journals (Sweden)

    J. Malik

    2012-04-01

    Full Text Available Homogeneity of die castings is influenced by wide range of technological parameters as piston velocity in filling chamber of die casting machine, filling time of mould cavity, temperature of cast alloy, temperature of the mould, temperature of filling chamber, surface pressure on alloy during mould filling, final pressure and others. Based on stated parameters it is clear, that main parameters of die casting are filling time of die mould cavity and velocity of the melt in the ingates. Filling time must ensure the complete filling of the mould cavity before solidification process can negatively influence it. Among technological parameters also belong the returning material, which ratio in charge must be constrained according to requirement on final homogeneity of die castings. With the ratio of returning material influenced are the mechanical properties of castings, inner homogeneity and chemical composition.

  11. Dispersion of nano-silica in monomer casting nylon6 and its effect on the structure and properties of composites

    Directory of Open Access Journals (Sweden)

    2010-07-01

    Full Text Available To promote dispersion of nano-silica in monomer casting nylon6 (MC nylon6, nano-silica was dispersed in melted caprolactam with the assistance of ultrasound, anionic polymerization was then initiated to form silica/MC nylon6 in-situ nanocomposites. It was found that hydrogen bonds were formed between nano-silica and caprolactam, in the meantime, ultrasound helped to break the nanoparticles aggregations into smaller ones or even mono-dispersing particles. Therefore, the agglomerated nanoparticles were pulled apart and stabilized by caprolactam. Additionally, the rapid anionic polymerization of caprolactam also contributed to the avoidance of re-agglomeration and deposition of nanoparticles during the polymerization process, leading to the uniform distribution of nanoparticles in the polymer matrix. Mechanical tests indicated that the silica/MC nylon6 in-situ nanocomposites prepared according to the above strategy were simultaneously toughened, strengthened and stiffened. Thermogravimetric analysis (TGA results showed that thermal stability of nanocomposites was notably improved compared to neat MC nylon6.

  12. High Cycle Fatigue Properties of Die-Cast Magnesium Alloy AZ91D with Addition of Different Concentrations of Cerium

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The effect of addition of different concentrations of Ce on high-cycle fatigue behavior of die-cast magnesium al-loy AZ91D was investigated. Mechanical fatigue tests were conducted at the stress ratio of R = 0.1, and fatigue strength was evaluated using up-and-down loading method. The results show that the grain size of AZ91D alloy is remarkably refined, and the amount of porosity decreases and evenly distributes with the addition of Ce. The fatigue strength of AZ91D alloy at room temperature increases from 96.7 up to 116.3 MPa (1% Ce) and 105.5 MPa (2% Ce), respectively, at the number of cycles to failure, Nf = 1 × 107. The fatigue crack of AZ91D alloy initiates at porosities and inclusions, and propagates along grain boundaries. The fatigue striations on fractured surface appear with Ce addition. The fatigue fracture surface of test specimens shows mixed-fracture characteristics of quasi-cleavage and dimple.

  13. Microstructures and Properties of FeAl-Fe3AlC0.5 Composites Prepared by SHS Casting

    Institute of Scientific and Technical Information of China (English)

    Jun DINC; Jun YANG; Qinling BI; Jiqiang MA; Weimin LIU; Qunji XUE

    2008-01-01

    FeAl composites with 21, 37 and 50 wt pct Fe3AIC0.5 were fabricated by a self-propagating high temperature synthesis (SHS) casting. Phases and microstructures were analyzed by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Microhardness and bending strength of the composites were measured. The composites with 21 and 50 wt pct Fe3AlCo.5 mainly consisted of FeAI and Fe3AlC0.5 phases, whereas the composite with 37 wt pct Fe3AIC0.5 was composed of FeAl, Fe3AlC0.5 and graphite phases. The bonding of the reinforcement and the matrix was good. Hardness and bending strength of the composite with 37 wt pct Fe3AlC0.5 was lower than those of the 21 and 50 wt pct composites owing to the presence of the soft graphite phase.

  14. Effects of chromium and nitrogen content on the microstructures and mechanical properties of as-cast Co-Cr-Mo alloys for dental applications.

    Science.gov (United States)

    Yoda, Keita; Suyalatu; Takaichi, Atsushi; Nomura, Naoyuki; Tsutsumi, Yusuke; Doi, Hisashi; Kurosu, Shingo; Chiba, Akihiko; Igarashi, Yoshimasa; Hanawa, Takao

    2012-07-01

    The microstructure and mechanical properties of as-cast Co-(20-33)Cr-5Mo-N alloys were investigated to develop ductile Co-Cr-Mo alloys without Ni addition for dental applications that satisfy the requirements of the type 5 criteria in ISO 22674. The effects of the Cr and N contents on the microstructure and mechanical properties are discussed. The microstructures were evaluated using scanning electron microscopy with energy-dispersive X-ray spectroscopy (EDS), X-ray diffractometry (XRD), and electron back-scattered diffraction pattern analysis. The mechanical properties were evaluated using tensile testing. The proof strength and elongation of N-containing 33Cr satisfied the type 5 criteria in ISO 22674. ε-phase with striations was formed in the N-free (20-29)Cr alloys, while there was slight formation of ε-phase in the N-containing (20-29)Cr alloys, which disappeared in N-containing 33Cr. The lattice parameter of the γ-phase increased with increasing Cr content (i.e. N content) in the N-containing alloys, although the lattice parameter remained almost the same in the N-free alloys because of the small atomic radius difference between Co and Cr. Compositional analyses by EDS and XRD revealed that in the N-containing alloys Cr and Mo were concentrated in the cell boundary, which became enriched in N, stabilizing the γ-phase. The mechanical properties of the N-free alloys were independent of the Cr content and showed low strength and limited elongation. Strain-induced martensite was formed in all the N-free alloys after tensile testing. On the other hand, the proof strength, ultimate tensile strength, and elongation of the N-containing alloys increased with increasing Cr content (i.e. N content). Since formation of ε-phase after tensile testing was confirmed in the N-containing alloys the deformation mechanism may change from strain-induced martensite transformation to another form, such as twinning or dislocation slip, as the N content increases. Thus the N

  15. Microstructure, thermal behavior and mechanical properties of squeeze cast SiC, ZrO2 or C reinforced ZA27 composites

    International Nuclear Information System (INIS)

    Research highlights: → ZA27 with 5% SiC, ZrO2 or C particles are synthesized by stirring then squeezed. → Particles refine the structure. 50 MPa decreases porosity% and increases density. → α and β nucleation temperatures of the composites are lower than those of the matrix. → Particles accelerate age hardening and increase peak hardness of the composites → Particles reduce the CTEs of composites compared to those of the matrix. - Abstract: ZA27 alloy based composites were synthesized by stirring method, followed by squeeze casting. Stir casting was employed successfully to incorporate 5 vol.% of various reinforcement particulates, namely, SiC, ZrO2 or C. The porosity in the composites was decreased by squeeze pressure. The presence of particles and/or application of squeeze pressure during solidification resulted in considerable refinement in the structure of the composites. The microstructures, X-ray diffraction (XRD) and energy dispersive X-ray analysis (EDXA) results indicated that no significant reactions occurred at the interface between the SiC or C particles and ZA27 alloy. However, in case of ZrO2 reinforced ZA27, the ZrO2 reacted with Cu present in the molten ZA27 alloy, forming Cu5Zr. Thermal analysis showed that both α and β nucleation and growth temperatures of the composites were lower than those of the ZA27 alloy. The presence of particles in the as-cast or squeezed composites led to not only an accelerated age hardening response, but also an increase in the peak hardness of the composites. The values of coefficient of thermal expansion (CTE) of the composites were drastically lower as compared to those of the ZA27 alloy. The tensile properties of the composites decreased as a result of the addition of the particles. Scanning electron microscope (SEM) pictures of the composites indicated that cracks mainly initiated at particle-matrix interface, propagated through the matrix and linked up with other cracks leading to failure of the

  16. Effects of molybdenum content on the structure and mechanical properties of as-cast Ti-10Zr-based alloys for biomedical applications

    Energy Technology Data Exchange (ETDEWEB)

    Ho, Wen-Fu, E-mail: fujiiwfho@yahoo.com.tw [Department of Materials Science and Engineering, Da-Yeh University, Changhua, Taiwan (China); Wu, Shih-Ching; Hsu, Shih-Kuang [Department of Dental Technology and Materials Science, Central Taiwan University of Science and Technology, Taiwan (China); Institute of Biomedical Engineering and Materials Science, Central Taiwan University of Science and Technology, Taiwan (China); Li, Yu-Chi [Department of Materials Science and Engineering, Da-Yeh University, Changhua, Taiwan (China); Hsu, Hsueh-Chuan, E-mail: hchsu@ctust.edu.tw [Department of Dental Technology and Materials Science, Central Taiwan University of Science and Technology, Taiwan (China); Institute of Biomedical Engineering and Materials Science, Central Taiwan University of Science and Technology, Taiwan (China)

    2012-04-01

    The effects of molybdenum on the structure and mechanical properties of a Ti-10Zr-based system were studied with an emphasis on improving the strength/modulus ratio. Commercially pure titanium (c.p. Ti) was used as a control. As-cast Ti-10Zr and a series of Ti-10Zr-xMo (x = 1, 3, 5, 7.5, 10, 12.5, 15, 17.5 and 20 wt.%) alloys prepared using a commercial arc-melting vacuum pressure casting system were investigated. X-ray diffraction (XRD) for phase analysis was conducted with a diffractometer. Three-point bending tests were performed to evaluate the mechanical properties of all specimens. The experimental results indicated that these alloys had different structures and mechanical properties when various amounts of Mo were added. The as-cast Ti-10Zr has a hexagonal {alpha} Prime phase, and when 1 wt.% Mo was introduced into the Ti-10Zr alloy, the structure remained essentially unchanged. However, with 3 or 5 wt.%, the martensitic {alpha} Double-Prime structure was found. When increased to 7.5 wt.% or greater, retention of the metastable {beta} phase began. The {omega} phase was observed only in the Ti-10Zr-7.5Mo alloy. Among all Ti-10Zr-xMo alloys, the {alpha} Double-Prime -phase Ti-10Zr-5Mo alloy had the lowest elastic modulus. It is noteworthy that all the Ti-10Zr and Ti-10Zr-xMo alloys had good ductility. In addition, the Ti-10Zr-5Mo and Ti-10Zr-12.5Mo alloys exhibited higher bending strength/modulus ratios at 20.1 and 20.4, respectively. Furthermore, the elastically recoverable angles of these two alloys (26.4 Degree-Sign and 24.6 Degree-Sign , respectively) were much greater than those of c.p. Ti (2.7 Degree-Sign ). Given the importance of these properties for implant materials, the low modulus, excellent elastic recovery capability and high strength/modulus ratio of {alpha} Double-Prime phase Ti-10Zr-5Mo and {beta} phase Ti-10Zr-12.5Mo alloys appear to make them promising candidates. - Highlights: Black-Right-Pointing-Pointer The effects of Mo on the structure

  17. Effect of applied pressure on the quality of squeeze cast parts made from AlSi9Mg alloy

    Directory of Open Access Journals (Sweden)

    T. Reguła

    2011-07-01

    Full Text Available The results of the study of an influence of pressure in the direct squeeze casting process on the physical and mechanical properties of an AlSi9Mg alloy are presented. The specimens were made by casting the tested AlSi9Mg alloy under the conditions of variable squeeze pressure, using a PHM 160c type hydraulic press. Analyzing the results of the experiment, it has been found that, the applied pressure has an important impact on the quality of castings squeezed in liquid state. The effect of squeeze pressure proves the advisability of continuing the application of various liquid-phase methods using external pressure to improve the properties of castings produced.

  18. Microstructure and Mechanical Properties of High-Alloyed 23Cr-5Mn-2Ni-3Mo Cast Steel / Mikrostruktura I Właściwości Mechaniczne Wysokostopowego Staliwa 23Cr-5Mn-2Ni-3Mo

    Directory of Open Access Journals (Sweden)

    Kalandyk B.

    2015-12-01

    Full Text Available The article presents the microstructure and mechanical properties of cast duplex stainless steel type 23Cr-5Mn-2Ni-3Mo. It has been shown that the structure of the tested cast steel is composed of ferrite enriched in Cr, Mo and Si, and austenite enriched in Mn and Ni. In the initial state, at the interface, precipitates rich in Cr and Mo were present. A high carbon content (0.08%C in this cast steel indicates that probably those were complex carbides of the M23C6 type and/or σ phase. Studies have proved that the solution annealing conducted at 1060°C was not sufficient for their full dissolution, while at the solutioning temperature of 1150°C, the structure of the tested material was composed of ferrite and austenite.

  19. Properties of Spheroidal Graphite Cast Ion Required for the Dryers of Paper Machine%造纸机械烘缸用球墨铸铁材料的性能及要求

    Institute of Scientific and Technical Information of China (English)

    张卫民; 陈巧花; 李峰; 严国乔; 张国华; 兰春林

    2013-01-01

    造纸机械用铸铁烘缸是一种特殊的承压设备,其主要选材是灰铸铁和球墨铸铁.由于我国特种设备法规文件和行业标准之间存在一些不兼容的条文,在应用中产生了一些问题.通过对比分析,研究了美国ASME锅炉及压力容器规范以及欧盟标准中有关条款的内容,讨论了铸铁特别是球墨铸铁的机械性能参数和要求,提出了对我国行业标准条款修定的建议.%The cast iron dryer used in paper machines is a special kind of pressure vessel and the main materials of the dryer are gray cast iron and spheroidal graphite cast iron.Due to some incompatibilities between the government' s regulation and the industry standards,there exist some practical problems in application.This paper compares the relevant rules of the ASME codes and EU standards,the mechanical properties parameters of cast iron,especially spheroidal graphite cast iron were discussed and some suggestions for the revision of the national standards were put forward.

  20. Microstructure modification by La2O3 and its effect on wear resistance properties of as-cast ZL107 alloy

    Institute of Scientific and Technical Information of China (English)

    WAN Diqing

    2010-01-01

    Modification of ZL107 aluminum alloy has been successfully achieved by using La2O3. The different casting parameters, including casting temperature as well as holding time and modifier content, were carried out to investigate the modification effects. The results show that the best modifier content is 1.0 wt.%, and the casting temperature has little effect. In addition, the wear behavior of modified and unmodified ZL107 has been compared. The wear resistance of as-cast ZL107 aluminum alloy can be significantly improved after modification.

  1. Hybrid Laser-Arc Welding of 10-mm-Thick Cast Martensitic Stainless Steel CA6NM: As-Welded Microstructure and Mechanical Properties

    Science.gov (United States)

    Mirakhorli, Fatemeh; Cao, Xinjin; Pham, Xuan-Tan; Wanjara, Priti; Fihey, Jean-Luc

    2016-07-01

    Cast CA6NM martensitic stainless steel plates, 10 mm in thickness, were welded using hybrid laser-arc welding. The effect of different welding speeds on the as-welded joint integrity was characterized in terms of the weld bead geometry, defects, microstructure, hardness, ultimate tensile strength, and impact energy. Significant defects such as porosity, root humping, underfill, and excessive penetration were observed at a low welding speed (0.5 m/min). However, the underfill depth and excessive penetration in the joints manufactured at welding speeds above 0.75 m/min met the specifications of ISO 12932. Characterization of the as-welded microstructure revealed untempered martensite and residual delta ferrite dispersed at prior-austenite grain boundaries in the fusion zone. In addition, four different heat-affected zones in the weldments were differentiated through hardness mapping and inference from the Fe-Cr-Ni ternary phase diagram. The tensile fracture occurred in the base metal for all the samples and fractographic analysis showed that the crack path is within the martensite matrix, along primary delta ferrite-martensite interfaces and within the primary delta ferrite. Additionally, Charpy impact testing demonstrated slightly higher fracture energy values and deeper dimples on the fracture surface of the welds manufactured at higher welding speeds due to grain refinement and/or lower porosity.

  2. Advanced Lost Foam Casting Technology

    Energy Technology Data Exchange (ETDEWEB)

    Charles E. Bates; Harry E. Littleton; Don Askeland; Taras Molibog; Jason Hopper; Ben Vatankhah

    2000-11-30

    This report describes the research done under the six tasks to improve the process and make it more functional in an industrial environment. Task 1: Pattern Pyrolysis Products and Pattern Properties Task 2: Coating Quality Control Task 3: Fill and Solidification Code Task 4: Alternate Pattern Materials Task 5: Casting Distortion Task 6: Technology Transfer

  3. The effect of strontium on the microstructure, porosity and tensile properties of A356-10%B4C cast composite

    International Nuclear Information System (INIS)

    This study was undertaken to investigate the effect of different concentrations of strontium (0.05%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5% and 1%) on the microstructure, porosity content and tensile properties of A356-10%B4C particulate metal matrix composite. In this work, the matrix alloy and composite were characterized by optical microscope, scanning electron microscope equipped with EDS and XRD. The composite ingots were made by stir casting process. The results showed that the addition of 0.03%Sr strongly modified silicon eutectic phase in A356 monolithic alloy, but 0.5%Sr was needed to complete the modification of A356-10%B4C composite. Results also demonstrated that Sr addition increases shrinkage porosity and generates new intermetallics in the microstructure. Further investigations on tensile tests revealed optimum strontium levels for improving tensile properties. In the point of fracture behavior of the composite, modified specimens with 0.2%Sr showed broken B4C particles and acceptable cohesion between B4C and matrix.

  4. The influence of martensitic transformation on mechanical properties of cast high alloyed CrMnNi-steel under various strain rates and temperatures

    International Nuclear Information System (INIS)

    Metastable austenitic steels show excellent mechanical properties, such as high strength combined with excellent ductility and toughness due to martensitic transformation under mechanical loading (transformation induced plasticity effect). A good energy consumption, and, in the case of high-alloyed metastable austenitic steels, a high corrosion resistance, increase the potential of these materials for diverse applications, also in regard of safety requirements. Up to now, numerous wrought alloys were investigated concerning mechanical behaviour, TRIP-effect, martensitic transformation behaviour and modelling of transformation kinetics or stress-strain behaviour. New high alloyed cast CrMnNi-steels, developed at Technical University Bergakademie Freiberg, provide the chance to reduce processing steps, production time and costs. In order to understand the influence of temperature on the martensitic phase transformation behaviour and therefore on mechanical properties and failure, the mechanical response under tensile loading in a temperature range between -700C and 2000C was investigated. The mechanical behaviour under compressive loading was also examined in a wide range of strain rates between 10-4 s-1 and 103 s-1 to obtain information about the strain rate effect on stress-strain behaviour and microstructural changes.

  5. Improved material properties of solution-cast starch films: Effect of varying amylopectin structure and amylose content of starch from genetically modified potatoes.

    Science.gov (United States)

    Menzel, Carolin; Andersson, Mariette; Andersson, Roger; Vázquez-Gutiérrez, José L; Daniel, Geoffrey; Langton, Maud; Gällstedt, Mikael; Koch, Kristine

    2015-10-01

    High-amylose potato starches were produced through genetic modification resulting in changed granule morphology and composition, with higher amylose content and increased chain length of amylopectin. The increased amylose content and structural changes in amylopectin enhanced film-forming behavior and improved barrier and tensile properties in starch films. The molecular structure in these starches was related to film-forming properties. Solution-cast films of high-amylose starch revealed a homogeneous structure with increasing surface roughness at higher amylose content, possibly due to amylose aggregation. Films exhibited significantly higher stress and strain at break compared with films of wild-type starch, which could be attributable to the longer chains of amylopectin being involved in the interconnected network and more interaction between chains, as shown using transmission electron microscopy. The oxygen permeability of high-amylose starch films was significantly decreased compared with wild-type starch. The nature of the modified starches makes them an interesting candidate for replacement of non-renewable oxygen and grease barrier polymers used today. PMID:26076640

  6. Effect of carbon content on carbide morphology and mechanical properties of A.R. white cast iron with 10-12% tungsten

    Energy Technology Data Exchange (ETDEWEB)

    Heydari, D. [Department of Materials Science and Engineering, Sharif University of Technology, Tehran (Iran, Islamic Republic of); Skandani, A. Alipour [Department of Engineering Science and Mechanics, Virginia Tech, Blacksburg, VA 24061 (United States); Al Haik, M., E-mail: alhaik@vt.edu [Department of Engineering Science and Mechanics, Virginia Tech, Blacksburg, VA 24061 (United States)

    2012-04-30

    remained unchanged. X-ray diffraction, EDS, and electron microscopy identified the coarse GA zones microstructure to be mainly dendritic chromium carbide together with tungsten carbide and austenite phase residing in-between the chromium dendrites. After carrying out the proper heat treatment protocols, the chromium carbide in the coarse GA zones in the as-cast structure dissolved into tungsten carbide and martensite that were dispersed within the chromium carbide with island appearance (IA). Mechanical wear and hardness tests showed that the samples with higher IA volume fraction attained better wear resistance and higher hardness after heat treatment. The enhancement in the mechanical properties could be attributed to (i) the precipitation of chromium carbide in the form of IA morphology inhibited the crack propagation in the matrix. (ii) The precipitation of tungsten carbide both improved the matrix wear tolerance and promoted the transformation of austenite to a more wear-resistant and harder martensite phase.

  7. Recent Impacts on Mars: Cluster Properties and Seismic Signal Predictions

    Science.gov (United States)

    Justine Daubar, Ingrid; Schmerr, Nicholas; Banks, Maria; Marusiak, Angela; Golombek, Matthew P.

    2016-10-01

    Impacts are a key source of seismic waves that are a primary constraint on the formation, evolution, and dynamics of planetary objects. Geophysical missions such as InSight (Banerdt et al., 2013) will monitor seismic signals from internal and external sources. New martian craters have been identified in orbital images (Malin et al., 2006; Daubar et al., 2013). Seismically detecting such impacts and subsequently imaging the resulting craters will provide extremely accurate epicenters and source crater sizes, enabling calibration of seismic velocities, the efficiency of impact-seismic coupling, and retrieval of detailed regional and local internal structure.To investigate recent impact-induced seismicity on Mars, we have assessed ~100 new, dated impact sites. In approximately half of new impacts, the bolide partially disintegrates in the atmosphere, forming multiple craters in a cluster. We incorporate the resulting, more complex, seismic effects in our model. To characterize the variation between sites, we focus on clustered impacts. We report statistics of craters within clusters: diameters, morphometry indicating subsurface layering, strewn-field azimuths indicating impact direction, and dispersion within clusters indicating combined effects of bolide strength and elevation of breakup.Measured parameters are converted to seismic predictions for impact sources using a scaling law relating crater diameter to the momentum and source duration, calibrated for impacts recorded by Apollo (Lognonne et al., 2009). We use plausible ranges for target properties, bolide densities, and impact velocities to bound the seismic moment. The expected seismic sources are modeled in the near field using a 3-D wave propagation code (Petersson et al., 2010) and in the far field using a 1-D wave propagation code (Friederich et al., 1995), for a martian seismic model. Thus we calculate the amplitudes of seismic phases at varying distances, which can be used to evaluate the detectability

  8. Study of Impact of Selective Raw Cleaning on Extracts Properties

    Directory of Open Access Journals (Sweden)

    Zhalal A. Karabaev

    2012-08-01

    Full Text Available The article is focused on the study of the impact of the intensity of oil vacuum draws and deasphaltizates cleaning of Kazakhstan blended crudes on physicochemical properties of extracts and on the types and quantity of components, extracted from raw to determine feasibility of their extraction from fine cleaning extracts.

  9. Comparison of Impact Properties for Carbon and Low Alloy Steels

    Institute of Scientific and Technical Information of China (English)

    O.H. Ibrahim

    2011-01-01

    The impact properties of hot rolled carbon steel (used for the manufacture of reinforcement steel bars) and the quenched & tempered (Q&T) low alloy steel (used in the pressure vessel industry) were determined. The microstructure of the hot rolled carbon steel contained ferrite/pearlite phases, while that of the quenched and tempered low alloy steel contained bainite structure. Impact properties were determined for both steels by instrumented impact testing at temperatures between -150 and 200℃. The impact properties comprised total impact energy, ductile to brittle transition temperature, crack initiation and propagation energy, brittleness transition temperature and cleavage fracture stress. The Q&T low alloy steel displayed much higher resistance to ductile fracture at high test temperatures, while its resistance to brittle fracture at low test temperatures was a little higher than that of the hot rolled carbon steel. The results were discussed in relation to the difference in the chemical composition and microstructure for the two steels.

  10. Spring cleaning: rural water impacts, valuation, and property rights institutions.

    Science.gov (United States)

    Kremer, Michael; Leino, Jessica; Miguel, Edward; Zwane, Alix Peterson

    2011-01-01

    Using a randomized evaluation in Kenya, we measure health impacts of spring protection, an investment that improves source water quality. We also estimate households' valuation of spring protection and simulate the welfare impacts of alternatives to the current system of common property rights in water, which limits incentives for private investment. Spring infrastructure investments reduce fecal contamination by 66%, but household water quality improves less, due to recontamination. Child diarrhea falls by one quarter. Travel-cost based revealed preference estimates of households' valuations are much smaller than both stated preference valuations and health planners' valuations, and are consistent with models in which the demand for health is highly income elastic. We estimate that private property norms would generate little additional investment while imposing large static costs due to above-marginal-cost pricing, private property would function better at higher income levels or under water scarcity, and alternative institutions could yield Pareto improvements. PMID:21853618

  11. Study of potential advantages of pre-soaking on the properties of pre-cast concrete made with recycled coarse aggregate

    Directory of Open Access Journals (Sweden)

    Sánchez-Roldán, Z.

    2016-03-01

    Full Text Available Recycled aggregate (RA from construction and demolition waste is traditionally used for the manufacture of concrete for different applications. Due primarily to high water content required by RA, the quality of the concrete is determined by the amount of replacement RA. The aim of this study is to determine if RA pre-soaking enhances the properties of pre-cast concrete for street furniture, with low mechanical and structural requirements, in which 100% of the coarse fraction is replaced. The results of physical and mechanical tests performed on concrete specimens in which the RA was pre-soaked using five different methods applied are compared with a reference concrete sample and a concrete sample made with non-pre-soaked RA. The results show that non-pre-soaked RA offers improved physical-mechanical properties for pre-cast concrete, except for the workability; problems arising from poorer workability could be improved with the use of plasticizers, which can be easily included in the production process.El árido reciclado (AR procedente de residuos de construcción y demolición se utiliza tradicionalmente en la elaboración de hormigón para diferentes aplicaciones. Debido principalmente al mayor contenido en agua requerido por el AR, la calidad del hormigón está determinada por la cantidad de AR reemplazado. El objetivo de este estudio es determinar si el AR premojado mejora las propiedades del hormigón prefabricado para mobiliario urbano, con bajas exigencias mecánicas y estructurales, en el que se sustituye el 100% de la fracción gruesa. Los resultados de los ensayos físicos y mecánicos realizados sobre muestras de hormigón en las cuales el AR se ha premojado usando cinco métodos diferentes se han comparado con una muestra de hormigón de referencia y una muestra de hormigón fabricada con AR no premojado. Los resultados muestran que el AR no premojado proporciona propiedades físico-mecánicas mejoradas en el hormigón prefabricado

  12. Plastic casting resin poisoning

    Science.gov (United States)

    Epoxy poisoning; Resin poisoning ... Epoxy and resin can be poisonous if they are swallowed or their fumes are breathed in. ... Plastic casting resins are found in various plastic casting resin products.

  13. Analysis of the structure of castings made from chromium white cast iron resistant to abrasive wear

    Directory of Open Access Journals (Sweden)

    D. Kopyciński

    2009-10-01

    Full Text Available It has been proved that an addition of boron carbide and disintegrated steel scrap introduced as an inoculant to the chromium white cast iron changes the structure of castings. The said operation increases the number of crystallization nuclei for dendrites of the primary austenite. In this case, the iron particles act as substrates for the nucleation of primary austenite due to a similar crystallographic lattice. The more numerous are the dendrites of primary austenite and the structure more refined and the mechanical properties higher. Castings after B4C inoculation revealed a different structure of fine grained fracture. Primary precipitates of chromium carbide also appeared, reducing the mechanical properties of as-cast parts. Properly established heat treatment regime makes chromium iron castings regain their, originally high, mechanical properties.

  14. Heat treatment of long term serviced Cr – Mo cast steel

    Directory of Open Access Journals (Sweden)

    G. Golanski

    2010-01-01

    Full Text Available The paper presents results of research on the influence of heat treatment on the structure and properties of L20HM cast steel after long term operation at elevated temperature. Investigated cast steel was taken out from an outer frame of a steam turbine serviced for 167 424 hours at the temp. of 535 oC and pressure 12.75 MPa. In post-operating condition the investigated cast steel was characterized by mechanical properties below the required minimum and by high brittleness. Performed research on the influence of austenitizing parameters has revealed that the range of austenitizing temperatures for the examined cast steel: Ac3 + 30 ÷ 60 oC ensures obtaining of a fine austenite grain, homogeneous in size. It has been proved that tempering of bainititc – ferritic structure above 680 ÷ 690 oC causes an increase of impact energy along with a decrease of mechanical properties below the required minimum. Moreover, it has been noticed that applying of under-annealing instead of tempering, after full-annealing, guarantees the required impact energy of KV > 27J, with the mechanical properties similar to those after service.

  15. Investigation on mechanical properties of AlZrCr- A12O3 nanocomposites fabricated by stir casting

    International Nuclear Information System (INIS)

    Aluminum alloy composite with nano Al2O3 reinforcement will be designed to have good mechanical properties that correspond to its application. The addition of nano Al2O3 in aluminum is to increase strength and stiffness. In this study aluminum matrix made as a master alloy with the addition of zirconium (Zr) and cerium (Ce) to form Al-Zr-Ce alloys which was reinforced with nanoscale alumina particles known as nano aluminum composite which has high strength and stiffness. Master alloy Al-Zr-Ce used as a matrix content of 0.12 wt% Zr and 0.13 wt% Ce, while Al2O3 nano particles (<100nm) used as reinforcement was various in the range of 0-3 Vf%. Aluminum composite was produced by stirring of molten metal with a rotational speed of 500 rpm at a temperature of 750°C in an inert argon gas environment then characterized both mechanical properties and microstructure analysis. The tensile strength increased with increasing Al2O3 nano particles up to 1 Vf%. Mechanical properties of composites were slightly increased and there was no significant change in elongation and hardness, perhaps due to the non-uniformity distribution or clustering formation of particles in the matrix

  16. Microstructure and magnetic properties of Fe-Co-Nd-Y-B alloys obtained by suction casting method

    Institute of Scientific and Technical Information of China (English)

    J.Olszewski; J.Zbroszczyk; M.Hasiak; J.Kaleta; M.Nabia(l)ek; P.Bragiel; K.Sobczyk; W.Ciurzy(n)ska; J.(S)wierczek; A.(L)ukiewska

    2009-01-01

    The phase composition,magnetic properties i.e.coercivity and the magnetic polarization at room temperature for the bulk Fe67Co5Nd3Y6B19 and Fe64Co5Nd6Y6B19 alloys were studied.The bulk amorphous Fe67Co5Nd3Y6B19 alloy,inhomogeneous in the as-quenched state,crystallized after annealing at 948 K for 0.5 h and consisted of Nd2Fel4B-type,Fe2B and paramagnetic phases.The rapidly solidified Fe67Co5Nd3Y6B19 alloy contained the Nd2Fe14B-type and paramagnetic phases.The annealing of the bulk Fe67Co5Nd3Y6B19 alloy at 948 K for 0.5 h led to hard magnetic properties.However,the bulk Fe67Co5Nd3Y6B19 alloy exhibited good hard magnetic properties directly after preparation.

  17. Abrasive Wear Behavior of High Chromium Cast Iron and Hadfield Steel-- A Comparison

    Institute of Scientific and Technical Information of China (English)

    Mehdi Mazar Atabaki; Sajjad Jafari; Hassan Abdollah-pour

    2012-01-01

    Wear properties of two different crushers used for grinding raw materials of cement industry are compared using pin-on-disk wear test.The wear test was carried out with different loads on a pin.Abrasive wear behavior of two alloys was evaluated by comparing mass loss,wear resistance,microhardness and friction coefficient.The microstructure of the specimens was detected using optical microscope.The results showed that abrasive wear of high chromium cast iron is lower than that of Hadfield steel.Due to the presence of M7C3 carbides on the high chromium cast iron matrix,impact crushers exhibited higher friction coefficient

  18. Influence of neodymium addition on microstructure, tensile properties and fracture behavior of cast AI-Mg2Si metal matrix composite

    Institute of Scientific and Technical Information of China (English)

    WU Xiaofeng; ZHANG Guang'an; WU Fufa; WANG Zhe

    2013-01-01

    The influence of Nd on the microstructures,tensile properties and fracture behavior of cast Al-18 wt.%MgaSi in situ metal matrix composite was investigated.Experimental results showed that,after introducing a proper amount of Nd,both primary and eutectic Mg2Si in the Al-18 wt.%Mg2Si composite were well modified.The morphology of primary Mg2Si was changed from irregular or dendritic to polyhedral shape,and its average particle size was significantly decreased from 47.5 to 13.0 μm.Moreover,the morphology of the eutectic Mg2Si phase was altered from flake-like to a thin laminar,short fibrous or dot-like structure.Tensile tests revealed that Nd addition improved the tensile strength and ductility of the material.Compared with those of unmodified composite,the ultimate tensile strength and percentage elongation with 0.5% Nd were increased by 32.4% and 200%,respectively.At the same time,Nd addition changed the fracture behavior from brittle to ductile.

  19. Effects of Fe content on the microstructure and properties of CuNi10FeMn1 alloy tubes fabricated by HCCM horizontal continuous casting

    Science.gov (United States)

    Jiang, Yan-bin; Xu, Jun; Liu, Xin-hua; Xie, Jian-xin

    2016-04-01

    Heating-cooling combined mold (HCCM) horizontal continuous casting technology developed by our research group was used to produce high axial columnar-grained CuNi10FeMn1 alloy tubes with different Fe contents. The effects of Fe content (1.08wt%-2.01wt%) on the microstructure, segregation, and flushing corrosion resistance in simulated flowing seawater as well as the mechanical properties of the alloy tubes were investigated. The results show that when the Fe content is increased from 1.08wt% to 2.01wt%, the segregation degree of Ni and Fe elements increases, and the segregation coefficient of Ni and Fe elements falls from 0.92 to 0.70 and from 0.92 to 0.63, respectively. With increasing Fe content, the corrosion rate of the alloy decreases initially and then increases. When the Fe content is 1.83wt%, the corrosion rate approaches the minimum and dense, less-defect corrosion films, which contain rich Ni and Fe elements, form on the surface of the alloy; these films effectively protect the α-matrix and reduce the corrosion rate. When the Fe content is increased from 1.08wt% to 2.01wt%, the tensile strength of the alloy tube increases from 204 MPa to 236 MPa, while the elongation to failure changes slightly about 46%, indicating the excellent workability of the CuNi10FeMn1 alloy tubes.

  20. LLNL casting technology

    Science.gov (United States)

    Shapiro, A. B.; Comfort, W. J., III

    1994-01-01

    Competition to produce cast parts of higher quality, lower rejection rate, and lower cost is a fundamental factor in the global economy. To gain an edge on foreign competitors, the US casting industry must cut manufacturing costs and reduce the time from design to market. Casting research and development (R&D) are the key to increasing US competiveness in the casting arena. Lawrence Livermore National Laboratory (LLNL) is the home of a wide range of R&D projects that push the boundaries of state-of-the art casting. LLNL casting expertise and technology include: casting modeling research and development, including numerical simulation of fluid flow, heat transfer, reaction/solidification kinetics, and part distortion with residual stresses; special facilities to cast toxic material; extensive experience casting metals and nonmetals; advanced measurement and instrumentation systems. Department of Energy (DOE) funding provides the leverage for LLNL to collaborate with industrial partners to share this advanced casting expertise and technology. At the same time, collaboration with industrial partners provides LLNL technologists with broader insights into casting industry issues, casting process data, and the collective experience of industry experts. Casting R&D is also an excellent example of dual-use technology; it is the cornerstone for increasing US industrial competitiveness and minimizing waste nuclear material in weapon component production. Annual funding for casting projects at LLNL is $10M, which represents 1% of the total LLNL budget. Metal casting accounts for about 80% of the funding. Funding is nearly equally divided between development directed toward US industrial competitiveness and weapon component casting.

  1. Optimization of the Chemical Composition of Cast Iron Used for Casting Ball Bearing Grinding Disks

    Institute of Scientific and Technical Information of China (English)

    Aurel Crisan; Sorin Ion; Munteanu; Ioan Ciobanu; Iulian Riposan

    2008-01-01

    The chemical composition of cast iron used for casting ball bearing machining disks was varied to optimize the properties such as castability, hardenability, and durability in ball machining. The cast iron characteristics were most strongly dependent on the Ni content and the carbon saturation degree, So. This paper describes the types of test specimens, the working conditions, and the experimental results. The in-crease of the degree of carbon saturation reduces the tendency to form shrinkholes in the castings. The de-crease in the Ni content negatively affects the final hardening treatment. A way to control solidification de-fects in cast iron, by reducing the Ni content, has been verified on cast disks.

  2. Investigations of Protective Coatings for Castings of High-manganese Cast Steels

    Directory of Open Access Journals (Sweden)

    M. Holtzer

    2013-01-01

    Full Text Available When cast steel castings are made in moulding sands on matrices of high-silica sand, which has a low fire resistance the problem of theso-called chemical penetration is distinctly visible. Whereas this effect appears to a small degree only when moulding sand matrices are of chromite, zircon or olivine sands. Therefore in case of making castings of high-manganese cast steel (e.g. Hadfield steel sands not containing free silica should be applied (e.g. olivine sand or in case of a high-silica matrix protective coatings for moulds and cores should be used. Two protective coatings, magnesite alcoholic (marked as coating 1 and coating 2 originated from different producers and intended for moulds for castings of the Hadfield steel, were selected for investigations. Examinations of the basic properties were performed for these coatings: viscosity, thermal analysis, sedimentation properties, wear resistance. In order to estimate the effectiveness of protective coatings the experimental castings were prepared. When applying coating 1, the surface quality of the casting was worse and traces of interaction between the casting material (cast steel and the coating were seen. When protective coating 2 was used none interactions were seen and the surface quality was better.

  3. Effect of Cr, Ti, V, and Zr Micro-additions on Microstructure and Mechanical Properties of the Al-Si-Cu-Mg Cast Alloy

    Science.gov (United States)

    Shaha, S. K.; Czerwinski, F.; Kasprzak, W.; Friedman, J.; Chen, D. L.

    2016-05-01

    Uniaxial static and cyclic tests were used to assess the role of Cr, Ti, V, and Zr additions on properties of the Al-7Si-1Cu-0.5Mg (wt pct) alloy in as-cast and T6 heat-treated conditions. The microstructure of the as-cast alloy consisted of α-Al, eutectic Si, and Cu-, Mg-, and Fe-rich phases Al2.1Cu, Al8.5Si2.4Cu, Al5.2CuMg4Si5.1, and Al14Si7.1FeMg3.3. In addition, the micro-sized Cr/Zr/Ti/V-rich phases Al10.7SiTi3.6, Al6.7Si1.2TiZr1.8, Al21.4Si3.4Ti4.7VZr1.8, Al18.5Si7.3Cr2.6V, Al7.9Si8.5Cr6.8V4.1Ti, Al6.3Si23.2FeCr9.2V1.6Ti1.3, Al92.2Si16.7Fe7.6Cr8.3V1.8, and Al8.2Si30.1Fe1.6Cr18.8V3.3Ti2.9Zr were present. During solution treatment, Cu-rich phases were completely dissolved, while the eutectic silicon, Fe-, and Cr/Zr/Ti/V-rich intermetallics experienced only partial dissolution. Micro-additions of Cr, Zr, Ti, and V positively affected the alloy strength. The modified alloy in the T6 temper during uniaxial tensile tests exhibited yield strength of 289 MPa and ultimate tensile strength of 342 MPa, being significantly higher than that for the Al-Si-Cu-Mg base. Besides, the cyclic yield stress of the modified alloy in the T6 state increased by 23 pct over that of the base alloy. The fatigue life of the modified alloy was substantially longer than that of the base alloy tested using the same parameters. The role of Cr, Ti, V, and Zr containing phases in controlling the alloy fracture during static and cyclic loading is discussed.

  4. Evolution of the microstructure and magnetic properties of as-cast and melt spun Fe2NiAl alloy during aging

    Science.gov (United States)

    Menushenkov, V. P.; Gorshenkov, M. V.; Shchetinin, I. V.; Savchenko, A. G.; Savchenko, E. S.; Zhukov, D. G.

    2015-09-01

    Fe2NiAl-based alloy with the nominal composition Fe51.1Ni23.5Al23.7Si1.7 was prepared by casting and melt-spinning. Comparison of the phase composition, microstructure and magnetic properties of water-quenched bulk samples and melt spun ribbons after isothermal aging in the 500-900 °C range were carried out. TEM investigations of the decomposition of the solid solution into β- and β2 phases during cooling or quenching and subsequent aging have revealed different types of decomposition products. The optimal periodic modulated structure with coercive force Hc~700 Oe was observed after cooling of as-cast alloy at a critical rate. In this structure the paramagnetic β2 phase forms a continuous network that isolates elongated single domain ferromagnetic β particles. The water-quenched bulk samples and melt spun ribbons were characterized by zone structure with zones about 10 nm and 4 nm in size. The isothermal aging of quenched samples resulted in the formation of modulated microstructure dissimilar to those of the optimal state. The coarsening of ferromagnetic β particles as well as deterioration of the magnetic insulation of β particles occur in bulk samples after aging at Tag>700 °C that decreases Hc≤350 Oe. The dependence δM(H) was measured and negative values of δM(H) in the H=0-2000 Oe range indicate that magnetostatic interactions between the β particles are dominant. The melt spun ribbons were characterized by the presence of antiphase domain boundaries (APD) and discontinuous precipitation (DP) products at grain boundaries (GB). The cellular areas at GBs consisting of alternating lamellas of β‧- and β2‧ type phases were formed after aging the ribbons at Tag>500 °C. At Tag>700 °C the modulated structure formed inside grains and the wide intergranular double-layer of β and β2 phases develops by the coalescence of the primary DP products that decrease Hc≤250 Oe. MFM image of the magnetic structure correlated with the microstructure of the

  5. Impact Strength of Austenitic and Ferritic-Austenitic Cr-Ni Stainless Cast Steel in -40 and +20°C Temperature

    OpenAIRE

    Kalandyk B.; Zapała R.; Boroń Ł.; Solecka M.

    2014-01-01

    Studies described in this paper relate to common grades of cast corrosion resistant Cr-Ni steel with different matrix. The test materials were subjected to heat treatment, which consisted in the solution annealing at 1060°C followed by cooling in water. The conducted investigations, besides the microstructural characteristics of selected cast steel grades, included the evaluation of hardness, toughness (at a temperature of -40 and +20oC) and type of fracture obtained after breaking the specim...

  6. A multi-technique study of structure and dynamics of polyfluorenes cast films and the influence on their photoluminescent properties

    International Nuclear Information System (INIS)

    In the last few years the use of conjugated polymers as active layers in the so called 'organic electronics' has progressed rapidly from being an interesting academic material to become a reality on electronic industries, bein applied even for thin flexible displays. However, understanding how the structural and dynamic properties of the polymer chain may affect the light emission still remanins a challenge. Here we report a multi-technique study of the microstructure and dynamics in solid state of polyfluorene based polymers, poly(9.9-dioctylfluorenyl-2.7-diyl) (PFO) a semi-crystalline polymer and poly(9.9-dioctyl-2.7-divinylene-fluorenylene)-alt-co--{2-methoxy-5-(2-ethyl -hexyloxy-1,4-phenylene vinylene) (PFO-alt-co-MEHPV), a copolymer with mesomorfphic phase properties. The Wide-Angle X-ray Scattering (WAXS) measurements revelead the structures, the structural transformations and the local packing variations that occurred as a function of temperature as a result of polymer chain relaxations, also identified by Dynamic Mechanical Thermal Analysis (DMTA) and Solid-State Nuclear Magnetic Resonance (NMR). For PFO-altco-MEHPV, the variation in the packing and the chains motion could explain the changes produced in the fluorescence of the polymer. In contrast, for PFO, besides the molecular relacation and local packing variations in the more disordered regions, strong modifications in its luminescent behavior is observed as results of the phase transformations induced by temperature. (author)

  7. Effects of rolling temperature on microstructure, texture, formability and magnetic properties in strip casting Fe-6.5 wt% Si non-oriented electrical steel

    Science.gov (United States)

    Liu, Hai-Tao; Li, Hao-Ze; Li, Hua-Long; Gao, Fei; Liu, Guo-Huai; Luo, Zhong-Han; Zhang, Feng-Quan; Chen, Sheng-Lin; Cao, Guang-Ming; Liu, Zhen-Yu; Wang, Guo-Dong

    2015-10-01

    Fe-6.5 wt% Si non-oriented electrical steel sheets with a thickness of 0.50 mm were produced by using a new processing route: strip casting followed by hot rolling, intermediate temperature (150-850 °C) rolling and final annealing. The present study focused on exploring the effects of rolling temperature varying from 150 to 850 °C on the microstructure and texture evolution, the formability and final magnetic properties. The microstructure and texture evolution at the various processing steps were investigated in detail by using OM, XRD, EBSD and TEM. It was found that the formability during rolling, the microstructure and texture before and after annealing and final magnetic properties highly depended on rolling temperature. The formability during rolling was gradually improved with increasing rolling temperature due to the slipping of dislocation. In particular, the rolling temperature dominated the formation of in-grain shear bands in the rolled microstructure, which played an important role in the development of final recrystallization microstructure and texture. In the case of lower temperature (150-450 °C) rolling, an inhomogeneous microstructure with a large amount of in-grain shear bands was formed in the rolled sheets, which finally resulted in a fine and inhomogeneous annealing microstructure dominated by mild λ-fiber texture composed of cube and {001} components and α*-fiber texture concentrated on {115} component. By contrast, in the case of higher temperature (650-850 °C) rolling, a relatively homogeneous microstructure without in-grain shear bands was formed instead in the rolled sheets, which finally led to a coarse and relatively homogeneous annealing microstructure characterized by strong α-fiber and γ-fiber texture. Accordingly, on the whole, both the magnetic induction (B8 and B50) and iron loss (P15/50 and P10/400) decreased with raising rolling temperature.

  8. Effects of warm temper rolling on microstructure, texture and magnetic properties of strip-casting 6.5 wt% Si electrical steel

    Science.gov (United States)

    Li, Hao-Ze; Liu, Hai-Tao; Liu, Yi; Liu, Zhen-Yu; Cao, Guang-Ming; Luo, Zhong-Han; Zhang, Feng-Quan; Chen, Sheng-Lin; Lyu, Li; Wang, Guo-Dong

    2014-12-01

    6.5 wt% Si electrical steel thin sheets were produced by a processing route including strip casting, hot rolling, warm rolling, intermediate annealing, warm temper rolling and final annealing, in which the warm temper rolling reduction varied from 2.7% to 14.4%. A detailed study of the microstructural and textural evolutions through the whole processing route was carried out by optical microscopy, X-ray diffraction and electron backscattered diffraction analysis. The findings revealed that the final recrystallization microstructure, texture and magnetic properties relied heavily on the warm temper rolling reduction. As the warm temper rolling reduction increased from 2.7% to 14.4%, the finally recrystallized microstructures were more homogeneous and the average grain size was decreased. At the warm temper rolling reduction lower than 7.0%, the occurrence of the exaggeratedly large annealing grains which dominated the whole sheet thickness resulted in strong //ND fiber, parallel α-fiber, //ND fiber and many other strong hard-magnetization texture components. By contrast, at the warm temper rolling reduction higher than 7.0%, the recrystallization textures were characterized by weak //ND fiber, parallel α-fiber, //ND texture, together with fewer and weak hard-magnetization texture components. The mechanism responsible for the finally microstructural and textural changes was explained by strain induced boundary migration. As warm temper rolling reduction increased, the magnetic properties at high frequency were gradually improved due to smaller grain sizes and more desirable textures. The highest magnetic inductions of 1.383 T (B8), 1.484 T (B25) and 1.571 T (B50) in combination with the lowest iron losses at high frequencies of 19.11 W/Kg (W10/400) and 3.824 W/Kg (W2/1000) were obtained at 14.4% warm temper rolling reduction under the applied condition.

  9. Improved Life of Die Casting Dies of H13 Steel by Attaining Improved Mechanical Properties and Distortion Control During Heat Treatment

    Energy Technology Data Exchange (ETDEWEB)

    J. F. Wallace; D. Schwam

    1998-10-01

    The ultimate goal of this project is to increase die casting die life by using fast enough quenching rates to obtain good toughness and fatigue resistance in premium grade H-13 steel dies. The main tasks of the project were to compile a database on physical and mechanical properties of H-13; conduct gas quenching experiments to determine cooling rates of dies in difference vacuum furnaces; measure the as-quenched distortion of dies and the residual stresses; generate finite element analysis models to predict cooling rates, distortion, and residual stress of gas quenched dies; and establish rules and create PC-based expert system for prediction of cooling rates, distortion, and residual stress in vacuum/gas quenched H-13 dies. Cooling curves during gas quenching of H-13 blocks and die shapes have been measured under a variety of gas pressure. Dimensional changes caused by the gas quenching processes have been determined by accurate mapping of all surfaces with coordinate measuring machines before and after the quench. Residual stresses were determined by the ASTM E837 hole-drilling strain gage method. To facilitate the computer modeling work, a comprehensive database of H-13 mechanical and physical properties has been compiled. Finite element analysis of the heat treated shapes has been conducted using the TRAST/ABAQUS codes. There is a good fit between the predicted and measured distortion contours. However, the magnitude of the predicted distortion and residual stresses does not match well the measured values. Further fine tuning of the model is required before it can be used to predict distortion and residual stress in a quantitative manner. This last step is a prerequisite to generating rules for a reliable expert system.

  10. Model castings with composite surface layer - application

    Directory of Open Access Journals (Sweden)

    J. Szajnar

    2008-10-01

    Full Text Available The paper presents a method of usable properties of surface layers improvement of cast carbon steel 200–450, by put directly in foundingprocess a composite surface layer on the basis of Fe-Cr-C alloy. Technology of composite surface layer guarantee mainly increase inhardness and aberasive wear resistance of cast steel castings on machine elements. This technology can be competition for generallyapplied welding technology (surfacing by welding and thermal spraying. In range of studies was made cast steel test castings withcomposite surface layer, which usability for industrial applications was estimated by criterion of hardness and aberasive wear resistance of type metal-mineral and quality of joint cast steel – (Fe-Cr-C. Based on conducted studies a thesis, that composite surface layer arise from liquid state, was formulated. Moreover, possible is control of composite layer thickness and its hardness by suitable selection of parameters i.e. thickness of insert, pouring temperature and solidification modulus of casting. Possibility of technology application of composite surface layer in manufacture of cast steel slide bush for combined cutter loader is presented.

  11. Structural, morphological and optical properties of PEDOT:PSS/QDs nano-composite films prepared by spin-casting

    Science.gov (United States)

    Najeeb, Mansoor Ani; Abdullah, Shahino Mah; Aziz, Fakhra; Ahmad, Zubair; Rafique, Saqib; Wageh, S.; Al-Ghamdi, Ahmed A.; Sulaiman, Khaulah; Touati, Farid; Shakoor, R. A.; Al-Thani, N. J.

    2016-09-01

    This paper describes the structural, morphological and optical properties of the nano-composite of poly (3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) and quantum dots (QDs). The ZnSe and CdSe QDs have been synthesized, with the aid of Mercaptoacetic acid (MAA), by a colloidal method with an average size of ~5 to 7 nm. QDs have been embedded in PEDOT:PSS using a simple solution processing approach and has been deposited as thin films by spin coating technique. The QDs embedded PEDOT:PSS enhances the light absorption spectra of samples, prominently in terms of absorption intensity which may consequently improve sensitivity of the optoelectronic devices.

  12. Birefringence gradient development during drying of solution cast functional films and their mechanical, optical and gas barrier properties

    Science.gov (United States)

    Yucel, Orcun

    For the first time, the development of optical anisotropy gradient as a result of solvent evaporation for poly (amide-imide) (PAI) solution in Dimethylacetamide (DMAc) was investigated. Experiments were carried out using real time optical measurement with spectral birefringence technique coupled with off-line optical techniques such as Abbe refractometer and optical compensator method. Drying process induced temporal evolution of non-uniform out of plane birefringence profile through the thickness direction while in plane birefringence remained zero. The highest birefringence was observed at the substrate-solution interface at early stages of drying. Beyond a critical time, the formation of highly oriented layer was observed at the air-solution interface. This oriented layer progresses through the thickness direction as the solvent concentration is disproportionately reduced in these regions. Abbe refractometer results confirmed the anisotropy is preserved at longer drying times, air-solution interface birefringence becoming higher compared to substrate-solution interface. Overall, observations obtained by real-time measurement system agreed with off-line measurements. In additon, multifunctional single and triple-layer films exhibiting flexibility, high modulus and high gas barrier properties were developed using a soluble polyamide-imide (PAI) in dimethylacetamide (DMAc) with ammonium-modified montmorillonite (MMT, Cloisite 30B) mineral clay. The drying behavior and associated anisotropy development were determined real-time, using a newly developed real-time measurement system. Increase in organoclay content resulted in higher viscosity values. This behavior was reversed at high shear rates. Out-of-plane birefringence development occurred earlier for thinner neat samples caused by increased depletion rate of solvent. Addition of organoclay content resulted in a decrease in evaporation rate of solvent due to planar orientation of well exfoliated nanoplatelets as

  13. Effect of process parameters on properties of Al-Si alloys cast by Rapid Slurry Formation (RSF) technique

    International Nuclear Information System (INIS)

    Rapid slurry formation is a semi-solid metal forming technique, which is based on a so-called solid enthalpy exchange material (EEM). It is a fascinating technology offering the opportunity to manufacture net-shaped metal components of complex geometry in a single forming operation. At the same time, high mechanical properties can be achieved due to the unique microstructure and flow behaviour. The major process parameters used in the RSF process are rotation speed of the EEM, melt superheat, amount of EEM added (determining fs), and holding time. The process parameters can be well controlled with clear effects on the microstructure. There is a lack of theoretical modelling of the morphological evolution in these two-phase slurries.

  14. Colour Metallography of Cast Iron - Chapter 3: Spheroidal Graphite Cast Iron (Ⅰ

    Directory of Open Access Journals (Sweden)

    Zhou Jiyang

    2010-02-01

    Full Text Available Cast iron, as a traditional metal material, has advantages of low total cost, good castability and machinability, good wear resistance and low notch sensitivity, and is still facing tough challenge in quality, property and variety of types etc. Experts and engineers studying and producing iron castings all around world extremely concern this serious challenge. Over more than 30 years, a great of research work has been carried out on how to further improve its property, expand its application and combine cast iron technology with some hi-techs (for example, computer technology. Nevertheless, cast iron is a multi-element and multi-phase alloy and has complex and variety of structures and still has great development potential in structure and property. For further studying and developing cast iron, theoretical research work is important promise, and the study on solidification process and control mechanism of graphite morphology is fundamental for improving property of cast iron and developing new type of cast iron. Metallography of cast iron normally includes two sections: liquid phase transformation and solid phase transformation. The book, Colour Metallography of Cast Iron, uses colour metallography technique to study solidification structures of cast irons: graphite, carbides, austenite and eutectics; and focuses on solidification processes. With progress of modern solidification theory, the control of material solidification process becomes important measure for improving traditional materials and developing new materials. Solidification structure not only influences mechanical and physical properties of cast iron, but also affects its internal quality. The book uses a large amount of colour photos to describe the formation of solidification structures and their relations. Crystallization phenomena, which cannot be displayed with traditional metallography, are presented and more phase transformation information is obtained from these colour

  15. Impact of aging conditions on mechanical properties of thermoplastic polyurethane

    International Nuclear Information System (INIS)

    In this study, impact of environmental aging conditions on the mechanical properties of thermoplastic polyurethane (TPU) was investigated. Especially, effect of temperature on water diffusion has been studied. Water-sorption experiments, tensile test and dynamic mechanical thermal analysis (DMTA) were performed after immersion in distilled water at different temperatures (25, 70 and 90 oC). The sorption process was analyzed by gravimetric measurements at different temperatures. Also, diffusion coefficients of solvent molecules in the TPU samples were identified. Therefore the activation energy and the mixing enthalpy were deduced. The aging impact on some mechanical properties of this material has been investigated after various aging cycles. Degradation of mechanical properties was observed. In fact, elastic modulus and stress at 200% of strain were decreased. It was also shown that such degradation largely depends on both aging temperature and aging immersion duration. The storage modulus (E') was also affected by the hygrothermal (HT) environment. The modification of mechanical properties seems to be well correlated to structural observations obtained from scanning electron microscopy (SEM) photographs. Finally, through thermal aging experiments, it was deduced that the combination of temperature with water seems to be a major factor of TPU degradation.

  16. Prediction of aging degradation of cast stainless steel components in LWR systems

    International Nuclear Information System (INIS)

    A procedure and correlations are presented for predicting Charpy-impact energy, tensile flow stress, fracture toughness J-R curve, and JIC of aged cast stainless steels from known material information. The ''saturation'' impact strength and fracture toughness of a specific cast stainless steel, i.e., the minimum value that would be achieved for the material after long-term service, is estimated from the chemical composition of the steel. Mechanical properties as a function of time and temperature of reactor service are estimated from impact energy and flow stress of the unaged material and the kinetics of embrittlement, which are also determined from chemical composition. The JIC values are determined from the estimated J-R curve and flow stress. Examples of estimating mechanical properties of of cast stainless steel components during reactor service are presented. A common ''predicted lower-bound' J-R curve for cast stainless steels of unknown chemical composition is also defined for a given grade of steel, ferrite content, and temperature

  17. Asteroid Impact Deflection and Assessment (AIDA) mission - Properties of Impact Ejecta

    Science.gov (United States)

    Hamilton, Douglas P.; Fahnestock, Eugene G.; Schwartz, Stephen R.; Murdoch, Naomi; Asphaug, Erik; Cheng, Andrew F.; Housen, Kevin R.; Michel, Patrick; Miller, Paul L.; Stickle, Angela; Tancredi, Gonzalo; Vincent, Jean-Baptiste; Wuennemann, Kai; Yu, Yang; AIDA Impact Simulation Working Group

    2016-10-01

    The Asteroid Impact Deflection and Assessment (AIDA) mission is composed of NASA's Double Asteroid Redirection Test (DART) mission and ESA's Asteroid Impact Monitor (AIM) rendezvous mission. The DART spacecraft is designed to impact the small satellite of near-Earth asteroid 65803 Didymos in October 2022, while the in-situ AIM spacecraft observes. AIDA's Modeling and Simulation of Impact Outcomes Working Group is tasked with investigating properties of the debris ejected from the impact. The orbital evolution of this ejecta has important implications for observations that the AIM spacecraft will take as well as for the safety of the spacecraft itself. Ejecta properties including particle sizes, bulk densities, and velocities all depend on the poorly-known physical properties of Didymos' moon. The moon's density, internal strength, and especially its porosity have a strong effect on all ejecta properties. Making a range of assumptions, we perform a suite of numerical simulations to determine the fate of the ejected material; we will use simulation predictions to optimize AIM observations and safety. Ultimately, combining AIM's observations of the ejecta with detailed numerical simulations will help constrain key satellite parameters.We use distinct types of numerical tools to explore ejecta properties based on additional target parameters (different forms of friction, cohesion), e.g., the shock physics code iSALE, smoothed particle hydrodynamics codes, and the granular code PKDGRAV. Given the large discrepancy between the 6 km/s impact speed of DART and the moon's 6 cm/s escape speed, a great challenge will be to determine properties of the low-speed ejecta. Very low-speed material relevant to the safety of the AIM spacecraft and its ability to conduct its observations may loft from the crater at late stages of the impact process, or from other locations far from the impact site due to seismic energy propagation. The manner in which seismic waves manifests in

  18. The Improvement of Tribological and Fatigue Properties of Casting Magnesium Alloy AZ91 Performed Diamond Like Carbon Coating

    Science.gov (United States)

    Akebono, Hiroyuki; Suzuki, Hideto

    In recent years, magnesium alloy has been widely used because of its low weight and ease of recycling. However, because magnesium alloys provide inferior wear resistance, it is necessary to improve this property to use magnesium alloy for more machine parts. For this study, we produced a diamond like carbon (DLC) coating that has high hardness, low friction, and excellent wear resistance. With DLC coated onto a soft material such as magnesium alloy, the adhesion strength between the substrate and the coating poses an important problem. Therefore, in this study, to acquire high adhesion strength, the DLC coating process was performed using unbalanced magnetron sputtering (UBMS). A tungsten-doped inter-layer was formed on the substrate. Onto the inter-layer, nano-order DLC coatings of two kinds were laminated. Wear tests and fatigue tests were carried out. The DLC-coated magnesium alloy exhibited excellent wear friction. Furthermore, DLC coatings raised its fatigue reliability over that of the substrate alone.

  19. Optical properties of a long dynamic range chemical UV dosimeter based on solvent cast polyvinyl chloride (PVC).

    Science.gov (United States)

    Amar, Abdurazaq; Parisi, Alfio V

    2013-11-01

    The dosimetric properties of the recently introduced UV dosimeter based on 16 μm PVC film have been fully characterised. Drying the thin film in air at 50 °C for at least 28 days was found to be necessary to minimise the temperature effects on the dosimeter response. This research has found that the dosimeter response, previously reported to be mainly to UVB, has no significant dependence on either exposure temperature or dose rate. The dosimeter has negligible dark reaction and responds to the UV radiation with high reproducibility. The dosimeter angular response was found to have a similar pattern as the cosine function but deviates considerably at angles larger than 70°. Dose response curves exhibit monotonically increasing shape and the dosimeter can measure more than 900 SED. This is about 3 weeks of continuous exposure during summer at subtropical sites. Exposures measured by the PVC dosimeter for some anatomical sites exposed to solar radiation for twelve consecutive days were comparable with those concurrently measured by a series of PPO dosimeters and were in line with earlier results reported in similar studies.

  20. Impact of biocrust succession on water retention and repellency on open-cast lignite mining sites under reclamation in Lower Lusatia, NE-Germany

    Science.gov (United States)

    Gypser, Stella; Fischer, Thomas; Lange, Philipp; Veste, Maik

    2016-04-01

    Mining activities can strongly affect ecosystem properties by destruction of naturally developed soils and removal of vegetation. The unstructured substrates show high bulk densities, compaction, low water infiltration rates, reduced water holding capacities and higher susceptibility to wind and water erosion. In the initial stage of the ecosystem development, the post-mining sites are open areas without or with a low cover of higher vegetation. It is well-known that biocrusts are able to colonize the soil surface under such extreme conditions without human support and affect soil hydrological processes such as water infiltration, run-off or re-distribution. Investigations were conducted on two former lignite open-cast mining sites, an artificial sand dune on the reclaimed watershed Welzow "Neuer Lugteich" and a reforestation area in Schlabendorf (Brandenburg, north-east Germany). The aim was to relate the hydrological characteristics of the topsoil to successional stages of biological soil crusts on reclaimed soils and their influence on repellency index and water holding capacity compared to pure mining substrate. Our study emphasized the influence of changing successional stages and species composition of biological soil crusts, forming a small-scale crust pattern, on water repellency and retention on sandy soils in temperate climate. Different successional stages of soil crusts were identified from initial scattered green algae crusts, dominated by Zygogonium spec. and Ulothrix spec., and more developed soil crusts containing mosses such as Ceratodon purpureus and Polytrichum piliferum. Lichens of the Genus Cladonia were more pronouncedly contributed to biocrusts at later and mature stages of development. The repellency index on the one hand increased due to the cross-linking of sand particles by the filamentous green algae Zygogonium spec. which resulted in clogging of pores, and on the other hand decreased with the occurrence of moss plants due to absorption

  1. Recent development of ductile cast iron production technology in China

    Institute of Scientific and Technical Information of China (English)

    Cai Qizhou; Wei Bokang

    2008-01-01

    Recent progress in the production and technology of ductile cast iron castings in China is reviewed.The manufacture and process control of as-cast ductile iron are discussed.The microstructure.properties and application of partial austenitization normalizing ductile iron and austempered duclile iron(ADI)are briefly depicted.The new development of duclile iron production techniques,such as cored-wire injection(wire-feeding nodularization)process,tundish cover ladle nodularizing process,horizontal continuous casting,and EPC process (lost foam)for ductile iron castings,etc.,are summarized.

  2. Analysis of Dynamic Properties of Piezoelectric Structure under Impact Load

    Directory of Open Access Journals (Sweden)

    Taotao Zhang

    2015-10-01

    Full Text Available An analytical model of the dynamic properties is established for a piezoelectric structure under impact load, without considering noise and perturbations in this paper. Based on the general theory of piezo-elasticity and impact mechanics, the theoretical solutions of the mechanical and electrical fields of the smart structure are obtained with the standing and traveling wave methods, respectively. The comparisons between the two methods have shown that the standing wave method is better for studying long-time response after an impact load. In addition, good agreements are found between the theoretical and the numerical results. To simulate the impact load, both triangle and step pulse loads are used and comparisons are given. Furthermore, the influence of several parameters is discussed so as to provide some advices for practical use. It can be seen that the proposed analytical model would benefit, to some extent, the design and application (especially the airport runway of the related smart devices by taking into account their impact load performance.

  3. Characterization of Triaxial Braided Composite Material Properties for Impact Simulation

    Science.gov (United States)

    Roberts, Gary D.; Goldberg, Robert K.; Biniendak, Wieslaw K.; Arnold, William A.; Littell, Justin D.; Kohlman, Lee W.

    2009-01-01

    The reliability of impact simulations for aircraft components made with triaxial braided carbon fiber composites is currently limited by inadequate material property data and lack of validated material models for analysis. Improvements to standard quasi-static test methods are needed to account for the large unit cell size and localized damage within the unit cell. The deformation and damage of a triaxial braided composite material was examined using standard quasi-static in-plane tension, compression, and shear tests. Some modifications to standard test specimen geometries are suggested, and methods for measuring the local strain at the onset of failure within the braid unit cell are presented. Deformation and damage at higher strain rates is examined using ballistic impact tests on 61- by 61- by 3.2-mm (24- by 24- by 0.125-in.) composite panels. Digital image correlation techniques were used to examine full-field deformation and damage during both quasi-static and impact tests. An impact analysis method is presented that utilizes both local and global deformation and failure information from the quasi-static tests as input for impact simulations. Improvements that are needed in test and analysis methods for better predictive capability are examined.

  4. Cracks in high-manganese cast steel

    Directory of Open Access Journals (Sweden)

    A. Chojecki

    2009-10-01

    Full Text Available The reasons which account for the formation of in service cracks in castings made from Hadfield steel were discussed. To explain the source of existence of the nuclei of brittle fractures, the properties of cast steel were examined within the range of solidification temperatures, remembering that feeding of this material is specially difficult, causing microporosity in hot spots. This creates conditions promoting the formation of microcracks which tend to propagate during service conditions involving high dynamic stresses, and explains why the cracks are mainly characterized by a brittle nature. The reason for crack formation in service are micro-porosities formed during casting solidification.

  5. Effects of rolling temperature on microstructure, texture, formability and magnetic properties in strip casting Fe-6.5 wt% Si non-oriented electrical steel

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Hai-Tao, E-mail: liuht@ral.neu.edu.cn [State Key Laboratory of Rolling and Automation, Northeastern University, P.O. Box 105, Shenyang 110819 (China); Institute of Research of Iron and Steel, Shasteel, Zhangjiagang 215625, Jiangsu (China); Li, Hao-Ze [State Key Laboratory of Rolling and Automation, Northeastern University, P.O. Box 105, Shenyang 110819 (China); Li, Hua-Long [Institute of Research of Iron and Steel, Shasteel, Zhangjiagang 215625, Jiangsu (China); Gao, Fei; Liu, Guo-Huai [State Key Laboratory of Rolling and Automation, Northeastern University, P.O. Box 105, Shenyang 110819 (China); Luo, Zhong-Han; Zhang, Feng-Quan; Chen, Sheng-Lin [National Engineering Research Center for Silicon Steel, Wuhan Iron & Steel (Group) Corp, Wuhan 430083 (China); Cao, Guang-Ming; Liu, Zhen-Yu; Wang, Guo-Dong [State Key Laboratory of Rolling and Automation, Northeastern University, P.O. Box 105, Shenyang 110819 (China)

    2015-10-01

    Fe-6.5 wt% Si non-oriented electrical steel sheets with a thickness of 0.50 mm were produced by using a new processing route: strip casting followed by hot rolling, intermediate temperature (150–850 °C) rolling and final annealing. The present study focused on exploring the effects of rolling temperature varying from 150 to 850 °C on the microstructure and texture evolution, the formability and final magnetic properties. The microstructure and texture evolution at the various processing steps were investigated in detail by using OM, XRD, EBSD and TEM. It was found that the formability during rolling, the microstructure and texture before and after annealing and final magnetic properties highly depended on rolling temperature. The formability during rolling was gradually improved with increasing rolling temperature due to the slipping of dislocation. In particular, the rolling temperature dominated the formation of in-grain shear bands in the rolled microstructure, which played an important role in the development of final recrystallization microstructure and texture. In the case of lower temperature (150–450 °C) rolling, an inhomogeneous microstructure with a large amount of in-grain shear bands was formed in the rolled sheets, which finally resulted in a fine and inhomogeneous annealing microstructure dominated by mild λ-fiber texture composed of cube and {001}〈210〉 components and α*-fiber texture concentrated on {115}〈5–10 1〉 component. By contrast, in the case of higher temperature (650–850 °C) rolling, a relatively homogeneous microstructure without in-grain shear bands was formed instead in the rolled sheets, which finally led to a coarse and relatively homogeneous annealing microstructure characterized by strong α-fiber and γ-fiber texture. Accordingly, on the whole, both the magnetic induction (B{sub 8} and B{sub 50}) and iron loss (P{sub 15/50} and P{sub 10/400}) decreased with raising rolling temperature. - Highlights: • Fe−6

  6. Tensile Properties and Fracture Behavior of Aluminum Alloy Foam Fabricated from Die Castings without Using Blowing Agent by Friction Stir Processing Route

    Directory of Open Access Journals (Sweden)

    Yoshihiko Hangai

    2014-03-01

    Full Text Available Al foam has been used in a wide range of applications owing to its light weight, high energy absorption and high sound insulation. One of the promising processes for fabricating Al foam involves the use of a foamable precursor. In this study, ADC12 Al foams with porosities of 67%–78% were fabricated from Al alloy die castings without using a blowing agent by the friction stir processing route. The pore structure and tensile properties of the ADC12 foams were investigated and compared with those of commercially available ALPORAS. From X-ray computed tomography (X-ray CT observations of the pore structure of ADC12 foams, it was found that they have smaller pores with a narrower distribution than those in ALPORAS. Tensile tests on the ADC12 foams indicated that as their porosity increased, the tensile strength and tensile strain decreased, with strong relation between the porosity, tensile strength, and tensile strain. ADC12 foams exhibited brittle fracture, whereas ALPORAS exhibited ductile fracture, which is due to the nature of the Al alloy used as the base material of the foams. By image-based finite element (FE analysis using X-ray CT images corresponding to the tensile tests on ADC12 foams, it was shown that the fracture path of ADC12 foams observed in tensile tests and the regions of high stress obtained from FE analysis correspond to each other. Therefore, it is considered that the fracture behavior of ADC12 foams in relation to their pore structure distribution can be investigated by image-based FE analysis.

  7. Glovebox Advanced Casting System Casting Optimization

    Energy Technology Data Exchange (ETDEWEB)

    Fielding, Randall Sidney [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2016-03-01

    Casting optimization in the GACS included three broad areas; casting of U-10Zr pins, incorporation of an integral FCCI barrier, and development of a permanent crucible coating. U-10Zr casting was improved over last year’s results by modifying the crucible design to minimize contact with the colder mold. Through these modifications casting of a three pin batch was successful. Incorporation of an integral FCCI barrier also was optimized through furnace chamber pressure changes during the casting cycle to reduce gas pressures in the mold cavities which led to three full length pins being cast which incorporated FCCI barriers of three different thicknesses. Permanent crucible coatings were tested against a base case; 1500°C for 10 minutes in a U-20Pu-10Zr molten alloy. None of the candidate coating materials showed evidence of failure upon initial visual examination. In all areas of work a large amount of characterization will be needed to fully determine the effects of the optimization activities. The characterization activities and future work will occur next year.

  8. Casting and Mechanized Titanium Restorations

    OpenAIRE

    Madrigal, A.; Lopez, I; Suarez, MJ; Salido, MP.

    2002-01-01

    INTRODUCTION: New materials and methods for clinical dentistry are continuously being introduced. There is a growing interest in the use of titanium as a restorative material for several reasons: its relatively low cost, favorable physical properties and biocompatibility. However, titanium is technically more difficult to handle than conventional metal alloys. There are two fabrication methods for titanium restorations: casting and mechanized (a combination of machine duplication and spark er...

  9. Impact of Foliage Surface Properties on Vegetation Reflection and Absorption

    Science.gov (United States)

    Yang, B.; Knyazikhin, Y.; Yan, L.; Zhao, Y.; Jiao, J.

    2013-12-01

    Optical properties of phytoelements and their distribution in the canopy space (i.e., canopy structure) are among key factors that determine light environment in vegetation canopies, which in turn drives various physiological and physical processes required for the functioning of plants. Canopy radiative response is the source of information about ecosystem properties from remote sensing. Understanding of how radiation interacts with foliage and traverses in the 3D vegetation canopy is essential to both modeling and remote sensing communities. Radiation scattered by a leaf includes information from two dissimilar sources - the leaf surface and leaf interior. The first component of scattered radiation emanates from light reflected at the air-cuticle interface. This portion of reflected radiation does not interact with biochemical constituents inside the leaf and depends on the properties of the leaf surface. The leaf cuticle acts as a "barrier" for photons to enter the mesophyll and be absorbed; thus, tending to increase the leaf scattering. The second component mainly results from radiation interactions within the leaf-interior. The canopy radiation regime is sensitive to canopy structure, leaf surface properties and leaf biochemical constituents. Impact of leaf surface properties on canopy reflection and absorption is poorly understood. Radiation scattered at the surface of leaves is partly polarized. Fresnel reflection is the principal cause of light polarization. Polarization measurements provide a means to assess the impact of leaf surface properties on canopy radiation regime. We measured Bidirectional Reflectance Factor (BRF) in the principal plane and its polarized portion of needles and shoots of two coniferous species in the 400 to 1000 nm spectral interval. The needle and shoot BRF spectra were decomposed into polarized (PBRF) and diffuse (DBRF) components: BRF=PBRF+DBRF. Our analyses indicate: 1) PBRF in forward directions can account for up to 70% of

  10. A Study on the Microstructures and Toughness of Fe-B Cast Alloy Containing Rare Earth

    Science.gov (United States)

    Yi, Dawei; Zhang, Zhiyun; Fu, Hanguang; Yang, Chengyan; Ma, Shengqiang; Li, Yefei

    2015-02-01

    This study investigates the effect of cerium on the microstructures, mechanical properties of medium carbon Fe-B cast alloy. The as-cast microstructure of Fe-B cast alloy consists of the eutectic boride, pearlite, and ferrite. Compared with the coarse eutectic borides in the unmodified alloy, the eutectic boride structures in the modified alloy are greatly refined. Cerium promotes the formation of Ce2O3 phase. Ce2O3 can act as effective heterogeneous nuclei of primary austenite, and refine austenite and boride. After heat treatment, the impact toughness of the modified alloy is higher than that of the unmodified alloy because there are more broken borides in the modified alloy. Meanwhile, the fracture mechanism of medium carbon Fe-B alloy is depicted and analyzed by using fractography.

  11. Effects of Heat Treatment on Hardness and Dry Wear Properties of a Semi-Solid Processed Fe-27 wt pct Cr-2.9 wt pct C Cast Iron

    Institute of Scientific and Technical Information of China (English)

    A. Wiengmoon; T. Chairuangsri; N. Chomsang; N. Poolthong; J.T.H. Pearce

    2008-01-01

    Effects of heat treatments on hardness and dry wear properties of a semi-solid processed Fe-26.96 wt pct Cr- 2.91 wt pct C cast iron were studied. Heat treatments included tempering at 500℃, destabilisation at 1075℃ and destabilisation at 1075℃ plus tempering at 500℃, all followed by air cooling. Electron microscopy revealed that, in the as-cast condition, the primary proeutectic austenite was round in shape while the eutectic M7C3 carbide was found as radiating clusters mixed with directional clusters. Tempering did not change the microstructure significantly when observed by scanning or transmission electron microscopy. Destabilisation followed by air cooling led to a precipitation of secondary M23C6 carbide and a transformation of the primary austenite to martensite. Precipitation behaviour is comparable to that observed in the conventionally cast iron. Tempering after destabilisation resulted in a higher amount of secondary carbide precipitation within the tempered martensite in the eutectic structure. Vickers macrohardness and microhardness in the proeutectic zones were measured. Dry wear properties were tested by using a pin-on-disc method. The maximum hardness and the lowest dry wear rate were obtained from the destabilisation-plus-tempering heat treatment due to the precipitation of secondary carbides within the martensite matrix and a possible reduction in the retained austenite.

  12. Impacts of land leveling on lowland soil physical properties

    Directory of Open Access Journals (Sweden)

    José Maria Barbat Parfitt

    2014-02-01

    Full Text Available The practice of land leveling alters the soil surface to create a uniform slope to improve land conditions for the application of all agricultural practices. The aims of this study were to evaluate the impacts of land leveling through the magnitudes, variances and spatial distributions of selected soil physical properties of a lowland area in the State of Rio Grande do Sul, Brazil; the relationships between the magnitude of cuts and/or fills and soil physical properties after the leveling process; and evaluation of the effect of leveling on the spatial distribution of the top of the B horizon in relation to the soil surface. In the 0-0.20 m layer, a 100-point geo-referenced grid covering two taxonomic soil classes was used in assessment of the following soil properties: soil particle density (Pd and bulk density (Bd; total porosity (Tp, macroporosity (Macro and microporosity (Micro; available water capacity (AWC; sand, silt, clay, and dispersed clay in water (Disp clay contents; electrical conductivity (EC; and weighted average diameter of aggregates (WAD. Soil depth to the top of the B horizon was also measured before leveling. The overall effect of leveling on selected soil physical properties was evaluated by paired "t" tests. The effect on the variability of each property was evaluated through the homogeneity of variance test. The thematic maps constructed by kriging or by the inverse of the square of the distances were visually analyzed to evaluate the effect of leveling on the spatial distribution of the properties and of the top of the B horizon in relation to the soil surface. Linear regression models were fitted with the aim of evaluating the relationship between soil properties and the magnitude of cuts and fills. Leveling altered the mean value of several soil properties and the agronomic effect was negative. The mean values of Bd and Disp clay increased and Tp, Macro and Micro, WAD, AWC and EC decreased. Spatial distributions of all

  13. Expandable pattern casting research

    Science.gov (United States)

    1993-09-01

    The Expandable Pattern Casting (EPC) Process is a developing foundry technology that allows designers the opportunity to consolidate parts, reduce machining, and minimize assembly operations. An air gauging system was developed for measuring foam patterns; exact shrinkage depended on type and density of the foam. Compaction studies showed that maximum sand densities in cavities and under overhangs are achieved with vibrational amplitudes 0.001-0.004 in., and that sand moved most freely within a few inches of the top free surface. Key to complete mold filling while minimizing casting defects lies in removing the foam decomposition products. The most precise iron castings were made by EPC in four commercial EPC foundries, with attention paid to molding and compaction. EP cast 60-45-12 ductile iron had yield strengths, ultimate strengths, and elastic modulus similar to conventionally cast ductile iron cast from the same ladle.

  14. Evolution of the microstructure and magnetic properties of as-cast and melt spun Fe{sub 2}NiAl alloy during aging

    Energy Technology Data Exchange (ETDEWEB)

    Menushenkov, V.P., E-mail: menushenkov@gmail.com; Gorshenkov, M.V.; Shchetinin, I.V.; Savchenko, A.G.; Savchenko, E.S.; Zhukov, D.G.

    2015-09-15

    Fe{sub 2}NiAl-based alloy with the nominal composition Fe{sub 51.1}Ni{sub 23.5}Al{sub 23.7}Si{sub 1.7} was prepared by casting and melt-spinning. Comparison of the phase composition, microstructure and magnetic properties of water-quenched bulk samples and melt spun ribbons after isothermal aging in the 500–900 °C range were carried out. TEM investigations of the decomposition of the solid solution into β- and β{sub 2} phases during cooling or quenching and subsequent aging have revealed different types of decomposition products. The optimal periodic modulated structure with coercive force H{sub c}~700 Oe was observed after cooling of as-cast alloy at a critical rate. In this structure the paramagnetic β{sub 2} phase forms a continuous network that isolates elongated single domain ferromagnetic β particles. The water-quenched bulk samples and melt spun ribbons were characterized by zone structure with zones about 10 nm and 4 nm in size. The isothermal aging of quenched samples resulted in the formation of modulated microstructure dissimilar to those of the optimal state. The coarsening of ferromagnetic β particles as well as deterioration of the magnetic insulation of β particles occur in bulk samples after aging at T{sub ag}>700 °C that decreases H{sub c}≤350 Oe. The dependence δ{sub M}(H) was measured and negative values of δ{sub M}(H) in the H=0–2000 Oe range indicate that magnetostatic interactions between the β particles are dominant. The melt spun ribbons were characterized by the presence of antiphase domain boundaries (APD) and discontinuous precipitation (DP) products at grain boundaries (GB). The cellular areas at GBs consisting of alternating lamellas of β′- and β{sub 2}′ type phases were formed after aging the ribbons at T{sub ag}>500 °C. At T{sub ag}>700 °C the modulated structure formed inside grains and the wide intergranular double-layer of β and β{sub 2} phases develops by the coalescence of the primary DP products that

  15. STUDY ON MACRO AND MICRO MODELING ON SOLIDIFICATION PROCESS OF SHAPED CASTING

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Facing the market economy and global challenge the development of manufacturing industry especially casting industry is critical to the national economy. To reform the traditional casting industry by using computer technology is one of the hottest research frontiers studied by many researchers and engineers. Computer simulation of solidification process of shaped casting can assure the quality of casting, optimize the casting technology, shorten the lead time and therefore decrease the developing and manufacturing cost. Recently, numerical simulation of mold-filling and solidification processes of shaped casting and prediction of microstructure and property as well are extensively studied and put into application in many casting plants with many successful simulation cases.

  16. Caste and power

    DEFF Research Database (Denmark)

    Roy, Dayabati

    2011-01-01

    This paper explores the institution of caste and its operation in a micro-level village setting of West Bengal, an Indian state, where state politics at grass roots level is vibrant with functioning local self-government and entrenched political parties. This ethnographic study reveals that caste......–ideological field, the concept of caste-hierarchy seems to continue as an influencing factor, even in the operation of leftist politics....

  17. Control of microstructure of cast irons Indefinite Chill Double Pour-ICDP

    Directory of Open Access Journals (Sweden)

    T.Válek

    2011-10-01

    Full Text Available ICDP cast irons designated for working layer of centrifugal cylinders of rolling mill must have precisely defined properties. The most closely observed parameters of the ICDP (Indefinite Child Double Pour cast irons are the following: the amount of graphite in a microstructure and hardness of base metal material. Secretion of graphite in cast iron with ledeburitic basic metal compound is a complex process that can be controlled and managed with the use of thermal analysis. On the basis of the evaluation of cooling curve parameters of cast iron there is performed metallurgical adjustment of meltage by adding elements supporting graphite end carbide formation into cast iron. The identified structural and mechanical properties of ICDP cast irons were correlated with recorded KO. Subsequently, a methodology for control of the metallurgical adjustment of cast iron before casting was proposed so as to ensure the desired microstructure and properties the ICDP cast iron.

  18. Preferential dissolution behaviour in Ni–Cr dental cast alloy

    Indian Academy of Sciences (India)

    Viswanathan S Saji; Han Cheol Choe

    2010-08-01

    A Ni–Cr–Mo dental alloy was fabricated by three different casting methods, viz. centrifugal casting, high frequency induction casting and vacuum pressure casting. The dependence of cast microstructure on the electrochemical corrosion behaviour was investigated using potentiodynamic cyclic and potentiostatic polarization techniques, impedance spectroscopy and scanning electron microscopy. The experimental results were compared and discussed with those obtained for a Co–Cr–Mo counterpart. The results of the study showed that the variation in casting morphologies with casting methods has only marginal influence in the overall corrosion resistance of Ni–Cr and Co–Cr dental alloys. There was severe preferential dissolution of Ni rich, Cr and Mo depleted zones from the Ni–Cr–Mo alloy. The overall corrosion resistance property of the Co–Cr base alloy was better than that of the Ni–Cr base alloy.

  19. Microstructures and mechanical properties of AZ31-0.1Ca magnesium alloy produced by soft-contact electromagnetic casting and hot extrusion

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    An AZ31-0.1Ca magnesium alloy produced by Soft-contact electromagnetic continuous casting(SEMC) was investigated.The fine homogeneous structure and the precipitated phases were obtained by SEMC.The effects of microalloying of Ca and middle frequency electromagnetic field on AZ31-0.1Ca magnesium alloy were discussed.And the as-cast billets were extruded with different extrusion ratios subsequently.The alloy showed an ultrafine grain size of 2-5 μm due to dynamic recrytallization(DRX) in the course of hot ext...

  20. Effect composition of SiCp and TiB to the mechanical properties of composite Al7Si-Mg-SiCp by the method of semi solid stir casting

    Science.gov (United States)

    Bhiftime, E. I.; Sulardjaka, Nugroho, Sri

    2016-04-01

    Recently, studies on Aluminum Matrix Composite (AMC) were growing rapidly. AMC reinforced with SiCp particles in the semi solid stir casting method was the most simple way. In particular, the purpose of the present study was to investigate the effect composition of SiCp and TiB to the mechanical properties of the composites Al7Si-Mg-SiCp and Al7Si-Mg-TiB-SiCp. The composites used were Al7Si as the matrix and SiCp as the reinforcement (10, 15, 20 wt%). The casting method used on the study was the semi solid stir casting. The matrix was melted at the temperature of 800 °C. Then, the stirring process started at 590 °C with the speed of 500 rpm for 180 seconds. The composites was heated again until the pouring temperature was at 750 °C. The results of the present study indicated to be successful in which SiCp particles dispersed uniformly in the matrix composites. Further, the hardness value and porosity of the composites Al7Si-Mg-SiCp and Al7Si-Mg-TiB-SiCp increased along with the addition of TiB. Besides, the hardness value increased in the average of 10.5% at the variation of 20% SiCp. Whereas, the porosity value increased in the average of 54.3% at the variation of 20% SiCp.

  1. Combining Aluminum Heat Treat with Hot Isostatic Pressing:A Comparison of Structure, Properties, and Processing Routes for a Cast Al-Si-Mg Alloy

    Institute of Scientific and Technical Information of China (English)

    Stephen J. Mashl

    2004-01-01

    Bodycote researchers have successfully demonstrated that a T6 heat treatment can be integrated with Densal(R), a proprietary, aluminum specific, hot isostatic pressing (HIP) process. In this combined operation, at least a portion of the solution heat treatment is conducted at elevated pressure. During development, two issues, adiabatic cooling during depressurization and a possible variation in the kinetics of homogenization resulting from conducting the solution heat treat at elevated pressure were perceived as factors which could alter the heat treat response fiom that seen in conventional processing.This paper reviews the results of experiments performed to A1-Si-Mg (A356.0) castings subjected to both combined and conventional processing routes. Results indicate that the combined HIP and heat treat process is an efficient means of achieving a microstructure characteristic of a conventionally T6 processed material while eliminating porosity within the casting. Further, the fatigue life of an A356.0 casting processed using the combined cycle can be improved by more than an order of magnitude over the as-cast and T6 treated component.

  2. IMPACT OF COOKING HOMOGENEITY ON PULP STRENGTH PROPERTIES

    Institute of Scientific and Technical Information of China (English)

    Bofeng Mao

    2004-01-01

    Cooking homogeneity of kraft pulping can have significant impact on pulp strength properties. We have studied cooking homogeneity of two kraft digesters within Stora Enso. One of the digesters is a one-vessel hydraulic continuous digester (digester A)and the other one is a two-vessel vapor/liquor phase continuous digester (digester B). They are located in the same mill and use the same softwood chip quality. Due to the differences in chip pre-steaming and cooking facilities and conditions, significant differences in pulp strength properties, reject contents and kappa variations have been found between the pulps produced in the two digesters. Digester A has a modem chip bin with efficient pre-heating and air removal, whereas digester B has poor chip pre-steaming conditions. Our strength delivery studies show that although the two digesters produce pulps with the same kappa number and viscosity, the pulp produced in digester A has about 20% higher strength delivery, l%-unit (based on wood) lower reject content and lower kappa variations based on FTIR spectra analysis on pulp sheet than the pulp produced in digester B.Results of the studies indicate that more homogeneous cooking, i.e., lower lignin/kappa variation in the fibers, leads to improved pulp strength properties. Efficient chip pre-steaming is important/essential for achieving homogeneous cooking. Rebuilding the equipment for improving chip pre-steaming conditions of digester B is to be carried out.

  3. IMPACT OF COOKING HOMOGENEITY ON PULP STRENGTH PROPERTIES

    Institute of Scientific and Technical Information of China (English)

    BofengMao

    2004-01-01

    Cooking homogeneity of kraft pulping can havesignificant impact on pulp strength properties. Wehave studied cooking homogeneity of two kraftdigesters within Stora Enso. One of the digesters is aone-vessel hydraulic continuous digester (digester A)and the other one is a two-vessel vapor/liquor phasecontinuous digester (digester B). They are located inthe same mill and use the same softwood chipquality. Due to the differences in chip pre-steamingand cooking facilities and conditions, significantdifferences in pulp strength properties, reject contentsand kappa variations have been found between thepulps produced in the two digesters. Digester A has amodem chip bin with efficient pre-heating and airremoval, whereas digester B has poor chippre-steaming conditions. Our strength deliverystudies show that although the two digesters producepulps with the same kappa number and viscosity, thepulp produced in digester A has about 20% higherstrength delivery, l%-unit (based on wood) lowerreject content and lower kappa variations based onFTIR spectra analysis on pulp sheet than the pulpproduced in digester B.Results of the studies indicate that morehomogeneous cooking,variation in the fibers,i.e., lower lignin/kappa leads to improved pulpstrength properties. Efficient chip pre-steaming isimportant/essential for achieving homogeneouscooking. Rebuilding the equipment for improvingchip pre-steaming conditions of digester B is to becarded out.

  4. Rare Earth Additions in Continuously Cast Steel

    Science.gov (United States)

    Wilson, William G.; Heaslip, L. J.; Sommerville, I. D.

    1985-09-01

    Rare earth (lanthanide metals) addiiions to continuously cast steel are particularly advantageous because of their ability to refine as-cast structures, reduce segregation and increase hot ductility at temperatures just below that of solidification. The complete shape control of sulfides in steels containing Rare Earth Metals (REM), whether continuously cast or ingot cast, is primarily responsible for improvements in ductility related mechanical properties, weldability, fatigue resistance and resistance to hydrogen damage. Complete sulfide shape control can be obtained with REM additions at sulfur levels as high as.020%. The greatest improvements, however, are obtained with REM additions to low sulfur steels. However, to achieve full operational advantages afforded by REM, nozzle blockage problems must be circumvented. Water model studies indicate a possible solution.

  5. EVALUATION OF THE IMPACT OF THIN POURS ON SALTSTONE PROPERTIES

    Energy Technology Data Exchange (ETDEWEB)

    Cozzi, A.; Langton, C.; Fox, K.

    2012-10-02

    testing showed increased flow when the number of cold joints was increased. Compressive strength testing showed that the maximum load at the onset of cracking was reduced by approximately 26% for those samples that contained cold joints as compared to the monolithic samples. The number of cold joints in the sample had no significant impact on the maximum load prior to cracking. The porosity of the samples was not influenced by cold joints. This result was expected as the porosity is a material property affected by the properties of the components (premix and salt solution) and the water to premix ratio. Overall, the only obvious impact of cold joints in the samples was to significantly increase hydraulic conductivity in the direction parallel to the cold joints. An increasing number of cold joints (thin layers) in the simulated saltstone samples did not exacerbate this effect, nor did it have a negative impact on the Leachability Indices or porosity for surfaces exposed for approximately four days. The presence of a cold joint reduced the compressive strength of the material, although this impact was seen regardless of the number of cold joints in the sample.

  6. Cast iron - a predictable material

    OpenAIRE

    Jorg C. Sturm; Guido Busch

    2011-01-01

    High strength compacted graphite iron (CGI) or alloyed cast iron components are substituting previously used non-ferrous castings in automotive power train applications. The mechanical engineering industry has recognized the value in substituting forged or welded structures with stiff and light-weight cast iron castings. New products such as wind turbines have opened new markets for an entire suite of highly reliable ductile iron cast components. During the last 20 years, casting process s...

  7. Tearing resistance of aged cast austenitic stainless steels

    International Nuclear Information System (INIS)

    CF8 and CF8M type cast stainless steels containing about 10 to 25 % ferrite are used in the primary piping of light water reactors (PWRs and BWRs). It is now recognized that these materials are embrittled by thermal aging at the operating temperature (between 2900C and 3300C), mainly due to precipitation hardening of the ferrite by α', and other phases. Extensive research programs are under way in several countries to better understand the mechanisms of embrittlement and to determine the mechanical properties of components as a function of aging time and temperature. In earlier studies thermal aging embrittlement was mainly characterized by the evolutions of the tensile and Charpy impact properties. However the evaluation of reactor coolant circuit integrity through mechanical analyses requires the knowledge of fracture toughness properties. The first measurements of the tearing resistance of a CF8M type severely aged material were presented in 1983 by SLAMA, PETREQUIN and MAGER. Other contributions to the knowledge of the fracture toughness of aged materials were published, but were relative to medium or high toughness materials. The objective of this paper is to present the results of tearing resistance measurements made on a large spectrum of severely embrittled materials, which allow to give lower bound properties for aged CF8 and CF8M type cast stainless steels

  8. 碳含量对纳米结构白口铸铁组织与力学性能的影响%Effect of carbon content on microstructure and mechanical properties of nanostructure white cast iron

    Institute of Scientific and Technical Information of China (English)

    喇培清; 甄小娟; 胡苏磊; 李翠玲; 魏玉鹏; 卢学峰; 王鸿鼎; 魏福安

    2014-01-01

    The nanostructure white cast irons without expensive elements were prepared by aluminothermic reaction, the effect of carbon content on its microstructures and mechanical properties was studied by XRD, OM, SEM, tension and compression test . The results show that, the white cast irons consist of pearlite with different shapes and cementite, the lamellar pearlite decreases and granular pearlite increases with increasing the carbon content. The average lamellar spacing of the pearlite phase is 165, 231 and 250 nm, respectively. With increasing carbon content, the vickers hardness of nanostructure white cast iron is 552, 577 and 575 HV, compressive strength is 2 224, 2 460 and 2 220 MPa, and tensile strength is 383, 416 and 245 MPa, respectively, which are all first increases and then decreases with increasing carbon content; the elongation rate is 3%, 2.5% and 1%. The mechanical properties of nanostructure white cast iron without expensive alloying elements are the same to Ni-Hard2 cast iron.%以铝热反应法制备无昂贵合金元素添加的纳米结构白口铸铁,采用XRD、OM、SEM和拉伸及压缩等分析、测试手段研究碳含量对纳米结构白口铸铁组织和力学性能的影响。结果表明:随碳含量增加,白口铸铁由不同形态的珠光体和渗碳体组成,其中层片状珠光体含量减少,粒状珠光体含量增加;层片状珠光体的片间距分别为165、231和250 nm。碳含量为3.5%,3.7%和4.3%的纳米结构白口铸铁的维氏硬度分别为552、577和575 HV,抗压强度为2224、2460和2220 MPa,抗拉强度为383、416和245 MP,均呈现先增大后减小的趋势;伸长率为3%、2.5%和1%,呈现逐渐下降的趋势。无昂贵合金元素添加的纳米结构白口铸铁的力学性能与Ni-Hard 2铸铁相当。

  9. Expendable Pattern Casting Technology

    Science.gov (United States)

    1990-07-01

    The expendable pattern casting (EPC) process is a potential casting process breakthrough which could dramatically improve the competitiveness of the U.S. foundry industry. Cooperatively supported by U.S. Industry and the Department of Energy and managed by the American Foundrymen's Society, a project was started in May 1989 to develop and optimize expendable pattern casting technology. Four major tasks were conducted in the first phase of the project. Those tasks involved: (1) reviewing published literature to determine the major problems in the EPC process; (2) evaluating factors influencing sand flow and compaction; (3) evaluating and comparing casting precision obtained in the EPC process with that obtained in other processes; and (4) identifying critical parameters that control dimensional precision and defect formation in EP castings.

  10. Multi-layers castings

    Directory of Open Access Journals (Sweden)

    J. Szajnar

    2010-01-01

    Full Text Available In paper is presented the possibility of making of multi-layers cast steel castings in result of connection of casting and welding coating technologies. First layer was composite surface layer on the basis of Fe-Cr-C alloy, which was put directly in founding process of cast carbon steel 200–450 with use of preparation of mould cavity method. Second layer were padding welds, which were put with use of TIG – Tungsten Inert Gas surfacing by welding technology with filler on Ni matrix, Ni and Co matrix with wolfram carbides WC and on the basis on Fe-Cr-C alloy, which has the same chemical composition with alloy, which was used for making of composite surface layer. Usability for industrial applications of surface layers of castings were estimated by criterion of hardness and abrasive wear resistance of type metal-mineral.

  11. Dynamic control of crystallinity in polymer film casting process

    OpenAIRE

    Thananchai Leephakpreeda

    2005-01-01

    This paper presents an approach for dynamic control of crystallinity in polymer film casting process. As known, the transients of crystallization dictate the microstructures of semi-crystalline polymer during solidification. In turn, the properties of finished products can be determined by adjustable variables in polymer film casting process such as temperature of chill roll. In this work, an experimental model of the solidification in film casting process is derived by a system identificatio...

  12. PRINCIPALLY NEW EFFECTIVE CASTING PROCESS OF THE HOLLOW CYLINDRICAL SLUGS OF CAST IRON BY METHOD OF DIRECTIONAL SOLIDIFICATION

    Directory of Open Access Journals (Sweden)

    E. I. Marukovich

    2010-01-01

    Full Text Available The advantages of the new method of the hollow ingots production of cast iron are presented. The thermal state of crystallizer at cyclic temperature influences on its inside face, the ingot hardening and cast iron structure formation in conditions of intensive one-sided heat sink is examined. The comparative data on properties and exploitation characteristics of the parts, produced by different ways of casting is given.

  13. Predicting the impact of biochar additions on soil hydraulic properties

    Science.gov (United States)

    Spokas, Kurt; Lim, Tae Jun; Feyereisen, Gary; Novak, Jeff

    2015-04-01

    Different physical and chemical properties of biochar, which is made out of a variety of biomass materials, can impact water movement through amended soil. The objective of this research was to develop a decision support tool predicting the impact of biochar additions on soil saturated hydraulic conductivity (Ksat). Four different kinds of biochar were added to four different textured soils (coarse sand, fine sand, loam, and clay texture) to assess these effects at the rates of 0, 1, 2, and 5 % (w/w). The Ksat of the biochar amended soils were significantly influenced by the rate and type of biochar, as well as the original particle size of soil. The Ksat decreased when biochar was added to coarse and fine sands. Biochar with larger particles sizes (60%; >1 mm) decreased Ksat to a larger degree than the smaller particle size biochar (60%; soils. Increasing tortuosity in the amended sandy soil could explain this behavior. On the other hand, for the clay loam 1% and 2% biochar additions universally increased the Ksat with higher biochar amounts providing no further alterations. The developed model utilizes soil texture pedotransfer functions for predicting agricultural soil Ksat as a function of soil texture. The model accurately predicted the direction of the Ksat influence, even though the exact magnitude still requires further refinement.

  14. The ancient Chinese casting techniques

    Directory of Open Access Journals (Sweden)

    Tan Derui

    2011-02-01

    Full Text Available In the course of Chinese civilization, which lasted more than 5,000 years, casting production has made a huge contribution. In this paper, some representative metal castings were presented. According to their forming techniques, they can be grouped into stone mould casting, clay mould casting, ablation casting, lost wax casting, stack casting, permanent mould casting, sand casting, etc. According to their materials, they can be categorized into tin bronze, bimetallic bronze, malleable cast iron, ductile cast iron, brass, cupronickel alloy (Packtong, etc. According to their surface decorative techniques they can be devided into gem inlay, gilding, gold and silver inlay, copper inlay, engraved decoration, surface tin-enrichment, mother-of-pearl inlay, burnished works with gold or silver inlay, surface coloring and cloisonné enamel, etc.

  15. Economic impact of fuel properties on turbine powered business aircraft

    Science.gov (United States)

    Powell, F. D.

    1984-01-01

    The principal objective was to estimate the economic impact on the turbine-powered business aviation fleet of potential changes in the composition and properties of aviation fuel. Secondary objectives include estimation of the sensitivity of costs to specific fuel properties, and an assessment of the directions in which further research should be directed. The study was based on the published characteristics of typical and specific modern aircraft in three classes; heavy jet, light jet, and turboprop. Missions of these aircraft were simulated by computer methods for each aircraft for several range and payload combinations, and assumed atmospheric temperatures ranging from nominal to extremely cold. Five fuels were selected for comparison with the reference fuel, nominal Jet A. An overview of the data, the mathematic models, the data reduction and analysis procedure, and the results of the study are given. The direct operating costs of the study fuels are compared with that of the reference fuel in the 1990 time-frame, and the anticipated fleet costs and fuel break-even costs are estimated.

  16. Effect of Si on Wear Resistance of Bainitic Cast Steel under High Stress Impact%硅对贝氏体铸钢高应力冲击磨损性能的影响

    Institute of Scientific and Technical Information of China (English)

    黄进峰; 方鸿生; 徐平光; 郑燕康

    2001-01-01

    The high stress-wear resistance and mechanism for bainitic cast steels with different Si content (0.7 %~2.4 %) have been studied systematically.The experiments have shown that the wear loss of high Si bainitic cast steels is only about 1/2 times as that of low Si baini tic cast steels, showing better wear resistance of the former under high stress impact.The reason is that the impact wear mechanism is different for low and hi gh Si bainitic cast steels.Low Si bainitic cast steel has poor wear resistance under high stress impact because of its low toughness, coarse dendrite and micro -segregation, etc.So the damage cracks are easily formed in the wear surface b efore formation of white layer, and propagate inside the deformation zone and ma trix, exhibiting mechanism of deformation zone and matrix delamination.The imp act toughness of high Si bainitic cast steels are improved apparently for the re ason that the brittle cementite is replaced by ductile retained austentite film, resulting in the brittle delamination of white layer.%研究了不同硅含量(0.7 %~2.4 %,质量分数,下 同)贝氏体铸钢的抗高应力磨损性能和失效机制。结果表明:高硅贝氏体铸钢的耐磨性能较 低硅钢显著提高,其磨损失重约是低硅贝氏体铸钢的1/2。这是因为硅使贝氏体铸钢在高应 力冲击磨损下表现出不同的失效机制。低硅(0.7 %)贝氏体铸钢由于韧性低、组织结构粗大 及树枝晶的微区成分偏析,故材料抵抗冲击的能力很低,常在表面还未形成强烈变形层(白 层)甚至变形层时,就在变形层和材料基体内产生裂纹并扩展,故低硅贝氏体铸钢的失效方 式为变形层和基体剥落机制。而硅含量为1.6 %~2.4 %的高硅贝氏体铸钢,因脆性的渗碳体 被韧性的残余奥氏体所代替,钢的韧性显著提高,失效方式表现为白层的剥落机制。

  17. Light metal compound casting

    Institute of Scientific and Technical Information of China (English)

    Konrad; J.; M.; PAPIS; Joerg; F.; LOEFFLER; Peter; J.; UGGOWITZER

    2009-01-01

    ‘Compound casting’simplifies joining processes by directly casting a metallic melt onto a solid metal substrate. A continuously metallurgic transition is very important for industrial applications, such as joint structures of spaceframe constructions in transport industry. In this project, ‘compound casting’ of light metals is investigated, aiming at weight-saving. The substrate used is a wrought aluminium alloy of type AA5xxx, containing magnesium as main alloying element. The melts are aluminium alloys, containing various alloying elements (Cu, Si, Zn), and magnesium. By replacing the natural oxygen layer with a zinc layer, the inherent wetting difficulties were avoided, and compounds with flawless interfaces were successfully produced (no contraction defects, cracks or oxides). Electron microscopy and EDX investigations as well as optical micrographs of the interfacial areas revealed their continu- ously metallic constitution. Diffusion of alloying elements leads to heat-treatable microstructures in the vicinity of the joining interfaces in Al-Al couples. This permits significant variability of mechanical properties. Without significantly cutting down on wettability, the formation of low-melting intermetallic phases (Al3Mg2 and Al12Mg17 IMPs) at the interface of Al-Mg couples was avoided by applying a protective coating to the substrate.

  18. Effect of hot isostatic pressing on the structure and properties of cast polycrystalline gas-turbine blades made of nickel superalloys

    Science.gov (United States)

    Beresnev, A. G.

    2012-05-01

    A concept of a two-stage hot isostatic pressing (HIP) cycle is developed for castings made of nickel superalloys in order to minimize plastic deformation and the recrystallization ability of their structure. At the first stage of the cycle, diffusion pore dissolution is predominant due to the motion of vacancies toward grain boundaries in a polycrystal; at the second stage, retained coarse pores are filled during plastic deformation. The effect of uniform compression pressure during HIP and microstructure defects on the vacancy diffusion in nickel superalloys is estimated. A two-stage HIP regime is developed for processing of cast gas-turbine engine blades made of a ZhS6U alloy in order to substantially decrease the shrinkage porosity and to increase the high-temperature characteristics, including the creep and fatigue resistance.

  19. Tensile properties and fracture characteristics of spray cast alloy IC6 (Ni-7.8Al-14Mo-0.05B)

    Institute of Scientific and Technical Information of China (English)

    MI Guo-fa; WANG Hong-wei; TIAN Shi-fan; LI Zhou; ZENG Song-yan

    2007-01-01

    Tensile testing results of spray cast Ni3Al-based superalloy indicated that the yield strength and tensile strength increase with the increasing of temperature and reached maximum at around 760℃, then decrease with the increasing of temperature. After high temperature isostatic pressing (HIP), yield strength decreased and ductility and tensile strength increased. Stereographic projection showed that no matter at room temperature, medium temperature or high temperature, cracks extend along (111).

  20. Tensile properties and fracture characteristics of spray cast alloy IC6 (Ni-7.8Al-14Mo-0.05B

    Directory of Open Access Journals (Sweden)

    MI Guo-fa

    2007-02-01

    Full Text Available Tensile testing results of spray cast Ni3Al-based superalloy indicated that the yield strength and tensile strength increase with the increasing of temperature and reached maximum at around 760℃, then decrease with the increasing of temperature. After high temperature isostatic pressing (HIP, yield strength decreased and ductility and tensile strength increased. Stereographic projection showed that no matter at room temperature, medium temperature or high temperature, cracks extend along (111.

  1. Symptomatic stent cast.

    LENUS (Irish Health Repository)

    Keohane, John

    2012-02-03

    Biliary stent occlusion is a major complication of endoscopic stent insertion and results in repeat procedures. Various theories as to the etiology have been proposed, the most frequently studied is the attachment of gram negative bacteria within the stent. Several studies have shown prolongation of stent patency with antibiotic prophylaxis. We report the case of stent occlusion from a cast of a previously inserted straight biliary stent; a "stent cast" in an 86-year-old woman with obstructive jaundice. This was retrieved with the lithotrypter and she made an uneventful recovery. This is the first reported case of a biliary stent cast.

  2. Symptomatic stent cast.

    Science.gov (United States)

    Keohane, John; Moore, Michael; O'Mahony, Seamus; Crosbie, Orla

    2008-02-01

    Biliary stent occlusion is a major complication of endoscopic stent insertion and results in repeat procedures. Various theories as to the etiology have been proposed, the most frequently studied is the attachment of gram negative bacteria within the stent. Several studies have shown prolongation of stent patency with antibiotic prophylaxis. We report the case of stent occlusion from a cast of a previously inserted straight biliary stent; a "stent cast" in an 86-year-old woman with obstructive jaundice. This was retrieved with the lithotrypter and she made an uneventful recovery. This is the first reported case of a biliary stent cast.

  3. CENTRIFUGAL CASTING MACHINE

    Science.gov (United States)

    Shuck, A.B.

    1958-04-01

    A device is described that is specifically designed to cast uraniumn fuel rods in a vacuunn, in order to obtain flawless, nonoxidized castings which subsequently require a maximum of machining or wastage of the expensive processed material. A chamber surrounded with heating elements is connected to the molds, and the entire apparatus is housed in an airtight container. A charge of uranium is placed in the chamber, heated, then is allowed to flow into the molds While being rotated. Water circulating through passages in the molds chills the casting to form a fine grained fuel rod in nearly finished form.

  4. Physical Simulation of Investment Casting of Complex Shape Parts

    Science.gov (United States)

    Rahimian, Mehdi; Milenkovic, Srdjan; Maestro, Laura; De Azua, Aitor Eguidazu Ruiz; Sabirov, Ilchat

    2015-05-01

    Development of investment casting process has been a challenge for manufacturers of complex shape parts. Numerous experimental casting trials are typically carried out to determine the optimum casting parameters for fabrication of high-quality products. In this work, it is demonstrated that physical simulation of investment casting can successfully predict microstructure and hardness in as-cast complex shape parts. The physical simulation tool consists of a thermal model and melting/solidification experiments in thermo-mechanical simulator. The thermal model is employed to predict local cooling rate during solidification at each point of a casting. Melting/solidification experiments are carried out under controlled cooling rates estimated by the thermal model. Microstructural and mechanical characterization of the solidified specimens is performed; the obtained results predict the local microstructure and mechanical properties of the casting. This concept is applied to investment casting of complex shape nozzle guide vanes from Mar-M247 Ni-based superalloy. Experimental casting trials are performed and the outcomes of physical simulation tool are validated against experimental results. It is shown that phase composition, secondary dendrite arm spacing, grain size, γ/ γ' eutectic size and volume fraction, size and shape of carbide particles, and local microhardness can be predicted at each point of the casting via physical simulation.

  5. Laser surface treatment of grey cast iron for automotive applications

    NARCIS (Netherlands)

    Ocelik, V.; Tang, P.N.; de Boer, M.C.; de Oliveira, U.; de Hosson, J.T.M.; DeHosson, JTM; Brebbia, CA; Nishida, SI

    2005-01-01

    The surface of pearlitic grey cast iron was treated using a 2 kW Nd:YAG laser beam with the final aim to improve its surface properties, mainly for automotive applications. Two kinds of laser surface treatments were experimentally applied. In the laser surface hardening approach the surface of cast

  6. Solidification and microstructure of thin walled ductile cast iron

    DEFF Research Database (Denmark)

    Pedersen, Karl Martin

    2006-01-01

    In the recent years there has been an increasing interest in light constructions in order to save weight in e.g. cars. Ductile cast iron has good mechanical properties but it is necessary to re­duce the wall thicknesses of the castings in order to reduce the weight. Reducing the wall thicknesses ...

  7. The potential of centrifugal casting for the production of near net shape uranium parts

    Energy Technology Data Exchange (ETDEWEB)

    Robertson, E. [United States Air Force Academy, Colorado Springs, CO (US). Dept. of Engineering Mechanics

    1993-09-01

    This report was written to provide a detailed summary of a literature survey on the near net shape casting process of centrifugal casting. Centrifugal casting is one potential casting method which could satisfy the requirements of the LANL program titled Near Net Shape Casting of Uranium for Reduced Environmental, Safety and Health Impact. In this report, centrifugal casting techniques are reviewed and an assessment of the ability to achieve the near net shape and waste minimization goals of the LANL program by using these techniques is made. Based upon the literature reviewed, it is concluded that if properly modified for operation within a vacuum, vertical or horizontal centrifugation could be used to safely cast uranium for the production of hollow, cylindrical parts. However, for the production of components of geometries other than hollow tubes, vertical centrifugation could be combined with other casting methods such as semi-permanent mold or investment casting.

  8. Colour Metallography of Cast Iron

    Institute of Scientific and Technical Information of China (English)

    Zhou Jiyang; Liu Jincheng

    2011-01-01

    White Cast Iron (Ⅰ) White cast iron or ‘white iron' refers to the type of cast iron in which all of the carbon exists as carbide;there is no graphite in the as-cast structure and the fractured surface shows a white colour.White cast iron can be divided in three classes:· Normal white cast iron — this iron contains only C,Si,Mn,P and S,with no other alloying elements.· Low-alloy white cast iron — the total mass fraction of alloying elements is less than 5%.

  9. Diffusion of C and Cr During Creation of Surface Layer on Cast Steel Casting

    Directory of Open Access Journals (Sweden)

    Szajnar J.

    2014-10-01

    Full Text Available In paper a method of improvement in utility properties of unalloyed cast steel casting in result of diffusion of C and Cr in process of creation of surface layer is presented. The aim of paper was determination of diffusion range of basic elements of alloyed surface layer. Moreover a quantitative analysis of carbides phase strengthens alloyed surface layer of casting was carried out. The results of studies shown that important factors of surface layer creation are maximal temperature Tmax on granular insert – cast steel boundary dependent of pouring temperature, granularity Zw of Fe-Cr-C alloy insert and thickness of casting wall gśo. On the basis of obtained results was affirmed that with increase of thickness of casting wall increases range of diffusion in solid state in Fe-Cr-C grains and in liquid state. Moreover the range of Tmax = 13001500oC favours creation of the proper alloyed surface layers on cast steel.

  10. Research of estimation method of thermal aging embrittlement on cast austenitic stainless steel

    International Nuclear Information System (INIS)

    Thermal aging embrittlement of cast austenitic stainless steel components from the decommissioned Advanced Thermal prototype Reactor (ATR) Fugen power station has been characterized. Cast stainless steel materials were obtained from recirculation pump casing. The actual time at temperature for the materials was 138,000 h at 275°C. The Fugen serviced material show modest decrease in Charpy-impact properties and a small increase in micro-Vickers hardness in ferrite phase because of thermal aging at relatively low service temperatures. The fracture toughness prediction method (H3T model) predicts slightly lower values for Charpy-impact energy obtained from the Fugen material. The results from microstructural analysis suggest that the prediction method have the potential to provide higher accuracy by considering activation energy for embrittlement at low service temperatures. (author)

  11. Control of Cast Iron Microstructure

    Science.gov (United States)

    Graham, J.; Lillybeck, N.; Franco, N.; Stefanescu, D. M.

    1985-01-01

    The use of microgravity for industrial research in the processing of cast iron was investigated. Solidification experiments were conducted using the KC-135 and F-104 aircraft, and an experiment plan was developed for follow-on experiments using the Shuttle. Three areas of interest are identified: (1) measurement of thermophysical properties in the melt; (2) understanding of the relative roles of homogeneous nucleation, grain multiplication, and innocultants in forming the microstructure; and (3) exploring the possibility of obtaining an aligned graphite structure in hypereutectic Fe, Ni, and Co.

  12. Impact of soil properties on selected pharmaceuticals adsorption in soils

    Science.gov (United States)

    Kodesova, Radka; Kocarek, Martin; Klement, Ales; Fer, Miroslav; Golovko, Oksana; Grabic, Roman; Jaksik, Ondrej

    2014-05-01

    The presence of human and veterinary pharmaceuticals in the environment has been recognized as a potential threat. Pharmaceuticals may contaminate soils and consequently surface and groundwater. Study was therefore focused on the evaluation of selected pharmaceuticals adsorption in soils, as one of the parameters, which are necessary to know when assessing contaminant transport in soils. The goals of this study were: (1) to select representative soils of the Czech Republic and to measure soil physical and chemical properties; (2) to measure adsorption isotherms of selected pharmaceuticals; (3) to evaluate impact of soil properties on pharmaceutical adsorptions and to propose pedotransfer rules for estimating adsorption coefficients from the measured soil properties. Batch sorption tests were performed for 6 selected pharmaceuticals (beta blockers Atenolol and Metoprolol, anticonvulsant Carbamazepin, and antibiotics Clarithromycin, Trimetoprim and Sulfamethoxazol) and 13 representative soils (soil samples from surface horizons of 11 different soil types and 2 substrates). The Freundlich equations were used to describe adsorption isotherms. The simple correlations between measured physical and chemical soil properties (soil particle density, soil texture, oxidable organic carbon content, CaCO3 content, pH_H2O, pH_KCl, exchangeable acidity, cation exchange capacity, hydrolytic acidity, basic cation saturation, sorption complex saturation, salinity), and the Freundlich adsorption coefficients were assessed using Pearson correlation coefficient. Then multiple-linear regressions were applied to predict the Freundlich adsorption coefficients from measured soil properties. The largest adsorption was measured for Clarithromycin (average value of 227.1) and decreased as follows: Trimetoprim (22.5), Metoprolol (9.0), Atenolol (6.6), Carbamazepin (2.7), Sulfamethoxazol (1.9). Absorption coefficients for Atenolol and Metoprolol closely correlated (R=0.85), and both were also

  13. (Continuous casting 1985)

    Energy Technology Data Exchange (ETDEWEB)

    Wilde, R.A.

    1985-06-12

    The report covers the Continuous Casting '85 Conference including informal discussions with conference attendees. In general, the papers presented at the conference concerned an overview of continuous steel casting worldwide, state-of-the-art aspects of steel continuous casting technology including caster startup problems, modifications, control system strategies, energy use profiles, quality control aspects, steel chemistry control, refractories, operational aspects of continuous casters, etc. No papers were presented in the development of thin section or thin strip casting of steel. Informal discussions were held with several conference attendees including (1) Bernard Trentini, Executive Director of the Association Technique De La Siderurgie Francaise in Paris, France (similar to the American Iron and Steel Institute); (2) Dr. Wolfgang Reichelt and Dr. Peter Voss-Spilker both of Mannesmann Demag Huttentechnik -a continuous casting and other steel making machine builder in-lieu of meeting at their plant in Duisburg, FRG on May 31; (3) Ewan C. Hewitt of Devote McKee Corp., Sheffield, England; (4) Wilfried Heinemann, head of R D Dept. at Concast Standard AG in Zurich, Switzerland; and (5) Hideo Ueno, engineer of melting section, Mitsubishi Steel Mfg. Co. Ltd, Tokyo Japan. A visit was made to the Teesside Laboratories of British Steel Corp. for discussions of their thin section casting research program in particular and R D program in general.

  14. Impact of temperature on the biological properties of soil

    Science.gov (United States)

    Borowik, Agata; Wyszkowska, Jadwiga

    2016-01-01

    The aim of the study was to determine the response of soil microorganisms and enzymes to the temperature of soil. The effect of the temperatures: 5, 10, 15, 20, and 25°C on the biological properties of soil was investigated under laboratory conditions. The study was performed using four different soils differing in their granulometric composition. It was found that 15°C was the optimal temperature for the development of microorganisms in soil. Typically, in the soil, the highest activity of dehydrogenases was observed at 10-15°C, catalase and acid phosphatase - at 15°C, alkaline phosphatase at 20°C, urease and β-glucosidase at 25°C. The highest colony development index for heterotrophic bacteria was recorded in soils incubated at 25°C, while for actinomycetes and fungi at 15°C. The incubation temperature of soil only slightly changed the ecophysiological variety of the investigated groups of microorganisms. Therefore, the observed climate changes might have a limited impact on the soil microbiological activity, because of the high ability of microorganisms to adopt. The response of soil microorganisms and enzymes was more dependent on the soil granulometric composition, organic carbon, and total nitrogen than on its temperature.

  15. 冷速及高温回火对低合金高强铸钢组织性能的影响%Effect of cooling rate and high tempering on microstructure and mechanical properties of high-strength low-alloy(HSLA) cast steel

    Institute of Scientific and Technical Information of China (English)

    雷勇; 许晓嫦; 李良; 张奇; 徐浩浩; 赵凤晓

    2014-01-01

    为提高低合金高强铸钢( HSLA)的综合力学性能,满足恶劣环境下的使用要求。采用光学显微镜、扫描电镜、透射电镜、冲击试验机、万能材料试验机研究了3种不同冷速及高温回火对HSLA铸钢组织与力学性能的影响。结果表明:随冷速增加,淬火组织发生由多边形铁素体+针状铁素体+粒状贝氏体→粒状贝氏体+板条贝氏体→准上贝氏体+板条马氏体的演变。冷速为1℃/s的空冷样,具有最高的塑韧性;冷速最大的水冷样,其强度、硬度最高。冷却样经580℃回火,其晶界、板条界均有粒状、短棒状的纳米第二相析出,EDS分析表明,100~200 nm的析出相为合金渗碳体( M3 C),而50 nm以内的析出相为( V,Ti)( C,N)。空冷样回火后有较高强度、最高的塑韧性;油冷、水冷样回火后,Re提高,Rm略有下降,AkU降低与高温回火脆性的发生有关,但-40℃的AkU仍有60、40 J,具有较好的低温冲击韧性。可见,试验HSLA铸钢表现出良好的综合力学性能,能满足在恶劣环境下的使用要求。%To improve comprehensive mechanical properties of high strength low alloy(HSLA) cast steel, and meet application requirements of HSLA cast steel in harsh environments, the mechanical properties and microstructures of HSLA cast steel cooled at three different cooling rates and subsequently tempered at 580℃ were studied by optical microscope, scanning electron microscopy, transmission electron microscopy, impact tester and universal material test. With the cooling rate increasing, the microstructure evolved from ferrite + granular bainite, lath bainite, to lath martensite + quasi upper bainite. Higher plasticity and toughness were obtained at a slower cooling rate of 1℃/s. Water cooled sample had maximum strength and hardness, at the expensive of impact energy slightly. Nano-precipitates of granular, short rod were found along

  16. The Structure and Properties of Inductively Coupled Plasma Assisted Magnetron Sputtered Nanocrystalline NbN Coatings in Corrosion Protective Die Casting Molds.

    Science.gov (United States)

    Chun, Sung-Yong

    2016-02-01

    Niobium nitride coatings for the surface modified die casting molds with various ICP powers have been prepared using ICP assisted magnetron sputtering. The applied ICP power was varied from 0 to 200 W. The deposited coatings were characterized post-deposition using X-ray diffractometry (XRD) and atomic force microscopy (AFM). Single NbN phased coatings with nano-grain sized (hardness of each coating were evaluated from potentiostat and nanoindentator. Superior corrosion protective coatings in excess of 13.9 GPa were deposited with assistance of ICP plasma during sputtering.

  17. Aluminium Foam and Magnesium Compound Casting Produced by High-Pressure Die Casting

    Directory of Open Access Journals (Sweden)

    Iban Vicario

    2016-01-01

    Full Text Available Nowadays, fuel consumption and carbon dioxide emissions are two of the main focal points in vehicle design, promoting the reduction in the weight of vehicles by using lighter materials. The aim of the work is to evaluate the influence of different aluminium foams and injection parameters in order to obtain compound castings with a compromise between the obtained properties and weight by high-pressure die cast (HPDC using aluminium foams as cores into a magnesium cast part. To evaluate the influence of the different aluminium foams and injection parameters on the final casting products quality, the type and density of the aluminium foam, metal temperature, plunger speed, and multiplication pressure have been varied within a range of suitable values. The obtained compound HPDC castings have been studied by performing visual and RX inspections, obtaining sound composite castings with aluminium foam cores. The presence of an external continuous layer on the foam surface and the correct placement of the foam to support injection conditions permit obtaining good quality parts. A HPDC processed magnesium-aluminium foam composite has been developed for a bicycle application obtaining a suitable combination of mechanical properties and, especially, a reduced weight in the demonstration part.

  18. Dynamic fracture behavior of nodular cast iron

    International Nuclear Information System (INIS)

    Ferritic nodular cast iron has been found to be a much tougher material than previously believed based on Charpy impact test results. As a result this material is being considered as a substitute for Stainless Steel in nuclear waste transport containers. We have determined Klc and Kld values for nodular cast iron with varying values of silicon and percentage of pearlite in the matrix. Regular V-notch charpy bars and fatigue precracked charpy bars have been tested to determine the initiation and propagation energy and the effect of notch acuity on transition temperature. (author)

  19. Application of a criterion for cold cracking to casting high strength aluminum alloys

    NARCIS (Netherlands)

    Lalpoor, M.; Eskin, D.G.; Fjaer, H.G.; Ten Cate, A.; Ontijt, N.; Katgerman, L.

    2010-01-01

    Direct chill (DC) casting of high strength 7xxx series aluminium alloys is difficult mainly due to solidification cracking (hot cracks) and solid state cracking (cold cracks). Poor thermal properties along with extreme brittleness in the as-cast condition make DC-casting of such alloys a challenging

  20. Effects of electromagnetic field intensity on as-cast microstructures and mechanical properties of Al-Zn-Mg-Cu-Zr alloy

    Institute of Scientific and Technical Information of China (English)

    ZUO Yu-bo; ZHAO Zhi-hao; WANG Qi-wei; GUI Jian-zhong

    2006-01-01

    Al-Zn-Mg-Cu-Zr ingots with diameter of 200 mm were made by low frequency electromagnetic casting (LFEC) and conventional direct chill (DC) casting process. The results show that under the low fiequency electromagnetic field (25 Hz, 32 mT)the microstructures of LFEC ingot from the border to the center on the cross section are all equiaxed grains, and the grains are much finer and more uniform than that of DC ingot. The magnetic flux density plays an important role in the microstructure formation of LFEC ingots. With increasing the magnetic flux density from 0 mT to 32 mT, grains become finer (from about 120 μm to 30 μm) and more uniform. While, with increasing the magnetic flux density from 32 mT to 46 mT, the grains change much slowly. In the range of experimental parameters, the optimum magnetic flux density for LFEC process is found to be 32 mT.