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Sample records for superior wear resistance

  1. 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.

  2. Engine oil wear resistance

    Directory of Open Access Journals (Sweden)

    A.N. Farhanah

    2015-03-01

    Full Text Available Lubricants play a vital role in an internal combustion engine to lubricate parts and help to protect and prolong the engine life. Lubricant also will help to reduce wear by creating lubricating film between the moving parts hence reduce metal-to-metal contacts. Engine oil from three different manufacturers with the same SAE viscosity grade available in market does not mean it will have the same lubricity for an engine. In this study, commercial mineral lubrication oil (SAE 10W-30 from three manufacturers was investigated to compare the lubrication performance at three different temperatures (40˚C, 70˚C and 100˚C in 60 minutes time duration by using four ball wear tester. The speed will be varied from 1000 rpm to 2500 rpm. Results show that all three lubricants have different lubricity performance; the smaller the wear scar, the better the lubricant since the lubricant can protect the moving surfaces from direct metal-to-metal contact occur.

  3. Low friction wear resistant graphene films

    Science.gov (United States)

    Sumant, Anirudha V.; Berman, Diana; Erdemir, Ali

    2017-02-07

    A low friction wear surface with a coefficient of friction in the superlubric regime including graphene and nanoparticles on the wear surface is provided, and methods of producing the low friction wear surface are also provided. A long lifetime wear resistant surface including graphene exposed to hydrogen is provided, including methods of increasing the lifetime of graphene containing wear surfaces by providing hydrogen to the wear surface.

  4. Improvements of harrows wear resistance

    Directory of Open Access Journals (Sweden)

    Warouma Arifa

    2015-12-01

    Full Text Available Wear is the main reason for the loss of performance of the parts for agricultural machinery. It leads to the degradation of the soil working quality. This work aims to highlight the wear resistance of the harrows discs manufactured, consolidated and sharpened differently. The tests were conducted in the laboratory and the field of the Faculty of Exploitation and Repair of Agricultural Machinery of the State Technical University of Kirovograd (Ukraine in 2015. The technical equipment consists of devices for consolidation by electric discharge and for measurement the linear wear of discs, a harrow, a sand test bed, a tractor and discs made of different materials and technologies. Some parameterized were collected during the laboratory test each 5 ha and up to 20 ha of operation and in the fields each 30 ha until the time limit of exploitation. The Laboratory tests have shown that after twenty (20 ha of operation, the wear resistance of the experimental discs made of steel 65G and consolidated by electric discharge with simultaneous grinding (sharpening angle of 30° is 2.95 times higher than the discs in series made of steel 28MnB5. The field experiment gave the following results: According to agro technical requirements, the plowing depth limit of serial discs made of steel 28MnB5 was reached after an operating duration of 120 ha while for experimental discs made of steel 65G and consolidated by electric discharge with simultaneous grinding (sharpening angle of 30 degrees this duration is of 156 ha. The diameter wear limit of experimental discs was reached after an operating duration of 179 ha against 154 ha for the serial ones. Therefore, the new technology can be applied during the manufacture and / or the repair of the discs.

  5. Wear resistance properties of austempered ductile iron

    Science.gov (United States)

    Lerner, Y. S.; Kingsbury, G. R.

    1998-02-01

    A detailed review of wear resistance properties of austempered ductile iron (ADI) was undertaken to examine the potential applications of this material for wear parts, as an alternative to steels, alloyed and white irons, bronzes, and other competitive materials. Two modes of wear were studied: adhesive (frictional) dry sliding and abrasive wear. In the rotating dry sliding tests, wear behavior of the base material (a stationary block) was considered in relationship to countersurface (steel shaft) wear. In this wear mode, the wear rate of ADI was only one-fourth that of pearlitic ductile iron (DI) grade 100-70-03; the wear rates of aluminum bronze and leaded-tin bronze, respectively, were 3.7 and 3.3 times greater than that of ADI. Only quenched DI with a fully martensitic matrix slightly outperformed ADI. No significant difference was observed in the wear of steel shafts running against ADI and quenched DI. The excellent wear performance of ADI and its countersurface, combined with their relatively low friction coefficient, indicate potential for dry sliding wear applications. In the abrasive wear mode, the wear rate of ADI was comparable to that of alloyed hardened AISI 4340 steel, and approximately one-half that of hardened medium-carbon AISI 1050 steel and of white and alloyed cast irons. The excellent wear resistance of ADI may be attributed to the strain-affected transformation of high-carbon austenite to martensite that takes place in the surface layer during the wear tests.

  6. Wear Resistance and Wear Mechanism of a Hot Dip Aluminized Steel in Sliding Wear Test

    Science.gov (United States)

    Xue, Zhiyong; Hao, Xiaoyang; Huang, Yao; Gu, Lingyun; Ren, Yu; Zheng, Ruipeng

    2016-12-01

    Sliding wear experiments were conducted on a hot dip aluminized steel to investigate its wear resistance and wear mechanism. The wear tests were also carried out on a hot dip galvanized steel and the base material (steel Q345) as a comparison. Results show that the wear resistance and hardness of the hot dip aluminized steel are significantly higher than that of the hot dip galvanized steel and the steel Q345 at room temperature. The better wear resistance of the hot dip aluminized steel attributes mainly to the formation of a transition layer containing abundant Fe-Al intermetallic compounds and the transformation of wear-resisting oxides during the friction process. The main phase in the transition layer is Fe2Al5. The thickness of the transition layer is about 90-120 μm. When the wear load increases from 3 N to 19 N, the wear type of the aluminized layer transform from adhesive wear (3 N) into abrasive wear (7 N) and finally into slight wear mixed with oxidation (higher than 11 N).

  7. Sliding wear resistance of iron aluminides

    Indian Academy of Sciences (India)

    Garima Sharma; M Sundararaman; N Prabhu; G L Goswami

    2003-04-01

    Room temperature dry sliding wear behaviour of iron aluminides containing 28% aluminium and various amounts of chromium has been investigated using pin on disk wear tester. The aluminides were heat treated to have ordered 3 structure. It was found that wear rate of the aluminides increased with the increase of applied normal load and sliding speed. Wear resistance of the aluminides increased with increase in chromium content. SEM observation of the worn surface showed that the microcutting and microploughing were the dominant sliding wear mechanisms.

  8. Wear resistance and corrosion resistance of VCp particle reinforced stainless steel composites

    Institute of Scientific and Technical Information of China (English)

    YAO Xiu-rong; HAN Jie-cai; ZUO Hong-bo; LIU Zhao-jing; LI Feng-zhen; REN Shan-zhi

    2005-01-01

    The VCp reinforced stainless steel composite was produced by in-situ reaction casting. The composite was tested for its wear resistance under the wet abrasive condition and corrosion resistance, compared with the wear-resistant white iron and stainless steel. The results show that the wear resistance of the composite is slightly inferior to that of the white iron, but much better than that of the stainless steel under the wet grinding abrasive condition. The corrosion resistance of the composite is much better than that of the white iron in the acid medium,and a little worse than that of the stainless steel. Thus the composite exhibits superior properties of wear resistance and corrosion resistance.

  9. Tool wear mechanism in turning of novel wear-resisting aluminum bronze

    Institute of Scientific and Technical Information of China (English)

    倪东惠; 夏伟; 张大童; 郭国文; 邵明

    2003-01-01

    Tool wear and wear mechanism during the turning of a wear-resisting aluminum bronze have been stud-ied. Tool wear samples were prepared by using M2 high-speed steel and YW1 cemented carbide tools to turn a novelhigh strength, wear resisting aluminum bronze without coolant and lubricant. Adhesion of workpiece materials wasfound on tool's surface. Under the turning condition used in this study major wear mechanisms for turning aluminumbronze using M2 high-speed steel tool are diffusion wear, adhesive wear and plastic deformation and shear on thecrater. Partial melting of high-speed steel on the rake plays a role in the tool wear also. Major wear mechanisms forturning aluminum bronze using YW1 cemented carbide tool are diffusion wear, attrition wear and sliding wear. Tocontrol the machining temperature is essential to reduce tool wear.

  10. Wear Resistant Amorphous and Nanocomposite Coatings

    Energy Technology Data Exchange (ETDEWEB)

    Racek, O

    2008-03-26

    Glass forming materials (critical cooling rate <10{sup 4}K.s{sup -1}) are promising for their high corrosion and wear resistance. During rapid cooling, the materials form an amorphous structure that transforms to nanocrystalline during a process of devitrification. High hardness (HV 1690) can be achieved through a controlled crystallization. Thermal spray process has been used to apply coatings, which preserves the amorphous/nanocomposite structure due to a high cooling rate of the feedstock particles during the impact on a substrate. Wear properties have been studied with respect to process conditions and feedstock material properties. Application specific properties such as sliding wear resistance have been correlated with laboratory tests based on instrumented indentation and scratch tests.

  11. Brush seal shaft wear resistant coatings

    Science.gov (United States)

    Howe, Harold

    1995-03-01

    Brush seals suffer from high wear, which reduces their effectiveness. This work sought to reduce brush seal wear by identifying and testing several industry standard coatings. One of the coatings was developed for this work. It was a co-sprayed PSZ with boron-nitride added for a high temperature dry lubricant. Other coatings tested were a PSZ, chrome carbide and a bare rotor. Testing of these coatings included thermal shocking, tensile testing and wear/coefficient of friction testing. Wear testing consisted of applying a coating to a rotor and then running a sample tuft of SiC ceramic fiber against the coating. Surface speeds at point of contact were slightly over 1000 ft/sec. Rotor wear was noted, as well as coefficient of friction data. Results from the testing indicates that the oxide ceramic coatings cannot withstand the given set of conditions. Carbide coatings will not work because of the need for a metallic binder, which oxidizes in the high heat produced by friction. All work indicated a need for a coating that has a lubricant contained within itself and the coating must be resistant to an oxidizing environment.

  12. Influence of Cycle Temperature on the Wear Resistance of Vermicular Iron Derivatized with Bionic Surfaces

    Science.gov (United States)

    Sui, Qi; Zhang, Peng; Zhou, Hong; Liu, Yan; Ren, Luquan

    2016-11-01

    Depending on their applications, such as in brake discs, camshafts, etc., the wear behavior of vermicular iron is influenced by the thermal cycling regime. The failure of a working part during its service life is a consequence of both thermal fatigue and wear. Previously, the wear and thermal fatigue resistance properties of vermicular iron were separately investigated by researchers, rather than a study combining these two factors. In the present work, the effect of cycle temperature on the wear resistance of specimens with bionic units processed by laser has been investigated experimentally. The wear behavior pre- and post-thermal cycling has also been investigated, and the influence of different cycle temperatures on the wear resistance is discussed. The results indicate that the thermal cycling regime brought about negative influences with varying degrees, on the material properties, such as the microstructures, micro-hardness, cracks, and oxidation resistance properties. All these factors synergistically reduced the wear resistance of vermicular iron. In particular, the negative influence apparently increased with an increase in cycle temperature. Nevertheless, the post-thermal-cycle wear resistance of the specimens with bionic units was superior to those without bionic units. Hence, the laser bionic process is an effective way to improve the performance of vermicular iron in combined thermal cycling and wear service conditions.

  13. 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.

  14. Wear Resistant Rubber Tank Track Pads

    Science.gov (United States)

    1975-10-01

    stereospecific SBR (Stereon 750), SBR/polybutadiene blends (Fhilprene 1609/Cis-4 1350 (or Cis-4 1351), Ameripoi 1834/Ameripol CB 1352) and alfin ...polybutadiene blends has confirmed this improvement in tread wear. The uncertainty regarding the future commercial availibility of the alfin catalyzed...polybutadiene blend) (S212-2), and HYTRANS 1227-2S9-1 ( alfin catalyzed copolymer of butadiene/ styrene) (S223-4) to determine their effect on the resistance to

  15. Superior accuracy of model-based radiostereometric analysis for measurement of polyethylene wear

    DEFF Research Database (Denmark)

    Stilling, M; Kold, S; de Raedt, S

    2012-01-01

    The accuracy and precision of two new methods of model-based radiostereometric analysis (RSA) were hypothesised to be superior to a plain radiograph method in the assessment of polyethylene (PE) wear.......The accuracy and precision of two new methods of model-based radiostereometric analysis (RSA) were hypothesised to be superior to a plain radiograph method in the assessment of polyethylene (PE) wear....

  16. Wear-resistance of Aluminum Matrix Microcomposite Materials

    Directory of Open Access Journals (Sweden)

    M. Kandeva

    2011-03-01

    Full Text Available A procedure is developed for the study of wear of aluminum alloys AlSi7 obtained by casting, reinforced by TiC microparticles, before and after heat treatment. Tribological study is realized under conditions of friction on counterbody with fixed abrasive. Experimental results were obtained for mass wear, wear rate, wear intensity and wear-resistance of the alloys with different wt% of microparticles.

  17. Cavitation wear resistance of engine bearing materials

    Science.gov (United States)

    Rac, Aleksandar

    1994-04-01

    The resistance to cavitation erosion of aluminum alloy, and cast and sinte-red lead-bronze, materials which are most frequently used for engine bearings, has been evaluated. The tests were carried out in motor oil at a temperature of 80 C, using a magnetostrictive vibratory tester (20 kHz). The results showed that the cavitation erosion resistance was the greatest in cast lead-bronze. On the contrary, sintered lead-bronze, though of the same chemical composition, had the greatest erosion rate. Additionally, the investigation of the overlay plated bearings showed the overlay was nonresistive to this type of wear.

  18. THE WEAR RESISTANCE INCREASE OF CHROMIUM CAST IRON

    Directory of Open Access Journals (Sweden)

    V. M. Ilyushenko

    2016-01-01

    Full Text Available The article presents the results of the tests on the wear resistance of chromium cast irons of different compositions obtained in sand forms. It has been shown that increase of the wear resistance and mechanical properties of the cast iron is possible to obtain using the casting in metal molds. A further increase in wear resistance of parts produced in metal molds is possible by changing the technological parameters of casting and alloying by titanium.

  19. Correlation between Wear Resistance and Lifetime of Electrical Contacts

    Directory of Open Access Journals (Sweden)

    Jian Song

    2012-01-01

    Full Text Available Electrical contacts are usually plated in order to prevent corrosion. Platings of detachable electrical contacts experience wear because of the motion between contacts. Once the protecting platings have been worn out, electrical contacts will fail rapidly due to corrosion or fretting corrosion. Therefore the wear resistance of the platings is a very important parameter for the long lifetime of electrical contacts. Many measures which improve the wear resistance can diminish the conductivity of the platings. Due to the fact that platings of electrical contacts must have both a high wear resistance and a high electrical conductivity, the manufacturing of high performance platings of electrical contacts poses a great challenge. Our study shows firstly the correlation between the wear resistance of platings and lifetime of electrical contacts and then the measures, which improve the wear resistance without impairing the electrical performance of the contacts.

  20. Influence of carbon content on wear resistance and wear mechanism of Mn13Cr2 and Mn18Cr2 cast steels

    Directory of Open Access Journals (Sweden)

    Ding-shan Lu

    2015-01-01

    Full Text Available By means of impact abrasion tests, micro-hardness tests, and worn surface morphology observation via SEM, a comparison research based upon different impact abrasive wear conditions was conducted in this research to study the influence of different carbon contents (1.25wt.%, 1.35wt.%, and 1.45 wt.% on the wear resistance and wear mechanism of water-quenched Mn13Cr2 and Mn18Cr2 cast steels. The research results show that the wear resistance of the Mn18Cr2 cast steel is superior to that of the Mn13Cr2 cast steel under the condition of the same carbon content and different impact abrasive wear conditions because the Mn18Cr2 cast steel possesses higher worn work hardening capacity as well as a more desirable combination of high hardness and impact toughness than that of the Mn13Cr2 cast steel. When a 4.5 J impact abrasive load is applied, the wear mechanism of both steels is that plastic deformation fatigue spalling and micro-cutting coexist, and the former dominates. When the carbon content is increased, the worn work hardening effect becomes increasingly dramatic, while the wear resistance of both steels decreases, which implies that an increase in impact toughness is beneficial to improving the wear resistance under severe impact abrasive wear conditions. Under the condition of a 1.0 J impact abrasive load, the wear mechanism of both steels is that plastic deformation fatigue spalling and micro-cutting coexist, and the latter plays a leading role. The worn work hardening effect and wear resistance intensify when the carbon content is increased, which implies that a higher hardness can be conducive to better wear resistance under low impact abrasive condition.

  1. EVALUATION AND RECOMMENDATION OF SALTSTONE MIXER AUGER/PADDLES MATERIALS OF CONSTRUCTION FOR IMPROVED WEAR RESISTANCE

    Energy Technology Data Exchange (ETDEWEB)

    Mickalonis, J.; Torres, R.

    2012-08-15

    Wear and corrosion testing were conducted to evaluate alternate materials of construction for the Saltstone mixer auger and paddles. These components have been degraded by wear from the slurry processed in the mixer. Material test options included PVD coatings (TiN, TiCN, and ZrN), weld overlays (Stellite 12 and Ultimet) and higher hardness steels and carbides (D2 and tungsten carbide). The corrosion testing demonstrated that the slurry is not detrimental to the current materials of construction or the new candidates. The ASTM G75 Miller wear test showed that the high hardness materials and the Stellite 12 weld overlay provide superior wear relative to the Astralloy and CF8M stainless steel, which are the current materials of construction, as well as the PVD coatings and Ultimet. The following recommendations are made for selecting new material options and improving the overall wear resistance of the Saltstone mixer components: A Stellite 12 weld overlay or higher hardness steel (with toughness equivalent to Astralloy) be used to improve the wear resistance of the Saltstone mixer paddles; other manufacturing specifications for the mixer need to be considered in this selection. The current use of the Stellite 12 weld overlay be evaluated so that coverage of the 316 auger can be optimized for improved wear resistance of the auger. The wear surfaces of the Saltstone mixer auger and paddles be evaluated so that laboratory data can be better correlated to actual service. The 2-inch Saltstone mixer prototype be used to verify material performance.

  2. FIBROUS MONOLITH WEAR RESISTANT COMPONENTS FOR THE MINING INDUSTRY

    Energy Technology Data Exchange (ETDEWEB)

    Mike L. Fulcher; Kenneth L. Knittel

    2004-06-08

    The work performed on this program was to develop wear resistant, tough FM composite materials with efforts focused on WC-Co based FM systems. The materials were developed for use in mining industry wear applications. Components of interest were drill bit inserts for drilling blast holes. Other component applications investigated included wear plates for a variety of equipment such as pit shovels, wear surfaces for conveyors, milling media for ball milling operations, hydrocyclone cones, grader blades and dozer teeth. Cross-cutting technologies investigated included hot metal extrusion dies, drill bits for circuit board fabrication, cutting tools for cast iron and aluminum machining. An important part of the work was identification of the standard materials used in drilling applications. A materials trade study to determine those metals and ceramics used for mining applications provided guidance for the most important materials to be investigated. WC-Co and diamond combinations were shown to have the most desirable properties. Other considerations such as fabrication technique and the ability to consolidate shifted the focus away from diamond materials and toward WC-Co. Cooperating partners such as Kennametal and Kyocera assisted with supplies, evaluations of material systems, fabricated parts and suggestions for cross-cutting technology applications for FM architectures. Kennametal provided the raw materials (WC-Co and Al-TiCN powders) for the extent of the material evaluations. Kyocera shared their research into various FM systems and provided laboratory testing of fabricated materials. Field testing provided by partners Superior Rock Bit and Brady Mining and Construction provided insight into the performance of the fabricated materials under actual operational conditions. Additional field testing of cross-cutting technology, the extrusion of hot metals, at Extruded Metals showed the potential for additional market development.

  3. Comparative Study of Wear Resistance of Sewing Needles

    Institute of Scientific and Technical Information of China (English)

    FEI Dong-ye; ZHU Shi-gen

    2002-01-01

    Poor wearability is the most serious problem of domestic sewing needle, which is the main reason for their short service lives. The influences of needle materials,microstructures and manufacturing technologies on the wear resistance are analyzed in comparison with foreign sewing needles. A series of suitable measures are proposed to improve the wear resistance.

  4. Structural transformations in wear resistance of iron- and cobalt-based amorphous alloys during abrasive wear

    Science.gov (United States)

    Korshunov, L. G.; Shabashov, V. A.; Chernenko, N. L.

    2010-04-01

    The wear resistance and structural changes in a number of amorphous alloys based on iron and cobalt and in high-carbon tool steels are studied during wear by a fixed abrasive (crondum, Carborundum) at room temperature and -196°C. The abrasive wear resistance of the amorphous alloys is shown to be 1.6-3.1 lower than that of the high-carbon tool steels having a similar hardness. The relatively low level of the abrasive wear resistance of the amorphous alloys is assumed to be caused by strain softening of their surface during wear. A nanocrystalline structure is found to form in local microvolumes in a thin deformed surface layer of the alloys.

  5. Diamond-Dispersed Fiber-Reinforced Composite for Superior Friction and Wear Properties in Extreme Environments and Method for Fabricating the Same

    Science.gov (United States)

    Street, Kenneth (Inventor); Voronov, Oleg A (Inventor); Kear, Bernard H (Inventor)

    2017-01-01

    Systems, methods, and articles of manufacture related to composite materials are discussed herein. These materials can be based on a mixture of diamond particles with a matrix and fibers or fabrics. The matrix can be formed into the composite material through optional pressurization and via heat treatment. These materials display exceptionally low friction coefficient and superior wear resistance in extreme environments.

  6. Microstructure-Wear Resistance Correlation and Wear Mechanisms of Spark Plasma Sintered Cu-Pb Nanocomposites

    Science.gov (United States)

    Sharma, Amit Siddharth; Biswas, Krishanu; Basu, Bikramjit

    2014-01-01

    The dispersion of a softer phase in a metallic matrix reduces the coefficient of friction (COF), often at the expense of an increased wear rate at the tribological contact. To address this issue, unlubricated fretting wear tests were performed on spark plasma sintered Cu-Pb nanocomposites against bearing steel. The sintering temperature and the Pb content as well as the fretting parameters were judiciously selected and varied to investigate the role of microstructure (grain size, second-phase content) on the wear resistance properties of Cu-Pb nanocomposites. A combination of the lowest wear rate (~1.5 × 10-6 mm3/Nm) and a modest COF (~0.4) was achieved for Cu-15 wt pct Pb nanocomposites. The lower wear rate of Cu-Pb nanocomposites with respect to unreinforced Cu is attributed to high hardness (~2 to 3.5 GPa) of the matrix, Cu2O/Fe2O3-rich oxide layer formation at tribological interface, and exuding of softer Pb particles. The wear properties are discussed in reference to the characteristics of transfer layer on worn surface as well as subsurface damage probed using focused ion beam microscopy. Interestingly, the flash temperature has been found to have insignificant effect on the observed oxidative wear, and alternative mechanisms are proposed. Importantly, the wear resistance properties of the nanocomposites reveal a weak Hall-Petch-like relationship with grain size of nanocrystalline Cu.

  7. Wear resistant steels and casting alloys containing niobium carbide

    Energy Technology Data Exchange (ETDEWEB)

    Theisen, W.; Siebert, S.; Huth, S. [Lehrstuhl Werkstofftechnik, Ruhr-Univ. Bochum (Germany)

    2007-12-15

    Niobium, like titanium and vanadium, forms superhard MC carbides that remain relatively pure in technical alloys on account of their low solubility for other metallic alloying elements. However, because they have a greater hardness than the precipitated chromium carbides commonly used in wear-resistant alloys, they are suitable as alternative hard phases. This contribution deals with new wear-resistant steels and casting alloys containing niobium carbide. These include a secondary hardening hardfacing alloy, a composite casting alloy for wear applications at elevated temperatures, a white cast iron as well as two variants of a corrosion-resistant cold-work tool steel produced by melt metallurgy and by powder metallurgy. A heat-resistant casting alloy is also discussed. Based on equilibrium calculations the microstructures developing during production of the alloys are analysed, and the results are discussed with respect to important properties such as abrasive wear and corrosion resistance. (orig.)

  8. WEAR-RESISTANCE OF CHROMIC CAST IRONS OF EUTECTIC COMPOSITION

    Directory of Open Access Journals (Sweden)

    K. E. Baranovskij

    2009-01-01

    Full Text Available Casting of wear-resistant chrome cast irons in combined molds and iron chills is studied. Application of these ways of casting results in blending of carbides and increasing of hardness of castings.

  9. Wear resistance of nodular cast iron with carbides

    Directory of Open Access Journals (Sweden)

    G. Gumienny

    2011-07-01

    Full Text Available In this paper results of abrasive and adhesive wear resistance of selected grades of nodular cast iron with carbides are presented. It was demonstrated, that the maximum wear resistance has got nodular cast iron with the microstructure of upper bainite, lower bainite and carbides. This cast iron with hardened steel and sulfonitrided steel is the most advantageous friction pair during adhesive wear testing. It was found, that the least advantageous friction pair is pearlitic nodular cast iron with carbides and normalized steel.

  10. Effect of thermal fatigue on the wear resistance of graphite cast iron with bionic units processed by laser cladding WC

    Science.gov (United States)

    Jing, Zhengjun; Zhou, Hong; Zhang, Peng; Wang, Chuanwei; Meng, Chao; Cong, Dalong

    2013-04-01

    Thermal fatigue and wear exist simultaneously during the service life of brake discs. Previous researchers only studied thermal fatigue resistance or abrasion resistance of compact graphite cast iron (CGI), rather than combining them together. In this paper, wear resistance after thermal fatigue of CGI was investigated basing on the principle of bionics, which was close to actual service condition of the brake discs. In the meanwhile, the effect of thermal fatigue on wear resistance was also discussed. Non-smooth bionic units were fabricated by laser cladding WC powder with different proportions (50 wt.%, 60 wt.%, 70 wt.%). Microstructure and microhardness of the units were investigated, and wear mass losses of the samples were also compared. The results indicate that thermal fatigue has a negative effect on the wear resistance. After the same thermal fatigue cycles times, the wear resistance of laser cladding WC samples is superior to that of laser remelting ones and their wear resistance enhances with the increase of WC content.

  11. Corrosive wear. Evaluation of wear and corrosive resistant materials; Noetningskorrosion. Utvaerdering av noetnings- och korrosionsbestaendiga material

    Energy Technology Data Exchange (ETDEWEB)

    Persson, H.; Hjertsen, D.; Waara, P.; Prakash, B.; Hardell, J.

    2007-12-15

    With a new purchase of a waste conveyer screw at hand, for the 'A-warehouse' at the combined power and heating plant at E.ON Norrkoeping, the request for improved construction materials was raised. The previous screw required maintenance with very short intervals due to the difficult operation conditions. With the new screw the expectation is to manage 6 months of operation without interruption. The environment for the screw has two main components that sets the demand on the materials, on one hand the corrosive products that comes along and which forms at digestion of the waste and on the other hand the abrasive content in the waste. The term of the mechanism is wear-corrosion and can give considerably higher material loss than the two mechanisms wear and corrosion separately. Combination of a strong corrosive environment together with extensive wear is something that we today have limited knowledge about. The overall objective of the project has been to establish better wear and corrosive resistant construction materials for a waste conveyer screw that will lead to reduced operational disturbance costs. The evaluation has been performed in both controlled laboratory environments and in field tests, which has given us a better understanding of what materials are more suitable in this tough environment and has given us a tool for future predictions of the wear rate of the different material. The new conveyer screw, installed in February 2007 and with which the field test have been performed, has considerably reduced the wear of the construction and the target of 6 month maintenance-free operation is met with this screw for all the evaluated materials. The wear along the screw varies very much and with a clear trend for all the materials to increase towards the feeding direction of the screw. As an example, the wear plate SS2377 (stainless duplex steel) has a useful life at the most affected areas that is calculated to be 1077 days of operation with the

  12. Corrosion and wear resistant metallic layers produced by electrochemical methods

    DEFF Research Database (Denmark)

    Christoffersen, Lasse; Maahn, Ernst Emanuel

    1999-01-01

    Corrosion and wear-corrosion properties of novel nickel alloy coatings with promising production characteristics have been compared with conventional bulk materials and hard platings. Corrosion properties in neutral and acidic environments have been investigated with electrochemical methods....... Determination of polarisation resistance during 100 hours followed by stepwise anodic polarisation seems to be a promising technique to obtain steady state data on slowly corroding coatings with transient kinetics. A slurry test enables determination of simultaneous corrosion and abrasive wear. Comparison...

  13. A new production technique for wear resistant ring-hammers

    Directory of Open Access Journals (Sweden)

    Li Shifeng

    2011-11-01

    Full Text Available Based on a great number of laboratory experiments, a new technique has been developed for producing wear resistant ring-hammers. In this technology, lost foam casting with iron sand was combined to make mold; a special alloy was used to inoculate the molten steel, and proper heat treatment was used to further improve mechanical properties of wear resistant ring-hammers. The influence of this new production technology on the microstructure and mechanical properties of wear resistant ring-hammers was studied. Results show that iron sand molding, having the inherent characteristic of sand molding, changes the type of metallic compounds, refines crystal grains and increases the fineness of microstructure. Practical experience verified that the properties of the ring-hammers produced with this new technique are as follows: tensile strength (Rm 720 MPa, impact toughness (ak > 210 J•cm-2 and hardness > 200 HB. After water quenching from 1,080℃ (holding for 4 h and tempering at 320℃ for 3 h, the best wear resistance is obtained, and the wear resistance is 1.6 times higher than that of common high manganese ring-hammers.

  14. FIBROUS MONOLITH WEAR RESISTANT COMPONENTS FOR THE MINING INDUSTRY

    Energy Technology Data Exchange (ETDEWEB)

    Kenneth L. Knittel

    2005-05-09

    The work performed on this program was to develop wear resistant, tough FM composite materials with efforts focused on WC-Co based FM systems. The materials were developed for use in mining industry wear applications. Components of interest were drill bit inserts for drilling blast holes. Other component applications investigated included wear plates for a variety of equipment such as pit shovels, wear surfaces for conveyors, milling media for ball milling operations, hydrocyclone cones, grader blades and dozer teeth. Cross-cutting technologies investigated included hot metal extrusion dies, drill bits for circuit board fabrication, cutting tools for cast iron and aluminum machining. An important part of the work was identification of the standard materials used in drilling applications. A materials trade study to determine those metals and ceramics used for mining applications provided guidance for the most important materials to be investigated. WC-Co and diamond combinations were shown to have the most desirable properties. Other considerations such as fabrication technique and the ability to consolidate shifted the focus away from diamond materials and toward WC-Co. Cooperating partners such as Kennametal and Kyocera assisted with supplies, evaluations of material systems, fabricated parts and suggestions for cross-cutting technology applications for FM architectures. Kennametal provided the raw materials (WC-Co and Al-TiCN powders) for the extent of the material evaluations. Kyocera shared their research into various FM systems and provided laboratory testing of fabricated materials. Kyocera also continued research of the FM systems with the intention of developing commercial markets for a variety of applications. The continued development of FM technology by Kyocera is seen as a direct result of the cooperation established under this funding. Kyocera has a specific interest in the commercial development of the FM technology and have licensed it and have paid

  15. Wear resistance of experimental titanium alloys for dental applications.

    Science.gov (United States)

    Faria, Adriana Cláudia Lapria; Rodrigues, Renata Cristina Silveira; Claro, Ana Paula Rosifini Alves; da Gloria Chiarello de Mattos, Maria; Ribeiro, Ricardo Faria

    2011-11-01

    The present study evaluated microstructure, microhardness and wear resistance of experimental titanium alloys containing zirconium and tantalum. Alloys were melted in arc melting furnace according to the following compositions: Ti-5Zr, Ti-5Ta and Ti-5Ta-5Zr (%wt). Hemispheres and disks were obtained from wax patterns that were invested and cast by plasma. Microstructures were evaluated using optical microscopy and X-ray diffraction (XRD) analysis and also Vickers microhardness was measured. Hemispherical samples and disks were used for 2-body wear tests, performed by repeated grinding of the samples. Wear resistance was assessed as height loss after 40,000 cycles. The data were compared using ANOVA and post-hoc Tukey test. Ti-5Zr presented a Widmanstätten structure and the identified phases were α and α' while Ti-5Ta and Ti-5Ta-5Zr presented α, β, α' and α" phases, but the former presented a lamellar structure, and the other, acicular. The microhardness of Ti-5Zr was significantly greater than other materials and cp Ti presented wear resistance significantly lower than experimental alloys. It was concluded that wear resistance was improved when adding Ta and Zr to titanium and Zr increased microhardness of Ti-5Zr alloy.

  16. Wear resistance of TiAlSiN thin coatings.

    Science.gov (United States)

    Silva, F J G; Martinho, R P; Alexandre, R J D; Baptista, A P M

    2012-12-01

    In the last decades TiAIN coatings deposited by PVD techniques have been extensively investigated but, nowadays, their potential development for tribological applications is relatively low. However, new coatings are emerging based on them, trying to improve wear behavior. TiAlSiN thin coatings are now investigated, analyzing if Si introduction increases the wear resistance of PVD films. Attending to the application, several wear test configurations has been recently used by some researchers. In this work, TiAISiN thin coatings were produced by PVD Unbalanced Magnetron Sputtering technique and they were conveniently characterized using Scanning Electron Microscopy (SEM) provided with Energy Dispersive Spectroscopy (EDS), Atomic Force Microscopy (AFM), Electron Probe Micro-Analyzer (EPMA), Micro Hardness (MH) and Scratch Test Analysis. Properties as morphology, thickness, roughness, chemical composition and structure, hardness and film adhesion to the substrate were investigated. Concerning to wear characterization, two very different ways were chosen: micro-abrasion with ball-on-flat configuration and industrial non-standardized tests based on samples inserted in a feed channel of a selected plastic injection mould working with 30% (wt.) glass fiber reinforced polypropylene. TiAISiN coatings with a small amount of about 5% (wt.) Si showed a similar wear behavior when compared with TiAIN reported performances, denoting that Si addition does not improve the wear performance of the TiAIN coatings in these wear test conditions.

  17. Engineering wear-resistant surfaces in automotive aluminum

    Science.gov (United States)

    Kavorkijan, V.

    2003-02-01

    Inadequate wear resistance and low seizure loads prevent the direct use of aluminum alloys in automotive parts subject to intensive friction combined with high thermal and mechanical loading, such as brake discs, pistons, and cylinder liners. To enable the use of aluminum alloys in the production of automotive brake discs and other wear-resistant products, the insertion of a monolithic friction cladding rather than surface coating has been considered in this work. Three experimental approaches, two based on the pressure-less infiltration of porous ceramic preforms and one based on the subsequent hot rolling of aluminum and metal-matrix composite strips, are currently under investigation.

  18. INCREASING OF WEAR RESISTANCE OF THE GRAPHITIZED STEEL

    Directory of Open Access Journals (Sweden)

    I. V. Akimov

    2013-11-01

    Full Text Available Purpose. Graphitized steels are alloys, in which carbon is partly in form of graphite inclusions. Due to this such steels possess good antifriction properties, wear resistance, heat conductivity and a variety of other mechanical properties, which decently distinguish them from cast irons. However, such steels are not studied enough and practically are not used in mechanical engineering. Purpose of the work is the research of the possibility of wear resistance increase for graphitized steels in the conditions of metal-to-metal dry friction sliding to use them in the railway systems. Methodology. Graphitized hypoeutectoid, eutectoid and hypereutectoid steels have been used as a research material. Experimental alloys have been studied in the condition after thermal hardening. Hardness of alloys has been determined by the Vickers method. Wear resistance of steels has been studied in the conditions of metal-to-metal dry friction sliding with the use of МI-1 friction machine (disk to disk. Findings. Data, which allow assessing the wear resistance of experimental graphitized steels depending on carbon, silicon and copper content have been obtained in this work. The regression dependence obtained as a result of statistical processing of the experimental data allowed determining an optimal chemical content of the steel, which is characterized by high wear resistance. Originality. A dependence describing carbon, silicon and copper content on the specimen's weight loss during metal-to-metal dry friction tests has been obtained in the work. Practical value. The optimized content of the graphitized steel can be used for production of products working in the conditions of wear such as brake blocks of rolling stock, separators of high-speed bearings, dies and others.

  19. Fissure sealant materials: Wear resistance of flowable composite resins.

    Science.gov (United States)

    Asefi, Sohrab; Eskandarion, Solmaz; Hamidiaval, Shadi

    2016-01-01

    Background. Wear resistance of pit and fissure sealant materials can influence their retention. Wear characteristics of sealant materials may determine scheduling of check-up visits. The aim of this study was to compare wear resistance of two flowable composite resins with that of posterior composite resin materials. Methods. Thirty-five disk-shaped specimens were prepared in 5 groups, including two flowable composite resins (Estelite Flow Quick and Estelite Flow Quick High Flow), Filtek P90 and Filtek P60 and Tetric N-Ceram. The disk-shaped samples were prepared in 25-mm diameter by packing them into a two-piece aluminum mold and then light-cured. All the specimens were polished for 1minute using 600-grit sand paper. The samples were stored in distilled water at room temperature for 1 week and then worn by two-body abrasion test using "pin-on-disk" method (with distilled water under a 15-Nload at 0.05 m/s, for a distance of 100 meter with Steatite ceramic balls antagonists). A Profilometer was used for evaluating the surface wear. Data were analyzed with the one-way ANOVA. Results. Estelite Flow Quick exhibited 2708.9 ± 578.1 μm(2) and Estelite Flow Quick High Flow exhibited 3206 ± 2445.1 μm(2)of wear but there were no significant differences between the groups. They demonstrated similar wear properties. Conclusion. Estelite flowable composite resins have wear resistance similar to nano- and micro-filled and micro-hybrid composite resins. Therefore, they can be recommended as pit and fissure sealant materials in the posterior region with appropriate mechanical characteristics.

  20. Fissure sealant materials: Wear resistance of flowable composite resins

    Directory of Open Access Journals (Sweden)

    Sohrab Asefi

    2016-08-01

    Full Text Available Background. Wear resistance of pit and fissure sealant materials can influence their retention. Wear characteristics of sealant materials may determine scheduling of check-up visits. The aim of this study was to compare wear resistance of two flowable composite resins with that of posterior composite resin materials. Methods. Thirty-five disk-shaped specimens were prepared in 5 groups, including two flowable composite resins (Estelite Flow Quick and Estelite Flow Quick High Flow, Filtek P90 and Filtek P60 and Tetric N-Ceram. The disk-shaped samples were prepared in 25-mm diameter by packing them into a two-piece aluminum mold and then light-cured. All the specimens were polished for 1minute using 600-grit sand paper. The samples were stored in distilled water at room temperature for 1 week and then worn by two-body abrasion test using "pin-on-disk" method (with distilled water under a 15-Nload at 0.05 m/s, for a distance of 100 meter with Steatite ceramic balls antagonists. A Profilometer was used for evaluating the surface wear. Data were analyzed with the one-way ANOVA. Results. Estelite Flow Quick exhibited 2708.9 ± 578.1 μm2 and Estelite Flow Quick High Flow exhibited 3206 ± 2445.1 μm2of wear but there were no significant differences between the groups. They demonstrated similar wear properties. Conclusion. Estelite flowable composite resins have wear resistance similar to nano- and micro-filled and micro-hybrid composite resins. Therefore, they can be recommended as pit and fissure sealant materials in the posterior region with appropriate mechanical characteristics.

  1. Fissure sealant materials: Wear resistance of flowable composite resins

    Science.gov (United States)

    Asefi, Sohrab; Eskandarion, Solmaz; Hamidiaval, Shadi

    2016-01-01

    Background. Wear resistance of pit and fissure sealant materials can influence their retention. Wear characteristics of sealant materials may determine scheduling of check-up visits. The aim of this study was to compare wear resistance of two flowable composite resins with that of posterior composite resin materials. Methods. Thirty-five disk-shaped specimens were prepared in 5 groups, including two flowable composite resins (Estelite Flow Quick and Estelite Flow Quick High Flow), Filtek P90 and Filtek P60 and Tetric N-Ceram. The disk-shaped samples were prepared in 25-mm diameter by packing them into a two-piece aluminum mold and then light-cured. All the specimens were polished for 1minute using 600-grit sand paper. The samples were stored in distilled water at room temperature for 1 week and then worn by two-body abrasion test using "pin-on-disk" method (with distilled water under a 15-Nload at 0.05 m/s, for a distance of 100 meter with Steatite ceramic balls antagonists). A Profilometer was used for evaluating the surface wear. Data were analyzed with the one-way ANOVA. Results. Estelite Flow Quick exhibited 2708.9 ± 578.1 μm2 and Estelite Flow Quick High Flow exhibited 3206 ± 2445.1 μm2of wear but there were no significant differences between the groups. They demonstrated similar wear properties. Conclusion. Estelite flowable composite resins have wear resistance similar to nano- and micro-filled and micro-hybrid composite resins. Therefore, they can be recommended as pit and fissure sealant materials in the posterior region with appropriate mechanical characteristics. PMID:27651887

  2. On the Durability and Wear Resistance of Transparent Superhydrophobic Coatings

    Directory of Open Access Journals (Sweden)

    Ilker S. Bayer

    2017-01-01

    Full Text Available Transparent liquid repellent coatings with exceptional wear and abrasion resistance are very demanding to fabricate. The most important reason for this is the fact that majority of the transparent liquid repellent coatings have so far been fabricated by nanoparticle assembly on surfaces in the form of films. These films or coatings demonstrate relatively poor substrate adhesion and rubbing induced wear resistance compared to polymer-based transparent hydrophobic coatings. However, recent advances reported in the literature indicate that considerable progress has now been made towards formulating and applying transparent, hydrophobic and even oleophobic coatings onto various substrates which can withstand certain degree of mechanical abrasion. This is considered to be very promising for anti-graffiti coatings or treatments since they require resistance to wear abrasion. Therefore, this review intends to highlight the state-of-the-art on materials and techniques that are used to fabricate wear resistant liquid repellent transparent coatings so that researchers can assess various aptitudes and limitations related to translating some of these technologies to large scale stain repellent outdoor applications.

  3. Gears castings from ductile iron of improved abrasion wear resistance

    Directory of Open Access Journals (Sweden)

    D. Kopyciński

    2011-10-01

    Full Text Available The aim of this study was to develop an industrial technological process for the manufacturing of castings from alloyed ductile iron characterized by improved resistance to abrasion wear. The outcome of the study was the implementation of developed technology under the industrial conditions of ASPAMET Foundry Plant and start up of production of a wide range of cast gears.

  4. Evaluation Of Saltstone Mixer Paddle Configuration For Improved Wear Resistance

    Energy Technology Data Exchange (ETDEWEB)

    Reigel, M. M.; Fowley, M. D.; Pickenheim, B. R.

    2012-09-27

    A soft metal with low wear resistance (6000 series aluminum), was used to minimize run time while maximizing wear rate. Two paddle configurations were tested, with the first four paddles after the augers replaced by the wear paddles. The first configuration was all flat paddles, with the first paddle not aligned with the augers and is consistent with present SPF mixer. The second configuration had helical paddles for the first three stages after the augers and a flat paddle at the fourth stage. The first helical paddle was aligned with the auger flight for the second configuration. The all flat paddle configuration wear rate was approximately double the wear rate of the helical paddles for the first two sets of paddles after the augers. For both configurations, there was little or no wear on the third and fourth paddle sets based on mass change, indicating that the fully wetted premix materials are much less abrasive than the un-wetted or partially wetted premix. Additionally, inspection of the wear surface of the paddles at higher magnification showed the flat paddles were worn much more than the helical and is consistent with the wear rates. Aligning the auger discharge flight with the first set of helical paddles was effective in reducing the wear rate as compared to the flat paddle configuration. Changing the paddle configuration from flat to helical resulted in a slight increase in rheological properties. Although, both tests produced grout-like material that is within the processing rage of the SPF, it should be noted that cement is not included in the premix and water was used rather than salt solution, which does affect the rheology of the fresh grout. The higher rheological properties from the helical wear test are most likely due to the reduced number of shearing paddles in the mixer. In addition, there is variation in the rheological data for each wear test. This is most likely due to the way that the dry feeds enter the mixer from the dry feeder. The

  5. Advanced Wear-resistant Nanocomposites for Increased Energy Efficiency

    Energy Technology Data Exchange (ETDEWEB)

    Cook, B. A.; Harringa, J. L.; Russel, A. M.

    2012-12-01

    This report summarizes the work performed by an Ames-led project team under a 4-year DOE-ITP sponsored project titled, 'Advanced Wear-resistant Nanocomposites for Increased Energy Efficiency.' The Report serves as the project deliverable for the CPS agreement number 15015. The purpose of this project was to develop and commercialize a family of lightweight, bulk composite materials that are highly resistant to degradation by erosive and abrasive wear. These materials, based on AlMgB{sub 14}, are projected to save over 30 TBtu of energy per year when fully implemented in industrial applications, with the associated environmental benefits of eliminating the burning of 1.5 M tons/yr of coal and averting the release of 4.2 M tons/yr of CO{sub 2} into the air. This program targeted applications in the mining, drilling, machining, and dry erosion applications as key platforms for initial commercialization, which includes some of the most severe wear conditions in industry. Production-scale manufacturing of this technology has begun through a start-up company, NewTech Ceramics (NTC). This project included providing technical support to NTC in order to facilitate cost-effective mass production of the wear-resistant boride components. Resolution of issues related to processing scale-up, reduction in energy intensity during processing, and improving the quality and performance of the composites, without adding to the cost of processing were among the primary technical focus areas of this program. Compositional refinements were also investigated in order to achieve the maximum wear resistance. In addition, synthesis of large-scale, single-phase AlMgB{sub 14} powder was conducted for use as PVD sputtering targets for nanocoating applications.

  6. Development of wear resistant ceramic coatings for diesel engine components

    Energy Technology Data Exchange (ETDEWEB)

    Haselkorn, M.H. (Caterpillar, Inc., Peoria, IL (United States))

    1992-04-01

    Improved fuel economy and a reduction of emissions can be achieved by insulation of the combustion chamber components to reduce heat rejection. However, insulating the combustion chamber components will also increase the operating temperature of the piston ring/cylinder liner interface from approximately 150{degree}C to over 300{degree}C. Existing ring/liner materials can not withstand these higher operating temperatures and for this reason, new materials need to be developed for this critical tribological interface. The overall goal of this program is the development of piston ring/cylinder liner material pairs which would be able to provide the required friction and wear properties at these more severe operating conditions. More specifically, this program first selected, and then evaluated, potential d/wear resistant coatings which could be applied to either piston rings an or cylinder liners and provide, at 350{degree}C under lubricated conditions, coefficients of friction below 0.1 and wear rates of less than 25 {times} lO{sup {minus}6} mm/hour. The processes selected for applying the candidate wear resistant coatings to piston rings and/or cylinder liners were plasma spraying, chemical vapor, physical vapor and low temperature arc vapor deposition techniques as well as enameling techniques.

  7. Study of Stainless Steel Resistance in Conditions of Tribocorrosion Wear

    Directory of Open Access Journals (Sweden)

    Goran Rozing

    2015-07-01

    Full Text Available Analyzed was the influence of tribocorrosion wear due to effects of fatty acids present in the processed medium. The analysis was conducted on samples made of two austenitic and two martensitic stainless steels. Austenitic steels were tested in their nitrided state and martensitic in their induction hardened state. Conducted were laboratory tests of corrosion resistance of samples, analysis of the microstructure and hardness. To see how the applied processes for modifying the surface of stainless steels behave in realistic conditions, it was conducted the examination of samples/parts of a sunflower cake chain conveyer. Based on the comparison of results obtained in the laboratory and in real conditions, it was estimated that steels AISI 420 and AISI 431 with induction hardened surfaces have a satisfactory resistance to abrasive-adhesive wear in the presence of fatty acids.

  8. Antifriction and wear resistance of tin diffusion coating on brass

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    After brass is coated with tin, heat treatment makes the coating metal Sn and the substrate metal lic elements Cu and Zn diffuse with each other. This causes the c oating composition to be changed and the interface to be strengthened. The diffusion coating with a multiphase structure formed by this process has excellent properties of antifriction and wear resistance. With the aid of scanning electron microscopy, electronic probe microanalysis and X-ray diffraction, the mechanism of the properties is discussed.

  9. Dry wear behaviors of wear resistant composite coatings produced by laser cladding

    Institute of Scientific and Technical Information of China (English)

    Jiang Xu; Wenjin Liu; Minlin Zhong

    2004-01-01

    Using different proportional mixtures of Ni-coated MoS2, TiC and pure Ni powders, new typical wear resistant and selflubricant coatings were formed on low carbon steel by laser cladding process. The microstructures and phase composition of the composite coatings were studied by SEM and XRD. The typical microstructure of the composite coating is composed of multisulfide phases including binary element sulfide and ternary element sulfide, γ-Ni, TiC and Mo2C. Wear tests were carried out using an FALEX-6 type pin-on-disc machine. The friction coefficient and mass loss of three kinds of MoS2/TiC/Ni laser clad coatings are lower than those of quenched 45 steel, and the worn surfaces of the laser cladding coatings are very smooth. Because of high hardness combined with low friction, the laser cladding composite coating with a mixture of 70% Ni-coated MoS2, 20%TiC and 10%pure Ni powder presents better wear behaviors than the composite coating with other powder blends. The composition analysis of the worn surface of GCr15 bearing steel shows that the transferred film from the laser cladding coating to the opposite surface of GCr15beating steel contains an amount of sulfide, which can change the micro-friction mechanism and lead to a reduced friction coefficient.

  10. Porosity and wear resistance of flame sprayed tungsten carbide coatings

    Science.gov (United States)

    Winarto, Winarto; Sofyan, Nofrijon; Rooscote, Didi

    2017-06-01

    Thermal-sprayed coatings offer practical and economical solutions for corrosion and wear protection of components or tools. To improve the coating properties, heat treatment such as preheat is applied. The selection of coating and substrate materials is a key factor in improving the quality of the coating morphology after the heat treatment. This paper presents the experimental results regarding the effect of preheat temperatures, i.e. 200°C, 300°C and 400°C, on porosity and wear resistance of tungsten carbide (WC) coating sprayed by flame thermal coating. The powders and coatings morphology were analyzed by a Field Emission Scanning Electron Microscope equipped with Energy Dispersive Spectrometry (FE-SEM/EDS), whereas the phase identification was performed by X-Ray diffraction technique (XRD). In order to evaluate the quality of the flame spray obtained coatings, the porosity, micro-hardness and wear rate of the specimens was determined. The results showed that WC coating gives a higher surface hardness from 1391 HVN up to 1541 HVN compared to that of the non-coating. Moreover, the wear rate increased from 0.072 mm3/min. to 0.082 mm3/min. when preheat temperature was increased. Preheat on H13 steel substrate can reduce the percentage of porosity level from 10.24 % to 3.94% on the thermal spray coatings.

  11. Resistance of weldclads made by flux-cored arc welding technology against erosive wear

    Directory of Open Access Journals (Sweden)

    I. Pernis

    2013-07-01

    Full Text Available The paper deals with the tribological properties of investigated types of hardfacing materials at erosive wear process. Influence of impact angle of abrasive grains on wear resistance and microhardness changes of hardfacing layer were investigated too. From quantitative aspect weldclads wear resistance were evaluated on the base of weight loss. Results achieved showed that impact angle is one of determining factors of material’s wear measure.

  12. Wear Resistance of 3Cr2W8V Rough Surfaces

    Institute of Scientific and Technical Information of China (English)

    Zhou Hong; Wang Wei; Ren Lu-quan; Li Yue; Li Chen

    2005-01-01

    Three types of rough surface were processed by laser irradiation on the 3Cr2W8V material hot-work die steel surface.The wear experiments with smooth surface and rough surface samples were repeated on the pin-tray wear machine. According to the wear results, we studied the regularity of wear resistance of different rough surface samples. The results indicated that bionic rough surface can improve the wear resistance of the material and the wear resistance can be increased 1 -2times, compared with the smooth surface. Also, the wear resistance of the rough surface was affected by laser current and duration of impulse. The bigger the laser current or the impulse duration, the better is the wear resistance. When the distance between the same kind of units which are distributed on the surfaces is changed, the wear resistance changes. The wear resistance of a bionic rough surface on which the grid units were distributed at spacing of 1 mm was the best. And we designed the wear models.

  13. Development of wear resistant nanostructured duplex coatings by high velocity oxy-fuel process for use in oil sands industry.

    Science.gov (United States)

    Saha, Gobinda C; Khan, Tahir I; Glenesk, Larry B

    2009-07-01

    Oil sands deposits in Northern Alberta, Canada represent a wealth of resources attracting huge capital investment and significant research focus in recent years. As of 2005, crude oil production from the current oil sands operators accounted for 50% of Canada's domestic production. Alberta's oil sands deposits contain approximately 1.7 trillion barrels of bitumen, of which over 175 billion are recoverable with current technology, and 315 billion barrels are ultimately recoverable with technological advances. A major problem of operating machinery and equipment in the oil sands is the unpredictable failure from operating in this highly aggressive environment. One of the significant causes of that problem is premature material wear. An approach to minimize this wear is the use of protective coatings and, in particular, a cermet thin coating. A high level of coating homogeneity is critical for components such as bucketwheels, draglines, conveyors, shovels, heavyhauler trucks etc. that are subjected to severe degradation through abrasive wear. The identification, development and application of optimum wear solutions for these components pose an ongoing challenge. Nanostructured cermet coatings have shown the best results of achieving the degree of homogeneity required for these applications. In this study, WC-17Co cermet powder with nanocrystalline WC core encapsulated with 'duplex' Co layer was used to obtain a nanostructured coating. To apply this coating, high velocity oxy-fuel (HVOF) thermal spraying technique was used, as it is known for producing wear-resistant coatings superior to those obtained from plasma-based techniques. Mechanical, sliding wear and microstructural behavior of the coating was compared with those of the microstructured coating obtained from spraying WC-10Co-4Cr cermet powder by HVOF technique. Results from the nanostructured coating, among others, showed an average of 25% increase in microhardness, 30% increase in sliding wear resistance and

  14. Titanium aluminide intermetallic alloys with improved wear resistance

    Energy Technology Data Exchange (ETDEWEB)

    Qu, Jun; Lin, Hua-Tay; Blau, Peter J.; Sikka, Vinod K.

    2014-07-08

    The invention is directed to a method for producing a titanium aluminide intermetallic alloy composition having an improved wear resistance, the method comprising heating a titanium aluminide intermetallic alloy material in an oxygen-containing environment at a temperature and for a time sufficient to produce a top oxide layer and underlying oxygen-diffused layer, followed by removal of the top oxide layer such that the oxygen-diffused layer is exposed. The invention is also directed to the resulting oxygen-diffused titanium aluminide intermetallic alloy, as well as mechanical components or devices containing the improved alloy composition.

  15. Preparation of Wear Resistant Materials by Melting and Diffusion Process

    Institute of Scientific and Technical Information of China (English)

    YU Shihao; WEI Xueping; ZENG Hui

    2012-01-01

    A wear-resistant material reinforced with VCp was manufactured by the in-mold melting process,in which the high-vanadium alloy-rods were melted by high temperature liquid steel and elements diffused into the liquid.Microstructure of the material was examined by OM,SEM,and XRD,and alloy elements in the diffusion layer were studied by EDS,and the hardness of the material was tested by HRS.The experimental results show that the material gradually changes hardness,which is due to the uniformly existents of carbide particles on martensite matrix and the gradient distribution of vanadium and carbide.

  16. Standard Test Method for Abrasive Wear Resistance of Cemented

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2005-01-01

    1.1 This test method covers the determination of abrasive wear resistance of cemented carbides. 1.2 The values stated in inch-pound units are to be regarded as the standard. The SI equivalents of inch-pound units are in parentheses and may be approximate. 1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  17. Recent developments in wear- and corrosion-resistant alloys for the oil industry

    Energy Technology Data Exchange (ETDEWEB)

    Raghu, D. [Deloro Stellite Inc., Goshen, IN (United States). Stellite Coatings Div.; Wu, J.B.C. [Stoody Deloro Stellite, Inc., St. Louis, MO (United States)

    1997-11-01

    Oil production and refining pose very severe wear and corrosion environments. Material designers are challenged with the need to design and develop materials that combine high corrosion resistance with good wear resistance. Coupled with that is the need for these materials to meet requirements such as fracture toughness and resistance to sulfide and chloride stress corrosion cracking. Often, increasing wear resistance compromises the corrosion and welding characteristics. This article covers a variety of material developments that address the problems of wear and corrosion, including alloy design fundamentals and pertinent wear properties and general corrosion resistance compared to traditional wear-resistant materials. Proven applications, with particular reference to petroleum and petrochemical areas, are discussed. Potential applications are also cited.

  18. Effects of WC particle size on the wear resistance of laser surface alloyed medium carbon steel

    Science.gov (United States)

    Tong, Xin; Li, Fu-hai; Kuang, Min; Ma, Wen-you; Chen, Xing-chi; Liu, Min

    2012-01-01

    The CO2 laser surface alloying technique was used to form wear resistance layers on medium carbon steel with a kind of spherical WC powder. The effects of WC particle size on the abrasive wear resistance were thoroughly investigated. The results indicate that the laser alloyed layer is characterized by dendritic primary phase and ledeburite microstructure, consisting of austenite, martensite and carbides of Fe3W3C, W2C and WC. The laser surface alloying with WC powder could improve the abrasive wear resistance of the medium carbon steel by over 63%. The factors such as the hardness, the amount and the distribution of WC particle determined the laser alloyed samples' wear resistance, and the laser alloyed sample with WC powder of 88-100 μm diameter presented the best wear resistance in this study. Furthermore, the wear resistance mechanisms of the laser alloyed layers were also explored.

  19. Wear Resistance of Friction Pair of Metal Composite/Copper under Electric Current

    Science.gov (United States)

    Aleutdinova, M. I.; Fadin, V. V.; Rubtsov, V. Ye; Aleutdinov, K. A.

    2016-11-01

    Sliding of metal composites against copper counterbody under severe conditions (i.e. at the contact current density higher 50 A/cm2 and at high roughness of counterbody) is carried out. It is shown that the composite of composition of Cu-30% of graphite shows low wear resistance in these conditions. Higher wear resistance is inherent in the composites containing lead and bearing steel. Impregnation of these composites by industrial oil hasn't led to noticeable increase in wear resistance.

  20. Wear and impact resistance of HVOF sprayedceramic matrix composites coating

    Science.gov (United States)

    Prawara, B.; Martides, E.; Priyono, B.; Ardy, H.; Rikardo, N.

    2016-02-01

    Ceramic coating has the mechanical properties of high hardness and it is well known for application on wear resistance, but on the other hand the resistance to impact load is low. Therefore its use is limited to applications that have no impact loading. The aim of this research was to obtain ceramic-metallic composite coating which has improved impact resistance compared to conventional ceramic coating. The high impact resistance of ceramic-metallic composite coating is obtained from dispersed metallic alloy phase in ceramic matrix. Ceramic Matrix Composites (CMC) powder with chrome carbide (Cr3C2) base and ceramic-metal NiAl-Al2O3 with various particle sizes as reinforced particle was deposited on mild steel substrate with High Velocity Oxygen Fuel (HVOF) thermal spray coating. Repeated impact test showed that reinforced metallic phase size influenced impact resistance of CMC coating. The ability of CMC coating to absorb impact energy has improved eight times and ten times compared with original Cr3C2 and hard chrome plating respectively. On the other hand the high temperature corrosion resistance of CMC coating showed up to 31 cycles of heating at 800°C and water quenching cooling.

  1. Development of wear-resistant coatings for cobalt-base alloys

    Energy Technology Data Exchange (ETDEWEB)

    Cockeram, B.V.

    1999-10-22

    The level of nuclear plant radiation exposure due to activated cobalt wear debris could potentially be reduced by covering the cobalt-base materials with a wear resistant coating. Laboratory pin-on-disc and rolling contact wear tests were used to evaluate the wear performance of several coatings. Based on the results of these tests, multilayer Cr-nitride coatings and ion nitriding are the most promising approaches.

  2. The Effect of Nodular Cast Iron Metal Matrix on the Wear Resistance

    Directory of Open Access Journals (Sweden)

    G. Gumienny

    2012-04-01

    Full Text Available The paper presents results of studies on the effect of the nodular cast iron metal matrix composition on the abrasive and adhesive wear resistance. Nodular cast iron with different metal matrix obtained in the rough state and ADI were tested. To research of abrasive and adhesive wear the pearlitic and bainitic cast iron with carbides and without this component were chosen. The influence of the carbides amount for cast iron wear resistance was examined. It was found, that the highest abrasive and adhesive wear resistance under conditions of dry friction has a nodular cast iron with carbides with upper and lower bainite. Carbides in bainitic and pearlitic cast iron significantly increase the wear resistance in these conditions. In terms of fluid friction the largest wear resistance had cast iron group with the highest hardness.

  3. Microstructural effects on the sliding wear resistance of a cobalt-based alloy

    Energy Technology Data Exchange (ETDEWEB)

    Frenk, A. (Dept. of Materials, Swiss Federal Inst. of Technology, Lausanne (Switzerland)); Kurz, W. (Dept. of Materials, Swiss Federal Inst. of Technology, Lausanne (Switzerland))

    1994-05-01

    The influence of the microstructure on the dry sliding wear resistance of a hypo-eutectic Stellite 6 alloy was investigated under conditions leading to severe metallic wear of the hardfacing alloy. Conventional chill casting as well as laser surface cladding were used to produce a wide range of solidification microstructures. The hardness of the alloy was strongly dependent on the microstructure and in particular on the size of the dendrites. Under the sliding conditions investigated, severe delamination wear of the Stellite occurred. High coefficients of friction were measured and the structure in the subsurface was completely destroyed by the resulting stress cycles. During the stationary wear regime, no dependence of the wear rate on the as-solidified microstructure could therefore be determined. However, a strong influence on the wear resistance of alloying elements which affect the matrix properties was observed. Suggestions are made for the improvement of the wear resistance of such alloys under similar sliding conditions. (orig.)

  4. Effect of bionic coupling units' forms on wear resistance of gray cast iron under dry linear reciprocating sliding condition

    Science.gov (United States)

    Pang, Zuobo; Zhou, Hong; Xie, Guofeng; Cong, Dalong; Meng, Chao; Ren, Luquan

    2015-07-01

    In order to get close to the wear form of guide rails, the homemade linear reciprocating wear testing machine was used for the wear test. In order to improve the wear-resistance of gray cast iron guide rail, bionic coupling units of different forms were manufactured by a laser. Wear behavior of gray-cast-iron with bionic-coupling units has been studied under dry sliding condition at room temperature using the wear testing machine. The wear resistance was evaluated by means of weight loss measurement and wear morphology. The results indicated that bionic coupling unit could improve the wear resistance of gray cast iron. The wear resistance of gray cast iron with reticulation bionic coupling unit is the best. When the load and speed changed, reticulation bionic coupling unit still has excellent performance in improving the wear resistance of gray cast iron.

  5. Polyurethanes from the crystalline prepolymers resistant to abrasive wear

    Directory of Open Access Journals (Sweden)

    Domańska Agata

    2014-12-01

    Full Text Available The research aimed at the selection of polyurethanes synthesized from poly(tetramethylene ether glycol (PTMEG, as well as from two different isocyanates 4,4′-methylenebis(cyclohexylisocyanate (HMDI and 4.4′-methylenebis(phenyl isocyanate (MDI in order to obtain polyurethane with increased resistance to abrasive wear and degradation for bio-medical application. Polyurethanes were fabricated from crystalline prepolymers extended by water. The paper presents preliminary results on polyurethane surface wettability, friction coefficient for different couples of the co-working materials such as polyurethane-polyurethane, polyurethane-titanium alloy, polyurethane-alumina, in comparison to commonly used polyethylene-titanium alloy. Shear strength of polyurethane-alumina joint, as well as viscosity of prepolymers were also measured. The values of friction coefficient were compared to literature data on commercially available polyurethane with the trade name Pellethane. Polyurethanes obtained are characterized by low abrasive wear and low friction coefficient in couple with the titanium alloy, what makes them attractive as possible components of ceramic-polymer endoprosthesis joints.

  6. Study on dry friction and wear resistance of a WC-Co particle reinforced iron matrix composite material

    OpenAIRE

    Zhang Peng; Zeng Shaolian; Zhang Zhiguo

    2013-01-01

    In order to select a suitable material for the rolling mill guide application, the dry sliding friction and wear resistance of a tungsten carbide combining cobalt (WC-Co) particle reinforced chromium cast iron composite material were studied. In particular, the wear resistance was discussed in detail. The results showed that the composite material demonstrates 25 times the wear resistance of high Cr cast iron, and 9 times the wear resistance of heat resistant steel. However, the average frict...

  7. Wear resistant zirconium base alloy article for water reactors

    Energy Technology Data Exchange (ETDEWEB)

    Gillett, J.E.; Shockling, L.A.; Sherwood, D.G.

    1988-03-01

    In a water reactor operating environment, the combination having improved fretting wear resistance is described comprising: an elongated tubular water displacer rod; having a low neutron absorption cross section guide support plates distributed along the length of the water displacer rod; the water displacer rod intersecting the guide support plates through apertures in the guide support plates; the water displacer rod having a plurality of spaced apart annular electrospark deposited coatings, each coating facing the wall of a respective aperture, the electrospark deposited coatings comprising Cr/sub 2/C/sub 3/; wherein the water displacer rod has a tube wall composed of a zirconium base alloy; and wherein the guide support plates are composed of a stainless steel alloy.

  8. Characterization of the wear resistant aluminum oxide - 40% titaniumdioxide coating

    Directory of Open Access Journals (Sweden)

    Mihailo R. Mrdak

    2014-02-01

    Full Text Available Plasma spray coatings play an important role in the design of surface properties of engineering components in order to increase their durability and performance under different operating conditions. Coatings are the most often used for wear resistance. This paper presents the microstructure and mechanical properties Al2O3_­40wt.%TiO2 coating resistant to dry friction slide, grain abrasion and erosion of particles at operating temperatures up to 540°C. In order to obtain the optimal characteristics of coating was performed  optimization  of deposition parameters. The powder Al2O3­40wt.%TiO2 is deposited atmospheric plasma spraying (APS process with a plasma current of 700, 800 and 900A. Evaluate the quality of the coating Al2O3­40wt.%TiO2 were made on the basis of their hardness, tensile bond strength and microstructure. The best performance showed the deposited layers with 900A. The morphology of the powder particles Al2O3­40wt.%TiO2 was examined with SEM (Scanning Electron Microscope. Microstructure of the coatings was examined by light microscopy. Analysis of the deposited layers was performed in accordance with standard Pratt & Whitney. Evaluation of mechanical properties of the layers was done by examining HV0.3 microhardness and tensile strength of the tensile testing. Studies have shown that plasma currents significantly affects the mechanical properties and microstructure of coatings which are of crucial importance for the protection for components subjected to wear       

  9. A Study on the Wear Resistance of Nano-Material/E51

    Institute of Scientific and Technical Information of China (English)

    Yan GAO; Zhenjia WANG; Quanyou MA; Ge TANG; Ji LIANG

    2004-01-01

    Epoxy resin modified by nanometric γ-alumina or multi-walled carbon nanotubes (MCNTs) was prepared with solution mixing method, and the wear resistance of the composite was studied. The results show that when an optimum amount of nanometric alumina or MCNTs is filled in epikote51 (E51), the wear resistance of the composite will increase. When 8 wt pct nanometric γ-alumina is filled in E51, the wear resistance of the composite increases to 230%. When 10% MCNTs is filled in E51, the wear resistance of the composite increases to 226%. When nanometric alumina is filled in, the wear resistance of modified epikote51 will increase as the cure temperature is heightened.

  10. Standard test method for ranking resistance of plastics to sliding wear using block-on-ring wear test—cumulative wear method

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2003-01-01

    1.1 This test method covers laboratory procedures for determining the resistance of plastics to sliding wear. The test utilizes a block-on-ring friction and wear testing machine to rank plastics according to their sliding wear characteristics against metals or other solids. 1.2 An important attribute of this test is that it is very flexible. Any material that can be fabricated into, or applied to, blocks and rings can be tested. Thus, the potential materials combinations are endless. In addition, the test can be run with different gaseous atmospheres and elevated temperatures, as desired, to simulate service conditions. 1.3 Wear test results are reported as the volume loss in cubic millimetres for the block and ring. Materials of higher wear resistance will have lower volume loss. 1.4 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only. 1.5 This standard does not purport to address all of the safety concerns, if any, associated with it...

  11. Microstructure and wear resistance of spray-formed supermartensitic stainless steel

    Directory of Open Access Journals (Sweden)

    Guilherme Zepon

    2013-06-01

    Full Text Available Since the early 90's the oil industry has been encouraging the development of corrosion and wear resistant alloys for onshore and offshore pipeline applications. In this context supermartensitic stainless steel was introduced to replace the more expensive duplex stainless steel for tubing applications. Despite the outstanding corrosion resistance of stainless steels, their wear resistance is of concern. Some authors reported obtaining material processed by spray forming, such as ferritic stainless steel, superduplex stainless steel modified with boron, and iron-based amorphous alloys, which presented high wear resistance while maintaining the corrosion performance1,2. The addition of boron to iron-based alloys promotes the formation of hard boride particles (M2B type which improve their wear resistances3-9. This work aimed to study the microstructure and wear resistance of supermartensitic stainless steel modified with 0.3 wt. (% and 0.7 wt. (% processed by spray forming (SF-SMSS 0.3%B and SF-SMSS 0.7%B, respectively. These boron contents were selected in order to improve the wear resistance of supermartensitic stainless steel through the formation of uniformly distributed borides maintaining the characteristics of the corrosion resistant matrix. SF-SMSS 0.7%B presents an abrasive wear resistance considerably higher than spray-formed supermartensitic stainless steel without boron addition (SF-SMSS.

  12. CASTING OF DETAILS OF WEAR-RESISTANT CHROME CAST IRONS FOR CHROMIC MILLS IN COMBINED MOLDS AND CHILLS

    Directory of Open Access Journals (Sweden)

    K. E. Baranovskij

    2009-01-01

    Full Text Available Relative wear resistance of chrome cast irons of eutectic composition is determined in laboratory and industry conditions. Complex alloyed eutectic cast iron with increased wear resistance and mechanical characteristics is developed.

  13. Abrasive Wear Resistance of Tool Steels Evaluated by the Pin-on-Disc Testing

    Science.gov (United States)

    Bressan, José Divo; Schopf, Roberto Alexandre

    2011-05-01

    Present work examines tool steels abrasion wear resistance and the abrasion mechanisms which are one main contributor to failure of tooling in metal forming industry. Tooling used in cutting and metal forming processes without lubrication fails due to this type of wear. In the workshop and engineering practice, it is common to relate wear resistance as function of material hardness only. However, there are others parameters which influences wear such as: fracture toughness, type of crystalline structure and the occurrence of hard precipitate in the metallic matrix and also its nature. In the present investigation, the wear mechanisms acting in tool steels were analyzed and, by normalized tests, wear resistance performance of nine different types of tool steels were evaluated by pin-on-disc testing. Conventional tool steels commonly used in tooling such as AISI H13 and AISI A2 were compared in relation to tool steels fabricated by sintering process such as Crucible CPM 3V, CPM 9V and M4 steels. Friction and wear testing were carried out in a pin-on-disc automated equipment which pin was tool steel and the counter-face was a abrasive disc of silicon carbide. Normal load of 5 N, sliding velocity of 0.45 m/s, total sliding distance of 3000 m and room temperature were employed. The wear rate was calculated by the Archard's equation and from the plotted graphs of pin cumulated volume loss versus sliding distance. Specimens were appropriately heat treated by quenching and three tempering cycles. Percentage of alloying elements, metallographic analyses of microstructure and Vickers microhardness of specimens were performed, analyzed and correlated with wear rate. The work is concluded by the presentation of a rank of tool steel wear rate, comparing the different tool steel abrasion wear resistance: the best tool steel wear resistance evaluated was the Crucible CPM 9V steel.

  14. Wear resistance of a Cr3C2-NiCr detonation spray coating

    Science.gov (United States)

    Wang, Jun; Wang, Jun; Sun, Baode; Guo, Qixin; Nishio, Mitsuhiro; Ogawa, Hiroshi

    2002-06-01

    Coatings can be applied to surfaces to improve the surface characteristics over those of the bulk properties and are widely used in tribological applications either to reduce wear and/or to modify friction during contact. One of the foremost coating methods for combating wear is thermal spraying. To prolong the life of steel slab continuous casting rolls, Cr3C2-NiCr detonation spray coating was processed on the roll surface in a steelmaking plant in China. This article studies the mechanical properties and wear resistance of this coating. The abrasive and dry frictional wear testing were performed using a pin-on-disk tester. Experimental results show that the wear resistance of the coated samples, i.e., coating reduces the risk of seizure compared to uncoated samples, is much better than those of the uncoated steel at room and elevated temperatures with any load and sliding velocity. The coating wear mechanisms under different test conditions are discussed.

  15. Wear behaviour of wear-resistant adaptive nano-multilayered Ti-Al-Mo-N coatings

    Science.gov (United States)

    Sergevnin, V. S.; Blinkov, I. V.; Volkhonskii, A. O.; Belov, D. S.; Kuznetsov, D. V.; Gorshenkov, M. V.; Skryleva, E. A.

    2016-12-01

    Coating samples in the Ti-Al-Mo-N system were obtained by arc-PVD method at variable bias voltage Ub applied to the substrate, and the partial pressure of nitrogen P(N2) used as a reaction gas. The deposited coatings were characterized by a nanocrystalline structure with an average grain size of 30-40 nm and multilayered architecture with alternating layers of (Ti,Al)N nitride and Mo-containing phases with a thickness comparable to the grain size. Coatings of (Ti,Al)N-Mo-Mo2N and (Ti,Al)N-Mo2N compositions were obtained by changing deposition parameters. The obtained coatings had hardness of 40 GPa and the relative plastic deformation under microindentation up to 60%. (Ti,Al)N-Mo2N coatings demonstrated better physicomechanical characteristics, showing high resistance to crack formation and destruction through the plastic deformation mechanism without brittle fracturing, unlike (Ti,Al)N-Mo-Mo2N. The friction coefficient of the study coatings (against Al2O3 balls under dry condition using a pin-on-disc method) reached the values of 0.35 and 0.5 at 20 °C and 500 °C respectively, without noticeable wear within this temperature range. These tribological properties were achieved by forming MoO3 acting as a solid lubricant. At higher temperatures the deterioration in the tribological properties is due to the high rate of MoO3 sublimation from friction surfaces.

  16. The microstructural dependence of wear resistance in austenite containing plate steels

    Science.gov (United States)

    Wolfram, Preston Charles

    The purpose of this project was to examine the microstructural dependence of wear resistance of various plate steels, with interests in exploring the influence of retained austenite (RA). Materials resistant to abrasive wear are desirable in the industrial areas of agriculture, earth moving, excavation, mining, mineral processing, and transportation. Abrasive wear contributes to significant financial cost associated with wear to the industry. The motivation for the current study was to determine whether it would be beneficial from a wear resistance perspective to produce plate steels with increased amounts of retained austenite. This thesis investigates this motivation through a material matrix containing AR400F, Abrasive (0.21 wt pct C, 1.26 wt pct Mn, 0.21 wt pct Si, 0.15 wt pct Ni, 0.18 wt pct Mo), Armor (0.46 wt pct C, 0.54 wt pct Mn, 0.36 wt pct Si, 1.74 wt pct Ni, 0.31 wt pct Mo), 9260, 301SS, Hadfield, and SAE 4325 steels. The Abrasive, Armor and 9260 steels were heat treated using different methods such as quench and temper, isothermal bainitic hold, and quench and partitioning (Q&P). These heat treatments yielded various microstructures and the test matrix allowed for investigation of steels with similar hardness and varying levels of RA. The wear test methods used consisted of dry sand rubber wheel (DSRW), impeller-tumbler impact-abrasion (impeller), and Bond abrasion wear testing. DSRW and impeller wear resistance was found to increase with hardness and retained austenite levels at certain hardness levels. Some Q&P samples exhibited similar or less wear than the Hadfield steels in DSRW and impeller tests. Scanning electron microscopy investigation of wear surfaces revealed different wear mechanisms for the different wear test methods ranging from micro-plowing, to micro-cutting and to fragmentation.

  17. Increasing the wear resistance of ultra-high molecular weight polyethylene by adding solid lubricating fillers

    Energy Technology Data Exchange (ETDEWEB)

    Panin, S. V., E-mail: svp@ispms.tsc.ru [Institute of Strength Physics and Materials Science SB RAS, Tomsk, 634055, Russia and National Research Tomsk Polytechnic University, Tomsk, 634050 (Russian Federation); Kornienko, L. A.; Poltaranin, M. A.; Ivanova, L. R. [Institute of Strength Physics and Materials Science SB RAS, Tomsk, 634055 (Russian Federation); Suan, T. Nguen [National Research Tomsk Polytechnic University, Tomsk, 634050 (Russian Federation)

    2014-11-14

    In order to compare effectiveness of adding solid lubricating fillers for polymeric composites based on ultra-high molecular weight polyethylene (UHMWPE) with graphite, molybdenum disulfide and polytetrafluoroethylene, their tribotechnical characteristics under dry friction, boundary lubrication and abrasive wearing were investigated. The optimal weight fractions of fillers in terms of improving wear resistance have been determined. The supramolecular structure and topography of wear track surfaces of UHMWPE-based composites with different content of fillers have been studied.

  18. Influence on the wear resistance of the particle size used in coatings of Alumina

    Science.gov (United States)

    Santos, A.; Guzmán, R.; Ramirez, Z. Y.

    2017-01-01

    In the literature, it is common to find that the size of the particles used in coatings through thermal spraying processes influences the hardness and wear resistance thereof; this project aimed to quantify the importance of this parameter in the adhesive and abrasive wear resistance when aluminium oxide is deposited on a substrate of AISI 1020 steel, through a thermal spraying by flame process. The methodology consisted of: a) morphological characterization of the powder used in the coatings by scanning electron microscopy, b) deposition of coatings, c) testing of adhesive and abrasive wear (ASTM G99-05 Standard test method for wear testing with a pin-on-disk apparatus and ASTM G65–04 Standard test method for measuring abrasion using dry sand/rubber wheel apparatus), and d) statistical analysis to determine the influence of particle size on wear resistance. The average size of the powder used for coatings was 92, 1690, 8990 and 76790nm. The obtained results allow to identify an inversely proportional behaviour between particle size and wear resistance, in both types of wear (adhesive and abrasive) is shown a logarithmic trend indicating an increase in loss mass during the test as the particle size is also increased and therefore a decrease in wear resistance of the coating.

  19. Effect of porosity on wear resistance of SiCp/Cu composites prepared by pressureless infiltration

    Institute of Scientific and Technical Information of China (English)

    ZHANG Lin; QU Xuan-hui; DUAN Bo-hua; HE Xin-bo; QIN Ming-li

    2008-01-01

    The influence of porosity on the wear behavior of high volume fraction (61%) SiCp/Cu composite produced by pressureless infiltration was studied using a sliding, reciprocating and vibrating(SRV) machine. SiCp/Cu composites slid against hardened GCr15 bearing steel ball in the load range of 40-200 N. The results show that the wear rate increases with increasing porosity. The composite containing low porosity shows excellent wear resistance, which is attributed to the presence of mechanically mixed layer on the worn surface. In this case, the dominant wear mechanism is oxidative wear. Comparatively, the composite containing high porosity exhibits inferior wear resistance. Fracture and spalling of the particles are considered as the main causes of severe wear. Third body abrasion is the controlling wear mechanism. In addition, porosity has more important influence on wear rate at high load than at low load. This is associated with the fact that the fracture and spalling of particles is a process of crack initiation and propagation. At lower load, the pores beneath the worn surface can not propagate significantly, while the pores become unstable and easily propagate under high load, which results in a higher wear rate.

  20. Effect of heat treatment on the wear resistance of high-carbon and high-nitrogen steels subjected to abrasive wear

    Science.gov (United States)

    Filippov, M. A.; Belozerova, T. A.; Blinov, V. M.; Kostina, M. A.; Val'kov, E. V.

    2006-03-01

    The effect of quenching and tempering on the capacity of steels based on chromium-carbon, chromium-nitrogen, and carbon-manganese austenite for strain-induced martensitic transformation, hardening, and wear resistance in the process of abrasive wear is studied. The steels contain 1-1.2% C or N and 18% Cr or Mn. The wear resistance of the studied steels having a structure of metastable austenite is compared to that of steel 110G13.

  1. Comparative Study of Wear Resistance of the Composite with Microhybrid Structure and Nanocomposite

    Directory of Open Access Journals (Sweden)

    Pieniak Daniel

    2016-12-01

    Full Text Available The aim of the study was to compare microhardness and wear resistance of ceramic-polymer composites with micro and nano-hybrid structure. For the studies commercial composites were used, containing filler particles of the same type but different sizes, nano-sized (Filtek Ultimate and micro-sized (Filtek Z250 composites. Tribological testing was conducted using ball-on-disc micro-tribometer. Vickers testing method was applied for microhardness studies with the use of Futertech FM 700 device. It has been demonstrated that the wear of Filtek Ultimate is almost twice lower in comparison to wear of Filtek Z250 composite. It has been concluded that the use of filler nanoparticles significantly increased wear resistance of the material. Additionally, lack of correlation between material microhardness and wear resistance has been demonstrated.

  2. Effect of the Carbides and Matrix on the Wear Resistance of Nodular Cast Iron

    Directory of Open Access Journals (Sweden)

    G. Gumienny

    2013-07-01

    Full Text Available This paper presents the results of the abrasive wear resistance of selected types of nodular cast iron, including ADI, cooperating with quartz sand and 100 grit abrasive paper. It has been shown that carbides in nodular cast iron cause an increase in wear resistance of 6 to 12% depending on the surface fraction of the carbides and type of the matrix. For the same unit pressure the mass loss of the cast iron cooperating with quartz sand is many times larger than the cast iron cooperating with abrasive paper. For both abrasives the highest wear resistance showed nodular cast iron with upper and lower bainite and carbides.

  3. Effect of the Carbides and Matrix on the Wear Resistance of Nodular Cast Iron

    Directory of Open Access Journals (Sweden)

    Gumienny G.

    2013-09-01

    Full Text Available This paper presents the results of the abrasive wear resistance of selected types of nodular cast iron, including ADI, cooperating with quartz sand and 100 grit abrasive paper. It has been shown that carbides in nodular cast iron cause an increase in wear resistance of 6 to 12% depending on the surface fraction of the carbides and type of the matrix. For the same unit pressure the mass loss of the cast iron cooperating with quartz sand is many times larger than the cast iron cooperating with abrasive paper. For both abrasives the highest wear resistance showed nodular cast iron with upper and lower bainite and carbides.

  4. Wear and corrosion resistance of laser remelted and plasma sprayed Ni and Cr coatings on copper

    Institute of Scientific and Technical Information of China (English)

    梁工英; 黄俊达; 安耿

    2004-01-01

    Nickel and chromium coatings were produced on the copper sheet using plasma spraying and laser remelting. The sliding wear test was achieved on a block-on-ring tester and the corrosion test was carried out in an acidic atmosphere. The corrosive behaviors of both coatings and original copper samples were investigated by using an impedance comparison method. The experimental results show that the nickel and chromium coatings display better wear resistance and corrosion resistance relative to the original pure copper sample. The wear resistance of the coatings is 8 - 12 times as large as original samples, and the wear resistance of laser remelted samples is better than that of plasma sprayed ones. The corrosion resistance of laser remelted nickel and chromium samples is better than that of plasma sprayed samples respectively. The corrosion rate of chromium coatings is less than that of nickel coatings, and the laser remelted Cr coating exhibits the least corrosion rate.

  5. Enhancing the wear resistance of case carburized steel (En 353) by cryogenic treatment

    Science.gov (United States)

    Bensely, A.; Prabhakaran, A.; Mohan Lal, D.; Nagarajan, G.

    2005-12-01

    All mechanical components that undergo sliding or rolling contact are subject to some degree of wear. So wear is an important tribological phenomenon while studying the failure of components. The observed frequent failure of crown and pinion due to wear and fatigue lead to this study on effect of cryogenic treatment on the wear resistance of case carburized steel (En 353). This paper deals with the pin on disk wear test without lubrication as per ASTM standard, designation: G 99-95A. The test was carried out for three different load conditions and seven sliding speeds for the samples, which has undergone three different treatment conditions namely conventional heat treatment (CHT), shallow cryogenic treatment (SCT) and deep cryogenic treatment (DCT). It has been found that the wear resistance has been considerably increased due to shallow cryogenic treatment and deep cryogenic treatment includes much more improvement in wear resistance when compared to conventional heat treatment. Also it is concluded that for better wear resistance, it is advisable to go for deep cryogenic treatment. The results are consistent with the previous studies reported in the literature on cryogenic treatments for other materials.

  6. Effect of the microhardness difference between base metal and bionic coupling unit on wear resistance of gray cast iron

    Science.gov (United States)

    Pang, Zuobo; Zhou, Hong; Chang, Fang; Zhang, Peng; Cong, Dalong; Meng, Chao; Wang, Chuanwei; Ren, Luquan

    2015-12-01

    In order to improve the wear resistance of gray cast iron guide rail, the samples with different microhardness difference between bionic coupling units and base metal were manufactured by laser surface remelting. Wear behavior of gray cast iron with bionic coupling units has been studied under dry sliding condition at room temperature using a homemade liner reciprocating wear testing machine. The wear resistance was evaluated by means of weight loss measurement and wear morphology. The results indicated that when the microhardness difference is 561 HV0.2, the wear resistance of sample is the best.

  7. Effect of filler size on wear resistance of resin cement.

    Science.gov (United States)

    Shinkai, K; Suzuki, S; Katoh, Y

    2001-11-01

    The purpose of this study was to evaluate the effect of filler size on the wear of resin cements. Materials tested included four experimental dual-cure resin cements (Kuraray) consisting of different-sized filler particles. A rectangular box cavity was prepared on the flattened occlusal surface of extracted human molars. Ceramic inlays for the cavities were fabricated using the Cerec 2 system. The Cerec inlays were cemented with the respective cements and adhesive systems according to the manufacturer's directions. The restored surface was finished by wet-grinding with an 800-grit silicon carbide paper. Six specimens were prepared for each resin cement. Half of the specimens were subjected to a three-body wear test for 200,000 cycles, and the others were subjected to a toothbrush abrasion test for 30,000 cycles. The worn surface of each restoration was scanned by a profilometer (Surfcom 475 A) at eight different points for each restoration. The wear value was determined by measuring the vertical gap depth on the profilometric tracings. The data were statistically analyzed by one-way analysis of variance (ANOVA) and Scheffe's test. The results showed that, with increase of filler size, the wear value decreased in the toothbrush test and increased in the three-body wear test. The cement with 0.04-microm filler exhibited the lowest wear value among the materials in the three-body wear test, and the same wear value as the cement with 0.97-microm filler in the toothbrush test. Based upon the results of this study, it is concluded that the wear of resin cements was affected by the filler size as well as the mode of wear test.

  8. Comparison of Wear Resistance of Hawley and Vacuum Formed Retainers: An in-vitro Study

    Directory of Open Access Journals (Sweden)

    Moshkelgosha V

    2016-06-01

    Full Text Available Statement of Problem: As a physical property, wear resistance of the materials used in the fabrication of orthodontic retainers play a significant role in the stability and long term use of the appliances. Objectives: To evaluate the wear resistance of two commonly used materials for orthodontic retainers: Acropars OP, i.e. a polymethyl methacrylate based material, and 3A-GS060, i.e. a polyethylene based material. Materials and Methods: For each material, 30 orthodontic retainers were made according to the manufacturers’ instructions and a 30×30×2 mm block was cut out from the mid- palatal area of each retainer. Each specimen underwent 1000 cycles of wear stimulation in a pin on disc machine. The depth of wear of each specimen was measured using a Nano Wizard II atomic force microscope in 3 random points of each specimen’s wear trough. The average of these three measurements was calculated and considered as mean value wear depth of each specimen (µm. Results: The mean wear depth was 6.10µm and 2.15µm for 3A-GS060 and Acropars OP groups respectively. Independent t-test showed a significant difference between the two groups (p < 0.001. The results show Polymethyl methacrylate base (Acropars is more wear resistance than the polyethylene based material (3A-GS060. Conclusions: As the higher wear resistance of the fabrication material can improve the retainers’ survival time and its cost-effectiveness, VFRs should be avoided in situations that the appliance needs high wear resistance such as bite blocks opposing occlusal forces.

  9. Characteristics of high wear resistant Ni-base materials strengthened by precipitation hardening of wolfram silicide

    Energy Technology Data Exchange (ETDEWEB)

    Kiuchi, Kiyoshi; Ide, Hisayuki; Ishiyama, Takashi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1998-12-31

    The practical application of Co-base Stellite and Ni base Inconel for reactor core components with high allowable stress levels is considered to be limited by the formation of radioactive cruds and the susceptibility to IASCC respectively. For this view-point, W-silicide strengthened Cr-W-Si Ni-base high wear resistant alloy so-called HWI alloy was newly developed as an alternative material. The chemical composition and the alloy making process were optimized by applying the electron beam purification process and the thermo-mechanical treatment. The mechanical strength higher than it of above commercial alloys was easily obtained by both solid solution hardening and precipitation hardening, because this alloy has the excellent cold and hot workabilities. The irradiation resistance and the corrosion resistance superior than these of above commercial alloys were verified by several laboratory tests of HWI heats. To maintain austenite phase stability at the practical temperature and to enrich oxide former alloying elements were clarified to be the most important means for this alloy development. (author)

  10. Effect of molybdenum on the microstructure and wear resistance of Fe-based hardfacing coatings

    Energy Technology Data Exchange (ETDEWEB)

    Wang, X.H. [School of Materials Science and Engineering, Shandong University, Jinan 250061 (China)], E-mail: xinhongwang@sdu.edu.cn; Han, F. [Department of Mechanical and Electrical Engineering, College of Weifang, Weifang 261021 (China); Liu, X.M.; Qu, S.Y.; Zou, Z.D. [School of Materials Science and Engineering, Shandong University, Jinan 250061 (China)

    2008-08-20

    Fe-based hardfacing alloys containing molybdenum compound have been deposited on AISI 1020 steel substrates by shield manual arc welding (SMAW) process. The effect of Mo on the microstructure and wear resistance of the Fe-based hardfacing alloys were investigated by means of X-ray diffraction, optical microscopy, scanning electron microscopy (SEM) and electron probe microanalysis, as well as wear test. The results indicated that cuboidal and rod-type complex carbides were synthesized in the lath martensite matrix. The fraction of carbides in hardfacing layer increased with an increasing of Mo content. The hardfacing layer with good cracking resistance and wear resistance could be obtained when the amounts of Fe-Mo was controlled within a range of 3-4 wt.%. The improvement of hardness and wear resistance of the hardfacing layers attributed to the formation of Mo{sub 2}C carbide and the solution strengthening of Mo.

  11. Studies on Wear and Corrosion Resistances of Carbon Nitride Thin Films on Ti Alloy

    Institute of Scientific and Technical Information of China (English)

    LiJin-chai; GuoHuai-xi; LuXlan-feng; ZhangZhi-hong; YeMing-sheng

    2003-01-01

    CNx/SiCN composite films were prepared on titanium ( Ti ) alloy substrates by Radio Frequency Plasma Enhanced Chemical Vapor Deposition ( RF-PECVD ). As a buffer layer, SiCN ensured the adhesion of the CNx thin films on Ti substrates. X-ray diffraction (XRD) measurement revealed that the composite films possessed α-C3N4 structure.The microhardness of the films was 48 to 50 GPa. In or der totest the characteristics of wear and corrosion resistances, we prepared Ti alloy samples with and without CNx/SiCN composite films. Also for strengthening the effect of wear and corrosion, the wear tests were carried out under high load (12 MPa) and in 0. 9% NaCl solution. Results of the wear tests and the corrosive electrochemical measurements showed that the samples coated with CNx films had excellent charac-teristics of wear and corrosion resistances compared with Ti alloy substrate samples.

  12. Studies on Wear and Corrosion Resistances of Carbon Nitride Thin Films on Ti Alloy

    Institute of Scientific and Technical Information of China (English)

    Li Jin-chai; Guo Huai-xi; Lu Xian-feng; Zhang Zhi-hong; Ye Ming-sheng

    2003-01-01

    CNx/SiCN composite films were prepared on titanium ( Ti ) alloy substrates by Radio Frequency Plasma Enhanced Chemical Vapor Deposition ( RF-PECVD ). As a buffer layer, SiCN ensured the adhesion of the CNx thin films on Ti substrates. X-ray diffraction (XRD) measurement revealed that the composite films possessed α-C3N4 structure.The microhardness of the films was 48 to 50 GPa. In order to test the characteristics of wear and corrosion resistances, we prepared Ti alloy samples with and without CNx/SiCN composite films. Also for strengthening the effect of wear and corrosion, the wear tests were carried out under high load (12 MPa) and in 0. 9% NaCl solution. Results of the wear tests and the corrosive electrochemical measurements showed that the samples coated with CNx films had excellent characteristics of wear and corrosion resistances compared with Ti alloy substrate samples.

  13. Standard test method for ranking resistance of materials to sliding wear using block-on-ring wear test

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2005-01-01

    1.1 This test method covers laboratory procedures for determining the resistance of materials to sliding wear. The test utilizes a block-on-ring friction and wear testing machine to rank pairs of materials according to their sliding wear characteristics under various conditions. 1.2 An important attribute of this test is that it is very flexible. Any material that can be fabricated into, or applied to, blocks and rings can be tested. Thus, the potential materials combinations are endless. However, the interlaboratory testing has been limited to metals. In addition, the test can be run with various lubricants, liquids, or gaseous atmospheres, as desired, to simulate service conditions. Rotational speed and load can also be varied to better correspond to service requirements. 1.3 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only. Wear test results are reported as the volume loss in cubic millimetres for both the block and ring. Materials...

  14. IN VITRO WEAR RESISTANCE OF THREE TYPES OF POLYMETHYL METHACRYLATE DENTURE TEETH

    OpenAIRE

    Katia Rodrigues Reis; Gerson Bonfante; Luiz Fernando Pegoraro; Paulo Cesar Rodrigues Conti; Pedro Cesar Garcia de Oliveira; Osvaldo Bazzan Kaizer

    2008-01-01

    The wear resistance of denture teeth is important to the longevity of removable prostheses of edentulous patients. The ability of denture teeth to maintain a stable occlusal relationship over time may be influenced by this property. The purpose of this in vitro study was to evaluate the wear resistance of polymethyl methacrylate (PMMA) denture teeth based on their chemical composition when opposed by a ceramic antagonist. The maxillary canines (n=10) of 3 PMMA denture teeth (Trubyte Biotone, ...

  15. FIBROUS MONOLITH WEAR RESISTANT COMPONENTS FOR THE MINING INDUSTRY

    Energy Technology Data Exchange (ETDEWEB)

    Mark J. Rigali

    2001-10-01

    Published mechanical and thermal properties data on a variety of materials was gathered, with focus on materials that have potential with respect to developing wear resistant and damage tolerant composite for mining industry applications. Preliminary core materials of interest include but are not limited to: Diamond, Tungsten Carbide and Cemented Tungsten Carbides, Carbides of Boron, Silicon, Titanium and Aluminum, Diboride of Titanium and Aluminum, Nitrides of Aluminum, Silicon, Titanium, and Boron, Aluminum Oxide, Tungsten, Titanium, Iron, Cobalt and Metal Alloys. Preliminary boundary materials of interest include but are not limited to: W metal, WC-Co, W-Co, WFeNi, and Mo metal and alloys. Several FM test coupons were fabricated with various compositions using the above listed materials. These coupons were consolidated to varying degrees by uniaxial hot pressing, then cut and ground to expose the FM cell structure. One promising system, WC-Co core and WFeNi boundary, was consolidated to 97% of theoretical density, and demonstrates excellent hardness. Data on standard mechanical tests was gathered, and tests will begin on the consolidated test coupons during the upcoming reporting period. The program statements of work for ACR Inc. and its subcontractors, as well as the final contract negotiations, were finalized during the current reporting period. The program start date was February 22nd, 2001. In addition to the current subcontractors, Kennametal Inc., a major manufacturer of cutting tools and wear resistant tooling for the mining industry, expressed considerable interest in ACR's Fibrous Monolith composites for both machine and mining applications. At the request of Kennametal, ARC Inc fabricated and delivered several Fibrous Monolith coupons and components for testing and evaluation in the mining and machine tool applications. Additional samples of Diamond/Tungsten Carbide-6%Cobalt Fibrous Monolith were fabricated and delivered for testing Kennametal

  16. Microstructure and wear resistance of electro-thermal explosion sprayed stellite coating used for remanufacturing

    Institute of Scientific and Technical Information of China (English)

    JIN Guo; XU Bin-shi; WANG Hai-dou; LI Qing-fen; WEI Shi-cheng

    2005-01-01

    Electro-thermal explosion directional spraying was used to prepare the stellite coating on substrate of the AISI 1045 steel. The morphologies of cross-section and worn scar, porosity, distribution of elements, microhardness and wear resistance of the coating were determined by means of SEM, EDAX, micro-hardness tester and sliding wear tester. Because of the compact construction, good bonding and high hardness, the coating is characterized by good wear resistance. The results show that the mainly failure mode of the stellite coating is microplowing.

  17. Effects of TIG Surface Melting and Chromium Surface Alloying on Microstructure,Hardness and Wear Resistance of ADI

    Institute of Scientific and Technical Information of China (English)

    A Amirsadeghi; M Heydarzadeh Sohi; S F Kashani Bozorg

    2008-01-01

    Microhardness and wear resistance of different mierostruetures formed by TIG (tungsten inert gas) surface melting and chromium surface alloying (using ferrochromium) of ADI (austempered ductile iron) were studied.Surface melting resulted in the formation of a ledeburitic structure in the melted zone,and this structure has a hardness up to 896 HV as compared to 360 HV in that of ADI.Moreover,chromium surface alloying resulted in the formation of different structures including:(1) a hypereuteetic structure consisting of primary (Fe,Cr)7C3 carbides and a eutectie matrix of transformed austenite (into martensite and retained austenite),as also (Fe,Cr)7C3 carbides,with a hardness of 1 078 HV;(2) a hypoeutectic structure consisting of the same eutectic along with transformed primary austenite,with a hardness of 755 HV;and (3) a ledeburitic structure with an acieular morphology and a hardness of 896 HV.The results also indicated that surface melting reduced the wear rate of the ADI by approximately 37%.Also,chromium surface alloying yielded a superior wear behavior and reduced the wear rate of the treated specimens by about 38% and 70%,depending on the structures formed.

  18. Effect Of Laser Hardening On Microstructure And Wear Resistance In Medium. Carbon/Chromium Steels

    Science.gov (United States)

    Kusinski, Jan; Thomas, Gareth

    1986-11-01

    Metallographical (optical, TEM, SEM), spectroscopic, abrasive wear resistance and microhardness investiga-tions of Fe/Cr/Mn/C steels heat-treated by a continuous CO2 laser are described. Laser hardening resulted in wear resistance of 1.4 - 1.6 times better than that of conventionally hardened steels. Laser melting followed by rapid solidification allows formation of a solidified layer with high wear resistance only when the scanning velocity and mass of the samples were sufficient to realize high cooling rates. The variations in the wear resistance and microhardness with distance from the heated surface were similar. The grain refinement caused by rapid laser-heating and high stresses induced during cooling create essentially fine, highly dislocated lath and internally twinned martensites with some amount of stable, interlath retained austenite. This structure has in turn beneficial effects on wear resistance, and toughness. Laser-heat treatment for deep melting of the surface layers of the steels shows only a small improvement in wear resistance. Such heat-treatment results in delta ferrite retention (10Cr steel) and chromium segregation to cell-boundaries.

  19. Laser cladding of Zr-based coating on AZ91D magnesium alloy for improvement of wear and corrosion resistance

    Indian Academy of Sciences (India)

    Kaijin Huang; Xin Lin; Changsheng Xie; T M Yue

    2013-02-01

    To improve the wear and corrosion resistance of AZ91D magnesium alloy, Zr-based coating made of Zr powder was fabricated on AZ91D magnesium alloy by laser cladding. The microstructure of the coating was characterized by XRD, SEM and TEM techniques. The wear resistance of the coating was evaluated under dry sliding wear test condition at room temperature. The corrosion resistance of the coating was tested in simulated body fluid. The results show that the coating mainly consists of Zr, zirconium oxides and Zr aluminides. The coating exhibits excellent wear resistance due to the high microhardness of the coating. The main wear mechanism of the coating and the AZ91D sample are different, the former is abrasive wear and the latter is adhesive wear. The coating compared to AZ91D magnesium alloy exhibits good corrosion resistance because of the good corrosion resistance of Zr, zirconium oxides and Zr aluminides in the coating.

  20. IN VITRO WEAR RESISTANCE OF THREE TYPES OF POLYMETHYL METHACRYLATE DENTURE TEETH

    Science.gov (United States)

    Reis, Katia Rodrigues; Bonfante, Gerson; Pegoraro, Luiz Fernando; Conti, Paulo Cesar Rodrigues; de Oliveira, Pedro Cesar Garcia; Kaizer, Osvaldo Bazzan

    2008-01-01

    The wear resistance of denture teeth is important to the longevity of removable prostheses of edentulous patients. The ability of denture teeth to maintain a stable occlusal relationship over time may be influenced by this property. The purpose of this in vitro study was to evaluate the wear resistance of polymethyl methacrylate (PMMA) denture teeth based on their chemical composition when opposed by a ceramic antagonist. The maxillary canines (n=10) of 3 PMMA denture teeth (Trubyte Biotone, cross-linked PMMA; Trilux, highly cross-linked IPN (interpenetrating polymer network)-PMMA; and Vivodent, highly cross-linked PMMA) were secured in an in vitro 2-body wear-testing apparatus that produced sliding contact of the specimens (4.5 cycles/s, sliding distance of 20 mm, under 37°C running water) against glazed or airborne particle abraded ceramic. Wear resistance was measured as height loss (mm) under 300 g (sliding force) after 100,000 cycles, using a digital measuring microscope. Mean values were analyzed by 2-way ANOVA and Tukey's test (α=0.05). The wear of Trubyte Biotone (0.93 ± 0.14 mm) was significantly higher than that of both other types of teeth tested against abraded ceramic (p0.05) in wear among the 3 denture teeth evaluated against glazed ceramic. Trilux and Vivodent teeth tested against either glazed or airborne particle abraded ceramic did not differ significantly from each other (p<0.05). All teeth showed significantly more wear against airborne particle abraded ceramic than against glazed ceramic (p<0.05). In conclusion, the three types of PMMA denture teeth presented significantly different wear resistance against the abraded ceramic. The high-strength PMMA denture teeth were more wear-resistant than the conventional PMMA denture tooth. PMID:19089214

  1. In vitro wear resistance of three types of polymethyl methacrylate denture teeth

    Directory of Open Access Journals (Sweden)

    Katia Rodrigues Reis

    2008-06-01

    Full Text Available The wear resistance of denture teeth is important to the longevity of removable prostheses of edentulous patients. The ability of denture teeth to maintain a stable occlusal relationship over time may be influenced by this property. The purpose of this in vitro study was to evaluate the wear resistance of polymethyl methacrylate (PMMA denture teeth based on their chemical composition when opposed by a ceramic antagonist. The maxillary canines (n=10 of 3 PMMA denture teeth (Trubyte Biotone, cross-linked PMMA; Trilux, highly cross-linked IPN (interpenetrating polymer network-PMMA; and Vivodent, highly cross-linked PMMA were secured in an in vitro 2-body wear-testing apparatus that produced sliding contact of the specimens (4.5 cycles/s, sliding distance of 20 mm, under 37°C running water against glazed or airborne particle abraded ceramic. Wear resistance was measured as height loss (mm under 300 g (sliding force after 100,000 cycles, using a digital measuring microscope. Mean values were analyzed by 2-way ANOVA and Tukey's test (a=0.05. The wear of Trubyte Biotone (0.93 ± 0.14 mm was significantly higher than that of both other types of teeth tested against abraded ceramic (p0.05 in wear among the 3 denture teeth evaluated against glazed ceramic. Trilux and Vivodent teeth tested against either glazed or airborne particle abraded ceramic did not differ significantly from each other (p<0.05. All teeth showed significantly more wear against airborne particle abraded ceramic than against glazed ceramic (p<0.05. In conclusion, the three types of PMMA denture teeth presented significantly different wear resistance against the abraded ceramic. The high-strength PMMA denture teeth were more wear-resistant than the conventional PMMA denture tooth.

  2. Wear Resistance of CO2 Corrosion Product Scale Formed at High Temperature

    Institute of Scientific and Technical Information of China (English)

    LIN Guan-fa; ZHENG Mao-sheng; BAI Zhen-quan; FENG Yao-rong

    2006-01-01

    To investigate the correlation between structure characteristics and wear resistance of CO2 corrosion product scales at high temperature and high pressure, an autoclave was used to prepare CO2 corrosion product scales on N80 steel in carbon dioxide corrosion environment. The correlation between wear resistance of the scales and many other factors, such as temperature, pressure, morphology, structure, velocity of fluid medium, sand grain size, and so on, was comparatively analyzed by a self-assembled wear device, and the scale morphologies before or after being worn were observed by scanning electron microscope (SEM). And then the surface grain size and thickness of scale were measured. The results showed that the cross-section of the corrosion scale was of a double-layer structure, the outer layer of which was composed of regular crystals, whereas the inner layer was a thin scale of fine grains. The outer grain size and thickness of scale varied with temperature, and the initial wear loss was consistent with the surface grain size; at the same time, the total wear loss corresponded to the thickness of scale. Compared to wear resistance in different depths of the scale, it was found that the structure of scale was a double-layer structure in cross-section, and the wear resistance of inner layer was better than that of the outer layer; the closer the scale to the matrix, the greater was the wear resistance of scale; and the larger the size or the higher the rotary speed of solid grain in multiphase flowing medium, the more was the wear loss of scale.

  3. Wear resistance of four types of vacuum-formed retainer materials: a laboratory study.

    Science.gov (United States)

    Raja, Taiyub A; Littlewood, Simon J; Munyombwe, Theresa; Bubb, Nigel L

    2014-07-01

    To investigate the resistance to wear of four different vacuum-formed retainer (VFR) materials: Essix C+, Essix ACE, Duran, and Tru-Tain. Essix C+ is a polypropylene polymer; the other materials are polyethylene co-polymers. The study was undertaken at the Leeds Dental Institute, Leeds, UK, with 26 samples in each group. The specimens were vacuum-formed according to the manufacturers' guidelines, and a custom-made wear-simulation machine was used to conduct the test. Each specimen was subjected to 1000 cycles of the wear simulation, with steatite balls as the antagonist material. The resistance to wear of the VFR materials was evaluated by measuring the maximum wear depth using noncontact, three-dimensional surface profilometry. The wear depth was given in micrometers. The median wear depth was 63.20 µm for the Essix C+ group, 7.88 µm for the Essix ACE group, 9.75 µm for the Duran group, and 12.08 µm for the Tru-Tain group. The Kruskal-Wallis test to compare the four VFR materials detected a statistically significant difference between the groups (P study, the three polyethylene co-polymer materials-Essix ACE, Duran, and Tru-Tain-exhibited significantly less wear than the polypropylene material, Essix C+.

  4. Development of Stellite alloy composites with sintering/HIPing technique for wear-resistant applications

    Energy Technology Data Exchange (ETDEWEB)

    Opris, C.D. [Department of Mechanical and Aerospace Engineering, Carleton University, 1125 Colonel By Drive, Ottawa, Ont., K1S 5B6 (Canada); Liu, R. [Department of Mechanical and Aerospace Engineering, Carleton University, 1125 Colonel By Drive, Ottawa, Ont., K1S 5B6 (Canada)]. E-mail: rliu@mae.carleton.ca; Yao, M.X. [Deloro Stellite Inc., Belleville, Ont., K8N 5C4 (Canada); Wu, X.J. [Institute for Aerospace Research, National Research Council of Canada, Ottawa, Ont., K1A 0R6 (Canada)

    2007-07-01

    Cobalt-based superalloys, Stellite 694 and Stellite 712, composites were developed with the reinforcement of titanium-carbide particles for wear-resistant applications. The specimens were fabricated using the powder metallurgy technique, combined with hot isostatic pressing. Calorimetric effects of the alloy powders were investigated using the differential scanning calorimetry technique, which provided the theoretical basis of designing the sintering cycles. The phases formed in the microstructures were analyzed using the scanning electron microscope (SEM) and energy dispersive X-ray spectrum (EDS) techniques. The wear test was conducted on a ball-on-disc tribometer. It was demonstrated that the wear resistance of the alloys had been increased significantly by the titanium-carbide reinforcement and the hot isostatic pressing process had enhanced the wear resistance of the materials.

  5. Microstructure and Impact Wear Resistance of TiN Reinforced High Manganese Steel Matrix

    Institute of Scientific and Technical Information of China (English)

    MA You-ping; LI Xiu-lan; WANG Cheng-hui; LU Lu

    2012-01-01

    A high-manganese austenitic steel matrix (Mn13) composite reinforced with TiN ceramic particles was synthesized by means of Vacuum-Evaporation Pattern Casting (V-EPC). The composite microstructure and interface bonding of TiN/matrix were analyzed utilizing optical microscope (OM) and X-ray diffraction (XRD). The effects of different volume fraction of TiN on impact wear resistance were evaluated by MLD-10 impact wear test. The results showed that TiN was evenly distributed in composite layer and had a good interface bonding with matrix when the volume fractions of TiN were 27% and 36% respectively. However, cast defects and TiN agglomeration occurred when the TiN volume fraction increased to 48~. Compared with high-manganese austenitic steel (Mnl3), the im- pact wear resistance of the TiN-reinforced composite is better. In small impact load conditions, composite layer can effectively resist abrasives wear and TiN particles played an important role in determining impact wear resistance of composite layer. In large impact load, the synergistic roles of spalling of TiN particles and the increase of work hardening of Mn13 based material are responsible for impact wear resistance.

  6. Wear resistance of machine tools' bionic linear rolling guides by laser cladding

    Science.gov (United States)

    Wang, Yiqiang; Liu, Botao; Guo, Zhengcai

    2017-06-01

    In order to improve the rolling wear resistance (RWR) of linear rolling guides (LRG) as well as prolong the life of machine tools, various shape samples with different units spaces ranged from 1 to 5 mm are designed through the observation of animals in the desert and manufactured by laser cladding. Wear resistance tests reproducing closely the real operational condition are conducted by using a homemade linear reciprocating wear test machine, and wear resistance is evaluated by means of weight loss measurement. Results indicate that the samples with bionic units have better RWR than the untreated one, of which the reticulate treated sample with unit space 3 mm present the best RWR. More specifically, among the punctuate treated samples, the mass loss increases with the increase of unit space; among the striate treated samples, the mass loss changes slightly with the increase of unit space, attaining a minimum at the unit space of 4 mm; among the reticulate treated samples, with the increase of unit space, the mass loss initially decreases, but turns to increase after reaching a minimum at the unit space of 3 mm. Additionally, the samples with striate shape perform better wear resistance than the other shape groups on the whole. From the ratio value of laser treated area to contacted area perspective, that the samples with ratio value between 0.15 and 0.3 possess better wear resistance is concluded.

  7. Microstructure and wear resistance of in situ porous TiO/Cu composites

    Science.gov (United States)

    Qin, Qingdong; Huang, Bowei; Li, Wei

    2016-07-01

    An in situ porous TiO/Cu composite is successfully prepared using powder metallurgy by the reaction of Ti2CO and Cu powder. Morphological examination of the composite shows that the porosity of composites lies in the range between 10.2% and 35.2%. Dry sliding un-lubricated wear tests show that the wear resistance of the composite is higher than that of the Cu-Al alloy ingot. The coefficient of friction test shows that, as the volume fraction of the reinforced phase increases, the coefficient of friction decreases. The wear rate variation trend of the oil-lubricated wear test results is similar to that of the un-lubricated wear test results. The coefficient of friction for oil lubrication is similar for different volume fractions of the reinforced phase. The wear resistance of the composite at a sliding velocity of 200 rpm is slightly larger than that at 50 rpm. The porosity of the composites enhances the high-velocity oil-lubricated sliding wear resistance.

  8. Heat Treatment Effect on Microstructure, Hardness and Wear Resistance of Cr26 White Cast Iron

    Institute of Scientific and Technical Information of China (English)

    ZHOU Shaoping; SHEN Yehui; ZHANG Hao; CHEN Dequan

    2015-01-01

    High chromium cast iron(HCCI) is taken as material of coal water slurry pump impeller, but it is susceptible to produce serious abrasive wear and erosion wear because of souring of hard coal particles. The research on optimization of heat treatments to improve abrasive wear properties of HCCI is insufficient, so effect of heat treatments on the microstructure, hardness, toughness, and wear resistance of Cr26 HCCI is investigated to determine the optimal heat treatment process for HCCI. A series of heat treatments are employed. The microstructures of HCCI specimens are examined by using optical microscopy and scanning electron microscopy. The hardness and impact fracture toughness of as-cast and heat treated specimens are measured. The wear tests are assessed by a Type M200 ring-on block wear tester. The results show the following: With increase of the quenching temperature from 950℃ to 1050℃, the hardness of Cr26 HCCI increased to a certain value, kept for a time and then decreased. The optimal heat treatment process is 2 h quenching treatment at 1000℃, followed by a subsequent 2 h tempering at 400℃. The hardness of HCCI is related to the precipitation and redissolution of secondary carbides in the process of heat treatment. The subsequent tempering treatment would result in a slight decrease of hardness but increase of toughness. The wear resistance is much related to the “supporting” effect of the matrix and the“protective” effect of the hard carbide embedded in the matrix, and the wear resistance is further dependent on the hardness and the toughness of the matrix. This research can provide an important insight on developing an optimized heat treatment method to improve the wear resistance of HCCI.

  9. Heat treatment effect on microstructure, hardness and wear resistance of Cr26 white cast iron

    Science.gov (United States)

    Zhou, Shaoping; Shen, Yehui; Zhang, Hao; Chen, Dequan

    2015-01-01

    High chromium cast iron(HCCI) is taken as material of coal water slurry pump impeller, but it is susceptible to produce serious abrasive wear and erosion wear because of souring of hard coal particles. The research on optimization of heat treatments to improve abrasive wear properties of HCCI is insufficient, so effect of heat treatments on the microstructure, hardness, toughness, and wear resistance of Cr26 HCCI is investigated to determine the optimal heat treatment process for HCCI. A series of heat treatments are employed. The microstructures of HCCI specimens are examined by using optical microscopy and scanning electron microscopy. The hardness and impact fracture toughness of as-cast and heat treated specimens are measured. The wear tests are assessed by a Type M200 ring-on block wear tester. The results show the following: With increase of the quenching temperature from 950 °C to 1050 °C, the hardness of Cr26 HCCI increased to a certain value, kept for a time and then decreased. The optimal heat treatment process is 2 h quenching treatment at 1000 °C, followed by a subsequent 2 h tempering at 400 °C. The hardness of HCCI is related to the precipitation and redissolution of secondary carbides in the process of heat treatment. The subsequent tempering treatment would result in a slight decrease of hardness but increase of toughness. The wear resistance is much related to the "supporting" effect of the matrix and the "protective" effect of the hard carbide embedded in the matrix, and the wear resistance is further dependent on the hardness and the toughness of the matrix. This research can provide an important insight on developing an optimized heat treatment method to improve the wear resistance of HCCI.

  10. Abrasive Wear Resistance of the Iron- and WC-based Hardfaced Coatings Evaluated with Scratch Test Method

    Directory of Open Access Journals (Sweden)

    A. Vencl

    2013-06-01

    Full Text Available Abrasive wear is one of the most common types of wear, which makesabrasive wear resistance very important in many industries. Thehard facing is considered as useful and economical way to improve theperformance of components submitted to severe abrasive wear conditions, with wide range of applicable filler materials. The abrasive wear resistance of the three different hardfaced coatings (two iron‐based and one WC‐based, which were intended to be used for reparation of the impact plates of the ventilation mill, was investigated and compared. Abrasive wear tests were carried‐out by using the scratch tester under the dry conditions. Three normal loads of 10, 50 and 100 N and the constant sliding speed of 4 mm/s were used. Scratch test was chosen as a relatively easy and quick test method. Wear mechanism analysis showed significant influence of the hardfaced coatings structure, which, along with hardness, has determined coatings abrasive wear resistance.

  11. High vitamin E content, impact resistant UHMWPE blend without loss of wear resistance.

    Science.gov (United States)

    Oral, Ebru; Neils, Andrew; Muratoglu, Orhun K

    2015-05-01

    Antioxidant stabilization of radiation cross-linked ultrahigh molecular weight polyethylene (UHMWPE) has been introduced to improve the oxidative stability of total joint implant bearing surfaces. Blending of antioxidants (most commonly vitamin E) with UHMWPE resin powder followed by consolidation and uniform radiation cross-linking is currently available for use in both total hips and total knees. It was previously shown that the fatigue resistance of vitamin E-blended and irradiated UHMWPEs could be further improved by spatially manipulating the vitamin E concentration throughout the implant and limiting cross-linking to the surface of the implant where it is necessary for wear resistance. This was possible by designing a low concentration of vitamin E on the surface and higher concentration in the bulk of the implant because cross-linking is hindered in UHMWPE as a function of increasing vitamin E concentration. In this study, we hypothesized that such a surface cross-linked UHMWPE with low wear rate and high fatigue strength could be obtained by limiting the penetration of radiation into UHMWPE with uniform vitamin E concentration. Our hypothesis tested positive; we were able to obtain control of the surface cross-linked region by manipulating the energy of the irradiation, resulting in extremely low wear, and high impact strength. In addition, we discussed alternatives of improving the oxidation resistance of such a material by using additional vitamin E reservoirs. These results are significant because this material may allow increased use of antioxidant-stabilized, cross-linked UHMWPEs in high stress applications and in more active patients.

  12. Wear resistance of a metal surface modified with minerals

    Science.gov (United States)

    Kislov, S. V.; Kislov, V. G.; Balasch, P. V.; Skazochkin, A. V.; Bondarenko, G. G.; Tikhonov, A. N.

    2016-02-01

    The article describes the advantages of the new technology of mineral coating of metal products for the friction pair of mechanical systems. It presents the research results of the wear rate of the samples made of 12X13 steel (X12Cr13) with mineral layers, in the experiments with a piston ring sliding inside a cylinder liner with grease. The wear rate of the samples with mineral layers is lower almost by two factors than that of the samples made of grey foundry iron and untreated samples. As the result of slip/rolling abrasion tests of parts with mineral layers under conditions of high contact pressure, a suggestion was made concerning probable mechanics of surface wear.

  13. Variations in Wear Resistance of a Novel Triboalloy-Pseudoelastic TiNi Alloy - with Respect to its Pseudoelasticity and Hardness

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    It has recently been found that TiNi shape memory alloy has another attractive property: high resistance to wear. The wear resistance of this alloy benefits from its pseudoelasticity (PE). It has, however, been noticed that other mechanical properties also affect the wear resistance, especially the hardness. Research was conducted to investigate the correlation between the wear resistance and both the PE and hardness. It has been demonstrated that when the PE is high, lower hardness leads to higher wear resistance.

  14. Fretting Wear Behavior of Tin Plated Contacts:. Influence on Contact Resistance

    Science.gov (United States)

    Park, Young Woo; Sankara Narayanan, T. S. N.; Lee, Kang Yong

    The fretting wear behavior of tin plated copper alloy contacts and its influence on the contact resistance are addressed in this paper. Based on the change in the area of contact zone as well as the wear depth as a function of fretting cycles, a model was proposed to explain the observed low and stable contact resistance. The extent of wear of tin coating and the formation of wear debris as a function of fretting cycles were assessed by scanning electron microscopy (SEM). Energy dispersive X-ray line scanning (EDX), X-ray mapping, and EDX spot analysis were employed to characterize the nature of changes that occur at the contact zone. The study reveals that the fretted area increases linearly up to 8000 cycles due to the continuous removal of the tin coating and attains saturation when the fretting path length reaches a maximum. The observed low and stable contact resistance observed up to 8000 cycles is due to the common area of contact which provides an electrically conducting area. Surface analysis by SEM, EDX, and X-ray elemental mapping elucidate the nature of changes that occurred at the contact zone. Based on the change in contact resistance as a function of fretting cycles, the fretting wear and fretting corrosion dominant regimes are proposed. The interdependence of extent of wear and oxidation increases the complexity of the fretting corrosion behavior of tin plated contacts.

  15. Effect of La2O3 content on wear resistance of alumina ceramics

    Institute of Scientific and Technical Information of China (English)

    WU Tingting; ZHOU Jian; WU Bolin; LI Wenjie

    2016-01-01

    In order to improve the wear resistance, a kind of alumina ceramic with good wear resistance was created in an Al2O3-CaCO3-SiO2-MgO-La2O3 (ACSML) system. The effects of La2O3 content on sintering temperature, bulk density, and wear rate were investigated. The wear rate of sample was as low as 0.0393‰. The wear resistance of the sample containing La2O3 has im-proved 43% than that of the sample without La2O3. Appropriate La2O3 doping could inhibit grain growth, enhance density, and purify grain boundary. La2O3 could diffuse into Al2O3 to form a solid solution and react with Al2O3 to form high-aluminum low-lanthanum complex oxides. The combination among Al2O3, the solid solution layer, and the layer of high-aluminum low-lanthanum complex oxides combined closely, which could improve grain boundary cohesion. Besides, the homogeneous distributions of elements made uniform structure. Finally, the wear resistance of alumina ceramic was improved.

  16. A USE-WEAR ANALYSIS OF THE KNAPPED LITHIC GRAVE GOODS FROM GRUTA DO MORGADO SUPERIOR (TOMAR, PORTUGAL

    Directory of Open Access Journals (Sweden)

    Ana Cruz

    2015-12-01

    Full Text Available The Morgado Superior cave is a karst cave located in the municipality of Tomar (Santarém, Portugal. As other caves of the same area, it has provided stratigraphic data and votive deposits falling within the Holocene, more precisely in a diachronic time range that extends from the Neolithic to the early Bronze Age. In the Morgado Superior cave there are multiple burials with a few votive objects like jars, bone artefacts and lithic tools (blades, arrowheads etc., beads, pendants, and other decorative items in association with more than 8,000 human bones: the number of the grave goods elements is low if compared with the number of individuals buried in the cave. Concerning the use-wear study, we analyzed the grave goods in order to understand both their meaning in this funerary context and their function in the economy of this prehistoric society. We focused on the most representative elements of the grave goods: arrowheads and knapped lithic artefacts. This study led us to understand that the majority of the grave goods were everyday objects but with a strong symbolic value. Since in the Morgado Superior Cave there are a lot of grave goods showing prior breaks, their symbolic value does not seem to be lost even if the objects were broken. Thus, the use-wear analysis of the grave goods from the Morgado Superior Cave allowed us to identify the strong symbolic value of these elements for that human community, but at the same time to hypothesize a funerary practice that did not provide a special respect for the body and the grave goods of those dead previously buried in the cave. For these reasons we hypothesize a progressive spoliation (probably ritual of the previous grave goods. Through the use-wear study of the knapped lithic assemblage of the Morgado Superior Cave it was possible to reconstruct part of the ritual activities that were carried out in the site: the 90% of the lithic artefacts are used objects, all of the artefacts have been

  17. Wear Resistance of H13 and a New Hot-Work Die Steel at High temperature

    Science.gov (United States)

    Li, Shuang; Wu, Xiaochun; Chen, Shihao; Li, Junwan

    2016-07-01

    The friction and wear behaviors of a new hot-work die steel, SDCM-SS, were studied at high temperature under dry air conditions. The wear mechanism and microstructural characteristics of the SDCM-SS steel were also investigated. The results showed that the SDCM-SS steel had greater wear resistance compared with H13 steel; this was owed to its high oxidizability and temper stability. These features facilitate the generation, growth, and maintenance of a tribo-oxide layer at high temperature under relatively stable conditions. The high oxidizability and thermal stability of the SDCM-SS steel originate from its particular alloy design. No chromium is added to the steel; this ensures that the material has high oxidizability, and facilitates the generation of tribo-oxides during the sliding process. Molybdenum, tungsten, and vanadium additions promote the high temper resistance and stability of the steel. Many fine Mo2C and VC carbides precipitate during the tempering of SDCM-SS steel. During sliding, these carbides can delay the recovery process and postpone martensitic softening. The high temper stability postpones the transition from mild to severe wear and ensures that conditions of mild oxidative wear are maintained. Mild oxidative wear is the dominant wear mechanism for SDCM-SS steel between 400 and 700 °C.

  18. Imposed Thermal Fatigue and Post-Thermal-Cycle Wear Resistance of Biomimetic Gray Cast Iron by Laser Treatment

    Science.gov (United States)

    Sui, Qi; Zhou, Hong; Zhang, Deping; Chen, Zhikai; Zhang, Peng

    2017-08-01

    The present study aims to create coupling biomimetic units on gray cast iron substrate by laser surface treatment (LST). LSTs for single-step (LST1) and two-step (LST2) processes, were carried out on gray cast iron in different media (air and water). Their effects on microstructure, thermal fatigue, and post-thermal-cycle wear (PTW) resistance on the specimens were studied. The tests were carried out to examine the influence of crack-resistance behavior as well as the biomimetic surface on its post-thermal-cycle wear behavior and different units, with different laser treatments for comparison. Results showed that LST2 enhanced the PTW behaviors of gray cast iron, which then led to an increase in its crack resistance. Among the treated cast irons, the one treated by LST2 in air showed the lowest residual stress, due to the positive effect of the lower steepness of the thermal gradient. Moreover, the same specimen showed the best PTW performance, due to its superior crack resistance and higher hardness as a result of it.

  19. Nanocomposite TiSiBC Hard Coatings with High Resistance to Wear, Fracture and Scratching

    Science.gov (United States)

    Mahato, P.; Nyati, G.; Singh, R. J.; Mishra, S. K.

    2016-09-01

    The sliding wear under fretting condition, scratch adhesion, deformation behavior during micro- and nanoscratch studies have been studied for nanocomposite TiSiBC hard coating deposited on steel substrate by magnetron sputtering. The nanocomposite coatings having hardness and modulus around 30 and 300 GPa, respectively, showed a very significant decrease in fretting wear as compared to the uncoated steel. Pileup occurred along the sides of the scratch track due to plastic deformation of the substrate at the scratch load; however, cracks were not seen in films. The coefficient of friction remained scratch, higher wear resistance, higher toughness and low coefficient of friction.

  20. The comparative studies of ADI versus Hadfield cast steel wear resistance

    Directory of Open Access Journals (Sweden)

    Mieczysław Kaczorowski

    2011-04-01

    Full Text Available The results of comparative studies of wear resistance of ADI versus high manganese Hadfield cast steel are presented. For evaluation ofwear resistance three type of ADI were chosen. Two of them were of moderate strength ADI with 800 and 1000MPa tensile strength whilethe third was 1400MPa tensile strength ADI. The specimens were cut from ADI test YII type casting poured and heat treated in Institute ofFoundry in Krakow. The pin on disc method was used for wear resistance experiment. The specimens had a shape of 40mm long rod withdiameter 6mm. The load and speed were 100N and 0,54m/s respectively. It was concluded that the wear resistance of ADI is comparablewith high manganese cast steel and in case of low tensile grade ADI and is even better for high strength ADI than Hadfield steel.

  1. Study on the Correlation between Microstructure Corrosion and Wear Resistance of Ag-Cu-Ge Alloys

    Directory of Open Access Journals (Sweden)

    Antonio Cusma

    2015-03-01

    Full Text Available In this work, a morphological and structural characterization of a ternary Ag-Cu-Ge alloy of known composition was performed with the aim of evaluating how the passivation parameters (time and temperature influence the morphological features of the material surface. A nanomechanical characterization was performed in order to correlate the morphology and microstructure of the alloy with its tarnish, wear, and scratch resistance. It was found that the addition of germanium to the alloy not only provides the material with tarnish and fire-stain resistance, but it also improves the scratch and wear resistance owing to the formation of a dense and stable thin oxide layer.

  2. Wear resistance of a pressable low-fusing ceramic opposed by dental alloys.

    Science.gov (United States)

    Faria, Adriana Cláudia Lapria; de Oliveira, André Almeida; Alves Gomes, Erica; Silveira Rodrigues, Renata Cristina; Faria Ribeiro, Ricardo

    2014-04-01

    Dental alloys have increasingly replaced by dental ceramics in dentistry because of aesthetics. As both dental alloys and ceramics can be present in the oral cavity, the evaluation of the wear resistance of ceramics opposed by dental alloys is important. The aim of the present study was to evaluate wear resistance of a pressable low-fusing ceramic opposed by dental alloys as well as the microhardness of the alloys and the possible correlation of wear and antagonist microhardness. Fifteen stylus tips samples of pressable low-fusing ceramic were obtained, polished and glazed. Samples were divided into three groups according to the disk of alloy/metal to be used as antagonist: Nickel-Chromium (Ni-Cr), Cobalt-Chromium (Co-Cr) and commercially pure titanium (cp Ti). Vickers microhardness of antagonist disks was evaluated before wear tests. Then, antagonist disks were sandblasted until surface roughness was adjusted to 0.75μm. Wear tests were performed at a speed of 60 cycles/min and distance of 10mm, in a total of 300,000 cycles. Before and after wear tests, samples were weighted and had their profile designed in an optical comparator to evaluate weight and height loss, respectively. Ni-Cr and cp Ti caused greater wear than Co-Cr, presenting greater weight (p=.009) and height (p=.002) loss. Cp Ti microhardness was lower than Ni-Cr and Co-Cr (p<.05). There is a positive correlation between weight and height loss (p<.05), but weight (p=.204) and height (p=.05) loss are not correlated to microhardness. The results suggest that pressable low-fusing ceramic presents different wear according to the dental alloy used as antagonist and the wear is not affected by antagonist microhardness.

  3. Alternate paddle configuration for improved wear resistance in the saltstone mixer

    Energy Technology Data Exchange (ETDEWEB)

    Reigel, M. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Fowley, M. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2013-09-23

    The Saltstone Production Facility has a 10-inch Readco-Kurimoto continuous mixer that mixes the premix dry feeds and low-level waste salt solution to make fresh (uncured) saltstone. Inspection of the mixer in January 2013 showed significant wear on the third, fourth and fifth paddle pairs after the conveying augers. A 2-inch Readco-Kurimoto continuous mixer was used to test alternate paddle configurations for use in the 10-inch mixer to decrease the wear rate on the paddles. Two wear tests were conducted to investigate a method of reducing wear on the mixer paddles. The first test (wear test 2a) had a paddle configuration similar to the currently installed 10-inch mixer in the SPF. This test established baseline wear. The second test (wear test 2b) had a reconfigured paddle arrangement that replaced the flat paddles with helical paddles for paddle pairs 2 - 6 and aligned paddle pair 1 with the augers. The intent of the reconfiguration was to more effectively convey the partially wetted dry feeds through the transition region and into the liquid feed where paddle wear is reduced due to dry feeds and salt solution being mixed at the intended water to premix ratio. The design of the helical paddles provides conveyance through the transition region to the liquid feed inlet. The alignment with the auger is aimed to provide a smoother transition (minimizing the discontinuity between the auger and paddle pair 1) into the downstream paddles. A soft metal with low wear resistance (6000 series aluminum) was used for the wear testing paddles to determine wear patterns while minimizing run time and maximizing wear rate. For the two paddle configurations tested using the scaled 2-inch Readco-Kurimoto continuous mixer, with the first six paddles after the augers replaced by the wear paddles and the remaining paddles were stainless steel. Since the 10-inch SPF mixer is designed with the liquid inlet centered over paddle pairs 5 and 6, the scaled 2-inch mixer was configured the

  4. Study on quantitative relation between characteristics of striature bionic coupling unit and wear resistance of gray cast iron

    Science.gov (United States)

    Pang, Zuobo; Zhou, Hong; Zhang, Peng; Cong, Dalong; Meng, Chao; Wang, Chuanwei; Ren, Luquan

    2015-03-01

    In order to improve the wear resistance of gray cast iron guide rail, striature bionic coupling units of different characteristics were manufactured by laser surface remelting. Wear behavior of gray cast iron with striature bionic coupling units has been studied under dry sliding condition at room temperature using a homemade linear reciprocating wear testing machine. The wear resistance was evaluated by means of weight loss measurement and wear morphology. The results indicated that there is a relationship between weight loss and the area of striature bionic coupling units and α: Δm = Δm0 - 0.0212S × cos α - 0.0241S × sin α.

  5. Composites for Increased Wear Resistance: Current Achievements and Future Prospects

    Science.gov (United States)

    Lancaster, J. K.

    1984-01-01

    The various ways in which reductions in wear and/or friction can be achieved by the use of composite materials are reviewed. Reinforced plastics are emphasized and it is shown that fillers and fibers reduce wear via several mechanisms additional to their role of increasing overall mechanical strength, preferential transfer, counter face abrasion, preferential load support, or third-body formation on either the composite or its counterface. Examples are given from recent work on thin layer composites of the type widely used as dry bearings in aircraft flight control mechanisms. Developments in metal based composites and carbon-carbon composites for high energy brakes are discussed. The aspects which could benefit by increased fundamental understanding identified and the types of composites which appear to have greatest potential for further growth are indicated.

  6. NANOSCALE BOEHMITE FILLER FOR CORROSION AND WEAR RESISTANT POLYPHENYLENESULFIDE COATINGS.

    Energy Technology Data Exchange (ETDEWEB)

    SUGAMA,T.

    2003-06-26

    The authors evaluated the usefulness of nanoscale boehmite crystals as a filler for anti-wear and anti-corrosion polyphenylenesulfide (PPS) coatings exposed to a very harsh, 300 C corrosive geothermal environment. The boehmite fillers dispersed uniformly into the PPS coating, conferring two advanced properties: First, they reduced markedly the rate of blasting wear; second, they increased the PPS's glass transition temperature and thermal decomposition temperature. The wear rate of PPS surfaces was reduced three times when 5wt% boehmite was incorporated into the PPS. During exposure for 15 days at 300 C, the PPS underwent hydrothermal oxidation, leading to the substitution of sulfide linkages by the sulfite linkages. However, such molecular alteration did not significantly diminish the ability of the coating to protect carbon steel against corrosion. In fact, PPS coating filled with boehmite of {le} 5wt% adequately mitigated its corrosion in brine at 300 C. One concern in using this filler was that it absorbs brine. Thus, adding an excess amount of boehmite was detrimental to achieving the maximum protection afforded by the coatings.

  7. On the Problem of Wear Resistant Coatings Separation From Tools and Machine Elements

    Science.gov (United States)

    Petrushin, S. I.; Gubaidulina, R. H.; Gruby, S. V.; Likholat, A. V.

    2015-09-01

    The article considers separation of wear resistant coatings of tool and engineering materials which arises both during coating fabrication and use of the product. The cause of this phenomenon is assumed to be related to thermal residual stresses generating on the coating- substrate border. These stresses have been analyzed and methods are provided to calculate it after produced composite material is cooled down from the temperature of coating synthesis to the ambient temperature. A no-fracture condition has been stated in relation to coating- substrate thicknesses, temperature differences and physical and mechanical properties of combined materials. The issue of intermediate layer incorporation with pre-set parameters has been discussed. A co-effect of thermal residual and functional stresses on the strength of the boundary layer has been considered when heating, tension and compression of a product with wear resistant coating. Conclusions have been made, as well as recommendations to improve fracture strength of products with thin wear resistant coatings.

  8. Receiving Wear-Resistance Coverings Additives of Nanoparticles of Refractory Metals at a Laser Cladding

    Science.gov (United States)

    Murzakov, M. A.; Petrovskiy, V. N.; Bykovskiy, D. P.; Andreev, A. O.; Birukov, V. P.; Markushov, Y. V.

    2016-02-01

    Laser cladding technology was used to conduct experiments on production of wear-resistant coatings with additive nanoparticles of refractory metals (WC, TaC). Mechanical testing of coating abrasion was made using Brinell-Howarth method. The obtained data was compared with wear- resistance of commercial powder containing WC. It was found that at a concentration 10-15% coating with nanopowder additives shows a dramatic increase in wear-resistance by 4-6 times as compared to carbon steel substrate. There were conducted metallurgical studies of coatings on inverse electron reflection. There was determined elemental composition of deposited coating and substrate, and microhardness measured. It was found that structure of deposited coating with nanoparticles is fine.

  9. Microstructure and wear resistance of high chromium cast iron containing niobium

    Directory of Open Access Journals (Sweden)

    Zhang Zhiguo

    2014-05-01

    Full Text Available In the paper, the effect of niobium addition on the microstructure, mechanical properties and wear resistance of high chromium cast iron has been studied. The results show that the microstructure of the heat-treated alloys is composed of M7C3 and M23C6 types primary carbide, eutectic carbide, secondary carbide and a matrix of martensite and retained austenite. NbC particles appear both inside and on the edge of the primary carbides. The hardness of the studied alloys maintains around 66 HRC, not significantly affected by the Nb content within the selected range of 0.48%-0.74%. The impact toughness of the alloys increases with increasing niobium content. The wear resistance of the specimens presents little variation in spite of the increase of Nb content under a light load of 40 N. However, when heavier loads of 70 and 100 N are applied, the wear resistance increases with increasing Nb content.

  10. Wear resistance of alloy вт-22 with non-ferrous alloys at reverse

    Directory of Open Access Journals (Sweden)

    А.М. Хімко

    2010-01-01

    Full Text Available  The article presents the results of tests of non hardened titanium alloy ВТ-22 with aviation non-ferrous alloys in reverse sliding friction. The main objective of the work is the selection of the optimum combination of materials depending on changes in loading conditions. Study of alloy ВТ-22 wear resistance was carried out in pairs with БрОФ-10-1, БрБ2, БрАЖ-9-4, ВТ-22, МЛ5, Д16Т, 7Х21ГАН5Ш and 95Х18Ш. The dependencies of the materials wear at pressures 10, 20 and 30 Mpa we determined. The linear nature of titanium alloy wear curves indicates that the change in the wear mechanism occurs gradually. The histograms of non-ferrous materials wear and the total wear of the friction pair are presented. It is established that the bronze БрАЖ-9-4 is the most preferable material for contact with non hardened titanium alloy ВТ-22, the least wear among the tested materials. The established coefficients of the titanium alloy ВТ-22 friction in pair with aviation structural non-ferrous alloys are presented. The results of research will be relevant for the engineering industry, where non hardened titanium alloy ВТ-22 in pair with non-ferrous alloys is applied.

  11. Effect of QPQ nitriding time on microstructure and wear resistance of SAF2906 duplex stainless steel

    Science.gov (United States)

    Liu, D.; Wu, G. X.; Shen, L. X.

    2017-01-01

    QPQ salt bath treatment of SAF2906 duplex stainless steel was conducted at 570 °C for 60 min, 90 min,120 min,150 min and 180 min, followed by post-oxidation process with heating temperature of 400°C and holding duration of 30 min. The effect of QPQ nitriding time on microstructure and wear resistance of SAF2906 duplex stainless steel was investigated by means of OM, SEM, XRD, microhardness test, adhesion strength test and wear resistance test. Microstructure observation showed outer layer was composed of Fe3O4. The main phase of the intermediate layer was CrN, αN and Fe2-3N. The main phase of the inner layer was CrN and S. The adhesion strength test of the surface layer-substrate showed the QPQ treated samples have favorable adhesion strength of HF-1 level. With the increase of nitriding time, the growth rate of the compound layer gradually slowed down and the surface hardness first increased and then decreased, and the maximum hardness was 1283 HV0.2 at 150 min. The dry siliding results showed that the wear resistance of the QPQ treated samples was at least 20 times than that of the substrate, and the optimum nitriding time to obtain the best wear resistance is 150 min. The worn surface morphology observation showed the main wear mechanism of the substrate was plough wear, while micro-cutting is the main wear mechanism that causes the damage of the QPQ treated samples.

  12. Structural transformations and wear resistance of abrasive-affected amorphous Fe- and Co-based alloys

    Science.gov (United States)

    Korshunov, L. G.; Chernenko, N. L.

    2008-12-01

    The abrasive wear resistance of the Fe64Co30Si3B3, Fe82.6Nb5Cu3Si8B1.4, Co86.5Cr4Si7B2.5, and Fe81Si4B13C2 amorphous alloys (ribbon 30 μm thick) has been investigated upon sliding over fixed abrasives (corundum and silicon carbide). The character of fracture of the surface and structural transformations initiated in these materials by the abrasive action have been studied by the metallographic, X-ray diffraction, and electron-microscopic methods. It has been shown that the abrasive wear resistance of the amorphous alloys is smaller by a factor of 1.6-2.9 than that of the Kh12M and U8 tool steels possessing approximately the same level of hardness. A pronounced softening of the surface layer of the amorphous alloys in the process of wear, which is characterized by a decrease in their microhardness reaching 12.5%, has been found. It has been shown that in the surface layer of these amorphous alloys upon wear there arises a small amount (on the order of several volume percent) of the nanocrystalline structure, which does not exert a marked effect on the microhardness and wear resistance of the alloys. In the alloys under study, the main factor that is responsible for their comparatively low abrasive wear resistance is their local softening in the process of wear caused by specific features of deformation processes occurring heterogeneously under the action of high shear contact stresses.

  13. Wear Resistances of CO2 Corrosion Product Films in the Presence of Sand Particles

    Institute of Scientific and Technical Information of China (English)

    LI Jinling; ZHU Shidong; LIU Luzhen; QU Chengtun; YAN Yongli; YANG Bo

    2015-01-01

    Wear resistances of CO2 corrosion product iflms formed on P110 carbon steel at different CO2 partial pressures were investigated in water sand two-phase lfow by weight loss method, and the microstructures and compositions of corrosion product iflms were analyzed by scanning electron microscope (SEM) and X-ray diffraction (XRD), respectively. The results showed that the wear rate of CO2 corrosion product iflms increased until a maximum and then decreased with the increasing of the film-forming pressure, and the maximum occurred at 2 MPa. However, the maximal corrosion rate and the loose and porous CO2 corrosion product iflms were obtained at 4 MPa. And the wear rate decreased and then went to be lfat with increasing test time. Furthermore, the microstructures and compositions of corrosion product iflms and the impact and wear of sand particles played an important role on wear resistances. In addition, the wear rate and corrosion rate were iftted by cubic polynomial, respectively, which were well in accordance with the measured results.

  14. The hardness, adhesion, and wear resistance of coatings developed for cobalt-base alloys

    Energy Technology Data Exchange (ETDEWEB)

    Cockeram, B.V.; Wilson, W.L.

    2000-05-01

    One potential approach for reducing the level of nuclear plant radiation exposure that results from activated cobalt wear debris is the use of a wear resistant coating. However, large differences in stiffness between a coating/substrate can result in high interfacial stresses that produce coating de-adhesion when a coated substrate is subjected to high stress wear contact. Scratch adhesion and indentation tests have been used to identify four promising coating processes [1,2]: (1) the use of a thin Cr-nitride coating with a hard and less-stiff interlayer, (2) the use of a thick, multilayered Cr-nitride coating with graded layers, (3) use of the duplex approach, or nitriding to harden the material subsurface followed by application of a multilayered Cr-nitride coating, and (4) application of nitriding alone. The processing, characterization, and adhesion of these coating systems are discussed. The wear resistance and performance has been evaluated using laboratory pin-on-disc, 4-ball, and high stress rolling contact tests. Based on the results of these tests, the best coating candidate from the high-stress rolling contact wear test was the thin duplex coating, which consists of ion nitriding followed deposition of a thin Cr-nitride coating, while the thin Cr-nitride coating exhibited the best results in the 4-ball wear test.

  15. Elements inter-diffusion in the turning of wear-resistance aluminum bronze

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Inter-diffusion of elements between the tool and the workpiece during the turning of aluminum bronze using high-speed steel and cemented carbide tools have been studied. The tool wear samples were prepared by using M2 high-speed steel and YW1 cemented carbide tools to turn a novel high strength, wear-resistance aluminum bronze without coolant and lubricant. Adhesion of workpiece materials was found on all tools' surface. The diffusion couples made of tool materials and aluminum bronze were prepared to simulate the inter-diffusion during the machining. The results obtained from tool wear samples were compared with those obtained from diffusion couples. Strong inter-diffusion between the tool materials and the aluminum bronze was observed in all samples. It is concluded that diffusion plays a significant role in the tool wear mechanism.

  16. The microstructural aspects of abrasive wear resistance in composite electron beam clad coatings

    Science.gov (United States)

    Gnyusov, S. F.; Tarasov, S. Yu.

    2014-02-01

    The effect of microstructure and phase composition of composite coatings based on manganese-containing or nickel-containing austenitic steel and containing either 10 wt.% TiC or 15 wt.% WC on the abrasive wear resistance has been studied. Both post-deposition heat treatment and self-aging in the course of deposition served to improve the relative wear resistance coefficient by 38-42 and 5-12% for Fe-20%Mn-4%V-4%Mo + 15%WC and Fe-20%Ni-4%V-4%Mo + 15%WC coatings, respectively.

  17. Wear resistance and hot corrosion behaviour of laser cladding Co-based alloy

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    2Cr13 stainless steel was surface cladded with Co-based alloy using a high power carbon dioxide laser. The microstructure, wear resistance and corrosion properties of the clad layer were investigated. It is found that the high temperature corrosion behavior and wearing resistant property of the clad layer are 3 and 2.5 times higher than those of the parent metal. Under the high temperature molten lead sulphate salt corrosion condition, the clad layer fails by spalling which is caused by intergrannular corrosion within the clad layer. The fine dendritic structure and the oxide help to retard the penetration of the sulphur ion that induces the intergrannular corrosion.

  18. Comprehensive study of the abrasive wear and slurry erosion behavior of an expanded system of high chromium cast iron and microstructural modification for enhanced wear resistance

    Science.gov (United States)

    Chung, Reinaldo Javier

    High chromium cast irons (HCCIs) have been demonstrated to be an effective material for a wide range of applications in aggressive environments, where resistances to abrasion, erosion and erosion-corrosion are required. For instance, machinery and facilities used in mining and extraction in Alberta's oil sands suffer from erosion and erosion-corrosion caused by silica-containing slurries, which create challenges for the reliability and maintenance of slurry pumping systems as well as other processing and handling equipment. Considerable efforts have been made to determine and understand the relationship between microstructural features of the HCCIs and their wear performance, in order to guide the material selection and development for specific service conditions with optimal performance. The focus was previously put on a narrow group of compositions dictated by ASTM A532. However, with recent advances in casting technology, the HCCI compositional range can be significantly expanded, which potentially brings new alloys that can be superior to those which are currently employed. This work consists of three main aspects of study. The first one is the investigation of an expanded system of white irons with their composition ranging from 1 to 6 wt.% C and 5 to 45 wt.% Cr, covering 53 alloys. This work has generated wear and corrosion maps and established correlation between the performance and microstructural features for the alloys. The work was conducted in collaboration with the Materials Development Center of Weir Minerals in Australia, and the results have been collected in a database that is used by the company to guide materials selection for slurry pump components in Alberta oil sands and in other mining operations throughout the world. The second part consists of three case studies on effects of high chromium and high carbon, respectively, on the performance of the HCCIs. The third aspect is the development of an approach to enhance the wear resistance of

  19. Relationship among wear-resistance of three-body abrasion,substructure and property in martensite steels

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The effects of subsurface hardness on wear-resistance of martensitic steel 20Cr, 40CrSi, 60Mn, T8 and T10 in three-body abrasion under static load was investigated. It shows that the characteristic ofthe subsurface hardness distribution and the abrasive wear resistanceis related to the substructure near the worn surface. The substructure of the tested martensite steel has an apparent relationship with thecarbon content and steels with moderate carbon content and hardness exhibit good resistance to abrasive wear. The competition of the work-hardening effect and the temper softening effect, which resulted from deformation and friction heat generating during abrasive wear is considered to be a main reason for the relation among wear-resistance, hardness and substructure. At the test conditions, the wear-resistance of 40CrSi is the best.

  20. Analysis and Modelling of Electrode Wear in Resistance Spot Welding

    DEFF Research Database (Denmark)

    Madsen, Anders; Pedersen, Kim; Friis, Kasper Storgaard

    2010-01-01

    A model describing electrode wear as a function of weld number, initial tip diameter, truncated cone angle, welding current and electrode force is proposed. Excellent agreement between the model and experimental results is achieved, showing that the model can describe the change in electrode tip ...... a central cavity is formed and one where smaller pits are formed randomly across the electrode face. The influence of these two types of surface pits on the nugget size are investigated using the FE code SORPAS, revealing ring welds and undersized weld nuggets....

  1. Analysis and Modelling of Electrode Wear in Resistance Spot Welding

    DEFF Research Database (Denmark)

    Madsen, Anders; Pedersen, Kim; Friis, Kasper Storgaard

    2010-01-01

    diameter with increasing weld number at different weld settings. Furthermore a method for measuring the worn tip diameter in a fast and robust manner is developed. The method relies on a well-known technique for capturing the electrode tip area by the use of carbon imprints and a new developed image......-processing program written in MatLab. Very fine agreement between the present experimental results and previously published wear data is achieved. Finally the pitted areas on the electrode tip are analyzed using MatLab and an optical 3D surface measurement device. Two types of pitting are characterized. One where...

  2. Preparation and wear resistance of Ti-Zr-Ni quasicrystal and polyamide composite materials

    Science.gov (United States)

    Wang, Xinlu; Li, Xuesong; Zhang, Zhenjiang; Zhang, Shanshan; Liu, Wanqiang; Wang, Limin

    2011-07-01

    Ti-Zr-Ni icosahedral quasicrystal powders (Ti-QC), prepared by mechanical alloying and then annealing in a vacuum furnace, were used as a novel filler material in polyamide 12 (PA12). The melt processability of the composite was studied using a Haake torque rheometer. This indicates that PA12/Ti-QC composites can be melt-processed into a wear-resistant material. Further, these composites, fabricated by compression molding, were tested in sliding wear against a polished bearing steel counterface. The results from wear testing show that the addition of Ti-QC filler to PA12 enhances wear resistance and reduces volume loss by half compared with neat PA12. Furthermore, it is found that the hardness of the composite increases with increasing content of Ti-QC filler. In addition, PA12/Ti-QC composites exhibit a slightly higher crystallization temperature and better thermal stability than PA12. These combined results demonstrate that Ti-QC filler may be a desirable alternative when attempting to increase the wear resistance of PA12.

  3. Nanocrystallization of aluminized surface of carbon steel for enhanced resistances to corrosion and corrosive wear

    Energy Technology Data Exchange (ETDEWEB)

    Chen, C. [Dept. of Materials Physical and Chemical, University of Science and Technology Beijing, Beijing 100083 (China); Dept. of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta, T6G 2V4 (Canada); Li, D.Y., E-mail: dongyang.li@ualberta.c [Dept. of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta, T6G 2V4 (Canada); Shang, C.J. [Dept. of Materials Physical and Chemical, University of Science and Technology Beijing, Beijing 100083 (China)

    2009-12-15

    Aluminizing is often used to improve steel's resistances to corrosion, oxidation and wear. This article reports our recent attempts to further improve aluminized carbon steel through surface nanocrystallization for higher resistances to corrosion and corrosive wear. The surface nanocrystallization was achieved using a process combining sandblasting and recovery heat treatment. The entire surface modification process includes dipping carbon steel specimens into a molten Al pool to form an Al coat, subsequent diffusion treatment at elevated temperature to form an aluminized layer, sandblasting to generate dislocation network or cells, and recovery treatment to turn the dislocation cells into nano-sized grains. The grain size of the nanocrystallized aluminized surface layer was in the range of 20-100 nm. Electrochemical properties, electron work function (EWF), and corrosive wear of the nanocrystalline alloyed surfaces were investigated. It was demonstrated that the nanocrystalline aluminized surface of carbon steel exhibited improved resistances to corrosion, wear and corrosive wear. The passive film developed on the nanocrystallized aluminized surface was also evaluated in terms of its mechanical properties and adherence to the substrate.

  4. Producing cobalt–graphene composite coating by pulse electrodeposition with excellent wear and corrosion resistance

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Cansen; Su, Fenghua, E-mail: fhsu@scut.edu.cn; Liang, Jizhao

    2015-10-01

    Graphical abstract: - Highlights: • Graphene oxide/cobalt coatings are synthesized by pulse electrodeposition. • Incorporating GO refines the grain size and changes the microstructure of the coating. • Incorporating GO greatly improves the friction reduction and wear resistance of the coating. • The corrosion resistance is enhanced by the incorporation of GO. - Abstract: Cobalt (Co) and graphene oxide/cobalt (GO/Co) composite coatings were fabricated by pulse electrodeposition technique from an aqueous bath containing cobalt sulfate and GO, etc. Effect of the incorporations of GO on morphology, phase structure, average grain size and corrosion and wear resistance of the resulting composite coatings were evaluated in detail. Scanning electron microscope (SEM) and energy dispersed X-ray (EDX) show that the GO nanosheets disperse homogeneously in the composite coating and the incorporations of GO change the morphologies of the deposit from conical shaped structure to protruding structure. In addition, the co-deposition GO with Co ions favor the formation of hcp (1 0 0), (0 0 2) and (1 0 1) textures in the composite coating and have functions of grain refining and hardness enhancement. The wear tests show that the incorporations of GO in the coating improve the wear resistance and friction reduction of the deposit. The electrochemical corrosion tests using potentiodynamic polarization and electrochemical impedance spectroscopy show that the GO/Co composite coating possesses better corrosion resistance than the pure Co coating.

  5. Nano Structured Plasma Spray Coating for Wear and High Temperature Corrosion Resistance Applications

    Science.gov (United States)

    Ghosh, D.; Shukla, A. K.; Roy, H.

    2014-04-01

    The nano structured coating is a major challenge today to improve the different mechanical properties, wear and high temperature corrosion resistance behaviour of different industrial alloys. This paper is a review on synthesis of nano powder, plasma spraying methods, techniques of nano structured coating by plasma spray method, mechanical properties, tribological properties and high temperature corrosion behaviour of nano structured coating. Nano structured coatings of ceramic powders/composites are being developed for wide variety of applications like boiler, turbine and aerospace industries, which requires the resistance against wear, corrosion, erosion etc. The nano sized powders are subjected to agglomeration by spray drying, after which nano structured coating can be successfully applied over the substrate. Nano structured coating shows improved mechanical wear resistance and high temperature corrosion resistance. The significant improvement of wear and corrosion resistance is mainly attributed to formation of semi molten nano zones in case of nano structured coatings. The future scope of application of nano structured coating has also been highlighted in this paper.

  6. Effect of nano-size nickel particles on wear resistance and high temperature oxidation resistance of ultrafine ceramic coating

    Institute of Scientific and Technical Information of China (English)

    古一; 夏长清; 李佳; 吴安如

    2004-01-01

    In order to improve the wear resistance and high temperature oxidation resistance of titanium and titanium alloy, the high temperature ultra fine ceramic coating containing nano-size nickel particles was prepared by flow coat method on the surface of industrially pure titanium TB1-0. The effects of nano-size nickel particles on the wear resistance and high temperature oxidation resistance of coating substrate system were investigated through oxidation kinetics experiment and wear resistance test. The morphologies of the specimens were examined by means of optical microscopy, scanning electron microscopy and X-ray diffraction. The results show that the high temperature ultra fine ceramic coating has notable protection effect on industrially pure titanium TB1-0 from oxidation. The oxidation and wear resistance properties of the coating can be effectively improved by adding nano-size nickel particles. The decreases from 1. 1 to 0. 6 by adding nano-size nickel particles, and the coating containing 10% (mass fraction) nano-size nickel shows the optimum properties.

  7. Comparison of Wear Resistance Between Innovative Composites and Nano- and Microfilled Composite Resins

    Directory of Open Access Journals (Sweden)

    Asefi

    2016-02-01

    Full Text Available Background One of the most common causes of failure in class 2 posterior composite restorations is occlusal and proximal wear. Estelite composites used supra-nano monodispersing spherical fillers and a new photoinitiator, and the manufacturer claimed that the wear of these composites is less than 1 mm3 volumetric wear. Objectives Compare the wear resistance of new Estelite composites with that of other composites generations. Materials and Methods Thirty-five specimens were evaluated in five groups: three kinds of Estelite composites (Estelite Sigma Quick, Estelite Flow Quick, and Estelite Flow Quick High Flow, Filtek Z350, and Filtek Z250. All specimens were prepared in 25 mm disks and cured with laboratory light for 120 seconds (60 s for each side. Then, they were polished by 600 grit sand paper and stored for one week in distilled water at room temperature. We used a two-body abrasion test and the pin-on-disk method with distilled water as medium. All specimens were worn under 15 N load, 0.05 m/seconds speed, 100 m distance, and steatite ceramic balls antagonists. After wearing, we measured wear volume by calculating the wear track cross-section area with a profilometer and analyzed the data with the one-way analysis of variance (ANOVA test. Results The wear amounts of the composites are as follows in order: Estelite sigma quick (1886.9 ± 518.5 μm2, Estelite flow quick (2708.9 ± 578.1 μm2, Estelite high flow (3206 ± 2445.1 μm2, Filtek Z350 (3840 ± 1963.4 μm2, and Filtek Z250 (4667.2 ± 2351.1 μm2. No statistical difference was found among the groups (P value > 0.05. Conclusions Estelite sigma quick composite had wear resistance similar to that of nano- and microfilled composites. Estelite flowable composites demonstrated similar wear resistance to that of a posterior composite.

  8. DIFFUSION COUPLE BETWEEN HIGH STRENGTH WEAR-RESISTING ALUMINUM BRONZE AND MACHINING TOOLS MATERIALS

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    Diffusion couples of tool materials (prepared from commercially available high speed steel and YW1 carbide tools) and the wear-resisting aluminum bronze (KK) were prepared by casting to study the diffusion pattern and phase formation sequence in order to clarify the diffusion wear of the tools during the turning of the wear-resisting aluminum bronze. Optical micrographs show that good contact was obtained at the tool material-KK interface. After annealed at 900 ℃ for 6 h, strong inter-diffusion across the interface was observed. Microprobe analysis was used to study the elemental distribution across the interface and X-ray diffractometry was used to study the phases formed at the interface.

  9. Improved Wear Resistance of Low Carbon Steel with Plasma Melt Injection of WC Particles

    Science.gov (United States)

    Liu, Aiguo; Guo, Mianhuan; Hu, Hailong

    2010-08-01

    Surface of a low carbon steel Q235 substrate was melted by a plasma torch, and tungsten carbide (WC) particles were injected into the melt pool. WC reinforced surface metal matrix composite (MMC) was synthesized. Dry sliding wear behavior of the surface MMC was studied and compared with the substrate. The results show that dry sliding wear resistance of low carbon steel can be greatly improved by plasma melt injection of WC particles. Hardness of the surface MMC is much higher than that of the substrate. The high hardness lowers the adhesion and abrasion of the surface MMC, and also the friction coefficient of it. The oxides formed in the sliding process also help to lower the friction coefficient. In this way, the dry sliding wear resistance of the surface MMC is greatly improved.

  10. Effect of Heat Treatment on Wear Resistance of Nickel Aluminide Coatings Deposited by HVOF and PTA

    Science.gov (United States)

    Benegra, M.; Santana, A. L. B.; Maranho, O.; Pintaude, G.

    2015-08-01

    This study aims to compare the wear resistance of nickel aluminide coatings deposited using plasma transferred arc (PTA) and high-velocity oxygen fuel (HVOF) processes. Wear resistance was measured in rubber wheel abrasion tests. In both deposition processes, the same raw material (nickel aluminide powder) was atomized and deposited on a 316L steel plate substrate. After deposition, specimens were subjected to thermal cycling, aiming solubilization and precipitation. Coatings deposited using PTA developed different microstructures as a result of the incorporation of substrate elements. However, despite the presence of these microstructures, they performed better than coatings processed using HVOF before the heat treatment. After thermal cycling, the superficial hardness after the wear tests for both processes was similar, resulting in similar mass losses.

  11. Wear resistance of laser cladding and plasma spray welding layer on stainless steel surface

    Institute of Scientific and Technical Information of China (English)

    Xinlin Wang(王新林); Shihong Shi(石世宏); Qiguang Zheng(郑启光)

    2004-01-01

    The effect of coatings, which are formed with laser cladding and plasma spray welding on 1Cr18Ni9Ti base metal, on wear resistance is studied, A 5-kW transverse flowing CO2 laser is used for cladding Co base alloy powder pre-placed on the substrate. Comparing with the plasma spray coatings, the spoiled rate of products with laser clad layers was lower and the rate of finished products was higher. Their microstructure is extremely fine. They have close texture and small size grain. Their dilution resulting from the compositions of the base metal and thermal effect on base metal are less. The hardness, toughness,and strength of the laser cladding layers are higher. Wear tests show that the laser layers have higher properties of anti-friction, anti-scour and high-temperature sliding strike. The wear resistance of laser clad layers are about one time higher than that of plasma spray welding layer.

  12. Influence of aging solutions on wear resistance and hardness of selected resin-based dental composites.

    Science.gov (United States)

    Chladek, Grzegorz; Basa, Katarzyna; Żmudzki, Jarosław; Malara, Piotr; Nowak, Agnieszka J; Kasperski, Jacek

    2016-01-01

    The purpose of this study was to investigate the effect of different plasticizing aging solutions on wear resistance and hardness of selected universal resin-based dental composites. Three light cured (one nanofilled, two microhybride) and one hybride chemical cured composites were aged at 37 °C for 48 h in distillated water, ethyl alcohol solution or Listerine mouthwash. After aging the microhardness tests were carried out and then tribological tests were performed in the presence of aging solution at 37 °C. During wear testing coefficients of friction were determined. The maximal vertical loss in micrometers was determined with profilometer. Aging in all liquids resulted in a significant decrease in hardness of the test materials, with the largest values obtained successively in ethanol solution, mouthwash and water. The effect of the liquid was dependent on the particular material, but not the type of material (interpreted as the size of filler used). Introduction of mouthwash instead of water or ethanol solution resulted in a significant reduction in the coefficient of friction. The lowest wear resistance was registered after aging in ethanol and for the chemical cured hybrid composite, but the vertical loss was strongly material dependent. The effect of different aging solution, including commercial mouthrinse, on hardness and wear was material dependent, and cannot be deduced from their category or filler loading. There is no simple correlation between hardness of resin-based dental composites and their wear resistance, but softening of particular composites materials during aging leads to the reduction of its wear resistance.

  13. Clinical evaluation of a highly wear resistant composite.

    Science.gov (United States)

    Dickinson, G L; Gerbo, L R; Leinfelder, K F

    1993-04-01

    The purpose of this clinical study was to determine the long-term potential of a resin composite restorative material. A total of 62 restorations of a modified Herculite Incisal formulation were inserted into Class I and Class II preparations. A control group of the conventional Herculite formulation was also placed into Class I and Class II cavity preparations at an earlier date. The cavity preparations for both formulations were standardized to conform to that of conventional conservative amalgams. Deep portions of the preparations were lined with calcium hydroxide. The enamel margins were etched per manufacturers' directions followed by a dentin bonding agent. After application of the appropriate matrix, the restorations were placed incrementally. Each restoration was independently evaluated by two clinicians at baseline, 6-months, 1, 2 and 3 years in accordance with the USPHS criteria. In addition, all restorations were evaluated for wear using a series of optical standards (M-L). The color matching ability of the material never fell below 96%. The percent of restorations exhibiting a surface texture similar to enamel never fell below 90% Alfa. At the end of 3 years, the total average loss of material was only 28 microns. No clinical evidence of bulk fracture was detected with the modified Herculite formulation at 3 years. The wear rate of the modified formulation of Herculite was essentially one-half that of conventional Herculite XR. Marginal ditching, which is characteristic of most posterior resin composites in which the filler particle is 1 micron or less, was exhibited.(ABSTRACT TRUNCATED AT 250 WORDS)

  14. Wear analysis and cyclic fatigue resistance of electro discharge machined NiTi rotary instruments

    Directory of Open Access Journals (Sweden)

    F. Iacono

    2016-06-01

    Conclusions: The typical irregular surface of HyFlex EDM remained unaffected after multiple uses, confirming a high wear resistance. The new manufacturing process of electrical discharge machining had a substantial impact on fatigue lifetime of EDM files when compared with HyFlex CM. Within limitations of the present in vitro results, EDM files appeared suitable in shaping severely curved canals.

  15. Wear-resistant ball bearings for space applications. [coated with titanium carbide

    Science.gov (United States)

    Boving, H.; Hintermann, H. E.; Haenni, W.; Bondivenne, E.; Boeto, M.; Conde, M.

    1977-01-01

    Ball bearings for hostile environments were developed. They consist of normal ball bearing steel parts of which the rings are coated with hard, wear-resistant, chemical vapor deposited (C.V.D) TiC. Experiments in ultrahigh vacuum, using cages of various materials with self-lubricating properties, have shown that such bearings are suitable for space applications.

  16. A STEEL MATRIX WEAR RESISTANT COMPOSITE REINFORCED BY IN-SITU GRANULAR EUTECTICS

    Institute of Scientific and Technical Information of China (English)

    Z.M. Xu; T.X. Li; J.G. Li

    2001-01-01

    A new steel matrix wear resistant composite reinforced by in situ granular eutectics can be obtained by modifying with a Si-Ce-Ti compound in the steel melt. The result indicates that the in situ granular eutectic is a pseudo-eutectic of austenite and (Fe, Mn)3C, which is formed between austenite dendrites during solidification due to the segregation of C and Mn impelled by modifying elements. The quantity of in situ granular eutectic reaches up to 8% 12%, and its grain size is in the range from 10μm to 20μm. The austenite steel matrix wear resistant composite reinforced by in situ granular eutectic (abbreviated AGE composite) and austenite-bainite steel matrix wear resistant composite reinforced by in situ granular eutectic (abbreviated ABGE composite) are obtained in the as-cast state and by air hardening, respectively. The wear resistance of the AGE and ABGE composites can be more greatly increased than that of their matrix steels under low and medium impact working condition.

  17. Mesenchymal stem cell interaction with ultra smooth nanostructured diamond for wear resistant orthopaedic implants

    OpenAIRE

    Clem, William C.; Chowdhury, Shafiul; Catledge, Shane A.; Weimer, Jeffrey J.; Shaikh, Faheem M; Hennessy, Kristin M; Konovalov, Valery V.; Hill, Michael R; Waterfeld, Alfred; Bellis, Susan L.; Vohra, Yogesh K.

    2008-01-01

    Ultra smooth nanostructured diamond (USND) can be applied to greatly increase the wear resistance of orthopaedic implants over conventional designs. Herein we describe surface modification techniques and cytocompatibility studies performed on this new material. We report that hydrogen (H) -terminated USND surfaces supported robust mesenchymal stem cell (MSC) adhesion and survival, while oxygen (O) and fluorine (F) -terminated surfaces resisted cell adhesion, indicating that USND can be modifi...

  18. Effect of Plasma Nitriding Parameters on the Wear Resistance of Alloy Inconel 718

    Science.gov (United States)

    Kovací, Halim; Ghahramanzadeh ASL, Hojjat; Albayrak, Çigdem; Alsaran, Akgün; Çelik, Ayhan

    2016-11-01

    The effect of the temperature and duration of plasma nitriding on the microstructure and friction and wear parameters of Inconel 718 nickel alloy is investigated. The process of plasma nitriding is conducted in a nitrogen-hydrogen gaseous mixture at a temperature of 400, 500 and 600°C for 1 and 4 h. The modulus of elasticity of the nitrided layer, the micro- and nanohardness, the surface roughness, the friction factor and the wear resistance of the alloy are determined prior to and after the nitriding. The optimum nitriding regime providing the best tribological characteristics is determined.

  19. Processing Parameters Influence on Wear Resistance Behaviour of Friction Stir Processed Al-TiC Composites

    Directory of Open Access Journals (Sweden)

    E. T. Akinlabi

    2014-01-01

    Full Text Available Friction stir processing (FSP being a novel process is employed for the improvement of the mechanical properties of a material and the production of surface layer composites. The vital role of the integrity of surface characteristics in the mechanical properties of materials has made the research studies into surface modification important in order to improve the performance in practical applications. This study investigates the effect of processing parameters on the wear resistance behavior of friction stir processed Al-TiC composites. This was achieved through microstructural characterization by using both the optical and scanning electron microscope (SEM, microhardness profiling, and tribological characterization by means of the wear. The microhardness profiling of the processed samples revealed an increased hardness value, which was a function of the TiC particles incorporated when compared to the parent material. The wear resistance property was also found to increase as a result of the TiC powder addition. The right combination of processing parameters was found to improve the wear resistance property of the composites produced.

  20. Deposition of wear-resistant steel surfaces by the plasma rotating electrode coating process

    Science.gov (United States)

    Kim, Michael Robert

    A high-deposition rate thermal spray method was investigated for the purpose of coating aluminum cylinder bores with a wear resistant surface. This method, the plasma rotating electrode coating system (PROTEC) utilized transferred-arc melting of a rapidly rotating consumable electrode to create a droplet stream via centrifugal atomization. A cylindrical substrate was placed around the rotating rod, in the flight path of the droplets, to deposit a coating onto the internal surface of the cylinder. Selected coatings of 1045 steel deposited by the PROTEC coating method exhibited lower wear loss in lubricated sliding than wire-arc sprayed carbon steel coatings and gray cast iron. Splat cohesion was shown to be a significant factor in the wear resistance of PROTEC coatings. The relationship between deposition enthalpy and cooling rate of the coating was found to have the greatest effect on coating microstructure, and the coating cohesion. The most rapidly solidified coatings showed inferior splat cohesion in comparison to coatings that cooled more slowly. The increase in splat cohesion with decreased cooling rate was accompanied by the formation of a directionally oriented coating microstructure, likely formed during cellular solidification of the coating. A model describing the thermal state of the deposition process was used to predict the deposition conditions that would result in a cellular structure, and the level of splat cohesion required to produce a wear resistant coating.

  1. Wear resistance of ceramic coating on AZ91 magnesium alloy by micro-arc oxidation

    Institute of Scientific and Technical Information of China (English)

    ZHAO Hui; LIU Zheng; CHEN Li-jia; CHEN Ji; HAN Zhong

    2006-01-01

    The ceramic coating formed on AZ91 magnesium alloy by micro-arc oxidation (MAO) was characterized. The results show that the ceramic coating(3.4-23 μm in thickness)on the surface of AZ91 alloy was attained under different micro-arc oxidation treatment conditions, which consist mainly of MgO, Mg2SiO4 and MgSiO3 phases. Nano-hardness in a cross-sectional specimen was determined by nano-indentation experiment. The MAO coatings exhibit higher hardness than the substrate. Dry sliding wear tests for the MAO coatings and AZ91 alloy were also carried out using an oscillating friction and wear tester in a ball-on-disc contact configuration. The wear resistance of the MAO coatings is improved respectively under different treatment time as a result of different structures of ceramic coatings formed on AZ91 alloy.

  2. Wear resistance analysis of the aluminum 7075 alloy and the nanostructured aluminum 7075 - silver nanoparticles composites

    Directory of Open Access Journals (Sweden)

    Estrada-Ruiz R.H.

    2016-01-01

    Full Text Available Nanostructured composites of the aluminum 7075 alloy and carbon-coated silver nanoparticles were synthetized by the mechanical milling technique using a high-energy mill SPEX 8000M; the powders generated were compacted, sintered and hot-extruded to produce 1 cm-diameter bars. The composites were then subjected to a wear test using a pin-on-disc device to validate the hypothesis that second phase-ductile nanometric particles homogenously distributed throughout the metalmatrix improve the wear resistance of the material. It was found that silver nanoparticles prevent the wear of the material by acting as an obstacle to dislocations movement during the plastic deformation of the contact surface, as well as a solid lubricant when these are separated from the metal-matrix.

  3. On The Enhancement of Wear Resistance of Hardened Carbon Tool Steel (AISI 1095) With Cryogenic Quenching

    Institute of Scientific and Technical Information of China (English)

    V.Soundararajan; N.Alagurmurthi; K.Palaniradja

    2004-01-01

    Many experimental investigations reveal that it is very difficult to have a completely martensitic structure by any hardening process. Some amount of austenite is generally present in the hardened steel. This austenite existing along with martensite is normally referred as the retained austenite. The presence of retained austenite greatly reduces the mechanical properties and such steels do not develop maximum hardness even after cooling at rates higher than the critical cooling rates.Strength can be improved in hardened steels containing retained austenite by a process known as cryogenic quenching.Untransformed austenite is converted into martensite by this treatment. This conversion of retained austenite into martensite results in increased hardness, wear resistance and dimensional stability of steel. Wear can be defined as the progressive loss of materials from the operating surface of a body occurring as a result of relative motion at the surface. Hardness, load,speed, surface roughness, temperature are the major factors which influences wear. Many studies on wear indicate that increasing hardness decreases the wear of a material. With this in mind, to study the surface wear on a surface modified(Cryogenic treated) steel material an attempt has been made in this paper. In this study as a Part -I Hardening was carried out on carbon tool steel (AISI 1095) of different L/D ratio with conventional quenchants like purified water, aqueous solution and Hot mineral oil. As a Part -Ⅱ hardening was followed by quenching was carried out as said in Part- I and the hardened specimen were quenched in liquid Nitrogen which is at sub zero condition. The specimens were tested for its microstructure, hardness and wear loss. The results were compared and analyzed. The alloying elements increases the content of retained austenite hence the material used was AISI1095 (Carbon 0.9%, Si 0.2%, Mn0.4% and the rest Iron)

  4. The fabrication of flip-covered plasmonic nanostructure surfaces with enhanced wear resistance

    Science.gov (United States)

    Jung, Joo-Yun; Sung, Sang-Keun; Kim, Kwang-Seop; Cheon, So-Hui; Lee, Jihye; Choi, Jun-Hyuk; Lee, Eungsug

    2017-01-01

    Exposed nanostructure surfaces often suffer from external dynamic wear, particularly when used in human interaction, resulting in surface defects and the degradation of plasmonic resonance properties particularly in terms of transmittance extinction rate and peak-to-valley slope. In this work, a method for the fabrication of flip-covered silver nanostructure-arrayed surfaces is shown to enhance wear resistance. Selectively transferred silver dot and silver webbed-trench exposed reference samples were fabricated by metal nanoimprint, and flip-covered samples were created by flipping and bonding reference samples onto a PET film coated with an adhesive layer. The samples' spectral transmittance was measured before and after a dynamic wear test. Some spectral shift was observed due to the change in refractive index of the surrounding media, but this was not as significant as the effects of the other chosen geometry factors. It was found that dynamic wear had a greater effect on the plasmonic resonance behavior of the exposed samples than in those that had been flip-covered. This suggests that flip-covering may be an effective strategy for the protection of plasmonic resonators against dynamic wear. It is expected that the slight variations in spectral transmittance could be compensated through proper tuning of the sample geometry.

  5. Nanostructured wear resistant coating for reversible cultivator shovels: An experimental investigation

    Science.gov (United States)

    Dave, V.; Rao, G. P.; Tiwari, G. S.; Sanger, A.; Kumar, A.; Chandra, R.

    2016-04-01

    Cultivator, one of the agriculture farm tool, extensively suffers from the wear problem. In this paper, we report nanostructured chromium nitrite (CrN) coating for the cultivator shovels to mitigate wear problem. The (CrN) coating was developed using DC magnetron sputtering technique at 200 °C. The structural, morphological, hydrophobic and wear properties were investigated using X-ray diffractometer, scanning electron microscope, contact angle goniometer and custom designed soil bin assembly. The XRD reveals that the deposited coating was polycrystalline in nature with cubic structure. Also, The deposited coating was found to be anti wear resistant as well as hydrophobic in nature. The gravimetric wear for the coating developed at 200 °C coated was found out to be 8.15 gm and for non coated it was 14.48 gm tested for 100 hrs. The roughness of the coating plays an important role in determining the hydrophobicity of the coated film. Roughness and contact angle measured for 200 °C coated shovel was found out to be 11.17 nm and 105 ° respectively.

  6. Analysis of the relationship between the surface hardness and wear resistance of indirect composites used as veneer materials.

    Science.gov (United States)

    Faria, Adriana Cláudia Lapria; Benassi, Ubiratan Menezes; Rodrigues, Renata Cristina Silveira; Ribeiro, Ricardo Faria; Mattos, Maria da Gloria Chiarello de

    2007-01-01

    This study evaluated the surface hardness and wear resistance of indirect composites (Artglass and Solidex) and the existence of a correlation between these properties. Twenty-four specimens (12 per material) were fabricated using a polytetrafluoroethylene matrix (5.0 mm in diameter; 7.0 mm high) following an incremental technique. Polymerization was done with a xenon stroboscopic light curing unit. After polishing, the specimens were stored in water at 37 degrees C during either 1 day (n=6 per material) or 55 days (n=6 per material), after which Vickers surface hardness and wear resistance were assessed. Data were analyzed statistically by unpaired Student t-test, two-way ANOVA and Tukey's test. SURFACE HARDNESS: Artglass had higher surface hardness than Solidex after 1-day immersion period (p0.05). Comparing the materials at both periods, Artglass means differed significantly to each other (p0.05). WEAR RESISTANCE: Solidex had higher wear than Artglass after 1-day immersion period (p0.05). Comparing the materials at both periods, Artglass means differed significantly to each other (p0.05). These results suggest that Artglass was better than Solidex in terms of hardness and wear resistance after 1-day water immersion. However, it was more susceptible to degradation, showing greater wear after 55 days. In conclusion, there was an inverse correlation between surface hardness and wear resistance for both Artglass and Solidex indirect composites, that is the higher the hardness, the lower the wear.

  7. The relative effects of radiation crosslinking and type of counterface on the wear resistance of ultrahigh-molecular-weight polyethylene.

    Science.gov (United States)

    Bistolfi, Alessandro; Bellare, Anuj

    2011-09-01

    The lifetime of total joint replacement prostheses utilizing ultrahigh-molecular-weight polyethylene (UHMWPE) components has historically been determined by their wear resistance. It has been discovered that radiation crosslinking of UHMWPE can substantially increase its wear resistance. However, it is also well recognized that there is a radiation-dose-dependent decrease in several important mechanical properties of UHMWPE, such as fracture toughness and resistance to fatigue crack propagation. In this study, the effect of radiation crosslinking (followed by remelting) on the morphology, tensile properties and wear resistance of UHMWPE was investigated. Wear tests were conducted against both the commonly used cobalt-chromium counterface polished to implant grade smoothness as well as a smoother ceramic (alumina) counterface. The results showed that 50kGy dose radiation crosslinking increased the wear resistance of UHMWPE against the cobalt-chromium counterface 7-fold, but the coupling of remelted, crosslinked UHMWPE against the smoother alumina counterface led to a 20-fold increase in wear resistance. This study shows that the use of an alumina counterface would circumvent the need to use a high radiation dose in crosslinking UHMWPE, associated with poor mechanical properties, without compromising wear resistance.

  8. Study on the Thermal Fatigue Behavior of Hot Deformed Wear Resistance Cast Iron and Effect of Carbide

    Institute of Scientific and Technical Information of China (English)

    Dong Litao; Liu Rongchang; Li Xingyuan; Chen Xiuhong

    2007-01-01

    The thermal fatigue behavior of wear resistance cast iron with different quantity of deformation has been investigated. The results show that eutectic carbide is the main location and passage for initiation and extension of thermal fatigue cracks, approving that the more serious, the carbide breaks. The higher thermal fatigue resistance of wear resistance cast iron will be and thermal fatigue fracture belongs mainly to brittleness.

  9. Effect of post-welding heat treatment on wear resistance of cast-steel die with surfacing layer

    Directory of Open Access Journals (Sweden)

    Xu Wujiao

    2015-01-01

    Full Text Available The wear resistance capability of die surfacing layer under different Post-Welding Heat Treatments (PWHT was analysed by Finite Element (FE simulation and experiments. Taking hot forging process of a crankshaft as an example, a wear model of the hot forging die coated with surfacing layer was established using FE software DEFORM-3D. The simulation results indicated that the wear resistance capability of the die surfacing layer is optimal when tempering temperature and holding time are 550 °C and 4 h respectively. To verify the wear computational results, 16 groups of PWHT orthogonal wear tests were performed at a temperature of 400 °C, which is a similar temperature to that occurs in an actual hot forging die. The wear-test result showed a good agreement with the FE simulation. SEM observation of the wear debris on 16 specimens showed that oxidative wear is dominant when the temperature was in 400 °C. Furthermore, when tempering temperature and holding time were 550 °C and 4 h respectively, the carbide alloy dispersively distributes in the metallographic structure, which helps to improve the wear resistance of the surfacing layer.

  10. Study of the surface wear resistance and biological properties of the Ti-Zr-Nb-Sn alloy for dental restoration.

    Science.gov (United States)

    Hu, Xin; Wei, Qiang; Li, Chang-Yi; Deng, Jia-Yin; Liu, Shuang; Zhang, Lian-Yun

    2010-10-01

    A new titanium alloy (Ti-12.5Zr-3Nb-2.5Sn) was developed to meet the needs of clinical requirements for medical titanium alloys and improve the properties of existing titanium alloys. The as-prepared alloy was solution treated at 500 °C for 3 h in vacuum followed by water quenching. Tensile, wear and hardness tests were carried out to examine the mechanical properties of the Ti-Zr-Nb-Sn alloy. Oral mucous membrane irritation test was performed to evaluate the surface biological properties of the Ti-Zr-Nb-Sn alloy. The results suggested that the surface hardness and wear-resistant properties of the Ti-12.5Zr-3Nb-2.5Sn alloy were superior to commercially pure Ti. The oral mucous irritation test showed that all samples had no mucous membrane irritation. It indicates that Ti-12.5Zr-3Nb-2.5Sn has large potential to be used as dental restoration material.

  11. Study of the surface wear resistance and biological properties of the Ti-Zr-Nb-Sn alloy for dental restoration

    Energy Technology Data Exchange (ETDEWEB)

    Hu Xin; Li Changyi; Deng Jiayin; Liu Shuang; Zhang Lianyun [School of Dentistry, Tianjin Medical University, Tianjin 300070 (China); Wei Qiang [Tianjin Key Laboratory of Composite and Functional Materials, School of Materials Science and Engineering, Tianjin University, Tianjin 300072 (China)

    2010-10-01

    A new titanium alloy (Ti-12.5Zr-3Nb-2.5Sn) was developed to meet the needs of clinical requirements for medical titanium alloys and improve the properties of existing titanium alloys. The as-prepared alloy was solution treated at 500 {sup 0}C for 3 h in vacuum followed by water quenching. Tensile, wear and hardness tests were carried out to examine the mechanical properties of the Ti-Zr-Nb-Sn alloy. Oral mucous membrane irritation test was performed to evaluate the surface biological properties of the Ti-Zr-Nb-Sn alloy. The results suggested that the surface hardness and wear-resistant properties of the Ti-12.5Zr-3Nb-2.5Sn alloy were superior to commercially pure Ti. The oral mucous irritation test showed that all samples had no mucous membrane irritation. It indicates that Ti-12.5Zr-3Nb-2.5Sn has large potential to be used as dental restoration material.

  12. Development of wear-resistant coatings for cobalt-base alloys

    Energy Technology Data Exchange (ETDEWEB)

    Cockeram, B.V.

    1999-03-01

    The costs and hazards resulting from nuclear plant radiation exposure with activated cobalt wear debris could potentially be reduced by covering the cobalt-base materials with a wear resistant coating. However, the hardnesses of many cobalt-base wear alloys are significantly lower than conventional PVD hard coatings, and mechanical support of the hard coating is a concern. Four approaches have been taken to minimize the hardness differences between the substrate and PVD hard coating: (1) use a thin Cr-nitride hard coating with layers that are graded with respect to hardness, (2) use a thicker, multilayered coating (Cr-nitride or Zr-nitride) with graded layers, (3) use nitriding to harden the alloy subsurface followed by application of a multilayered coating of Cr-nitride, and (4) use of nitriding alone. Since little work has been done on application of PVD hard coatings to cobalt-base alloys, some details on process development and characterization of the coatings is presented. Scratch testing was used to evaluate the adhesion of the different coatings. A bench-top rolling contact test was used to evaluate the wear resistance of the coatings. The test results are discussed, and the more desirable coating approaches are identified.

  13. Development of wear resistant ceramic coatings for diesel engine components. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Haselkorn, M.H. [Caterpillar, Inc., Peoria, IL (United States)

    1992-04-01

    Improved fuel economy and a reduction of emissions can be achieved by insulation of the combustion chamber components to reduce heat rejection. However, insulating the combustion chamber components will also increase the operating temperature of the piston ring/cylinder liner interface from approximately 150{degree}C to over 300{degree}C. Existing ring/liner materials can not withstand these higher operating temperatures and for this reason, new materials need to be developed for this critical tribological interface. The overall goal of this program is the development of piston ring/cylinder liner material pairs which would be able to provide the required friction and wear properties at these more severe operating conditions. More specifically, this program first selected, and then evaluated, potential d/wear resistant coatings which could be applied to either piston rings an or cylinder liners and provide, at 350{degree}C under lubricated conditions, coefficients of friction below 0.1 and wear rates of less than 25 {times} lO{sup {minus}6} mm/hour. The processes selected for applying the candidate wear resistant coatings to piston rings and/or cylinder liners were plasma spraying, chemical vapor, physical vapor and low temperature arc vapor deposition techniques as well as enameling techniques.

  14. Microstructures and Mechanical Properties of a Wear-Resistant Alloyed Ductile Iron Austempered at Various Temperatures

    Science.gov (United States)

    Cui, Junjun; Chen, Liqing

    2015-08-01

    To further improve the mechanical performance of a new type of alloyed bainitic wear-resistant ductile iron, the effects of the various austempering temperatures have been investigated on microstructure and mechanical behaviors of alloyed ductile iron Fe-3.50C-1.95Si-3.58Ni-0.71Cu-0.92Mo-0.65Cr-0.36Mn (in weight percent). This alloyed ductile iron were firstly austenitized at 1123 K (850 °C) for 1 hour and then austempered in a salt bath at 548 K, 573 K, and 598 K (275 °C, 300 °C, and 325 °C) for 2 hours according to time-temperature-transformation diagram calculated by JMatPro software. The microstructures of austempered wear-resistant ductile irons consist of matrix of dark needle-like ferrite plus bright etching austenite and some amount of martensite and some dispersed graphite nodules. With increasing the austempering temperature, the amount of ferrite decreases in austempered ductile iron, while the amount of austenite and carbon content of austenite increases. There is a gradual decrease in hardness and increase in compressive strength with increasing austempering temperature. The increased austenite content and coarsened austenite and ferrite can lead to a hardness decrease as austempering temperature is increased. The increased compressive strength can be attributed to a decreased amount of martensitic transformation. The alloyed ductile iron behaves rather well wear resistance when the austempering is carried out at 598 K (325 °C) for 2 hours. Under the condition of wear test by dry sand/rubber wheel, the wear mechanisms of austempered ductile irons are both micro-cutting and plastic deformation.

  15. Selected Plastics Wear Resistance to Bonded Abrasive Particles Compared to Some Ferrous Materials

    Directory of Open Access Journals (Sweden)

    Milan Brožek

    2015-01-01

    Full Text Available Plastics are macromolecular materials without we cannot imagine any branch of human activity with. Plastics have unique properties, often very different from metals. At the choice of the concrete plastic for the concrete application it is necessary to evaluate its mechanical, physical, chemical and technological properties. In last years producers offer also plastics for production of parts exposed to different types of wear. In the contribution the results of wear resistance studying of 10 types of plastics (PTFE, PVC, POM-C, PC, PETP, PEEK, PA66, PP, PA6E and PE-UHMW of one producer are published and compared with test results of four different Fe alloys (grey iron, structural steel, cast steel wear resistant and high-speed steel. The laboratory tests were carried out using the pin-on-disk machine with abrasive cloth (according to ČSN 01 5084, when the abrasive clothes of three different grits (240, 120 and 60 were used. It corresponds to the average abrasive grain sizes of 44.5 µm, 115.5 µm and 275 µm. During the test the test sample was pressed to the abrasive cloth by the pressure of 0.1 MPa. The wear intensity was assessed by the volume, weight and length losses of tested samples. The technical-economical evaluation was the part of the carried out tests. It was univocally proved that at the intensive abrasive wear using the abrasive cloth the best results shows the High-Speed Steel HSS Poldi Radeco 19 810 according to ČSN 41 9810, although its price is relatively high. Other tested Fe alloys, namely grey iron according to ČSN 42 2415, structural steel 11 373 according to ČSN 41 1373 and wear resistant cast steel VPH 6 showed also very favourable properties at the material low price. In comparison with Fe alloys the wear of all plastics was considerably higher and the plastics were considerably more expensive.

  16. Highly wear-resistant ultra-thin per-fluorinated organic monolayers on silicon(1 1 1) surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Pujari, Sidharam P. [Laboratory of Organic Chemistry, Wageningen University, Dreijenplein 8, 6703 HB Wageningen (Netherlands); Zuilhof, Han, E-mail: Han.Zuilhof@wur.nl [Laboratory of Organic Chemistry, Wageningen University, Dreijenplein 8, 6703 HB Wageningen (Netherlands); Department of Chemical and Materials Engineering, King Abdulaziz University, Jeddah (Saudi Arabia)

    2013-12-15

    This study reports on fluorine-containing alkyne-derived monolayers onto Si(1 1 1) substrates to obtain densely packed, highly wear-resistant surfaces. The nano-wear properties were measured using atomic force microscopy (AFM). The presence of the fluorinated monolayers was found to enhance the wear properties of the silicon surfaces, with a decrease of the depth of wear scratches of up to 120 times as compared to the unmodified surface. Ultimately, the scratch depth was only 6 nm for a heptadecafluoro-alkyl based monolayer for scratching normal forces as high as 38 μN.

  17. Enhancement of wear and corrosion resistance of beta titanium alloy by laser gas alloying with nitrogen

    DEFF Research Database (Denmark)

    Chan, Chi-Wai; Lee, Seunghwan; Smith, Graham

    2016-01-01

    , the quaternary Ti-Nb-Zr-Ta (TNZT) alloys have received the highest attention as a promising replacement for Ti6Al4V due to their lower elastic modulus and outstanding long term stability against corrosion in biological environments. However, the inferior wear resistance of TNZT is still a problem that must...... be resolved before commercialising in the orthopaedic market. In this work, a newly developed laser surface treatment technique was employed to improve the surface properties of Ti-35.3Nb-7.3Zr-5.7Ta alloy. The surface structure and composition of the laser-treated TNZT surface were examined by grazing...... findings showed that the laser surface treatment technique reported in this work can effectively improve the wear and corrosion resistance of TNZT....

  18. High Strength and Wear Resistant Aluminum Alloy for High Temperature Applications

    Science.gov (United States)

    Lee, Jonathan A.; Munafo, Paul M. (Technical Monitor)

    2002-01-01

    In this paper, a new high strength and wear resistant aluminum cast alloy invented by NASA-MSFC for high temperature applications will be presented. Developed to meet U.S. automotive legislation requiring low-exhaust emission, the novel NASA 398 aluminum-silicon alloy offers dramatic improvement in tensile and fatigue strengths at elevated temperatures (500 F-800 F), enabling new pistons to utilize less material, which can lead to reducing part weight and cost as well as improving performance. NASA 398 alloy also offers greater wear resistance, surface hardness, dimensional stability, and lower thermal expansion compared to conventional aluminum alloys for several commercial and automotive applications. The new alloy can be produced economically using permanent steel molds from conventional gravity casting or sand casting. The technology was developed to stimulate the development of commercial aluminum casting products from NASA-developed technology by offering companies the opportunity to license this technology.

  19. Wear Resistance of Deposited Layer Using Nickel-Based Composite Powders by Plasma-Arc Surfacing

    Institute of Scientific and Technical Information of China (English)

    DONG Li-hong; ZHU Sheng; XU Bin-shi; DU Ze-yu

    2004-01-01

    Nickel-based composite alloy powders were deposited on the surface of Q235 steel by plasma-arc surfacing in this work. Optimal proportions of elements intensifying the composite powders were ascertained by orthogonal design of three factors and three levels and orthogonal polynomial regression analysis , which Cr , Mn , W were 10% ,4% and 7 % respectively.Phase and structure of deposited materials were characterized by optical microscope and X- ray diffraction. Hardness tests and wear resistance tests were carried out to determine the performance of the deposited layers. The results show that the microstructure of deposited layers of composite powders mainly consist of γ-( Ni, Fe ) , γ- Ni, WC, W2 C, Mn31Si12, Cr23 C6,Cr7 C3, Cr, NiB, Ni2B etc. Wear resistance and hardness of the surface increased evidently.

  20. Chemically robust carbon nanotube – PTFE superhydrophobic thin films with enhanced ability of wear resistance

    Directory of Open Access Journals (Sweden)

    Kewei Wang

    2017-06-01

    Full Text Available A chemically robust superhydrophobic nanocomposite thin film with enhanced wear resistance is prepared from a composite comprising polytetrafluoroethylene (PTFE and carbon nanotubes. The superhydrophobic thin films with hierarchical structure are fabricated by spraying an environmentally friendly aqueous dispersion containing carbon nanotubes and PTFE resin on silicon wafer. Thin films with a contact angle of 154.1°±2° and a sliding angle less than 2° remain superhydrophobic after abrading over 500 times under a pressure of 50 g/cm2. The thin film is also extremely stable even under much stress conditions. To further the understanding of the enhancement of wear resistance, we investigated the formation of microsized structure and their effects. The growth of microbumps is caused by attracting solution droplet to the hydrophilic islands on hydrophobic surface.

  1. Wear-Resistance Performance of ZA-27 Alloys Reinforced by Rare Earth Compounds

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The morphology of ZA-27 alloy reinforced by RE compounds and its wear-resistance were studied. It is found that some nodular second phases appear due to the addition of Si and RE, which can disperse in grain boundaries or between dendrite crystals so that the alloy has been refined. Energy spectrum analysis of scanning electron microscope shows that the second phases are complex compounds containing RE, Al, Zn and Si. The micro-hardness test indicates that micro-hardness values of the compounds are higher than those of the matrix. The wear-resistance of ZA-27 alloy reinforced by RE compounds is 4 times as high as that of ZA-27 alloy and also higher than that of ZA-27 alloy containing Si phase. The impact toughness of the alloy containing RE and Si is higher than that of the alloy containing Si.

  2. Structure and abrasive wear resistance of R6M5 steel-tungsten carbide composite coatings

    Science.gov (United States)

    Gnyusov, S. F.

    2012-09-01

    Features of the structure formation, composition, and abrasive wear resistance of R6M5 steel-tungsten carbide (R6M5-WC) composite coatings have been studied as dependent on the WC content. The introduction of ˜20 wt % WC into the hardening composition leads to an increase in the fraction of M6C carbide (in the form of eutectic inclusions with average size ˜5.9 μm at grain boundaries and dispersed ˜0.25 μm particles in the volume of grains), while a large proportion of metastable austenite (˜88 vol %) is still retained. The R6M5-WC coatings exhibit high abrasive wear resistance, which is ensured by the γ → α' martensite transformation during friction and a muiltimodal size distribution of hardening particles.

  3. 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.

  4. Nitriding of Hard Fe Electrodeposition and Its Effects on Wear Resistance

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Nitriding is employed for the hard Fe electrodeposition toproduce a hard-facing and antiwear coating. It only takes 1 h for the hard Fe coating, which is much shorter than nitriding the Fe and steel. The results showed that the nitriding can increase the microhardness, wear resistance of the coating, as well as the bonding strength of the coating with the substrate. Additionally it can eliminate the brittleness, turn the internal stress of the coating from tension to compression.The wear resistance of the nitrided Fe coating is 4.6 times as high as that of Cr coating. It is simple and economic to combine hard Fe electroplating and nitriding, which is a good technology of the tribological surface modification.

  5. IMPROVEMENT OF WEAR-RESISTANCE AND SERVICE LIFE OF MULTI-DISK BRAKE MECHANISMS OF «BELARUS» TRACTOR BY LASER THERMAL HARDENING OF FAST WEARING PARTS

    Directory of Open Access Journals (Sweden)

    O. S. Kobjakov

    2008-01-01

    Full Text Available Problems concerning wear resistance improvement of «Belarus» tractor brake mechanism parts are considered in the paper. Properties of ВЧ-50-pig iron are investigated as a result of laser thermal hardening by various technological methods.

  6. Realizing of the process approach to quality management of wear resistant coatings

    OpenAIRE

    МЄДВЄДЄВА, Н. А.; Національний авіаційний університет

    2016-01-01

    A process-oriented model of technological process of wear-resistant coatings by electrocontactstrengthening of sprayed coatings (ECSSC) during the recovery machine parts is proposed. Itsstructural description has allowed to reproduce the process approach in conformity with internationalstandard ISO 9001:2015. Also, visual and more formalized presentation of interactionof the quality management system with technological process, working environment and thedynamics of its implementation was don...

  7. Enhancement of wear and corrosion resistance of beta titanium alloy by laser gas alloying with nitrogen

    Energy Technology Data Exchange (ETDEWEB)

    Chan, Chi-Wai, E-mail: c.w.chan@qub.ac.uk [School of Mechanical and Aerospace Engineering, Queen' s University Belfast, BT9 5AH (United Kingdom); Lee, Seunghwan [Department of Mechanical Engineering, Technical University of Denmark, DK-2800 Kgs. Lyngby (Denmark); Smith, Graham [Department of Natural Sciences, University of Chester, Thornton Science Park, Chester CH2 4NU (United Kingdom); Sarri, Gianluca [School of Mathematics and Physics, Queen' s University Belfast, Belfast BT7 1NN (United Kingdom); Ng, Chi-Ho [School of Mechanical and Aerospace Engineering, Queen' s University Belfast, BT9 5AH (United Kingdom); Laser Engineering and Manufacturing Research Centre, Faculty of Science and Engineering, University of Chester, Parkgate Road, Chester CH1 4BJ (United Kingdom); Sharba, Ahmed [School of Mathematics and Physics, Queen' s University Belfast, Belfast BT7 1NN (United Kingdom); Man, Hau-Chung [Department of Industrial and Systems Engineering, Faculty of Engineering, The Hong Kong Polytechnic University, Hong Kong (China)

    2016-03-30

    Graphical abstract: - Highlights: • Laser technology is a fast, clean and flexible method for surface hardening of TNZT. • Laser can form a protective hard layer on TNZT surface without altering surface roughness. • The laser-formed layer is metallurgically bonded to the substrate. • Laser-treated TNZT is highly resistant to corrosion and wear in Hank's solution. - Abstract: The relatively high elastic modulus coupled with the presence of toxic vanadium (V) in Ti6Al4V alloy has long been a concern in orthopaedic applications. To solve the problem, a variety of non-toxic and low modulus beta-titanium (beta-Ti) alloys have been developed. Among the beta-Ti alloy family, the quaternary Ti–Nb–Zr–Ta (TNZT) alloys have received the highest attention as a promising replacement for Ti6Al4V due to their lower elastic modulus and outstanding long term stability against corrosion in biological environments. However, the inferior wear resistance of TNZT is still a problem that must be resolved before commercialising in the orthopaedic market. In this work, a newly developed laser surface treatment technique was employed to improve the surface properties of Ti–35.3Nb–7.3Zr–5.7Ta alloy. The surface structure and composition of the laser-treated TNZT surface were examined by grazing incidence X-ray diffraction (GI-XRD) and X-ray photoelectron spectroscopy (XPS). The wear and corrosion resistance were evaluated by pin-on-plate sliding test and anodic polarisation test in Hanks’ solution. The experimental results were compared with the untreated (or base) TNZT material. The research findings showed that the laser surface treatment technique reported in this work can effectively improve the wear and corrosion resistance of TNZT.

  8. Controlled graphitization as a potential option for improving wear resistance of unalloyed white irons

    Science.gov (United States)

    Patwardhan, A. K.; Kumar, S.; Singh, Prakash

    1998-08-01

    Effect of heat treatment on the microstructure and resistance to abrasive wear has been studied in an unalloyed white iron used for manufacturing cylindrical pebbles used as grinding media by the cement and other industries. Heat treatment comprised holding at 800 °C, 850 °C, 900 °C, and 950 °C for 30, 60, 90, 120, and 180 minutes followed by oil quenching. Heat treatment in general improved the wear resistance over that in the as-cast (as-received) state. The extent of maximum improvement differed with temperature and in the decreasing order occurred at (1) 180 minutes, 800 °C, OQ; (2) 30 minutes, 950 °C, OQ; (3) 90 minutes, 900 °C, OQ; and (4) 180 minutes, 850 °C, OQ. From the point of view of commercial application, the heat treatment at (2) is most favored. Microstructural changes occurring during heat treating comprised (1) changes in matrix microstructure; (2) a reduction in volume fraction of massive carbides due to its part graphitization/destabilization; and (3) changes in graphite morphology, size, and distribution. Amongst the aforesaid changes, graphitization has emerged as the key parameter in improving wear resistance. Graphite morphology in a near-nodular form of optimum size and distribution was found to be most effective. Upon increasing the heat-treating temperature, the tendency of nodules to develop spikes increased. Similarly, interlinking of graphite flakes was also observed. These features and the possible formation of free ferrite adversely affected wear resistance. The role of other beneficial changes in the microstructure, e.g., globularization of carbides, possible retention of austenite, and formation of optimum volume fraction of martensite, have been duly considered while optimizing microstructure(s). The key feature of the present study is that, despite its fundamental significance, it has a well-focused application potential.

  9. Nano-hardness, wear resistance and pseudoelasticity of hafnium implanted NiTi shape memory alloy.

    Science.gov (United States)

    Zhao, Tingting; Li, Yan; Liu, Yong; Zhao, Xinqing

    2012-09-01

    NiTi shape memory alloy was modified by Hf ion implantation to improve its wear resistance and surface integrity against deformation. The Auger electron spectroscopy and x-ray photoelectron spectroscopy results indicated that the oxide thickness of NiTi alloy was increased by the formation of TiO₂/HfO₂ nanofilm on the surface. The nano-hardness measured by nano-indentation was decreased even at the depth larger than the maximum reach of the implanted Hf ion. The lower coefficient of friction with much longer fretting time indicated the remarkable improvement of wear resistance of Hf implanted NiTi, especially for the sample with a moderate incident dose. The formation of TiO₂/HfO₂ nanofilm with larger thickness and decrease of the nano-hardness played important roles in the improvement of wear resistance. Moreover, Hf implanted NiTi exhibited larger pseudoelastic recovery strain and retained better surface integrity even after being strained to 10% as demonstrated by in situ scanning electron microscope observation. Crown Copyright © 2012. Published by Elsevier Ltd. All rights reserved.

  10. Comparison of Wear Resistance Mechanisms of Die Steel Implanted with C and mo Ions

    Science.gov (United States)

    Cheng, M. F.; Yang, J. H.; Luo, X. D.; Zhang, T. H.

    Mo and C ions extracted from a metal vapor vacuum arc ion source were implanted into the surface of die steel (H13) to compare the wear resistance mechanisms of the implanted samples, respectively. The concentration depth profiles of implanted ions were measured using Rutherford backscattering spectroscopy and calculated by a code called TRIDYN. The structures of the implanted steel were observed by X-ray photoelectron spectroscopy and grazing-angle X-ray diffraction, respectively. It was found that the conventional heat-treated H13 steel could not be further hardened by the subsequent implanted C ions, and the thickness of the implanted layer was not an important factor for the Mo and C ion implantation to improve the wear resistance of the H13 steel. Mo ion implantation could obviously improve the wear resistance of the steel at an extraction voltage of 48 kV and a dose of 5 × 1017cm-2 due to formation of a modification layer of little oxidation with Mo2C in the implanted surface.

  11. Preparation and Properties of Superamphiphobic Wear-resistance PPS-based Coating

    Directory of Open Access Journals (Sweden)

    WANG Huai-yuan

    2017-01-01

    Full Text Available Superamphiphobic wear-resistance PPS-based coatings were prepared by a simple spraying method with a pore-forming reagent of NH4HCO3 and nano-filler of carbon nanotubes (CNTs.The surface morphology and the hydrophobicity,oleophobicity of the coating were analyzed by scanning electron microscope (SEM and contact angle meter.The wear-resistance of the coating was verified by sanding method with given load.The results indicate that a rough surface is obtained after pore-forming,and the porous structures in combination with the CNTs construct the special micro/nano-scale network structures.When the mass fraction of NH4HCO3 is 5%,the contact angles of the coating for water,glycerine and ethylene glycol are 162°,158° and 152°,showing superamphiphobic property.After polished 10000 times by abrasive paper,the coating shows slight friction marks and remains high hydrophobicity,exhibiting excellent wear-resistance.

  12. CO2 laser cladding heterogeneous ceramic-metal wear-resistant coatings

    Science.gov (United States)

    Fomin, V. M.; Malikov, A. G.; Orishich, A. M.

    2016-10-01

    The microstructure, hardness property and wear resistance of WC, Ni-Cr and Fe powders deposited by laser cladding at varying processing parameters were investigated. The results of the present study revealed the prospects of multilayer cladding of R6M5 high-speed tool steel (analog of M2 steel (USA) and HS6-5-2 steel (EU)) onto low-alloy steel with the use of a laser beam. Controlling thermal cycles of laser cladding, it is possible to obtain a clad coating made of high-speed steel having the structure of high-alloy austenite-martensite mixture with disperse inclusions of carbides up to 10 mm thick, i.e., it is actually possible to create bimetal structures. The wear resistance of the laser-clad self-fluxing PG-10N-01 (Ni-Cr-B-Si-C) alloy increases by a factor of 5 due to addi-tional hardening by cast tungsten carbide (WC) with spherical particles. As a result, it becomes higher than the wear resistance of high-speed steel by more than a factor of 3.

  13. Study on dry friction and wear resistance of a WC-Co particle reinforced iron matrix composite material

    Directory of Open Access Journals (Sweden)

    Zhang Peng

    2013-05-01

    Full Text Available In order to select a suitable material for the rolling mill guide application, the dry sliding friction and wear resistance of a tungsten carbide combining cobalt (WC-Co particle reinforced chromium cast iron composite material were studied. In particular, the wear resistance was discussed in detail. The results showed that the composite material demonstrates 25 times the wear resistance of high Cr cast iron, and 9 times the wear resistance of heat resistant steel. However, the average friction factor in the stable friction stage showed a relationship of μComposites/45 # steel > μHigh chromium cast iron/45 # steel > μHeat resistant steel/45 # steel. The wear resistance mechanism of the composite material was associated with the reinforcing particles, which protruded from the worn surface to bear the friction load when the matrix material surface was worn, thereby reducing the abrasive and adhesive wear. In addition, the matrix material possessed suitable hardness and toughness, providing a support to the reinforcements.

  14. High performance corrosion and wear resistant composite titanium nitride layers produced on the AZ91D magnesium alloy by a hybrid method

    Directory of Open Access Journals (Sweden)

    Michał Tacikowski

    2014-09-01

    Full Text Available Composite, diffusive titanium nitride layers formed on a titanium and aluminum sub-layer were produced on the AZ91D magnesium alloy. The layers were obtained using a hybrid method which combined the PVD processes with the final sealing by a hydrothermal treatment. The microstructure, resistance to corrosion, mechanical damage, and frictional wear of the layers were examined. The properties of the AZ91D alloy covered with these layers were compared with those of the untreated alloy and of some engineering materials such as 316L stainless steel, 100Cr6 bearing steel, and the AZ91D alloy subjected to commercial anodizing. It has been found that the composite diffusive nitride layer produced on the AZ91D alloy and then sealed by the hydrothermal treatment ensures the corrosion resistance comparable with that of 316L stainless steel. The layers are characterized by higher electrochemical durability which is due to the surface being overbuilt with the titanium oxides formed, as shown by the XPS examinations, from titanium nitride during the hydrothermal treatment. The composite titanium nitride layers exhibit high resistance to mechanical damage and wear, including frictional wear which is comparable with that of 100Cr6 bearing steel. The performance properties of the AZ91D magnesium alloy covered with the composite titanium nitride coating are substantially superior to those of the alloy subjected to commercial anodizing which is the dominant technique employed in industrial practice.

  15. The Use of Nitriding to Enhance Wear Resistance of Cast Irons and 4140 Steel

    Science.gov (United States)

    Yang, Zaidao

    This research is focused on using nitriding to enhance the wear resistance of austempered ductile iron (ADI), ductile iron (DI), and gray iron (GI), and 4140 steel. Three gas nitriding processes, namely "Gas nitriding + nitrogen cooled down to 800°F (Blue)", "Gas nitriding + cooled down to 300°F (Gray)", and "Gas nitriding + oil quenched (Oil)" were used for the cast irons. Three salt bath nitriding processes, namely Isonite, QP (Quench, Polish) and QPQ (Quench, Polish, Quench) were used for the 4140 steel. This study was carried out through optical metallography, roughness measurements, microhardness, and SEM. The ball-on-disc wear tests were conducted under lubricated conditions. It was found that COF for all materials in all nitrided conditions was small (<0.045). The best wear performance was seen for ADI processed using the Gray and Oil gas nitriding processes. For the 4140 steel, The surface microhardness of the ISONITE specimen was around 1400HV. QP and QPQ processes produce a surface microhardness of 2000-2200HV, which suggests that they may show improved wear behaviour compared to ISONITE- treated steels.

  16. Improve Wear Resistance on Al 332 Alloy Matrix- Micro -Nano Al2O3 Particles Reinforced Composite

    Directory of Open Access Journals (Sweden)

    Rawnaq Ahmed Mohamed

    2014-03-01

    Full Text Available The wear behavior of alumina particulate reinforced A332 aluminium alloy composites produced by a stir casting process technique were investigated. A pin-on-disc type apparatus was employed for determining the sliding wear rate in composite samples at different grain size (1 µm, 12µm, 50 nm and different weight percentage (0.05-0.1-0.5-1 wt% of alumina respectively. Mechanical properties characterization which strongly depends on microstructure properties of reinforcement revealed that the presence of ( nano , micro alumina particulates lead to simultaneous increase in hardness, ultimate tensile stress (UTS, wear resistances. The results revealed that UTS, Hardness, Wear resistances increases with the increase in the percentage of reinforcement of Al2O3 when compared to the base alloy A332. The wear rates of the composites were considerably less than that of the aluminum alloy at all applied loads with increasing percentage of reinforcement when compared to the base alloy A332.

  17. THE USE OF THE METHOD OF SIMULATION MODELING TO ESTIMATE THE EFFECT OF STRUCTURE PARAMETERS ON THE WEAR RESISTANCE OF THE BEARINGS OF THE MOTORS OF ELECTRIC LOCOMOTIVES

    Directory of Open Access Journals (Sweden)

    Т. M. Meshcheriakova

    2008-03-01

    Full Text Available A method of structure simulation was used to investigate the influence of the hard phase quantity on parameters of the wear resistance of antifriction alloy B16. A method of optimization of linear intensity of wear depending on the quantitative correlation between the structural components is developed; the calculation data obtained correlate with the results of the wear resistance tests.

  18. Wear-Resistant Alloy for Protection of Contact Surfaces of Working Aircraft Engine Blades from Oxidation at High Temperatures

    Directory of Open Access Journals (Sweden)

    Cherepova, T.S.

    2014-07-01

    Full Text Available Wear-resistant and heat-resistant cast cobalt-based alloy for hardening of the contact surfaces of working blades of aircraft gas turbine engines instead of commercial alloys ХТН-61 and ВЖЛ-2 was developed. High levels of heat resistance were achieved by complex doping (modification of the alloy. Based on studies of heat resistance, wear resistance, the structure and melting point of the alloys, the optimum chemical and phase composition of the developed alloy was defined.

  19. Improvement of Scratch and Wear Resistance of Polymers by Fillers Including Nanofillers

    Directory of Open Access Journals (Sweden)

    Witold Brostow

    2017-03-01

    Full Text Available Polymers have lower resistance to scratching and wear than metals. Liquid lubricants work well for metals but not for polymers nor for polymer-based composites (PBCs. We review approaches for improvement of tribological properties of polymers based on inclusion of fillers. The fillers can be metallic or ceramic—with obvious consequences for electrical resistivity of the composites. Distinctions between effectiveness of micro- versus nano-particles are analyzed. For example, aluminum nanoparticles as filler are more effective for property improvement than microparticles at the same overall volumetric concentration. Prevention of local agglomeration of filler particles is discussed along with a technique to verify the prevention.

  20. Improvement of Scratch and Wear Resistance of Polymers by Fillers Including Nanofillers.

    Science.gov (United States)

    Brostow, Witold; Lobland, Haley E Hagg; Hnatchuk, Nathalie; Perez, Jose M

    2017-03-16

    Polymers have lower resistance to scratching and wear than metals. Liquid lubricants work well for metals but not for polymers nor for polymer-based composites (PBCs). We review approaches for improvement of tribological properties of polymers based on inclusion of fillers. The fillers can be metallic or ceramic-with obvious consequences for electrical resistivity of the composites. Distinctions between effectiveness of micro- versus nano-particles are analyzed. For example, aluminum nanoparticles as filler are more effective for property improvement than microparticles at the same overall volumetric concentration. Prevention of local agglomeration of filler particles is discussed along with a technique to verify the prevention.

  1. Plasma powder coating of rods of hydraulic cylinders with white wear resistance cast iron

    Directory of Open Access Journals (Sweden)

    S. P. Nefedyev

    2014-01-01

    Full Text Available The article considers the features to form a structure and properties of Fe-C-Cr-V system coverings provided by the plasma and powder coating (build-up on the low carbon steel.It is shown that it is possible to restore a rod of hydraulic cylinders of small diameter by the plasma and powder coating. Thus, to avoid buckling and provide the built-up metal structure with the best wear resistance it is necessary to find a reasonable approach to a choice of the operation conditions to provide coating.The paper offers a way for efficient control of heat input at coating and a superheat value of the welding bath. It is noted that the coverings, which have been built up at the smallest heat input in a substrate, possess the best wear resistance, with a fusion zone formed with an austenitic crystallization interlayer.The paper defines consistent patterns to form a structure of coverings under various operation conditions of a plasma and powder coating. It shows the influence of the cooling speed after built-up metal crystallization on the formation of covering structure components.The paper formulates requirements for operation conditions of plasma and powder coating to provide coverings to be subjected to shock and abrasive wear, and shows the influence of additional heat treatment on formation of structure and properties of the built-up metal.The article under review meets available lacks in studying high-carbon chrome-vanadium coverings and is useful for scientists, graduates, and students investigating the wear resistance coating materials and effective methods for their deposition.

  2. Influence of processing parameters on microstructure and wear resistance of Ti+TiC laser clad layer on titanium alloy

    Institute of Scientific and Technical Information of China (English)

    WU Wan-liang; SUN Jian-feng; DONG Sheng-min; LIU Rongx-iang

    2006-01-01

    Laser cladding experiments were carried out on Ti-6Al-4V alloy with Ti+33%TiC(volume fraction) powders. Laser processing parameters were studied systematically to investigate the influences on the surface quality. Microstructure, microhardness and wear resistance of the clad layer were evaluated. The results show that the laser parameter has considerable influence on microstructure and wear resistance of laser clad layer. With the optimized technical parameters, a clad layer with good surface quality and uniform microstructure was obtained. The microhardness of the clad layer HV0.2 is 1 080, and the wear rate is reduced by 57 times.

  3. The Tribological Performance of Hardfaced/ Thermal Sprayed Coatings for Increasing the Wear Resistance of Ventilation Mill Working Parts

    Directory of Open Access Journals (Sweden)

    A. Vencl

    2015-09-01

    Full Text Available During the coal pulverizing, the working parts of the ventilation mill are being worn by the sand particles. For this reason, the working parts are usually protected with materials resistant to wear (hardfaced/thermal sprayed coatings. The aim of this study was to evaluate the tribological performance of four different types of coatings as candidates for wear protection of the mill’s working parts. The coatings were produced by using the filler materials with the following nominal chemical composition: NiFeBSi-WC, NiCrBSiC, FeCrCTiSi, and FeCrNiCSiBMn, and by using the plasma arc welding and flame and electric arc spraying processes. The results showed that Ni-based coatings exhibited higher wear resistance than Fe-based coatings. The highest wear resistance showed coating produced by using the NiFeBSi-WC filler material and plasma transferred arc welding deposition process. The hardness was not the only characteristic that affected the wear resistance. In this context, the wear rate of NiFeBSi-WC coating was not in correlation with its hardness, in contrast to other coatings. The different wear performance of NiFeBSi-WC coating was attributed to the different type and morphological features of the reinforcing particles (WC.

  4. A nanometric cushion for enhancing scratch and wear resistance of hard films.

    Science.gov (United States)

    Gotlib-Vainshtein, Katya; Girshevitz, Olga; Sukenik, Chaim N; Barlam, David; Cohen, Sidney R

    2014-01-01

    Scratch resistance and friction are core properties which define the tribological characteristics of materials. Attempts to optimize these quantities at solid surfaces are the subject of intense technological interest. The capability to modulate these surface properties while preserving both the bulk properties of the materials and a well-defined, constant chemical composition of the surface is particularly attractive. We report herein the use of a soft, flexible underlayer to control the scratch resistance of oxide surfaces. Titania films of several nm thickness are coated onto substrates of silicon, kapton, polycarbonate, and polydimethylsiloxane (PDMS). The scratch resistance measured by scanning force microscopy is found to be substrate dependent, diminishing in the order PDMS, kapton/polycarbonate, Si/SiO2. Furthermore, when PDMS is applied as an intermediate layer between a harder substrate and titania, marked improvement in the scratch resistance is achieved. This is shown by quantitative wear tests for silicon or kapton, by coating these substrates with PDMS which is subsequently capped by a titania layer, resulting in enhanced scratch/wear resistance. The physical basis of this effect is explored by means of Finite Element Analysis, and we suggest a model for friction reduction based on the "cushioning effect" of a soft intermediate layer.

  5. Development of New Wear-Resistant Surface Coating at Elevated Temperature

    Institute of Scientific and Technical Information of China (English)

    LI Shang-ping; FENG Di; LUO He-li; ZHANG Xi-e; CAO Xu

    2006-01-01

    Because of good oxidation resistance at high temperature and excellent mechanical properties of Ni3Al and high hot hardness, and good oxidation resistance of chromium carbide, chromium carbide particle reinforced Ni3Al matrix composite would possess excellent wear resistance at elevated temperature. Cr3C2-NiAl-Ni welding wire was produced by pressureless sintering process in vacuum. When the welding wire was welded on the surface of carbon steel, under the action of the physical heat of arc, NiAl reacted with nickel to form Ni3Al and carbide particle reinforced Ni3Al matrix composite was formed on the welding layers. Cr3C2 was dissolved during welding and dispersed Cr7C3 was formed, which strengthened the Ni3Al matrix significantly. The Cr7C3-Ni3Al interface was broadened, and a zone of interdiffusion and a new phase M23C6 were formed, indicating that a good bond has been formed. The hardness of Cr7C3/Ni3Al composite at room and elevated temperatures is much higher than that of stellite alloys. In addition, Cr7C3/Ni3Al composite possesses better high temperature oxidation resistance than stellite 12 alloy. So Cr7C3/ Ni3Al composite can become an attractive potential candidate for elevated temperature wear-resistant surface material.

  6. Transparent, superhydrophobic, and wear-resistant surfaces using deep reactive ion etching on PDMS substrates.

    Science.gov (United States)

    Ebert, Daniel; Bhushan, Bharat

    2016-11-01

    Surfaces that simultaneously exhibit superhydrophobicity, low contact angle hysteresis, and high transmission of visible light are of interest for many applications, such as optical devices, solar panels, and self-cleaning windows. Superhydrophobicity could also find use in medical devices where antifouling characteristics are desirable. These applications also typically require mechanical wear resistance. The fabrication of such surfaces is challenging due to the competing goals of superhydrophobicity and transmittance in terms of the required degree of surface roughness. In this study, deep reactive ion etching (DRIE) was used to create rough surfaces on PDMS substrates using a O2/CF4 plasma. Surfaces then underwent an additional treatment with either octafluorocyclobutane (C4F8) plasma or vapor deposition of perfluorooctyltrichlorosilane (PFOTCS) following surface activation with O2 plasma. The effects of surface roughness and the additional surface modifications were examined with respect to the contact angle, contact angle hysteresis, and optical transmittance. To examine wear resistance, a sliding wear experiment was performed using an atomic force microscope (AFM).

  7. Wear Resistance and Structure of Electrodeposited RE-Ni-W-P-SiC-PTFE Composite Materials

    Institute of Scientific and Technical Information of China (English)

    GuoZhongcheng; ZhuXiaoyun; YangXianwan

    2004-01-01

    Effects of heat treatment temperature and time on hardness and wear resistance of RE-Ni-W-P-SiC-PTFE and RE-Ni-W-P-SiC composite coatings were studied. The results indicated that the hardness of the composite coatings as-deposited was lower and the mass loss (i.e. rate of abrasion) was higher, while the hardness increased and the rate of abrasion decreased with the increase of heat treatment temperature. The rate of abrasion was the lowest and hardness was the highest at 400℃ . The hardness decreased and the rate of abrasion increased with the temperature increasing continuously. Both the hardness and wear resistance also increased with the prolongation of heat treatment time, reaching their peak values when the heat treatment time was 2 h. The experimental results also showed that the hardness of the coatings decreased with PTFE quantity enhancing, but the wear rate diminished correspondingly. X-ray diffraction analysis indicated that the structure of RE-Ni-W-P-SiC-PTFE composite coating as-deposited is amorphous, and it partly became crystal when heat treatment temperature was over 3000℃.

  8. Recycled Aluminium Cans/Eggshell Composites: Evaluation of Mechanical and Wear Resistance Properties

    Directory of Open Access Journals (Sweden)

    J.O. Agunsoye

    2015-03-01

    Full Text Available Aluminium based metal matrix composites have been produced from recycled aluminium cans and 150µm sized eggshell particles using a stir cast process. The mechanical properties of the control and aluminium can/eggshell composites produced have been investigated. The microstructures of the aluminium can/eggshell composites were examined with the aids of Scanning Electron Microscope (SEM after the sample surfaces have been carefully prepared and etched with aqueous solution of 0.5 cm3 nitric acid. Micrographs revealed that there was a homogenous distribution of eggshell particles within the aluminium can matrix. An indication of effective stirring action during the melting process. The wear resistance was also investigated under different applied loads (6 to 14 N on an abrasive surface emery paper of grade 220. The results revealed an increase in Young’s modulus of elasticity and yield stress from 1,206.45 and 50.23 Mpa respectively of the cast aluminium can with 0 % eggshell particle to the maximum of 3,258.87and 73.2 MPa of aluminium can/12 % eggshell composites. The hardness values increased from 66.23 to 75.13 VN. There was a gradual increase in wear rate of the tested samples as the applied load increased. However, the wear resistance of the aluminium can/6 % eggshell and aluminium can/12 % eggshell composites increased significantly. Hence, recycling of aluminium cans and eggshells can be harnessed into development of useful engineering metal matrix composite materials.

  9. Microstructure and Wear Resistance of Laser Clad Cobalt-Based Alloy/SiCp Composite Coating

    Institute of Scientific and Technical Information of China (English)

    LI Ming-xi; SI Song-hua; HE Yi-zhu; SUN Guo-xiong

    2004-01-01

    The SiCp (20 %) reinforced cobalt-based alloy composite coatings deposited by laser cladding on IF steel were introduced. The microstructure across the whole section of such coatings was examined using optical microscope, scanning electron microscope (SEM) and X-ray diffractometer (XRD), and the wear resistance of the coatings was measured by MM-200 type wear testing machine. The results show that the SiCp is completely dissolved during laser cladding and the primary phase in the coatings is γ-Co. The other phases, such as Si2W, CoWSi, Cr3Si and CoSi2, are formed by carbon, silicon reacting with other elements existing in the melting pool. There are various crystallization morphologies in different zones, such as planar crystallization at the interface, followed by cellular and dendrite crystallization from interface to the surface. The direction of solidification changes from one direction perpendicular to interface to multi-directions at the central and upper regions of the clad. The wear resistance of the clad is improved by adding SiCp.

  10. Wear Resistance and Mechanical Behaviour of Epoxy/Mollusk Shell Biocomposites developed for Structural Applications

    Directory of Open Access Journals (Sweden)

    I.O. Oladele

    2016-09-01

    Full Text Available Epoxy resin is one of the strongest commercially exploitable thermosetting polymers in the polymer family; however its expensive nature in comparison with other thermosetting polymers such as vinylester and polyester limits its applications as a structural material. Inexpensive fillers on the other hand, especially those derived from agro-industrial wastes are very important in reducing the overall cost of polymer composites and furthermore influential in enhancing some of their engineering properties. In the present study, the wear resistance and mechanical behaviour of epoxy polymer matrix filled with <75 and 75 μm calcined particles of African land snail shells have been comparatively investigated. The wear resistance and the mechanical behaviour of the composites were studied via Taber Abraser and INSTRON universal testing machine. Also, the elemental constituents of the calcined snail shell and the epoxy biocomposites were characterized by X-Ray Fluorescence Spectroscopy and Scanning Electron Microscopy/Energy Dispersion Spectroscopy. From the experimental results, it was observed that, at the highest filler loading, smaller particle size presented a biocomposite with significant enhancement in wear and mechanical properties. However, it was also observed that increase in particle size showed no significant enhancement in the mechanical properties of the biocomposites.

  11. Development of wear-resistant ceramic coatings for diesel engine components

    Energy Technology Data Exchange (ETDEWEB)

    Naylor, M.G.S. (Cummins Engine Co., Inc., Columbus, IN (United States))

    1992-06-01

    The tribological properties of a variety of advanced coating materials have been evaluated under conditions which simulate the piston ring -- cylinder liner environment near top ring reversal in a heavy duty diesel engine. Coated ring'' samples were tested against a conventional pearlitic grey cast iron liner material using a high temperature reciprocating wear test rig. Tests were run with a fresh CE/SF 15W40lubricant at 200 and 350{degrees}C, with a high-soot, engine-tested oil at 200{degrees}C and with no lubrication at 200{degrees}C. For lowest wear under boundary lubricated conditions, the most promising candidates to emerge from this study were high velocity oxy-fuel (HVOF) Cr{sub 3} C{sub 2} - 20% NiCr and WC - 12% Co cermets, low temperature arc vapor deposited (LTAVD) CrN and plasma sprayed chromium oxides. Also,plasma sprayed Cr{sub 2}O{sub 3} and A1{sub 2}O{sub 3}-ZrO{sub 2} materials were found to give excellent wear resistance in unlubricated tests and at extremely high temperatures (450{degrees}C) with a syntheticoil. All of these materials would offer substantial wear reductions compared to the conventional electroplated hard chromium ring facing and thermally sprayed metallic coatings, especially at high temperatures and with high-soot oils subjected to degradation in diesel environments. The LTAVD CrN coating provided the lowest lubricated wear rates of all the materials evaluated, but may be too thin (4 {mu}m) for use as a top ring facing. Most of the coatings evaluated showed higher wear rates with high-soot, engine-tested oil than with fresh oil, with increases of more than a factor of ten in some cases. Generally, metallic materials were found to be much more sensitive to soot/oil degradation than ceramic and cermet coatings. Thus, decreased soot sensitivity'' is a significant driving force for utilizing ceramic or cermet coatings in diesel engine wear applications.

  12. Influence of the layer architecture of DLC coatings on their wear and corrosion resistance

    Energy Technology Data Exchange (ETDEWEB)

    Bobzin, Kirsten; Bagcivan, Nazlim; Theiss, Sebastian; Weiss, Raphael [RWTH Aachen (Germany). Inst. fuer Oberflaechentechnik; Depner, Udo; Trossmann, Torsten; Ellermeier, Joerg; Oechsner, Matthias [Technische Univ. Darmstadt (Germany). Inst. fuer Werkstoffkunde

    2012-06-15

    In this work, the influence of diamond-like carbon top layers deposited on two different types of layer architecture on wear and corrosion resistance is investigated. Physical vapour deposition coatings with a-C:H top layer of various thicknesses were deposited on plasma nitrided 42CrMo4 by reactive magnetron sputter ion plating. Beneath the top layer, an architecture with and without a-C interlayers was deposited. Investigations using potentiodynamic polarisation testing in artificial seawater as well as an impact tribometer show that it is possible to protect low-alloy heat treatable steel from both corrosion and wear by using pretreatment and an appropriate diamond-like carbon coating. Thicker a-C:H top layers as well as the addition of a-C interlayers resulted in an overall improvement in the coating behaviour. (orig.)

  13. Wear resistant PTFE thin film enabled by a polydopamine adhesive layer

    Energy Technology Data Exchange (ETDEWEB)

    Beckford, Samuel [Microelectronics-Photonics Graduate Program, University of Arkansas, Fayetteville, AR 72701 (United States); Zou, Min, E-mail: mzou@uark.edu [Department of Mechanical Engineering, University of Arkansas, 863 West Dickson Street, Fayetteville, AR 72701 (United States); Institute for Nanoscience and Engineering, University of Arkansas, Fayetteville, AR 72701 (United States)

    2014-02-15

    The influence of a polydopamine (PDA) adhesive layer on the friction and wear resistance of polytetrafluoroethylene (PTFE) thin films coated on stainless steel was investigated. The friction and wear tests were carried out using a ball on flat configuration under a normal load of 50 g, sliding speed of 2.5 mm/s, and stroke length of 15 mm. It is found that the PDA/PTFE film is able to withstand approximately 500 times more rubbing cycles than the PTFE film alone. X-ray photoelectron spectroscopy (XPS) results show that a tenacious layer of PTFE remains adhered to the PDA layer, which enables the durability of the PDA/PTFE film. Because of the relatively low thickness of the film, PDA/PTFE shows great potential for use in applications where durable, thin films are desirable.

  14. Wear-resistance and anti-scuffing of multi-arc ion plating molybdenum films

    Institute of Scientific and Technical Information of China (English)

    WANG Hai-dou; XU Bin-shi; LIU Jia-jun; ZHUANG Da-ming

    2004-01-01

    The multi-arc ion plating technology was employed to prepare the molybdenum films with thickness of 3 μm on the AISI 1045 steel. The wear and scuffing tests were carried out on the ball-on-disc tester. AFM and SEM equipped with EDS were adopted to observe and analyze the morphologies and element compositions of surface,cross-section and worn scar of the Mo film. The phase structure was studied by XRD and the bonding strength between Mo film and substrate was measured by scratching tester. The tribological experiments show that the Mo film possesses a good wear-resistance and an excellent anti-scuffing property. The failure mechanism of Mo film under extreme condition is flaking off.

  15. Investigations of the effects of particle properties on the wear resistance of the particle reinforced composites using a novel wear model

    Science.gov (United States)

    Prabhu, T. Ram

    2016-08-01

    A wear model is developed based on the discrete lattice spring-mass approach to study the effects of particle volume fraction, size, and stiffness on the wear resistance of particle reinforced composites. To study these effects, we have considered three volume fractions (10%, 20% and 30%), two sizes (10 × 10 and 4 × 4 sites), and two different stiffness of particles embedded in the matrix in a regular pattern. In this model, we have discretized the composite system (400 × 100 sites) into the lumped masses connected with interaction spring elements in two dimensions. The interaction elements are assumed as linear elastic and ideal plastic under applied forces. Each mass is connected to its first and second nearest neighbors by springs. The matrix and particles sites are differentiated by choosing the different stiffness values. The counter surface is simulated as a rigid body that moves on the composite material at a constant sliding speed along the horizontal direction. The governing equations are formed by equating the spring force between the pair of sites given by Hooke’s law plus external contact forces and the force due to the motion of the site given by the equation of motion. The equations are solved for the plastic strain accumulated in the springs using an explicit time stepping procedure based on a finite difference form of the above equations. If the total strain accumulated in the spring elements connected to a lump mass site exceeds the failure strain, the springs are considered to be broken, and the mass site is removed or worn away from the lattice and accounts as a wear loss. The model predicts that (i) increasing volume fraction, reducing particle size and increasing particle stiffness enhance the wear resistance of the particle reinforced composites, (ii) the particle stiffness is the most significant factor affecting the wear resistance of the composites, and (iii) the wear resistance reduced above the critical volume fraction (Vc), and Vc

  16. Enhanced wear and corrosion resistance of plasma electrolytic carburized layer on T8 carbon steel

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Jie; Wang, Bin; Zhang, Yifan; Liu, Run [Key Laboratory for Beam Technology and Materials Modification of Ministry of Education, College of Nuclear Science and Technology, Beijing Normal University, Beijing 100875 (China); Beijing Radiation Center, Beijing 100875 (China); Xia, Yuan; Li, Guang [Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190 (China); Xue, Wenbin, E-mail: xuewb@bnu.edu.cn [Key Laboratory for Beam Technology and Materials Modification of Ministry of Education, College of Nuclear Science and Technology, Beijing Normal University, Beijing 100875 (China); Beijing Radiation Center, Beijing 100875 (China)

    2016-03-01

    A hardening layer of 70 μm on T8 carbon steel was fabricated by plasma electrolytic carburizing (PEC) in glycerol solution at 380 V with 3 min treatment. The discharge process was characterized using optical emission spectroscopy (OES), and the electron temperature in plasma envelope was determined. Meanwhile, diffusion coefficient of carbon was calculated on the basis of carbon concentration profile. The tribological property of carburized steel under dry sliding against ZrO{sub 2} ball was measured by a ball-disc friction and wear tester. The corrosion behaviors were evaluated by potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). It was found that the carburized layer mainly contained α-Fe and Fe{sub 3}C phases with maximum hardness of 620 HV. The PEC treatment significantly decreased the friction coefficient from 0.4 to 0.1. The wear rate of PEC treated steel was about 5.86 × 10{sup −6} mm{sup 3}/N·m, which was less than 1/4 of T8 steel substrate. After PEC treatment, the wear and corrosion resistance of T8 steel were improved. Particularly, the pitting corrosion of steel substrate was obviously suppressed. - Highlights: • Electron temperature in plasma electrolytic carburizing process is determined. • Diffusion coefficient of carbon in PEC is higher than conventional carburizing. • Wear and corrosion resistance of T8 steel are both improved after PEC treatment. • Pitting corrosion of steel substrate is obviously suppressed by PEC treatment.

  17. Inventions in the nanotechnological area considerably increase wear- and chemical resistance of construction products

    Directory of Open Access Journals (Sweden)

    VLASOV Vladimir Alexeevich

    2014-08-01

    Full Text Available The invention «Reinforced flaked element made of natural or conglomerate stone and its multilayer protective coating (RU 2520193» is referred to construction materials. Reinforced flaked element made of natural or conglomerate stone consists of: natural or conglomerate materials as the basis; multilayer coating which protects the mentioned basis from chemical substances and wearing mechanical factors influencing on this element where the multilayer coating includes at least three layers formed by one or many film-forming compositions which comprise top layer with scratch-resistant nanoparticles and encircled with polyester, melamine, phenolic, acryl or epoxy resin (or any combination of them which provides protection against scratches; damper intermediate layer made of epoxy and/or acryl resin which provides impact resistant; lower layer adjoining to the basis and containing particles of Al2O3 or silicon carbide plus acryl polymer and providing resistance to abrasive wear. Technical result is increased wear- and chemical resistance of flaked elements from natural or conglomerate materials. The invention «Fine organic suspension of carbon metal-containing nanostructures and the method to produce it (RU 2515858» is referred to the area of physical and colloid chemistry and can be used to obtain polymer compositions. Fine organic suspension of carbon metal-containing nanostructures is produced by interaction between nanostructures and polyethylenepolyamine. At first the powder of carbon metalcontaining nanostructures (which are nanoparticles of 3d-metal such as copper, cobalt, nickel stabilized in carbon nanostructures is mechanically milled, then it is mechanically ground with polyethylenepolyamine introduced portionally unless and until the content of nanostructures is less 1 g/ml. The invention results in decreased power inputs as the obtained fine organic suspension of carbon and metal-containing nanostructures is able to recover due to

  18. Wear Resistance Analysis of A359/SiC/20p Advanced Composite Joints Welded by Friction Stir Welding

    Directory of Open Access Journals (Sweden)

    O. Cuevas Mata

    Full Text Available Abstract Advancement in automotive part development demands new cost-effective materials with higher mechanical properties and improved wear resistance as compared to existing materials. For instance, Aluminum Matrix Composites (AMC shows improved mechanical properties as wear and abrasion resistance, high strength, chemical and dimensional stability. Automotive industry has focused in AMC for a variety of applications in automotive parts in order to improve the fuel economy, minimize vehicle emissions, improve design options, and increase the performance. Wear resistance is one of the most important factors in useful life of the automotive components, overall in those components submitted to mechanical systems like automotive brakes and suspensions. Friction Stir Welding (FSW rises as the most capable process to joining AMC, principally for the capacity to weld without compromising their ceramic reinforcement. The aim of this study is focused on the analysis of wear characteristics of the friction-stir welded joint of aluminum matrix reinforced with 20 percent in weight silicon carbide composite (A359/SiC/20p. The experimental procedure consisted in cut samples into small plates and perform three welds on these with a FSW machine using a tool with 20 mm shoulder diameter and 8 mm pin diameter. The wear features of the three welded joints and parent metal were analyzed at constant load applying 5 N and a rotational speed of 100 rpm employing a Pin-on - Disk wear testing apparatus, using a sapphire steel ball with 6 mm diameter. The experimental results indicate that the three welded joints had low friction coefficient compared with the parent metal. The results determine that the FSW process parameters affect the wear resistance of the welded joints owing to different microstructural modifications during welding that causes a low wear resistance on the welded zone.

  19. High Density Infrared (HDI) Transient Liquid Coatings for Improved Wear and Corrosion Resistance

    Energy Technology Data Exchange (ETDEWEB)

    Ronald W. Smith

    2007-07-05

    This report documents a collaborative effort between Oak Ridge National Laboratory (ORNL), Materials Resources International and an industry team of participants to develop, evaluate and understand how high density infrared heating technology could be used to improve infiltrated carbide wear coatings and/or to densify sprayed coatings. The research included HDI fusion evaluations of infiltrated carbide suspensions such (BrazeCoat® S), composite suspensions with tool steel powders, thermally sprayed Ni-Cr- B-Si (self fluxing alloy) and nickel powder layers. The applied work developed practical HDI / transient liquid coating (TLC) procedures on test plates that demonstrated the ability to fuse carbide coatings for industrial applications such as agricultural blades, construction and mining vehicles. Fundamental studies helped create process models that led to improved process understanding and control. The coating of agricultural blades was demonstrated and showed the HDI process to have the ability to fuse industrial scale components. Sliding and brasive wear tests showed that high degree of wear resistance could be achieved with the addition of tool steel powders to carbide particulate composites.

  20. High Density Infrared (HDI) Transient Liquid Coatings for Improved Wear and Corrosion Resistance

    Energy Technology Data Exchange (ETDEWEB)

    Ronald W. Smith

    2007-07-05

    This report documents a collaborative effort between Oak Ridge National Laboratory (ORNL), Materials Resources International and an industry team of participants to develop, evaluate and understand how high density infrared heating technology could be used to improve infiltrated carbide wear coatings and/or to densify sprayed coatings. The research included HDI fusion evaluations of infiltrated carbide suspensions such (BrazeCoat® S), composite suspensions with tool steel powders, thermally sprayed Ni-Cr- B-Si (self fluxing alloy) and nickel powder layers. The applied work developed practical HDI / transient liquid coating (TLC) procedures on test plates that demonstrated the ability to fuse carbide coatings for industrial applications such as agricultural blades, construction and mining vehicles. Fundamental studies helped create process models that led to improved process understanding and control. The coating of agricultural blades was demonstrated and showed the HDI process to have the ability to fuse industrial scale components. Sliding and brasive wear tests showed that high degree of wear resistance could be achieved with the addition of tool steel powders to carbide particulate composites.

  1. Low friction and wear resistant coating systems on Ti6Al4V alloy

    Directory of Open Access Journals (Sweden)

    B.G. Wendler

    2008-02-01

    Full Text Available Purpose: Development of an original multiplex hybrid treatment of Ti6Al4V alloy: diffusion hardening+intermediate hard gradient TiCxNy layer with use of continuous CAE+top low friction and wear resistant hard amorphous a-C layer with use of pulsed CAE method.Design/methodology/approach: Ti6Al4V substrates were diffusion hardened with interstitial O or N atoms with use of glow discharge plasma in the atmosphere Ar+O2 or Ar+N2. Next they were deposited with a hard gradient TiCxNy layer and with a hard amorphous a-C coating as the top one. The morphology, microstructure, chemical and phase composition, chemical bonds, microhardness and tribological properties during dry friction of the alloy after multiplex treatment have been investigated with use of SEM, EDS, XRD, XPS, Vickers diamond indenter and ball-on-plate test.Findings: An important increase of hardness of the near surface zone of the Ti6Al4V alloy has been achieved (from ~350VHN to ~1000 VHN, good adhesion between the gradient TiCxNy coating and the Ti6Al4V substrate as well as an important decrease of dry friction coefficient (down to ~0.15 and a substantial increase of the resistance to wear (up to two orders of magnitude in comparison with non treated Ti alloy.Research limitations/implications: The research will be continued on greater number of specimens and against other counterbodies.Practical implications: It looks like that the Ti alloys can be used as mobile parts of machines due to high resistance to wear and low friction.Originality/value: A novel original multiplex hybrid treatment of Ti alloys has been developed at the Lodz University of Technology.

  2. Improving the corrosion wear resistance of AISI 316L stainless steel by particulate reinforced Ni matrix composite alloying layer

    Energy Technology Data Exchange (ETDEWEB)

    Xu Jiang; Zhuo Chengzhi; Tao Jie; Liu Linlin [Department of Material Science and Engineering, Nanjing University of Aeronautics and Astronautics, 29 Yudao Street, Nanjing 210016 (China); Jiang Shuyun [Department of Mechanical Engineering, Southeast University, 2 Sipailou, Nanjing 210096 (China)], E-mail: xujiang73@nuaa.edu.cn

    2009-01-07

    In order to overcome the problem of corrosion wear of AISI 316L stainless steel (SS), two kinds of composite alloying layers were prepared by a duplex treatment, consisting of Ni/nano-SiC and Ni/nano-SiO{sub 2} predeposited by brush plating, respectively, and subsequent surface alloying with Ni-Cr-Mo-Cu by a double glow process. The microstructure of the two kinds of nanoparticle reinforced Ni-based composite alloying layers was investigated by means of SEM and TEM. The electrochemical corrosion behaviour of composite alloying layers compared with the Ni-based alloying layer and 316L SS under different conditions was characterized by potentiodynamic polarization test and electrochemical impedance spectroscopy. Results showed that under alloying temperature (1000 deg. C) conditions, amorphous nano-SiO{sub 2} particles still retained the amorphous structure, whereas nano-SiC particles were decomposed and Ni, Cr reacted with SiC to form Cr{sub 6.5}Ni{sub 2.5}Si and Cr{sub 23}C{sub 6}. In static acidic solution, the corrosion resistance of the composite alloying layer with the brush plating Ni/nano-SiO{sub 2} particles interlayer is lower than that of the Ni-based alloying layer. However, the corrosion resistance of the composite alloying layer with the brush plating Ni/nano-SiO{sub 2} particles interlayer is prominently superior to that of the Ni-based alloying layer under acidic flow medium condition and acidic slurry flow condition. The corrosion resistance of the composite alloying layer with the brush plating Ni/nano-SiC particles interlayer is evidently lower than that of the Ni-based alloying layer, but higher than that of 316L SS under all test conditions. The results show that the highly dispersive nano-SiO{sub 2} particles are helpful in improving the corrosion wear resistance of the Ni-based alloying layer, whereas carbides and silicide phase are deleterious to that of the Ni-based alloying layer due to the fact that the preferential removal of the matrix

  3. Effects of heat treatment on properties of multi-element low alloy wear-resistant steel

    Directory of Open Access Journals (Sweden)

    SONG Xu-ding

    2007-02-01

    Full Text Available The paper has studied the mechanical properties and heat treatment effects on multi-element low alloy wear-resistant steel (MLAWS used as a material for the liner of rolling mill torii. The results show that when quenched at 900-920℃ and tempered at 350-370℃, the MLAWS has achieved hardness above 60 HRC, tensile strength greater than 1 600 MPa, impact toughness higher than 18J/cm2 and fracture toughness greater than 37 MPa

  4. Development of a new wear resistant coating by arc spraying of a steel-based cored wire

    Institute of Scientific and Technical Information of China (English)

    Lidong ZHAO; Binyou FU; Dingyong HE; Pia KUTSCHMANN

    2009-01-01

    In the present study, a cored wire of 304 L stainless steel as sheath material and NiB and WC-12Co as filler materials was designed and deposited to produce a new wear resistant coating containing amorphous phase by arc spraying. The microstructure of the coating was investigated. The porosity and hardness of the coating were determined. The wear performance of the coating was evaluated. The XRD and TEM analyses showed that there are high volume of amorphous phase and very fine crystalline grains in the coating. DTA measurements revealed that the crystallization of the amorphous phase occurred at 579.2℃. Because metallurgical processes for single droplets were non-homogenous during spraying, the lamellae in the coating have different hardness values, which lie between about 700 and 1250HV10og. The abrasive wear test showed that the new Fe-based coating was very wear resistant.

  5. 高硼低碳耐磨合金磨料磨损性能研究%Study on Abrasive Wear Performance of High Boron Low Carbon Wear-resistant Alloy

    Institute of Scientific and Technical Information of China (English)

    麻健梅; 王顺波; 苏广才; 汤宏群

    2013-01-01

    借助光学显微镜和SEM电镜观察,运用磨损试验手段及对比研究法,研究了高硼低碳耐磨合金的磨料磨损性能.结果表明,在中、低冲击工况下,高硼低碳耐磨合金的磨损质量损失、相对磨损率均小于高铬铸铁和高锰钢,且磨面磨损形成的沟槽少,压坑小,这显示出了良好的耐磨料磨损性.%The high boron low carbon wear-resistant alloy abrasive wear performance was researched by OM, SEM observation, wear test methods and comparision approach. The results show that in the medium or low impact conditions, the wear mass loss and relative wear rate of high boron low carbon wear-resistant alloy are less than that of high chromium cast iron and high manganese steel. The number of the wear grooves and the pits on the wear surface morphology is smaller, which shows the good characteristics in abrasive wear performance of high boron low carbon wear-resistant alloy.

  6. Increasing wear resistance of copper friction pair with electrically-conductive tribological Cu-Mo-S coatings

    Science.gov (United States)

    Zharkov, S. Yu.; Sergeev, V. P.; Fedorischeva, M. V.; Sergeev, O. V.; Kalashnikov, M. P.

    2016-11-01

    The composite solid lubricant Cu-Mo-S coating was produced by pulse magnetron sputtering system. The electrical resistivity of deposited Cu-Mo-S coatings was (22.8±3) × 10-8 Ohm×m. Cu-Mo-S coatings decrease the wear rate of the copper friction pair by 38 times. The decrease in the wear rate occurs owing to the formation of a transferred film on the counterface.

  7. Formation of Structure of Wear-Resistant Steels 150KhNML and Kh12MFL Upon Quenching

    Science.gov (United States)

    Filippov, M. A.; Gervas'ev, M. A.; Plotnikov, G. N.; Zhilin, A. S.; Nikiforova, S. M.

    2016-03-01

    The effect of the temperature of heating for quenching on the content of retained austenite and its resistance to the deformation-induced martensitic transformation, the hardening capacity, and the resistance to abrasive wear are studied for high-carbon tool steels 150KhNML and Kh12MFL of pearlitic and ledeburitic classes.

  8. Effects of Alloying Elements on Microstructure, Hardness, Wear Resistance, and Surface Roughness of Centrifugally Cast High-Speed Steel Rolls

    Science.gov (United States)

    Ha, Dae Jin; Sung, Hyo Kyung; Park, Joon Wook; Lee, Sunghak

    2009-11-01

    A study was made of the effects of carbon, tungsten, molybdenum, and vanadium on the wear resistance and surface roughness of five high-speed steel (HSS) rolls manufactured by the centrifugal casting method. High-temperature wear tests were conducted on these rolls to experimentally simulate the wear process during hot rolling. The HSS rolls contained a large amount (up to 25 vol pct) of carbides, such as MC, M2C, and M7C3 carbides formed in the tempered martensite matrix. The matrix consisted mainly of tempered lath martensite when the carbon content in the matrix was small, and contained a considerable amount of tempered plate martensite when the carbon content increased. The high-temperature wear test results indicated that the wear resistance and surface roughness of the rolls were enhanced when the amount of hard MC carbides formed inside solidification cells increased and their distribution was homogeneous. The best wear resistance and surface roughness were obtained from a roll in which a large amount of MC carbides were homogeneously distributed in the tempered lath martensite matrix. The appropriate contents of the carbon equivalent, tungsten equivalent, and vanadium were 2.0 to 2.3, 9 to 10, and 5 to 6 pct, respectively.

  9. Effect of Contact Temperature Rise During Sliding on the Wear Resistance of TiNi Shape Memory Alloys

    Directory of Open Access Journals (Sweden)

    S.K. Roy Chowdhury

    2013-03-01

    Full Text Available The high wear resistance of TiNi shape memory alloys has generally been attributed to its pseudoelastic nature. In the present work the hardening effect due to its phase transformation from martensite to austenite due to frictional heating during sliding has been considered. Based on existing constitutive models that represent the experimental results of TiNi shape memory alloys a theoretical model of the dependence of wear-resistance on the contact temperature rise has been developed. The analysis was further extended to include the operating and surface roughness parameters. The model essentially indicates that for these alloys wear decreases with the rise in contact temperature over a wide range of load, speed and surface roughness combination during sliding. This means that the wear resistance of these alloys results from the very cause that is normally responsible for the increased wear and seizure of common engineering materials. Preliminary wear tests were carried out with TiNi alloys at varying ambient temperature and varying load-speed combinations and the results agree well with the theoretical predictions.

  10. The effects of manganese phosphate coating wear resistance of chilled ductile iron camshafts

    Directory of Open Access Journals (Sweden)

    Tarık Gün

    2013-06-01

    Full Text Available The ductile iron camshafts are preferred due to high toughness and strength features in the automobile industry. Through the coolants used in the camshaft production high surface hardness is achieved. In this study, the wear resistance effects of ductile iron chill produced camshafts coated with manganese phosphate are researched. The camshaft surfaces produced as ductile iron chill are coated with manganese phosphate. The coating surfaces are observed with scanning electron microscope (SEM. The changes occurring on the cam profiles are measured with running the wear resistance of the manganese phosphate coating on the camshafts on the engine test rig with 30 minutes interval in 1000rpm. In order to compare the results of uncoated camshafts run on engines are checked against simultaneously. As result, the manganese phosphate coated cams were 2,8 times less worn up than the uncoated cams. The manganese phosphate coated ductile iron chill camshafts are less worn up according to uncoated camshafts because of the oil holding feature of manganese phosphate coating.

  11. Microstructure and Wear Resistance of Chromium Carbide Coating IN SITU Synthesized by VEB

    Science.gov (United States)

    Lu, Binfeng; Li, Liping; Lu, Fenggui; Tang, Xinhua

    2014-08-01

    In this paper, (Cr, Fe)7C3(M7C3)/γ-Fe composite layer has been in situ fabricated on a low carbon steel surface by vacuum electron beam irradiation (VEB). Three kinds of powder mixtures were placed on a low carbon steel substrate, which was then irradiated with electron beam in vacuum condition. The microstructure and wear resistance of the composite layers has been studied by means of optical microscope (OM), X-ray diffraction (XRD), scanning electron microscope (SEM), microhardness tester and tribological tester. The chemical composition of all specimens were carefully analyzed using energy-dispersive X-ray spectroscopy (EDAX) technique. Depending on three different powder mixtures, hypereutectic and hypoeutectic microstructures were obtained on surface composite layers. No pores and cracks were found on the coatings. The amount of carbides formed in the surface composite layer was mainly determined by carbon concentration. The microstructure close to the fusion line was largely primary austenite dendrite. The hardness and wear resistance of the surface composite layer has been greatly improved due to the extensive distribution of carbides.

  12. Microstructure and Abrasive Wear Resistance of 18Cr-4Ni-2.5Mo Cast Steel

    Directory of Open Access Journals (Sweden)

    B. Kalandyk

    2012-12-01

    Full Text Available An influence of a decreased Cr content on the microstructure of the highly alloyed Cr-Ni cast steel, duplex type, melted under laboratoryconditions, was characterized in the paper. The microstructure investigations were performed in the initial state and after the heat treatment (solution annealing at 1060C as well as the phase transformation kinetics at continuous cooling was measured. The wear resistance of the investigated cast steel was tested and compared with the 24%Cr-5%Ni-2.5%Mo cast steel.The Cr content decrease, in ferritic-austenitic cast steels (duplex, from 24-26%Cr to 18% leads to the changes of the castingsmicrostructure and eliminating of a brittle  phase. In dependence of the casting cooling rate, apart from ferrite and austenite, also fine martensite precipitates occur in the casting structure. It was shown that the investigated cast steel is characterised by a slightly lower wear resistance than the typical cast steel duplex grades.

  13. Influence Of Lubricants On Wear Resistance Of Aluminum Alloy Strips Series 2XXX

    Directory of Open Access Journals (Sweden)

    Żaba K.

    2015-09-01

    Full Text Available The article presents a properly planned and designed tests of the abrasive wear resistance 2024 aluminum alloy strips under friction conditions involving various lubricants. Test were focused on the selection of the best lubricant for use in industrial environment, especially for sheet metal forming. Three lubricants of the Orlen Oil Company and one used in the sheet metal forming industry, were selected for tests. Tests without the use of lubricant were performed for a comparison. The tester T-05 was used for testing resistance to wear. As the counter samples were used tool steel - NC6 and steel for hot working - WCL, which are typical materials used for tools for pressing. The results are presented in the form of the force friction, abrasion depth, weight loss and coefficient of friction depending on the lubricant used and the type of counter samples. The results allowed for predicting set lubricant-material for tools which can be applied to sheet metal made of aluminum alloy 2024.

  14. Wear Resistance of Mo-Implanted H13 Steel by a Metal Vapour Vacuum Arc Source

    Science.gov (United States)

    Yang, Jian-Hua; Zhang, Tong-He

    2003-10-01

    Pulsed molybdenum ion beams extracted from a metal vapour vacuum arc ion source at voltage of 25 kV or 48 kV were implanted into H13 steel with a high implantation dose of 5×1017 ions·cm-2 and a time-averaged ion beam current density of about 300 µA·cm-2. We have investigated the steel implanted for wear resistance by an optical interference microscope and a pin-on-disc apparatus. The Rutherford backscattering spectroscopy demonstrated that rather low-energy ions could penetrate quite deep into the substrates. It was observed by x-ray photoelectron spectroscopy and transmission-electron microscopy that carbide of molybdenum appeared in the doped region. The results showed that dramatically improved wear resistance of H13 steel after molybdenum ion implantation at 48 kV was attributed to the development of Mo2C precipitates in the doped zone and to the formation of the implantation affected zone below the doped zone.

  15. Wear-Resistant Ultrahigh-Molecular-Weight Polyethylene-Based Nano- and Microcomposites for Implants

    Directory of Open Access Journals (Sweden)

    S. V. Panin

    2012-01-01

    Full Text Available The influence of modification by hydroxyapatite (HA nano- and microparticles on tribotechnical properties of ultrahigh-molecular-weight polyethylene (UHMWPE was investigated to develop polymer implants for endoprosthesis. It was shown that modification of UHMWPE by hydroxyapatite nanoparticles within range of 0.1–0.5 wt.% results in increase of wear resistance at dry sliding by 3 times. On the other hand adding of 20 wt.% of micron size HA gives rise to the same effect. The effect of increasing wear resistance is not substantially changed at surface treatment of the nano- and microcomposites by N+ ion beams as compared with nonirradiated blends. Preliminary joint mechanical activation of UHMWPE powder and fillers results in more uniform distribution of nanofillers in the matrix and, as a result, formation of more ordered structure. Structure within bulk material and surface layers was studied by means of optical profilometry, scanning electron microscopy, infrared spectroscopy, and differential scanning calorimetry. It is shown that adding of hydroxyapatite nanoparticles and high-energy surface treatment of the composite by N+ ion implantation improve tribotechnical properties of UHMWPE due to formation of chemical bonds in the composite (crosslinking and ordering of permolecular structure.

  16. Wear Resistance of Mo-Implanted H13 Steel by a Metal Vapour Vacuum Arc Source

    Institute of Scientific and Technical Information of China (English)

    杨建华; 张通和

    2003-01-01

    Pulsed molybdenum ion beams extracted from a metal vapour vacuum arc ion source at voltage of 25kV or 48kV were implanted into H13 steel with a high implantation dose of 5×1017 inons·cm-2 and a time-averaged ion beam current density of about 300μA·cm-2. We have investigated the steel implanted for wear resistance by an optical interference microscope and a pin-on-disc apparatus. The Rutherford backscattering spectroscopy demonstrated that rather low-energy ions could penetrate quite deep into the substrates. It was observed by x-ray photoelectron spectroscopy and transmission-electron microscopy that carbide of molybdenum appeared in the doped region. The results showed that dramatically improved wear resistance of H13 steel after molybdenum ion implantation at 48 kV was attributed to the development of Mo2 C precipitates in the doped zone and to the formation of the implantation affected zone below the doped zone.

  17. Improving the wear resistance of titanium alloys under high contact loads

    Energy Technology Data Exchange (ETDEWEB)

    Ivasishin, O.M.; Markovskii, P.E.; Mikulyak, O.V. [Inst. of Metal Physics, Kiev (Ukraine)] [and others

    1992-01-01

    One of the basic shortcomings of titanium alloys is their poor antifriction properties. The wear resistance of titanium alloys can be improved by applying special coatings to their surface by various methods. However, the formation of surface layers whose properties differ greatly from the properties of the metallic substrate is accompanied, as a rule, by considerable impairment of the ductile and fatigue characteristics of the alloy. Besides, the material of the coating or the technology of its application are not always able to ensure the required resistance under large contact loads, both of the coating itself and of the adjacent zones of the material of the substrate (which are often weakened by thermal or thermochemical effects). 8 refs., 1 fig.

  18. Review on Improving Wear and Corrosion Resistance of Steels via Plasma Electrolytic Saturation Technology

    Science.gov (United States)

    Lin, Naiming; Xie, Ruizhen; Zhou, Peng; Zou, Jiaojuan; Ma, Yong; Wang, Zhenxia; Han, Pengju; Wang, Zhihua; Tang, Bin; Tian, Wei

    2016-03-01

    Plasma electrolytic saturation (PES) technique which holds the advantages of short treating time and limited heating influence and immediate quenching effect is conducted under high voltage power supply in some electrolyte has been extensively applied to enhance the surface performance of metallic materials. Steel is widely used in various fields thanks to its promising merits of easy workability, plasticity, toughness and weldability. It accounts for a large proportion in the application scope of the metal materials. Steel surfaces with good corrosion resistance, promising wear resistance and high hardness would be obtained by PES. Meanwhile, uniformed coatings can be formed without special requirements for substrate geometries using the PES. This paper first presents a brief introduction of the technological principle of PES. The status on studies and applications of PES for improving surface performance of steels has been reviewed.

  19. Development of low-friction and wear-resistant surfaces for low-cost Al hot stamping tools

    Directory of Open Access Journals (Sweden)

    Dong Y.

    2015-01-01

    Full Text Available In this study, advanced surfaces and coatings have been developed using plasma thermochemical treatment, PVD coating, electroless Ni-BN plating and duplex surface engineering to produce low-friction and wear-resistant surfaces for cast iron stamping tools. Their microstructural and nano-mechanical properties were systematically analysed and the tribological behaviour of these new surfaces and coatings were evaluated. The experimental results have shown that under dry sliding condition, the tribological behaviour of aluminium differed great from that of steel regardless of the counterpart material. Highly reactive aluminium had a strong tendency to solder with tool surfaces during dry sliding. However, the lubricity of gray cast irons can be significantly improved by Ni-BN and DLC coatings. The coefficient of friction reduced from about 0.5 for untreated cast irons to about 0.2 sliding against aluminium. Duplex treatment combining plasma nitrocarburising with low-friction coatings showed superior durability than both DLC and Ni-BN coatings.

  20. Effect of dry cryogenic treatment on Vickers hardness and wear resistance of new martensitic shape memory nickel-titanium alloy.

    Science.gov (United States)

    Vinothkumar, Thilla Sekar; Kandaswamy, Deivanayagam; Prabhakaran, Gopalakrishnan; Rajadurai, Arunachalam

    2015-01-01

    The aim of this study is to investigate the role of dry cryogenic treatment (CT) temperature and time on the Vickers hardness and wear resistance of new martensitic shape memory (SM) nickel-titanium (NiTi) alloy. The null hypothesis tested was that there is no difference in Vickers hardness and wear resistance between SM NiTi alloys following CT under two soaking temperatures and times. The composition and the phase transformation behavior of the alloy were examined by X-ray energy dispersive spectroscopy and differential scanning calorimetry, respectively. Fifteen cylindrical specimens and 50 sheet specimens were subjected to different CT conditions: Deep cryogenic treatment (DCT) 24 group: -185°C, 24 h; DCT six group: -185°C, 6 h; shallow cryogenic treatment (SCT) 24 group: -80°C, 24 h; SCT six group: -80°C, 6 h; and control group. Wear resistance was assessed from weight loss before and after reciprocatory wet sliding wear. The as-received SM NiTi alloy contained 50.8 wt% nickel and possessed austenite finish temperature (Af) of 45.76°C. Reduction in Vickers hardness of specimens in DCT 24 group was highly significant (P < 0.01; Tukey's honest significant difference [HSD]). The weight loss was significantly higher in DCT 24 group (P < 0.05; Tukey's HSD). Deep dry CT with 24 h soaking period significantly reduces the hardness and wear resistance of SM NiTi alloy.

  1. Development of (fe–b–c-based filler for wear-resistant composite coatings

    Directory of Open Access Journals (Sweden)

    О. V. Sukhovа

    2014-12-01

    Full Text Available Purpose. Development of multi-alloyed filler for abrasive wear-resistant composites. Methodology. The methods of microstructural, X-ray and energy-dispersive X-ray analyses were used to achieve research purpose. Micro-mechanical properties of structural constituents and abrasive wear-resistance of composites were determined. Findings. The complete dissolution of chromium and vanadium in the borides of Fe2В and FeВ that are initial structural constituents of Fe–В–С peritectic alloys has been established. These elements primarily dissolve in iron monoboride. Dissolution of molybdenum and niobium is not practically observed. As a result the phases of Мо2В, Мо2(В,С or NbВ2 can be seen in the structure. Alloying with chromium and vanadium increases compression strength and crack resistance coefficient, but that with molybdenum and niobium enhances total microhardness and hardness of the alloys. Structure formation of the interfaces between the filler and the binder of the composites based on МNМts 20-20 binder is governed by dissolution and diffusion processes when multi-alloyed (Fe–В–С alloy is applied as filler of the composites. The phase and the structural composition of contact interaction zones can be explained by re-crystallization of the filler surface layers after dissolution caused by contact with the molten binder. Consequently the macroheterogeneous structure of the composites is free of defects and strong adhesion between the filler and the binder is assured. Contact interaction intensity can be controlled by the choice of temperature- and-time infiltration regimes. Originality. The peculiarities in the formation of structure and properties of Fe2В- and FeВ-based solid solutions observed in the structure of the Fe–В–С peritectic alloys were investigated that allowed us to recommend composition of multicomponent alloy to be applied as filler of (Cu–Ni–Mn-matrix macroheterogeneous composites. Practical

  2. Effect of Fe2B boride orientation on abrasion wear resistance of Fe-B cast alloy

    Directory of Open Access Journals (Sweden)

    Da-wei Yi

    2017-07-01

    Full Text Available The microstructures and abrasion wear resistance of directional solidification Fe-B alloy have been investigated using optical microscopy, X-ray diffraction, scanning electron microscopy and laser scanning microscopy. The results show that the microstructure of as-cast Fe-B alloy consists of ferrite, pearlite and eutectic boride. After heat treatment, the microstructure is composed of boride and martensite. The plane which is perpendicular to the boride growth direction possesses the highest hardness. In two-body abrasive wear tests, the silicon carbide abrasive can cut the boride and martensite matrix synchronously, and the wear mechanism is micro cutting mechanism. The worn surface roughness and the wear weight loss both increase with the increasing contact load. Moreover, when the boride growth direction is perpendicular to the worn surface, the highest hardness plane of the boride can effectively oppose abrasion, and the martensite matrix can surround and support borides perfectly.

  3. Reinforcement of the bulk crowns excavator technology by dispersion hardening of titanium carbide to increase wear resistance

    Science.gov (United States)

    Chumanov, I.; Anikeev, A.; Chumanov, V.

    2017-02-01

    Dispersed particles embedded in the metal, improve the mechanical properties, particularly wear resistance. Introduction of the metal particles in a controlled and their distribution is difficult because of the density difference and the metal particles introduced. This article provides a method for the introduction of particles in the volume of metal, it contains a proposed strengthening technique described experiment course. During the experiment, the volume-reinforced castings from wear-resistant steel, the results of studies of the microstructure by optical and scanning electron microscopy, and mechanical tests of prototypes have been obtained.

  4. Film Layer Structure and Wear Resistance on High Strength Room Temperature Blackening of Cu-Se-P System

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yu-feng; ZHOU Hou-qiang; WANG Jian-cheng

    2004-01-01

    In this paper,the high strength room temperature blackening film on steel surface were prepared, the structure and the forming principle of the film were studied. The Cu-Se-P system with high strength composition blackening was researched, and the factors that affect the wear resistance of the film were analyzed. The experiment shows that the procedure have many advantages, such as short treatment time, high efficiency, low cost, high adhesive strength, perfect wear resistance, which posed a new approach for blackening of machine parts.

  5. Social vigilantism: measuring individual differences in belief superiority and resistance to persuasion.

    Science.gov (United States)

    Saucier, Donald A; Webster, Russell J

    2010-01-01

    Social vigilantism (SV) is an enduring individual difference that assesses the tendency of individuals to impress and propagate their "superior" beliefs onto others to correct others' more "ignorant" opinions. After establishing a reliable measure of SV, three studies showed that SV was associated with greater expressions of belief superiority (whether reacting to others holding dissimilar or similar beliefs) and greater resistance to persuasion (via increased rates of counterarguing and greater attitude stability after persuasion appeals) even after controlling for relevant individual differences (narcissism, dogmatism, psychological reactance, and need for cognition), as well as attitude importance and extremity. Thus, SV predicts expressions of belief superiority and resistance to persuasion above and beyond characteristics of the attitude and individual difference variables previously studied in the attitude literature. SV is a meaningful construct in increasing the understanding of persuasion, attitude resistance, and attitude dissemination that can be applied in a variety of psychological domains.

  6. Microstructure and wear resistance of CP titanium alloyed with a mixture of N2 and CO gases

    Science.gov (United States)

    Grenier, M.; Dube, D.; Adnot, A.; Fiset, M.

    1998-05-01

    Laser surface processing is a promising technique for alloying and synthesis of wear resistant coatings. To this end, commercially pure titanium was laser gas-alloyed with a mixture of nitrogen and carbon monoxide, and the influence of processing parameters was studied. The surface treatments were performed using a 400 W Nd:YAG pulsed laser. The composition of the gas mixture was set at either 100% N2, 67% N2 + 33% CO, 50% N2 + 50% CO, 33% N2 + 67% CO or 100% CO. The microstructure of the reacted layer of specimen was studied by optical and scanning electron microscopy. Their thickness was characterized and surface hardness profiles were determined. X-ray diffraction, Auger electron spectroscopy and X-ray photoelectron spectroscopy were used for determination of crystalline structure and chemical composition of phases. The study of processing parameters such as incident power density, pulse length and pulse rate showed that the optimum conditions for wear resistance were influenced by the composition of the gas mixture. Abrasive and erosive wear tests on laser-treated surfaces showed a substantial improvement in wear resistance over untreated titanium. This reduction in wear rate is attributed to the formation of the hard compounds TiN, TiCO and TiCNO in the resolidified layer.

  7. Influence of Orientations of Bionic Unit Fabricated by Laser Remelting on Fatigue Wear Resistance of Gray Cast Iron

    Science.gov (United States)

    Chen, Zhi-Kai; Zhou, Ti; Zhang, Hai-feng; Yang, Wan-shi; Zhou, Hong

    2015-06-01

    Fatigue wear resistance improvements were researched by studying experimental samples with gray cast iron fabricated with bionic units in different orientations. Experimental samples were modified by laser surface remelting, including parallel, vertical, and gradient units to the wear direction. The remelting pool was then studied to determine the micro-hardness, microstructure, alteration of phase, and etc. Lab-control fatigue wear test method was applied with the treated and untreated samples tested under the laboratorial conditions. Wear resistance result was considered as the rolling contact fatigue (RCF) resistance and mechanisms of the modified samples were experimentally investigated and discussed. Results suggested that all treated samples demonstrated the beneficial effect on the RCF improvement due to lack of graphite and reinforcement of treated region. Results also indicated the sample with fastigiated units was more effective than that with vertical units or parallel units to the wear direction. Influence of the sample unit's angle which intensely depended on the conditions of actual application, however, was not identified.

  8. Sand-wear resistance of brush electroplated nanocomposite coating in oil and its application to remanufacturing

    Institute of Scientific and Technical Information of China (English)

    DONG Shi-yun; XU Bin-shi; DU Ling-zhong; YANG Hua

    2005-01-01

    Sand-wear resistance of nano scale alumina particle reinforced nickel matrix composite coating (n-Al2O3/ Ni) prepared by brush electroplating technique was investigated via wear tests in sand-contaminated oil lubricant,comparing with that of AISI1045 steel and brush electroplated Ni coating. Effects of testing load, sand content and sand size on worn volume of the three materials, and also coating surface roughness on worn volume of the brush electroplated coatings were accessed. Results show that the worn volume of all the three materials increases with increasing of testing load, sand content and sand size. In the same conditions, n-Al2 O3/Ni composite coating has the smallest worn volume while AISI1045 steel has the largest because of the n-Al2 O3 particle effects. As to n-Al2 O3/Ni and Ni coatings, the surface-polished coatings have obviously lower worn volume than the as-plated coatings. The brush electroplated n-Als O3/Ni composite coating was employed to remanufacture the sand-worn bearing seats of a heavy vehicle and good results were gained.

  9. Improvement of Wear Resistance of Magnesium Alloy AZ91HP by High Current Pulsed Electron Beam Treatment

    Institute of Scientific and Technical Information of China (English)

    GAO Bo; HAO Sheng-zhi; ZOU Jian-xin; JIANG Li-min; ZHOU Ji-yang; DONG Chuang

    2004-01-01

    Surface modification of magnesium alloy AZ91HP (9wt%Al, 0.5wt%Zn, 0.5wt%Mn, Mg remaining percentage) by high current pulsed electron beam (HCPEB) treatment was studied in this paper. The secondary phase Mg17Al12 is nearly completely dissolved and as a result, a super-saturated solid solution forms on the re-melted surface.The microhardness is increased both in and far beyond the heat-affected zone (HAZ), reaching about 250μm.Measurements on sliding wear have shown that the wear resistance of the treated samples was improved by a factor of about 2.4 as compared to the as-received sample. It is also found that the sliding wear resistance can be further improved by surface alloying with TiN.

  10. The Effects of Austenitizing Conditions on the Microstructure and Wear Resistance of a Centrifugally Cast High-Speed Steel Roll

    Science.gov (United States)

    Kang, Minwoo; Lee, Young-Kook

    2016-07-01

    The influences of austenitizing conditions on the microstructure and wear resistance of a centrifugally cast high-speed steel roll were investigated through thermodynamic calculation, microstructural analysis, and high-temperature wear tests. When the austenitizing temperature was between 1323 K and 1423 K (1050 °C and 1150 °C), coarse eutectic M2C plates were decomposed into a mixture of MC and M6C particles. However, at 1473 K (1200 °C), the M2C plates were first replaced by both new austenite grains and MC particles without M6C particles, and then remaining M2C particles were dissolved during the growth of MC particles. The wear resistance of the HSS roll was improved with increasing austenitizing temperature up to 1473 K (1200 °C) because the coarse eutectic M2C plates, which are vulnerable to crack propagation, changed to disconnected hard M6C and MC particles.

  11. Wear resistance of WC/Co HVOF-coatings and galvanic Cr coatings modified by diamond nanoparticles

    Science.gov (United States)

    Kandeva, M.; Grozdanova, T.; Karastoyanov, D.; Assenova, E.

    2017-02-01

    The efforts in the recent 20 years are related to search of ecological solutions in the tribotechnologies for the replacement of galvanic Cr coatings in the contact systems operating under extreme conditions: abrasion, erosion, cavitation, corrosion, shock and vibration loads. One of the solutions is in the composite coatings deposited by high velocity gas-flame process (HVOF). The present paper presents comparative study results for mechanical and tribological characteristics of galvanic Cr coatings without nanoparticles, galvanic Cr coatings modified by diamond nanoparticles NDDS of various concentration 0.6; 10; 15 и 20% obtained under three technological regimes, and composite WC-12Co coating. Comparative results about hardness, wear, wear resistance and friction coefficient are obtained for galvanic Cr-NDDS and WC-12Co coatings operating at equal friction conditions of dry friction on abrasive surface. The WC-12Co coating shows 5.4 to 7 times higher wear resistance compared to the galvanic Cr-NDDS coatings.

  12. Tribological tests of wear-resistant coatings used in the production of drill bits of horizontal and inclined drilling

    Science.gov (United States)

    Maslov, A. L.; Markova, I. Yu; Zakharova, E. S.; Polushin, N. I.; Laptev, A. I.

    2017-05-01

    It is known that modern drilling bit body undergoes significant abrasive wear in the contact area with the solid and the retracted cuttings. For protection of the body rationally use wear-resistant coating, which is welded directly to the body of bit. Before mass use of the developed coverings they need to be investigated by various methods that it was possible to characterize coatings and on the basis of the obtained data to perform optimization of both composition of coatings and technology. Such methods include microstructural studies tribological tests, crack resistance and others. This work is devoted to the tribological tests of imported brand of coatings WokaDur NiA and and domestic brand of coating HR-6750 (both brands manufactured by Ltd “Oerlikon Metco Rus”), used to protect the bit body from abrasive wear.

  13. Skid resistance performance of asphalt wearing courses with electric arc furnace slag aggregates.

    Science.gov (United States)

    Kehagia, Fotini

    2009-05-01

    Metallurgical slags are by-products of the iron and steel industry and are subdivided into blast furnace slag and steel slag according to the different steel-producing processes. In Greece, slags are mostly produced from steelmaking using the electric arc furnace process, and subsequently are either disposed in a random way or utilized by the cement industry. Steel slag has been recently used, worldwide, as hard aggregates in wearing courses in order to improve the skidding resistance of asphalt pavements. At the Highway Laboratory, Department of Civil Engineering of Aristotle University of Thessaloniki research has been carried out in the field of steel slags, and especially in electric arc furnace (EAF) slag, to evaluate their possible use in highway engineering. In this paper, the recent results of anti-skidding performance of steel slag aggregates in highway pavements are presented.

  14. High Strength and Wear Resistant Aluminum Alloy for High Temperature Applications

    Science.gov (United States)

    Lee, Jonathan A.; Chen, Po Shou

    2003-01-01

    Originally developed by NASA as high performance piston alloys to meet U.S. automotive legislation requiring low exhaust emission, the novel NASA alloys now offer dramatic increase in tensile strength for many other applications at elevated temperatures from 450 F (232 C) to about 750 F (400 C). It is an ideal low cost material for cast automotive components such as pistons, cylinder heads, cylinder liners, connecting rods, turbo chargers, impellers, actuators, brake calipers and rotors. It can be very economically produced from conventional permanent mold, sand casting or investment casting, with silicon content ranging from 6% to 18%. At high silicon levels, the alloy exhibits excellent thermal growth stability, surface hardness and wear resistant properties.

  15. Plasma Electrolytic Oxidation (PEO) Coatings on an A356 Alloy for Improved Corrosion and Wear Resistance

    Science.gov (United States)

    Peng, Zhijing

    Plasma electrolytic oxidizing (PEO) is an advanced technique that has been used to deposit thick and hard ceramic coatings on aluminium (Al) alloys. This work was however to use the PEO process to produce thin ceramic oxide coatings on an A356 Al alloy for improving corrosion and wear resistance of the alloy. Effects of current density and treatment time on surface morphologies and thickness of the PEO coatings were investigated. The improvement of galvanic corrosion properties of the coated A356 alloy vs. steel and carbon fibre were evaluated in E85 fuel or NaCl environments. Tribological properties of the coatings were studied with comparison to the uncoated A356 substrate and other commercially-used engine bore materials. The research results indicated that the PEO coatings could have excellent tribological and corrosion properties for aluminium engine applications.

  16. Wear Resistance of Steels with Surface Nanocrystalline Structure Generated by Mechanical-Pulse Treatment

    Science.gov (United States)

    Nykyforchyn, Hryhoriy; Kyryliv, Volodymyr; Maksymiv, Olha

    2017-02-01

    The influence of the surface mechanical-pulse treatment based on high-speed friction with a rapid cooling by the technological environment on the wear resistance of medium- and high-carbon steels was considered. The treatment due to a severe plastic deformation enabled obtaining the nanocrystalline structure with a grain size of 14-40 nm. A high positive effect of this treatment was obtained not only because of metal nanocrystallization but also thanks to other factors, namely, structural-phase transformations, carbon saturation of the surface due to decomposition of the coolant and the friction coefficient decrease. Higher carbon content leads to better strengthening of the surface, and its microhardness can reach 12 GPa.

  17. Evaluation of Two Total Hip Bearing Materials for Resistance to Wear Using a Hip Simulator

    Directory of Open Access Journals (Sweden)

    Kenneth R. St. John

    2015-06-01

    Full Text Available Electron beam crosslinked ultra high molecular weight polyethylene (UHMWPE 32 mm cups with cobalt alloy femoral heads were compared with gamma-irradiation sterilized 26 mm cups and zirconia ceramic heads in a hip wear simulator. The testing was performed for a total of ten million cycles with frequent stops for cleaning and measurement of mass losses due to wear. The results showed that the ceramic on UHMWPE bearing design exhibited higher early wear than the metal on highly crosslinked samples. Once a steady state wear rate was reached, the wear rates of the two types of hip bearing systems were similar with the ceramic on UHMPWE samples continuing to show a slightly higher rate of wear than the highly crosslinked samples. The wear rates of each of the tested systems appear to be consistent with the expectations for low rates of wear in improved hip replacement systems.

  18. EFECT OF PLASMA IMMERSION ION IMPLANTATION TREATEMENT IN THE WEAR RESISTANCE OF Ti-6Al-4V ALLOY

    Directory of Open Access Journals (Sweden)

    Zepka, Susana

    2015-07-01

    Full Text Available The objective of this work was the evaluation of wear resistance of Ti-6Al-4V alloy after plasma immersion ion implantation (PIII in different immersion times. The goal of this process was the modification of surface properties of the alloy to obtain better tribology properties. In this process, atoms can be injected on the material´s surface changing the mechanical properties in the region near the surface independently of thermodynamics variables, as solubility and difusivity. The samples were submitted to 120 e 180 minutes of implantation at 250°C in the three samples for each condition. The wear analyses were made by pin-on-disk process, where the lost volumes and wear coefficients were compared in the samples. It was observed the decreasing of attrite coefficient and the lost volume of the material during wear test. The implanted sample by 180 minutes has showed the wear coefficient 35.12% lower in comparison of the sample without treatment, and 11.09% lower in comparison of implanted sample by 120 minutes. It can be observed that the sample implanted by 180 minutes showed lower wear coefficient.

  19. Preparation and Wear Resistance of Aluminum Composites Reinforced with In Situ Formed TiO/Al2O3

    Science.gov (United States)

    Qin, Q. D.; Huang, B. W.; Li, W.; Zeng, Z. Y.

    2016-05-01

    An in situ TiO/Al2O3-reinforced Al composite is successfully prepared using a powder metallurgy route by the reaction of Ti2CO and Al powder. The Ti2CO powder is produced by carrying out a carbothermic reduction of titanium dioxide at 1000 °C. XRD results show that the final product is composed of Al, TiO, Al2O3, and Al3Ti. Morphology examination of the composite reveals the presence of bigger blocks of TiO and fine particles of Al2O3 and the volume fraction of reinforcement is found to range between 18 and 55%. As the volume fraction of the reinforced materials approaches 50%, the particles start to agglomerate. Dry sliding wear tests conducted using a conventional pin-on-disk testing machine show that the wear resistance of the composite is higher than that of the pure aluminum ingot. The wear rate of the composite increases almost linearly with the increase in the wear distance. The sliding wear test shows that as the volume fraction of the reinforced phase increases, the coefficient of friction decreases. The wear mechanism is also discussed.

  20. Electrodeposition of diamond-like carbon films on titanium alloy using organic liquids: Corrosion and wear resistance

    Energy Technology Data Exchange (ETDEWEB)

    Falcade, Tiago, E-mail: tiago.falcade@ufrgs.br [Federal University of Rio Grande do Sul, 9500 Bento Goncalves Ave. Sector 4, Building 75, 2nd floor, Porto Alegre, RS (Brazil); Shmitzhaus, Tobias Eduardo, E-mail: tobiasschmitzhaus@gmail.com [Federal University of Rio Grande do Sul, Porto Alegre, RS (Brazil); Gomes dos Reis, Otavio, E-mail: otavio_gomes214@hotmail.com [Federal University of Rio Grande do Sul, Porto Alegre, RS (Brazil); Vargas, Andre Luis Marin; Huebler, Roberto [Pontificia Universidade Catolica do Rio Grande do Sul (Brazil); Mueller, Iduvirges Lourdes, E-mail: ilmuller@ufrgs.br [Federal University of Rio Grande do Sul, Porto Alegre, RS (Brazil); Fraga Malfatti, Celia de, E-mail: celia.malfatti@ufrgs.br [Federal University of Rio Grande do Sul, Porto Alegre, RS (Brazil)

    2012-12-15

    Highlights: Black-Right-Pointing-Pointer The electrodeposition may be conducted at room temperature. Black-Right-Pointing-Pointer The DLC films have good resistance to corrosion in saline environments. Black-Right-Pointing-Pointer The films have lower coefficient of friction than the uncoated substrate. Black-Right-Pointing-Pointer The abrasive wear protection is evident in coated systems. - Abstract: Diamond-like carbon (DLC) films have been studied as coatings for corrosion protection and wear resistance because they have excellent chemical inertness in traditional corrosive environments, besides presenting a significant reduction in coefficient of friction. Diamond-like carbon (DLC) films obtained by electrochemical deposition techniques have attracted a lot of interest, regarding their potential in relation to the vapor phase deposition techniques. The electrochemical deposition techniques are carried out at room temperature and do not need vacuum system, making easier this way the technological transfer. At high electric fields, the organic molecules polarize and react on the electrode surface, forming carbon films. The aim of this work was to obtain DLC films onto Ti6Al4V substrate using as electrolyte: acetonitrile (ACN) and N,N-dimethylformamide (DMF). The films were characterized by atomic force microscopy (AFM), scanning electron microscopy (SEM), Raman spectroscopy, potentiodynamic polarization and wear tests. The results show that these films can improve, significantly, the corrosion resistance of titanium and its alloys and their wear resistance.

  1. Effect of hardening temperature on the phase composition and wear resistance of roll steels with 5% Cr

    Science.gov (United States)

    Gervas'ev, M. A.; Khudorozhkova, Yu. V.; Filippov, M. A.

    2011-01-01

    The effect of a wide range of hardening temperatures on the capacity of cold-rolling roll steels with 5% Cr (65Kh5SMF and 9Kh5SMF) for strain-induced martensitic transformation and hardening is determined. The abrasive wear resistance of the steels is studied.

  2. Plasma immersion ion implantation on 15-5PH stainless steel: influence on fatigue strength and wear resistance

    Science.gov (United States)

    Bonora, R.; Cioffi, M. O. H.; Voorwald, H. J. C.

    2017-05-01

    Surface improvement in steels is of great interest for applications in industry. The aim of this investigation is to study the effect of nitrogen ion implantation on the axial fatigue strength and wear resistance of 15-5 PH stainless steel. It is well know that electroplated coatings, which are used to improve abrasive wear and corrosion properties, affects negatively the fatigue strength. It is also important to consider requirements to reduce the use of coated materials with electroplated chromium and cadmium, that produce waste, which is harmful to health and environment. The HVOF (High velocity oxygen fuel) process provides hardness, wear strength and higher fatigue resistance in comparison to electroplated chromium. Plasma immersion ion implantation has been used to enhance the hardness, wear, fatigue and corrosion properties of metals and alloys. In the present research the fatigue life increased twice for 15-5 PH three hours PIII treated in comparison to base material. From the abrasive wear tests a lower pin mass reduction was observed, associated to the superficial treatments. The improvement of fatigue and mechanical performance is attributed to a combination of nitrides phase structure and compressive residual stresses during the PIII treatment.

  3. Microstructure Characterization and Wear-Resistant Properties Evaluation of an Intermetallic Composite in Ni-Mo-Si System.

    Science.gov (United States)

    Huang, Boyuan; Song, Chunyan; Liu, Yang; Gui, Yongliang

    2017-02-04

    Intermetallic compounds have been studied for their potential application as structural wear materials or coatings on engineering steels. In the present work, a newly designed intermetallic composite in a Ni-Mo-Si system was fabricated by arc-melting process with commercially pure metal powders as starting materials. The chemical composition of this intermetallic composite is 45Ni-40Mo-15Si (at %), selected according to the ternary alloy diagram. The microstructure was characterized using optical microscopy (OM), scanning electron microscopy (SEM), X-ray diffraction (XRD), and energy dispersive spectroscopy (EDS), and the wear-resistant properties at room temperature were evaluated under different wear test conditions. Microstructure characterization showed that the composite has a dense and uniform microstructure. XRD results showed that the intermetallic composite is constituted by a binary intermetallic compound NiMo and a ternary Mo₂Ni₃Si metal silicide phase. Wear test results indicated that the intermetallic composite has an excellent wear-resistance at room-temperature, which is attributed to the high hardness and strong atomic bonding of constituent phases NiMo and Mo₂Ni₃Si.

  4. Microstructure Characterization and Wear-Resistant Properties Evaluation of an Intermetallic Composite in Ni–Mo–Si System

    Directory of Open Access Journals (Sweden)

    Boyuan Huang

    2017-02-01

    Full Text Available Intermetallic compounds have been studied for their potential application as structural wear materials or coatings on engineering steels. In the present work, a newly designed intermetallic composite in a Ni–Mo–Si system was fabricated by arc-melting process with commercially pure metal powders as starting materials. The chemical composition of this intermetallic composite is 45Ni–40Mo–15Si (at %, selected according to the ternary alloy diagram. The microstructure was characterized using optical microscopy (OM, scanning electron microscopy (SEM, X-ray diffraction (XRD, and energy dispersive spectroscopy (EDS, and the wear-resistant properties at room temperature were evaluated under different wear test conditions. Microstructure characterization showed that the composite has a dense and uniform microstructure. XRD results showed that the intermetallic composite is constituted by a binary intermetallic compound NiMo and a ternary Mo2Ni3Si metal silicide phase. Wear test results indicated that the intermetallic composite has an excellent wear-resistance at room-temperature, which is attributed to the high hardness and strong atomic bonding of constituent phases NiMo and Mo2Ni3Si.

  5. Electroless Ni-P/Ni-B duplex coatings: preparation and evaluation of microhardness, wear and corrosion resistance

    Energy Technology Data Exchange (ETDEWEB)

    Narayanan, T.S.N. Sankara; Krishnaveni, K.; Seshadri, S.K

    2003-12-20

    The present work deals with the formation of Ni-P/Ni-B duplex coatings by electroless plating process and evaluation of their hardness, wear resistance and corrosion resistance. The Ni-P/Ni-B duplex coatings were prepared using dual baths (acidic hypophosphite- and alkaline borohydride-reduced electroless nickel baths) with both Ni-P and Ni-B as inner layers and with varying single layer thickness. Scanning electron microscopy (SEM) was used to assess the duplex interface. The microhardness, wear resistance and corrosion resistance of electroless nickel duplex coatings were compared with electroless Ni-P and Ni-B coatings of similar thickness. The study reveals that the Ni-P and Ni-B coatings are amorphous in their as-plated condition and upon heat-treatment at 450 deg. C for 1 h, both Ni-P and Ni-B coatings crystallize and produce nickel, nickel phosphide and nickel borides in the respective coatings. All the three phases are formed when Ni-P/Ni-B and Ni-B/Ni-P duplex coatings are heat-treated at 450 deg. C for 1 h. The duplex coatings are uniform and the compatibility between the layers is good. The microhardness, wear resistance and corrosion resistance of the duplex coating is higher than Ni-P and Ni-B coatings of similar thickness. Among the two types of duplex coatings studied, hardness and wear resistance is higher for coatings having Ni-B coating as the outer layer whereas better corrosion resistance is offered by coatings having Ni-P coating as the outer layer.

  6. Wear resistance of thick diamond like carbon coatings against polymeric materials used in single screw plasticizing technology

    Science.gov (United States)

    Zitzenbacher, G.; Liu, K.; Forsich, C.; Heim, D.

    2015-05-01

    Wear on the screw and barrel surface accompany polymer single screw plasticizing technology from the beginning. In general, wear on screws can be reduced by using nitrided steel surfaces, fused armour alloys on the screw flights and coatings. However, DLC-coatings (Diamond Like Carbon) comprise a number of interesting properties such as a high hardness, a low coefficient of friction and an excellent corrosion resistance due to their amorphous structure. The wear resistance of about 50 µm thick DLC-coatings against polyamide 6.6, polybutylene terephthalate and polypropylene is investigated in this paper. The tribology in the solids conveying zone of a single screw extruder until the beginning of melting is evaluated using a pin on disc tribometer and a so called screw tribometer. The polymeric pins are pressed against coated metal samples using the pin on disc tribometer and the tests are carried out at a defined normal force and sliding velocity. The screw tribometer is used to perform tribological experiments between polymer pellets and rotating coated metal shafts simulating the extruder screw. Long term experiments were performed to evaluate the wear resistance of the DLC-coating. A reduction of the coefficient of friction can be observed after a frictional distance of about 20 kilometers using glass fibre reinforced polymeric materials. This reduction is independent on the polymer and accompanied by a black layer on the wear surface of the polymeric pins. The DLC-coated metal samples show an up to 16 µm deep wear track after the 100 kilometer test period against the glass fiber filled materials only.

  7. Researches concerning the ultasonic energy influence on the resistence to the abrasive wear of loaded welded parts

    Directory of Open Access Journals (Sweden)

    Gh. Amza

    2013-01-01

    Full Text Available The researches presented in the paper refer to the effect of ultrasounds propagation in the liquid metal bath on the process of transferring the additive material through the electric arch and on the crystallization process, and all these effects are analyzed for loaded welded parts solicited at the abrasive wear. All these influences are conferred to these two basic phenomena due to the ultrasounds propagation in liquid environments, namely, ultra-acoustic cavitation and acceleration of the diffusion process. The results concerns the resistance to the wear obtained for the loaded parts through manual welding with electric arch and classically covered electrode and ultrasonically activated.

  8. 1300 MPa High Strength Steel for Bolt with Superior Delayed Fracture Resistance

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    By the increase in Mo content, the addition of microalloying elements V and Nb and by reducing the contents of Mn, P and S based on the composition of steel 42CrMo, we have developed a 1300 MPa-grade high strength steel (ADF1) for bolts. The sustained load bending test, sustained load tensile test and stress corrosion cracking test have been carried out to evaluate the delayed fracture resistance of steel ADF1 and commercial steel 42CrMo. The results showed that steel ADF1 has superior delayed fracture resistance to that of 42CrMo steel. It's concluded that the superior delayed fracture resistance of ADF1 is mainly due to the increase of tempering temperature, fine homogeneously distributed MC carbide and fine prior austenite grain size.

  9. Effect of molybdenum on wear resistance of Cr-Nb hard-faced S355JR steel

    Energy Technology Data Exchange (ETDEWEB)

    Thongchitrugsa, Nut; Chianpairot, Amnuaysak; Hartung, Fritz; Lothongkum, Gobboon [Chulalongkorn Univ., Bangkok (Thailand). Dept. of Metallurgical Engineering

    2014-03-01

    The effect of Mo on the abrasive wear resistance of (20-23)Cr-(7-8)Nb hard-faced S355JR steel by shielded metal arc welding (SMAW) was studied. Four types of flux, consisting of fixed Cr and Nb but varying Mo contents, coated on hard-facing electrode were used. Microstructure, micro hardness, and abrasive wear resistance of the hard-faced surface were investigated by ASTM G65 D procedure. The original microstructures consist of the primary coarse and eutectic carbides. Mo affects morphology of carbides by decreasing primary carbide size. When Mo content in the hard-faced surface was up to 6.43 wt.-%, the highest abrasive wear resistance and micro hardness were obtained. The decrease of primary carbide size is attributed to the increased nucleation induced by Mo addition. Network structure was observed when the Mo content reaches 10.19 wt.-%. The main mechanisms of wear are micro-cutting and carbide pulling out. (orig.)

  10. The fabrication, nano/micro-structure, heat- and wear-resistance of the superhydrophobic PPS/PTFE composite coatings.

    Science.gov (United States)

    Wang, Huaiyuan; Zhao, Jingyan; Zhu, Youzhuang; Meng, Yang; Zhu, Yanji

    2013-07-15

    A simple engineering method was used to fabricate stability and wear-resistance of superhydrophobic PPS-based PPS/PTFE surfaces through nano/micro-structure design and modification of the lowest surface energy groups (-CF2-), which was inspired by the biomimic lotus leaves. The hydrophobic properties and wear-resistance of the coatings were measured by a contact angle meter and evaluated on a pin-on-disk friction and wear tester, respectively. Moreover, the surfaces of the PPS/PTFE composite coatings were investigated by means of scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), X-ray diffractometry (XRD), and thermogravimetry (TG) analysis. Results showed that the highest contact angle of the PPS/PTFE surface, with papillae-like randomly distributed double-scale structure, could reach up to 162°. When 1 wt.% PDMS was added, the highest contact angle could hold is 172°. The coatings also retained superhydrophobicity, even under high temperature environment. The investigation also indicated that the coatings were not only superhydrophobic but also oleophobic behavior at room temperature, such as the crude oil, glycerol, and oil-water mixture. The PPS/45%PTFE coatings had more stable friction coefficient and excellent wear-resistance (331,407 cycles) compared with those with less than 45% of PTFE.

  11. Investigation on Interface Structure and Wear-resistant Properties of HVOF Sprayed Carbides Coating onto Copper Substrate

    Institute of Scientific and Technical Information of China (English)

    HOU Li-feng; ZHANG Heng-jin; WEI Ying-hui; YAN Kai; HU Lan-qing; XU Bing-she

    2004-01-01

    In this paper, we deposited carbides on copper substrate by High velocity oxy-fuel (HVOF) spraying. The structure of the coating and microstructure of the substrate-coating interface have been investigated by means of scanning electron microscope (SEM) and transmission electron microscopy (TEM). We observed the worn surface of the coating and investigated the wear mechanism. The results show that the microstructure of the interface between HVOF sprayed coating and substrate which consists of the amorphous layers, nanocrystalls in the coating and dislocation cells in copper substrate,etc. is complex. The amorphous layers are formed from heated adhesion after rapidly cooling, while the nanocrystalls come from the fragmentation of half-molten carbides. At the same time we found that the wear-resistant properties of the WC-Co coating is better than that of Cr3C2-NiCr coating at room temperature. The early wear-resistance of the HVOF sprayed coating is poor because of the roughness of its surface or bad bond of hard composite particles. The high velocity of molten droplets is propitious to fill up the interspaces between carbides, so as to make the coating more compact and reduce its porosities, thus the wear-resistance of carbides coatings is improved.

  12. Investigation on Interface Structure and Wear-resistant Properties of HVOF Sprayed Carbides Coating onto Copper Substrate

    Institute of Scientific and Technical Information of China (English)

    HOULi-feng; ZHANGHeng-jin; WEIYing-hui; YANKai; HULan-qing; XUBing-she

    2004-01-01

    In this paper, we deposited carbides on copper substrate by High velocity oxy-fuel (HVOF) spraying. The structure of the coating and microstructure of the substrate-coating interface have been investigated by means of scanning electron microscope (SEM) and transmission electron microscopy (TEM). We observed the worn surface of the coating and investigated the wear mechanism. The results show that the microstructure of the interface between HVOF sprayed coating and substrate which consists of the amorphous layers, nanocrystalls in the coating and dislocation cells in copper substrate, etc. is complex. The amorphous layers are formed from heated adhesion after rapidly cooling, while the nanocrystalls come from the fragmentation of half-molten carbides. At the same time we found that the wear-resistant properties of the WC-Co coating is better than that of Cr3C2-NiCr coating at room temperature. The early wear-resistance of the HVOF sprayed coating is poor because of the roughness of its surface or bad bond of hard composite particles. The high velocity of molten droplets is propitious to fill up the interspaces between carbides, so as to make the coating more compact and reduce its porosities, thus the wear-resistance of carbides coatings is improved.

  13. Research on microstructure and wear resistance of coatings obtained by adding nanoparticles of refractory compounds in laser cladding

    Science.gov (United States)

    Murzakov, M. A.; Chirikov, S. N.; Markushov, Y. V.

    2016-09-01

    The paper is aimed at research of coatings, which are achieved by means of laser cladding with additives of nanoparticles of high-melting compounds in form of tungsten carbide and tantalum (WC and TaC). In the course of experiment, various ceramic powder concentrations were tested. Main technological characteristics were determined. Power density amounted to 0.68-0.98 MW/cm2. During the coating wear resistance measurement, it was discovered that increase in nanopowder concentration extended wear resistance of coating 2-6 times. Wear resistance measurement and wear coefficient calculation were performed using Brinell-Howarth method. The load was 15 N, load time was 10 minutes. Optical metallographic microscope Neophot-30 was used to study microstructure of the deposited coatings. To reveal microstructure of the deposited coatings, the samples were exposed to chemical etching. Elemental composition of the samples was determined by the methods of X- ray microanalysis in testing solution using electron microscope EVO-50 under acceleration voltage 10-20 kV (probe current 5-50 nA) using energy- and wavelength-dispersive spectrometers.

  14. Effects of increase extent of voltage on wear and corrosion resistance of micro-arc oxidation coatings on AZ91D alloy

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The effects of increase extent of voltage on the wear resistance and corrosion resistance of micro-arc oxidation(MAO)coatings on AZ91D magnesium alloy were investigated in silicate electrolyte.The results show that with increasing extent of voltage,both of the thickness and bonding force of MAO coatings first increase,and then decrease.These parameters are all up to their maximum values when the increase extent of voltage is 20 V.The roughness of the coatings always increases.The coating has the best corrosion resistance when the increase extent of voltage is not below 25 V,and the coating has the best wear resistance when the increase extent of voltage is 10 V.The wear mechanisms for the micro-arc oxidation are abrasive wear and micromachining wear.These are related to their microstructures.

  15. Improving wear resistance of magnesium alloy AZ91D by TiN-CrN multilayer coating

    Institute of Scientific and Technical Information of China (English)

    MIAO Qiang; CUI Cai-e; PAN Jun-de; ZHANG Ping-ze

    2006-01-01

    Applying a novel method of arc-glow plasma depositing, a 2 μm-thick coating with 12 sub-layers of TiN and CrN was deposited alternately on the surface of magnesium alloy AZ91D to improve its wear resistance. The wear behavior was investigated by test of ball on disc sliding. The composition and microstructure of the coating were also analyzed by means of X-ray diffraction (XRD) and glow discharge spectrum (GDS), and the morphology of TiN-CrN film was surveyed through scanning electronic microscopy (SEM) and atom force microscopy (AFM).The adhesion strength between film and matrix was evaluated by ways of stick-peeling test. The surface micro-hardness of the coating is above HK0.011 433, and the specific wear ratio of specimens coated with TiN-CrN films tested decreases greatly compared to that of the bare metal.

  16. Influences of the microstructure on the wear resistance of cobalt-based ahoy coatings obtained by plasma transferred arc process

    Institute of Scientific and Technical Information of China (English)

    HOU Qingyu; GAO Jiasheng

    2005-01-01

    The microstructure, substructure, and wear characteristic of cobalt-based alloy coatings obtained by plasma transferred arc (PTA) process were investigated using optical metallurgical microscope, X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), and dry sand abrasion tester (DSAT). The aging effect on the structure and wear resistance of the cobalt-based PTA coating was also studied. The results show that the as-welded coating consists of cobalt-based solid solution with face-centered cubic structure and hexagonal (Cr, Fe)7C3. There are a lot of stacking faults existing in the cobalt-based solid solution. After aging at 600℃ for 60 h, the microstructure becomes coarse, and another carbide (Cr, Fe)23C6 precipitates. As a result, the wear mass loss of the aged sample is higher than that of the as-welded sample.

  17. Effect of Rare Earths-Treated Glass Fiber on Impact Wear-Resistance of Metal-Plastic Multilayer Composites

    Institute of Scientific and Technical Information of China (English)

    程先华; 薛玉君; 谢超英

    2002-01-01

    The friction and wear properties under impact load and dry friction conditions of metal-plastic multilayer composites filled with glass fiber, treated with rare earth elements, were investigated. The worn surfaces were observed and analyzed by scanning electron microscopy (SEM). It shows that applying rare earth elements surface modifier to treat the glass fiber surface can enhance the interfacial adhesion between the glass fiber and polytetrafluoroethylene (PTFE), as well as promote the interface properties of the composites. This helps to form a uniformly distributed and high adhesive transfer film on the counterface and abate the friction between the composite and the counterface. As a result, the wear of composite is greatly reduced. The composite exhibits excellent friction properties and impact wear-resistance.

  18. Surface-gradient cross-linked polyethylene acetabular cups: oxidation resistance and wear against smooth and rough femoral balls.

    Science.gov (United States)

    Shen, Fu-Wen; McKellop, Harry

    2005-01-01

    Two methods were developed and evaluated for cross-linking the bearing surface of a polyethylene acetabular cup to a limited depth, in order to improve its resistance to wear without degrading the mechanical properties of the bulk of the component. In the first method, low-energy electron beams were used to cross-link only the bearing surface of the cups to a maximum depth of about 2 mm. The cups then were annealed at 100 degrees C in vacuum for 3 or 6 days to reduce the residual free radicals, and the resultant resistance to oxidation was compared by artificially aging the cups at 80 degrees C in air. Chemically cross-linked surface layers were produced by coating the bearing surfaces of the cups with a thin layer of polyethylene powder mixed with 1% weight peroxide, and compressing them at 6.9 MPa (1000 psi) and 170 degrees C. This resulted in a cross-linked surface layer that extended about 3 mm deep, with a gradual transition to conventional (noncross-linked) polyethylene in the bulk of the implant. In hip simulator wear tests with highly polished (implant quality) femoral balls, both types of surface cross-linking were found to improve markedly the wear resistance of the acetabular cups. In tests with roughened femoral balls, the wear rates were much higher and were comparable to those obtained with similarly roughened balls against noncross-linked polyethylene cups in a previous study, indicating that the full benefit of cross-linking may not be realized under conditions of severe third-body abrasion. Nevertheless, these results show a promising approach for optimizing the wear resistance and the bulk mechanical properties of polyethylene components in total joint arthroplasty.

  19. Effect of dry cryogenic treatment on Vickers hardness and wear resistance of new martensitic shape memory nickel-titanium alloy

    Science.gov (United States)

    Vinothkumar, Thilla Sekar; Kandaswamy, Deivanayagam; Prabhakaran, Gopalakrishnan; Rajadurai, Arunachalam

    2015-01-01

    Objectives: The aim of this study is to investigate the role of dry cryogenic treatment (CT) temperature and time on the Vickers hardness and wear resistance of new martensitic shape memory (SM) nickel-titanium (NiTi) alloy. The null hypothesis tested was that there is no difference in Vickers hardness and wear resistance between SM NiTi alloys following CT under two soaking temperatures and times. Materials and Methods: The composition and the phase transformation behavior of the alloy were examined by X-ray energy dispersive spectroscopy and differential scanning calorimetry, respectively. Fifteen cylindrical specimens and 50 sheet specimens were subjected to different CT conditions: Deep cryogenic treatment (DCT) 24 group: −185°C, 24 h; DCT six group: −185°C, 6 h; shallow cryogenic treatment (SCT) 24 group: −80°C, 24 h; SCT six group: −80°C, 6 h; and control group. Wear resistance was assessed from weight loss before and after reciprocatory wet sliding wear. Results: The as-received SM NiTi alloy contained 50.8 wt% nickel and possessed austenite finish temperature (Af) of 45.76°C. Reduction in Vickers hardness of specimens in DCT 24 group was highly significant (P < 0.01; Tukey's honest significant difference [HSD]). The weight loss was significantly higher in DCT 24 group (P < 0.05; Tukey's HSD). Conclusion: Deep dry CT with 24 h soaking period significantly reduces the hardness and wear resistance of SM NiTi alloy. PMID:26929689

  20. Abrasive wear behavior of heat-treated ABC-silicon carbide

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Xiao Feng; Lee, Gun Y.; Chen, Da; Ritchie, Robert O.; De Jonghe, Lutgard C.

    2002-06-17

    Hot-pressed silicon carbide, containing aluminum, boron, and carbon additives (ABC-SiC), was subjected to three-body and two-body wear testing using diamond abrasives over a range of sizes. In general, the wear resistance of ABC-SiC, with suitable heat treatment, was superior to that of commercial SiC.

  1. Electroless Ni-P-PTFE-Al2O3 Dispersion Nanocomposite Coating for Corrosion and Wear Resistance

    Science.gov (United States)

    Sharma, Ankita; Singh, A. K.

    2014-01-01

    With the aim to produce a coating having good corrosion and wear resistance alongside hardness but lesser friction coefficient, Ni-P-PTFE-Al2O3 (NiPPA) dispersion coating was developed. This was achieved by introducing nanosized polytetrafluoroethylene (PTFE) and alumina (Al2O3) in the Ni-P matrix deposited on mild steel substrate. The coating was characterized using scanning electron microscopy, energy dispersive analysis of x-ray, and x-ray diffractrometry. Microhardness and wear resistance of the coating was measured using Vicker's hardness tester and Pin-on-Disc method, respectively. The corrosion behavior was measured using electrochemical polarization and immersion tests with and without exposure in 3.5% NaCl solution. It is observed that codeposition of Al2O3 and PTFE particles with Ni-P coating results in comparatively smooth surface with nodular grains. The NiPPA coating was observed to have moderate hardness between electroless Ni-P-PTFE and Ni-P-Al2O3 coating and good wear resistance with lubricating effect. Addition of both PTFE and Al2O3 is observed to enhance corrosion resistance of the Ni-P coating. However, improvement in corrosion resistance is more due to addition of Al2O3 than PTFE. Continuous exposure for 10-20 days in corrosive solution is found to deteriorate corrosion protection properties of the coating.

  2. Martensitic stainless steel seamless linepipe with superior weldability and CO{sub 2} corrosion resistance

    Energy Technology Data Exchange (ETDEWEB)

    Miyata, Y.; Kimura, M.; Koseki, T.; Toyooka, T.; Murase, F. [Kawasaki Steel Corp., Handa, Aichi (Japan)

    1997-08-01

    Two types of new martensitic stainless steel with good weldability and superior corrosion resistance have been developed for line pipe application. Both steels are suitable for welding without preheating owing to lowering C and N contents, and they show good low temperature toughness in welds without PWHT. One is applied to sweet environments. It gives better resistance to CO{sub 2} corrosion than the 13Cr martensitic stainless steel for OCTG. Lowering C and addition of Ni contribute to reduction of general corrosion rate in the CO{sub 2} environment. The addition of Cu improves the pitting resistance. The other is applied to light sour environments. It gives good SSC resistance in welds owing to the improvement of the pitting resistance due to Mo addition. The seamless pipes of these martensitic stainless steels are applicable as substitutes for a part of duplex stainless steel flow lines.

  3. Wear resistance of the biocompatible phospholipid polymer-grafted highly cross-linked polyethylene liner against larger femoral head.

    Science.gov (United States)

    Moro, Toru; Takatori, Yoshio; Kyomoto, Masayuki; Ishihara, Kazuhiko; Kawaguchi, Hiroshi; Hashimoto, Masami; Tanaka, Takeyuki; Oshima, Hirofumi; Tanaka, Sakae

    2015-07-01

    The use of larger femoral heads to prevent the dislocation of artificial hip joints has recently become more common. However, concerns about the subsequent use of thinner polyethylene liners and their effects on wear rate have arisen. Previously, we prepared and evaluated the biological and mechanical effects of a novel highly cross-linked polyethylene (CLPE) liner with a nanometer-scaled graft layer of poly(2-methacryloyloxyethyl phosphorylcholine) (PMPC). Our findings showed that the PMPC-grafted particles were biologically inert and caused no subsequent bone resorptive responses and that the PMPC-grafting markedly decreased wear in a hip joint simulator. However, the metal or ceramic femoral heads used in this previous study had a diameter of 26 mm. Here, we investigated the wear-resistance of the PMPC-grafted CLPE liner with a 40-mm femoral head during 10 × 10(6) cycles of loading in the hip joint simulator. The results provide preliminary evidence that the grafting markedly decreased gravimetric wear rate and the volume of wear particles, even when coupled with larger femoral heads. Thus, we believe the PMPC-grafting will prolong artificial hip joint longevity both by preventing aseptic loosening and by improving the stability of articular surface.

  4. Enhancement of the Wear Resistance and Microhardness of Aluminum Alloy by Nd:YaG Laser Treatment

    Directory of Open Access Journals (Sweden)

    Haitham T. Hussein

    2014-01-01

    Full Text Available Influence of laser treatment on mechanical properties, wear resistance, and Vickers hardness of aluminum alloy was studied. The specimens were treated by using Nd:YaG laser of energy 780 mj, wavelength 512 nm, and duration time 8 ns. The wear behavior of the specimens was studied for all specimens before and after treatment by Nd:YaG laser and the dry wear experiments were carried out by sing pinon-disc technique. The specimens were machined as a disk with diameter of 25 mm and circular groove in depth of 3 mm. All specimens were conducted by scanning electron microscopy (SEM, energy-dispersive X-ray florescence analysis (EDS, optical microscopy, and Vickers hardness. The results showed that the dry wear rate was decreased after laser hardening and increased Vickers hardness values by ratio of 2.4 : 1. The results showed that the values of wear rate for samples having circular grooves are less than samples without grooves after laser treatment.

  5. Enhancement of the wear resistance and microhardness of aluminum alloy by Nd:YaG laser treatment.

    Science.gov (United States)

    Hussein, Haitham T; Kadhim, Abdulhadi; Al-Amiery, Ahmed A; Kadhum, Abdul Amir H; Mohamad, Abu Bakar

    2014-01-01

    Influence of laser treatment on mechanical properties, wear resistance, and Vickers hardness of aluminum alloy was studied. The specimens were treated by using Nd:YaG laser of energy 780 mj, wavelength 512 nm, and duration time 8 ns. The wear behavior of the specimens was studied for all specimens before and after treatment by Nd:YaG laser and the dry wear experiments were carried out by sing pinon-disc technique. The specimens were machined as a disk with diameter of 25 mm and circular groove in depth of 3 mm. All specimens were conducted by scanning electron microscopy (SEM), energy-dispersive X-ray fluorescence analysis (EDS), optical microscopy, and Vickers hardness. The results showed that the dry wear rate was decreased after laser hardening and increased Vickers hardness values by ratio of 2.4:1. The results showed that the values of wear rate for samples having circular grooves are less than samples without grooves after laser treatment.

  6. Non-Magnetic, Tough, Corrosion- and Wear-Resistant Knives From Bulk Metallic Glasses and Composites

    Science.gov (United States)

    Hoffman, Douglas C.; Potter, Benjamin

    2013-01-01

    Quality knives are typically fabricated from high-strength steel alloys. Depending on the application, there are different requirements for mechanical and physical properties that cause problems for steel alloys. For example, diver's knives are generally used in salt water, which causes rust in steel knives. Titanium diver's knives are a popular alternative due to their salt water corrosion resistance, but are too soft to maintain a sharp cutting edge. Steel knives are also magnetic, which is undesirable for military applications where the knives are used as a tactical tool for diffusing magnetic mines. Steel is also significantly denser than titanium (8 g/cu cm vs. 4.5 g/cu cm), which results in heavier knives for the same size. Steel is hard and wear-resistant, compared with titanium, and can keep a sharp edge during service. A major drawback of both steel and titanium knives is that they must be ground or machined into the final knife shape from a billet. Since most knives have a mirrored surface and a complex shape, manufacturing them is complex. It would be more desirable if the knife could be cast into a net or near-net shape in a single step. The solution to the deficiencies of titanium, steel, and ceramic knives is to fabricate them using bulk metallic glasses (or composites). These alloys can be cast into net or near-net shaped knives with a combination of properties that exceed both titanium and steel. A commercially viable BMG (bulk metallic glass) or composite knife is one that exhibits one or all of the following properties: It is based on titanium, has a self-sharpening edge, can retain an edge during service, is hard, is non-magnetic, is corrosion-resistant against a variety of corrosive environments, is tough (to allow for prying), can be cast into a net-shape with a mirror finish and a complex shape, has excellent wear resistance, and is low-density. These properties can be achieved in BMG and composites through alloy chemistry and processing. For

  7. Orthogonal experiment investigation on wear resistance of MoSi2

    Institute of Scientific and Technical Information of China (English)

    CHEN Ping; TANG Guoning; ZHANG Hou'an; LIU Houcai

    2003-01-01

    The influence of lubricant conditions, wear loads, and counterparts on the friction and wear characteristics of an MoSi2 material was investigated by means of orthogonal analysis. Orthogonal experiment results show that the order of influencing degree of the factors is lubricant condition > load > counterpart. MoSi2 has excellent friction-wear comprehensive properties against higher-hardness counterparts on the higher load and 20 oil lubricant conditions.

  8. Friction and Wear Behaviors of Nanostructured Metals

    Institute of Scientific and Technical Information of China (English)

    Zhong HAN; Yusheng ZHANG; Ke LU

    2008-01-01

    Nanostructured (ns) materials, i.e., polycrystalline materials with grain sizes in the nanometer regime (typically below 100 nm), have drawn considerable attention in the past decades due to their unique properties such as high strength and hardness. Wear resistance of ns materials, one of the most important properties for engineering materials, has been extensively investigated in the past decades. Obvious differences have been identified in friction and wear behaviors Between the ns materials and their corresponding coarse-grained (cg) counterparts, consistently correlating with their unique structure characteristics and mechanical properties. On the other hand, the superior tribological properties of ns materials illustrate their potential applications under contact loads. The present overview will summarize the important progresses achieved on friction and wear behaviors of ns metallic materials, including ultrafine-grained (ufg) materials in recent years. Tribological properties and effects on friction and wear behaviors of ns materials will be discussed under different wear conditions including abrasive wear, sliding wear, and fretting wear. Their correlations with mechanical properties will be analyzed. Perspectives on development of this field will be highlighted as well.

  9. Facile and scalable preparation of highly wear-resistance superhydrophobic surface on wood substrates using silica nanoparticles modified by VTES

    Energy Technology Data Exchange (ETDEWEB)

    Jia, Shanshan; Liu, Ming [College of Materials Science and Engineering, Central South University of Forestry and Technology, Changsha 410004 (China); Wu, Yiqiang, E-mail: wuyq0506@126.com [College of Materials Science and Engineering, Central South University of Forestry and Technology, Changsha 410004 (China); Hunan Provincial Collaborative Innovation Center for High-efficiency Utilization of Wood and Bamboo Resources, Central South University of Forestry and Technology, Changsha 410004 (China); Luo, Sha [College of Materials Science and Engineering, Central South University of Forestry and Technology, Changsha 410004 (China); Qing, Yan, E-mail: qingyan0429@163.com [College of Materials Science and Engineering, Central South University of Forestry and Technology, Changsha 410004 (China); Hunan Provincial Collaborative Innovation Center for High-efficiency Utilization of Wood and Bamboo Resources, Central South University of Forestry and Technology, Changsha 410004 (China); Chen, Haibo [College of Materials Science and Engineering, Central South University of Forestry and Technology, Changsha 410004 (China)

    2016-11-15

    Graphical abstract: Highly wear-resistance superhydrophobic surface on wood substrates was fabricated using silica nanoparticles modified by VTES. Display Omitted - Highlights: • Superhydrophobic surface on wood substrates was efficiently fabricated using nanoparticles modified by VTES. • The superhydrophobic surface exhibited a CA of 154° and a SAclose to 0°. • The superhydrophobic surface showed a durable and robust wear-resistance performance. - Abstract: In this study, an efficient, facile method has been developed for fabricating superhydrophobic surfaces on wood substrates using silica nanoparticles modified by VTES. The as-prepared superhydrophobic wood surface had a water contact angle of 154° and water slide angle close to 0°. Simultaneously, this superhydrophobic wood showed highly durable and robust wear resistance when having undergone a long period of sandpaper abrasion or being scratched by a knife. Even under extreme conditions of boiling water, the superhydrophobicity of the as-prepared wood composite was preserved. Characterizations by scanning electron microscopy, energy-dispersive X-ray spectroscopy, and Fourier transform infrared spectroscopy showed that a typical and tough hierarchical micro/nanostructure was created on the wood substrate and vinyltriethoxysilane contributed to preventing the agglomeration of silica nanoparticles and serving as low-surface-free-energy substances. This superhydrophobic wood was easy to fabricate, mechanically resistant and exhibited long-term stability. Therefore, it is considered to be of significant importance in the industrial production of functional wood, especially for outdoor applications.

  10. Effect of Austenite Transformation on Abrasive Wear and Corrosion Resistance of Spheroidal Ni-Mn-Cu Cast Iron

    Directory of Open Access Journals (Sweden)

    Medyński D.

    2016-09-01

    Full Text Available Within the presented work, the effect of austenite transformation on abrasive wear as well as on rate and nature of corrosive destruction of spheroidal Ni-Mn-Cu cast iron was determined. Cast iron contained: 3.1÷3.4 %C, 2.1÷2.3 %Si, 2.3÷3.3 %Mn, 2.3÷2.5 %Cu and 4.8÷9.3 %Ni. At a higher degree of austenite transformation in the alloys with nickel equivalent below 16.0%, abrasive wear resistance was significantly higher. Examinations of the corrosion resistance were carried out with the use of gravimetric and potentiodynamic method. It was shown that higher degree of austenite transformation results in significantly higher abrasive wear resistance and slightly higher corrosion rate, as determined by the gravimetric method. However, results of potentiodynamic examinations showed creation of a smaller number of deep pinholes, which is a favourable phenomenon from the viewpoint of corrosion resistance.

  11. Azide resistance in Rhizobium ciceri linked with superior symbiotic nitrogen fixation.

    Science.gov (United States)

    Bhaskar, V Vijay

    2004-12-01

    Isolated azide resistant (AzR) native R. ciceri strain 18-7 was resistant to sodium azide at 10 microg/ml. To find if nif-reiteration is responsible for azide resistance and linked to superior symbiotic nitrogen fixation, transposon (Tn5) induced azide sensitive mutants were generated. Using 4 kb nif-reiterated Sinorhizobium meliloti DNA, a clone C4 that complemented azide sensitivity was isolated by DNA hybridization from genomic library of chickpea Rhizobium strain Rcd301. EcoRI restriction mapping revealed the presence of 7 recognition sites with a total insert size of 19.17 kb. Restriction analysis of C4 clone and nif-reiterated DNA (pRK 290.7) with EcoRI and XhoI revealed similar banding pattern. Wild type strain 18-7, mutant M126 and complemented mutant M126(C4) were characterized for symbiotic properties (viz., acetylene reduction assay, total nitrogen content, nodule number and fresh and dry weight of the infected plants) and explanta nitrogenase activity. Our results suggested that azide resistance, nif-reiteration, and superior symbiotic effectiveness were interlinked with no correlation between ex-planta nitrogenase activity and azide resistance in R. ciceri.

  12. Wear-resisting oxide films for 900{degree}C. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Peterson, M.B. [Wear Sciences Corp., Arnold, MD (United States); Li, S.Z. [Inst. of Metal Research, Shenyang (China); Murray, S.F. [Rensselaer Polytechnic Inst., Troy, NY (United States)

    1994-03-01

    For the past 50 years, temperatures in advanced heat engines have been increasing. New-generating engines will require lubricants for 1,000 C and higher. One of the most critical applications is the regenerator seals on the automotive gas turbine. In this seal, a metal plate slides against a porous ceramic surface for several thousand hours at speeds on the order of 10 cm/sec. For long-term usage above 900 C it will probably be necessary to use oxide lubricants. If effective ones can be found, then a simple solution would be available for an application like the regenerator seal: fabricate it with an alloy which forms a lubricating oxide. The objective of this study was to explore this concept for the regenerator seal. A study was conducted to develop low-friction, wear-resistant surfaces on high-temperature alloys for the temperature range 26 C to 900 C. The approach investigated consisted of modifying the naturally occurring oxide film in order to improve its tribological properties. Improvement was needed at low temperatures where the oxide film, previously formed at high-temperature, spalls due to stresses induced by sliding. Experiments with titanium, tungsten, and tantalum additions showed a beneficial effect when added to nickel and nickel alloys. Low friction was maintained down to 100 C from 900 C. For unalloyed nickel friction and surface damage increased at 400 C to 500 C. Other approaches proved less successful and require further study.

  13. Hardness and wear resistance of carbon nanotube reinforced aluminum-copper matrix composites.

    Science.gov (United States)

    Nam, Dong Hoon; Kim, Jae Hwang; Cha, Seung Il; Jung, Seung Il; Lee, Jong Kook; Park, Hoon Mo; Park, Hyun Dal; Hong, Hyung

    2014-12-01

    Recently, carbon nanotubes (CNTs) have been attracted to reinforcement of composite materials due to their extraordinary mechanical, thermal and electrical properties. Many researchers have attempted to develop CNT reinforced metal composites with various fabrication methods and have shown possibilities for structural and functional applications. Among them, CNT reinforced Al matrix composites have become very attractive due to their huge structural application in industry. In this study, CNT reinforced Al-Cu matrix composites with a microstructure of homogeneous dispersion of CNTs in the Al-Cu matrix are investigated. The CNT/Al-Cu composites are fabricated by mixing of CNT/Cu composite powders and Al powders by high energy ball mill process followed by hot extrusion process. The hardness and wear resistance of the CNT/Al-Cu composites are enhanced by 1.4 and 3 times, respectively, compared to those values for the Al-Cu matrix. This remarkable enhancement mainly originates from the homogeneous dispersion of CNTs in Al-Cu matrix and self-lubricant effect of CNTs.

  14. Effect of microstructure on the wear resistance of borided Fe-Cr alloys

    Energy Technology Data Exchange (ETDEWEB)

    Dybkov, Vasyl I. [Institute of Problems of Materials Science, Kyiv (Ukraine)

    2013-07-15

    Two boride layers were found to form at the interface between reacting phases in the course of boriding of Fe-Cr alloys (10, 15, 25 and 30% Cr) and chromium steels (13 and 25% Cr) in the temperature range of 850-950 C and reaction times 3600-43200 s (1-12h). In the case of Fe-10%Cr and Fe-15%Cr alloys and 13% Cr steel, the outer boride layer bordering the boriding agent consists of the (Fe,Cr)B phase, whereas the inner boride layer adjacent to the solid substrate consists of the (Fe,Cr)2B phase. Each layer is thus a homogeneous phase (type I microstructure). In contrast, on the surface of Fe-25%Cr and Fe-30%Cr alloys and 25% Cr steel each of the two boride layers consists of two phases and has a peculiar network-platelet morphology. The outer boride layer comprises the (Fe,Cr)B and (Cr,Fe)B phases, while the inner consists of the (Fe,Cr){sub 2}B and (Cr,Fe){sub 2}B phases (type II microstructure). It is such boride layers that exhibit the highest wear resistance. (orig.)

  15. Wear resistant Fe-base alloys with niobium carbide; Verschleissbestaendige Fe-Basislegierungen mit Niobkarbid

    Energy Technology Data Exchange (ETDEWEB)

    Theisen, W. [Lehrstuhl Werkstofftechnik, Institut fuer Werkstoffe, Fakultaet fuer Maschinenbau, Ruhr-Universitaet Bochum (Germany)

    2004-06-01

    Martensitic Fe-base alloys from the system Fe-Cr-C are widely used as chilled cast irons and tool steels. Because of the low hardness of their FeCr-carbides this paper reports about new alloys with primarily solidified harder niobium carbides. It focuses on a secondary hardenable welding alloy, a coating material for composite castings, a chilled casting and a corrosion resistant cold work tool steel, which are investigated with respect to their process related microstructure and abrasive wear behaviour. (Abstract Copyright [2004], Wiley Periodicals, Inc.) [German] Martensitische Fe-Basislegierungen des Systems Fe-Cr-C finden heute als Hartguss und Werkzeugstahl vielfaeltige Anwendung. Da ihre FeCr-Karbide ueber eine relativ geringe Haerte verfuegen, wird in diesem Beitrag ueber neue Legierungen mit primaer ausgeschiedenen haerteren Niobkarbiden berichtet. Im Mittelpunkt stehen eine sekundaer haertende, rissfrei aufschweissbare Hartlegierung, eine warmfester Schichtwerkstoff fuer Verbundguss, ein weisses Gusseisen und ein korrosionsbestaendiger Kaltarbeitsstahl, die hinsichtlich ihrer herstellungsbedingten Gefuege analysiert und bezueglich Furchungsverschleiss untersucht wurden. (Abstract Copyright [2004], Wiley Periodicals, Inc.)

  16. Study on wear resistant cast B-containing 1Cr18Ni9Ti stainless steel

    Institute of Scientific and Technical Information of China (English)

    Kuang Jiacai; Jiang Zhiqiang; Zhang Shiyin; Ye Chang; Liu Qicheng

    2009-01-01

    The developed 1Cr18Ni9Ti austenitic stainless steel containing 1.63 wt.%B have been characterized by X-ray diffraction (XRD), electron probe microanalyzer (EPMA), optical microscopy (OM), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS) and Vickers microhardness measurement. The microstructural evolution and property of high boron stainless steel after solution treatment at the temperature of 1050℃ are also investigated. The results show that the main compositions of borides are Fe, Cr and B, and with small amount of Ni, Mn and C elements. Silicon is insoluble in the borides. The hardness of borides is over 1,500 HV. It has been found that borides do not decompose during solution treatment, but part of borides dissolves into the matrix. The effect of increasing the solubility of boron element in the austenitic matrix favours the hardness enhancement by 8.54%. High boron stainless steel has excellent wear resistance in corrosive environment. Lifetime of transfer pipe made of high boron-containing stainless steel is 1.5-1.8 times longer than that of boron-free 1Cr18Ni9Ti stainless steel.

  17. Enhanced wear resistance by compressive strengthening : A novel combination of laser and ion implantation technology

    NARCIS (Netherlands)

    Beurs, H. de; Hosson, J.Th.M. De

    1988-01-01

    In general, neon implantation is not very effective in reducing wear rates. However, neon implantation into laser-melted steel turns out to reduce the wear rate substantially as a result of a conversion of residual tensile stresses into compressive ones. Nitrogen implantation, on the other hand, at

  18. Wear-resistant and antismudge superoleophobic coating on polyethylene terephthalate substrate using SiO2 nanoparticles.

    Science.gov (United States)

    Wang, Yongxin; Bhushan, Bharat

    2015-01-14

    It is of interest to create superoleophobic surfaces that exhibit high oil contact angle, low contact angle hysteresis, high wear resistance, antismudge properties, and optical transparency for industrial applications. In the superoleophobic surfaces developed to date, the mechanical durability data is lacking. By dip-coating polyethylene terephthalate substrate with hydrophobic SiO2 nanoparticles and methylphenyl silicone resin, followed by O2 plasma treatment and vapor deposition of 1H,1H,2H,2H-perfluorooctyltrichlorosilane, a durable superoleophobic surface was fabricated. The degree of superoleophobicity was found to be dependent on the particle-to-binder ratio. The coatings were found to exhibit wear resistance on microscale and macroscale, antismudge properties, and transparency.

  19. Hardness, elastic modulus, and wear resistance of hafnium oxide-based films grown by atomic layer deposition

    Energy Technology Data Exchange (ETDEWEB)

    Berdova, Maria; Liu, Xuwen; Franssila, Sami, E-mail: sami.franssila@aalto.fi [Department of Materials Science and Engineering, Aalto University, 02150 Espoo (Finland); Wiemer, Claudia; Lamperti, Alessio; Tallarida, Grazia; Cianci, Elena [Laboratorio MDM, IMM CNR, Via C. Olivetti 2, 20864 Agrate Brianza (MB) (Italy); Fanciulli, Marco [Laboratorio MDM, IMM CNR, Via C. Olivetti 2, 20864 Agrate Brianza (MB), Italy and Dipartimento di Scienza dei Materiali, Università degli studi di Milano Bicocca, 20126 Milano (Italy)

    2016-09-15

    The investigation of mechanical properties of atomic layer deposition HfO{sub 2} films is important for implementing these layers in microdevices. The mechanical properties of films change as a function of composition and structure, which accordingly vary with deposition temperature and post-annealing. This work describes elastic modulus, hardness, and wear resistance of as-grown and annealed HfO{sub 2}. From nanoindentation measurements, the elastic modulus and hardness remained relatively stable in the range of 163–165 GPa and 8.3–9.7 GPa as a function of deposition temperature. The annealing of HfO{sub 2} caused significant increase in hardness up to 14.4 GPa due to film crystallization and densification. The structural change also caused increase in the elastic modulus up to 197 GPa. Wear resistance did not change as a function of deposition temperature, but improved upon annealing.

  20. Mechanical And Microstructural Evaluation Of A Wear Resistant Steel; Avaliacao mecanica e microestrutural de um aco resistente ao desgaste

    Energy Technology Data Exchange (ETDEWEB)

    Santos, F.L.F. dos; Vieira, A.G.; Correa, E.C.S.; Pinheiro, I.P., E-mail: falletti@hotmail.co [Centro Federal de Educacao Tecnologica de Minas Gerais (CEFET/MG), Belo Horizonte, MG (Brazil). Dept. de Engenharia de Materiais

    2010-07-01

    In the present work, the analysis of the mechanical properties and the microstructural features of a high strength low alloy steel, containing chromium, molybdenum and boron, subjected to different heat treatments, was conducted. After austenitizing at 910 deg C for 10 minutes, three operations were carried out: oil quenching, oil quenching followed by tempering at 200 deg C for 120 minutes and austempering at 400 deg C for 5 minutes followed by water cooling. The analysis was performed through tensile and hardness tests, optical microscopy and X-ray diffraction. The bainitic structure led to high strength and toughness, both essential mechanical properties for wear resistant steels. The occurrence of allotriomorphic ferrite and retained austenite in the samples also increased the wear resistance. This phenomenon is related to the fact that both structures are able to be deformed and, in the case of the retained austenite, the transformation induced plasticity TRIP effect may take place as the material is used. (author)

  1. Mechanical Properties and Erosive Wear Resistance of Zirconia Toughened Al2O3-TiC Ceramics

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The effect of ZrO2 content on the fracture toughness, flexural strength and Vickers hardness as well as the erosive wear resistant properties of zirconia toughened Al2O3-TiC ceramic composites has been investigated. The results showed that the improvement in fracture toughness and flexure strength of composites with the content of zirconia less than 50% and 10% in mass fraction respectively, is primarily attributed to stress-induced transformation toughening by the analyse of X-ray diffraction. The dependance of erosion wear resistance on the attack angle and the content of ZrO2 particles of the composites was also revealed. It is found that the erosion rate of the composites has a sharp rise at a attack angle over 65€?. This phenomenon is due to a brittle response to the erosion test by microstructural observation on eroded surface.

  2. Enhancement of wear and ballistic resistance of armour grade AA7075 aluminium alloy using friction stir processing

    Institute of Scientific and Technical Information of China (English)

    I. SUDHAKAR; V. MADHU; G. MADHUSUDHAN REDDY; K. SRINIVASA RAO

    2015-01-01

    Industrial applications of aluminium and its alloys are restricted because of their poor tribological properties. Thermal spraying, laser surfacing, electron beam welding are the most widely used techniques to alter the surface morphology of base metal. Preliminary studies reveal that the coating and layering of aluminium alloys with ceramic particles enhance the ballistic resistance. Furthermore, among aluminium alloys, 7075 aluminium alloy exhibits high strength which can be compared to that of steels and has profound applications in the designing of lightweight fortification structures and integrated protection systems. Having limitations such as poor bond integrity, formation of detrimental phases and interfacial reaction between reinforcement and substrate using fusion route to deposit hard particles paves the way to adopt friction stir processing for fabricating surface composites using different sizes of boron carbide particles as reinforcement on armour grade 7075 aluminium alloy as matrix in the present investigation. Wear and ballistic tests were carried out to assess the performance of friction stir processed AA7075 alloy. Significant improvement in wear resistance of friction stir processed surface composites is attributed to the change in wear mechanism from abrasion to adhesion. It has also been observed that the surface metal matrix composites have shown better ballistic resistance compared to the substrate AA7075 alloy. Addition of solid lubricant MoS2 has reduced the depth of penetration of the projectile to half that of base metal AA7075 alloy. For the first time, the friction stir processing technique was successfully used to improve the wear and ballistic resistances of armour grade high strength AA7075 alloy.

  3. Enhancement of wear and ballistic resistance of armour grade AA7075 aluminium alloy using friction stir processing

    Directory of Open Access Journals (Sweden)

    I. Sudhakar

    2015-03-01

    Full Text Available Industrial applications of aluminium and its alloys are restricted because of their poor tribological properties. Thermal spraying, laser surfacing, electron beam welding are the most widely used techniques to alter the surface morphology of base metal. Preliminary studies reveal that the coating and layering of aluminium alloys with ceramic particles enhance the ballistic resistance. Furthermore, among aluminium alloys, 7075 aluminium alloy exhibits high strength which can be compared to that of steels and has profound applications in the designing of lightweight fortification structures and integrated protection systems. Having limitations such as poor bond integrity, formation of detrimental phases and interfacial reaction between reinforcement and substrate using fusion route to deposit hard particles paves the way to adopt friction stir processing for fabricating surface composites using different sizes of boron carbide particles as reinforcement on armour grade 7075 aluminium alloy as matrix in the present investigation. Wear and ballistic tests were carried out to assess the performance of friction stir processed AA7075 alloy. Significant improvement in wear resistance of friction stir processed surface composites is attributed to the change in wear mechanism from abrasion to adhesion. It has also been observed that the surface metal matrix composites have shown better ballistic resistance compared to the substrate AA7075 alloy. Addition of solid lubricant MoS2 has reduced the depth of penetration of the projectile to half that of base metal AA7075 alloy. For the first time, the friction stir processing technique was successfully used to improve the wear and ballistic resistances of armour grade high strength AA7075 alloy.

  4. Clinical safety and wear resistance of the phospholipid polymer-grafted highly cross-linked polyethylene liner.

    Science.gov (United States)

    Moro, Toru; Takatori, Yoshio; Tanaka, Sakae; Ishihara, Kazuhiko; Oda, Hiromi; Kim, Yoon Taek; Umeyama, Takashige; Fukatani, Eisei; Ito, Hideya; Kyomoto, Masayuki; Oshima, Hirofumi; Tanaka, Takeyuki; Kawaguchi, Hiroshi; Nakamura, Kozo

    2016-11-03

    To reduce the production of wear particles and subsequent aseptic loosening, we created a human articular cartilage-mimicked surface for a highly cross-linked polyethylene liner, whose surface grafted layer consisted of a biocompatible phospholipid polymer, poly(2-methacryloyloxyethyl phosphorylcholine). Although our previous in vitro findings showed that poly(2-methacryloyloxyethyl phosphorylcholine)-grafted particles were biologically inert and caused no subsequent bone resorptive responses, and poly(2-methacryloyloxyethyl phosphorylcholine) grafting markedly decreased wear in hip joint simulator tests, the clinical safety, and in vivo wear resistance of poly(2-methacryloyloxyethyl phosphorylcholine)-grafted highly cross-linked polyethylene liners remained open to question. Therefore, in the present study, we evaluated clinical and radiographic outcomes of poly(2-methacryloyloxyethyl phosphorylcholine)-grafted highly cross-linked polyethylene liners 5 years subsequent to total hip replacement in 68 consecutive patients. No reoperation was required for any reason, and no adverse events were associated with the implanted liners. The average Harris Hip Score increased from 38.6 preoperatively to 96.5 5 years postoperatively, and health-related quality of life, as indicated by the Short Form 36 Health Survey, improved. Radiographic analyses showed no periprosthetic osteolysis or implant migration. Between 1 and 5 years postoperatively, the mean steady-state wear rate was 0.002 mm/year, which represented a marked reduction relative to other highly cross-linked polyethylene liners, and appeared to be unaffected by patient-related or surgical factors. Although longer follow up is required, poly(2-methacryloyloxyethyl phosphorylcholine)-grafted highly cross-linked polyethylene liners improved mid-term clinical outcomes. The clinical safety and wear-resistance results are encouraging with respect to the improvement of long-term clinical outcomes with poly(2

  5. The effects of vanadium on the microstructure and wear resistance of centrifugally cast Ni-hard rolls

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Minwoo, E-mail: aonia@yonsei.ac.kr [Department of Materials Science and Engineering, Yonsei University, Seoul 120-749 (Korea, Republic of); Suh, Yongchan, E-mail: ycsuh@hyundai-steel.com [Roll Development Team, HYUNDAI STEEL, 444 Songnae-dong, Nam-gu, Pohang, Gyeongbuk 790-785 (Korea, Republic of); Oh, Yong-Jun, E-mail: yjoh@hanbat.ac.kr [Department of Advanced Materials Science and Engineering, Hanbat National University, Daejeon 305-719 (Korea, Republic of); Lee, Young-Kook, E-mail: yklee@yonsei.ac.kr [Department of Materials Science and Engineering, Yonsei University, Seoul 120-749 (Korea, Republic of)

    2014-10-01

    Highlights: • V addition changed the pro-eutectic phase from austenite to vermicular (V,Nb)C. • Pro-eutectic (V,Nb)C particles were segregated to the inner part of the roll. • Wear loss was inversely proportional to MC fraction under the same graphite fraction. • Cementite particles acted as the initiation site and propagation path of cracks. • High-temperature wear sequence of centrifugally cast Ni-hard rolls was suggested. - Abstract: The effects of V on the microstructure and wear resistance of centrifugally cast Ni-hard rolls are investigated under a constant fraction of graphite using electron microscopes and a revolving disk-type high-temperature wear tester. The volume fraction of (V,Nb)C particles was increased at the expense of the volume fraction of cementite with an increase in the V concentration. However, the volume fraction of graphite was held nearly constant by controlling the concentration ratio of Si and Cr. As the V concentration was higher than 3 wt.%, the pro-eutectic phase was changed from austenite to (V,Nb)C carbide. The pro-eutectic vermicular (V,Nb)C particles were segregated to the inner part of the roll during centrifugal casting. The wear resistance was improved with an addition of V due to the high volume fractions of the coarse eutectic and pro-eutectic (V,Nb)C particles and the precipitation hardening of fine (V,Nb)C particles in the martensitic matrix. The worn surface showed that cementite particles acted as the initiation site and propagation route of cracks.

  6. Effects of cathodic voltages on structure and wear resistance of plasma electrolytic oxidation coatings formed on aluminium alloy

    Energy Technology Data Exchange (ETDEWEB)

    Li, Qingbiao [State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); School of Science, Lanzhou University of Technology, Lanzhou 730050 (China); Liang, Jun, E-mail: jliang@licp.cas.cn [State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Liu, Baixing; Peng, Zhenjun [State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Wang, Qing [School of Science, Lanzhou University of Technology, Lanzhou 730050 (China)

    2014-04-01

    Highlights: • The PEO coating growth rate increased with the cathodic voltage increasing. • Higher cathodic voltage resulted in more compact coating structure. • The compact structure led to low surface roughness and high wear resistance. - Abstract: Plasma electrolytic oxidation (PEO) coatings were prepared on aluminium alloy using pulsed bipolar power supply at constant anodic voltage and different cathodic voltages. The samples were prepared to attain the same coating thickness by adjusting the processing time. The scanning electron microscope (SEM), energy dispersive spectrometer (EDS), X-ray diffraction (XRD) and tribometer were employed to investigate the microstructure, element content, phase composition and wear resistance of the coatings respectively. It was found that the coating growth rate enhanced obviously and the coatings exhibited a more compact structure with thicker inner layer and lower surface roughness when the cathodic voltage increased. The coatings were mainly composed of crystalline γ-Al{sub 2}O{sub 3} and amorphous silicate oxides and their relative content changed with the cathodic voltage. The wear resistance of the coatings improved significantly with the increase of cathodic voltage.

  7. The structure, properties and a resistance to abrasive wear of railway sections of steel with a different pearlite morphology

    Energy Technology Data Exchange (ETDEWEB)

    Aniolek, K [Institute of Materials Science, University of Silesia, Bankowa 12, 40-007 Katowice (Poland); Herian, J, E-mail: jerzy.herian@polsl.pl [Department of Materials Technology, Silesian University of Technology, Krasinskiego 8, 40-019 Katowice (Poland)

    2011-05-15

    The article presents the characteristics of pearlite rail steels used in the construction of railways. The article discusses the influence of isothermal annealing process parameters on the pearlite morphology and properties of the R260 steel. The pearlite structure with a diverse pearlite morphology was obtained in the physical modeling of the isothermal annealing on the 3800 Gleeble Simulator. After the heat treatment, the existence of the pearlite microstructure with pearlite colonies was identified. They were smaller in relation to colonies after the hot rolling process. It was shown that the reduction of isothermal holding temperature influences the decrease of the interlamellar distance in the pearlite steel. On the basis of the received results, the dependences between the resistance to the abrasive wear and the pearlite morphology for operational conditions occurring in the switches were estimated. The resistance to the abrasive wear tests were conducted for steel with a different morphology of pearlite on the Amsler stand in conditions of rolling- sliding frictions. The resistance to the abrasive wear of R260 steel with a different pearlite morphology increases, when the interlamellar distance in cementite decreases and decreases as the load and slip increase.

  8. Improvement in Abrasion Wear Resistance and Microstructural Changes with Deep Cryogenic Treatment of Austempered Ductile Cast Iron (ADI)

    Science.gov (United States)

    Šolić, Sanja; Godec, Matjaž; Schauperl, Zdravko; Donik, Črtomir

    2016-10-01

    The application of a deep cryogenic treatment during the heat-treatment processes for different types of steels has demonstrated a significant influence on their mechanical and tribological properties. A great deal of research was conducted on steels, as well as on other kinds of materials, such as hard metal, gray cast iron, aluminum, aluminum alloys, etc., but not on austempered ductile iron (ADI). In this research the influence of a deep cryogenic treatment on the microstructure and abrasive wear resistance of austempered ductile iron was investigated. The ductile cast iron was austempered at the upper ausferritic temperature, deep cryogenically treated, and afterwards tempered at two different temperatures. The abrasion wear resistance was tested using the standard ASTM G65 method. The microstructure was characterized using optical microscopy, field-emission scanning electron microscopy, electron back-scattered diffraction, and X-ray diffraction in order to define the microstructural changes that influenced the properties of the ADI. The obtained results show that the deep cryogenic treatment, in combination with different tempering temperatures, affects the matrix microstructure of the austempered ductile iron, which leads to an increase in both the abrasion wear resistance and the hardness.

  9. Improving the Wear Resistance of Moulds for the Injection of Glass Fibre–Reinforced Plastics Using PVD Coatings: A Comparative Study

    Directory of Open Access Journals (Sweden)

    Francisco Silva

    2017-02-01

    Full Text Available It is well known that injection of glass fibre–reinforced plastics (GFRP causes abrasive wear in moulds’ cavities and runners. Physical vapour deposition (PVD coatings are intensively used to improve the wear resistance of different tools, also being one of the most promising ways to increase the moulds’ lifespan, mainly when used with plastics strongly reinforced with glass fibres. This work compares four different thin, hard coatings obtained using the PVD magnetron sputtering process: TiAlN, TiAlSiN, CrN/TiAlCrSiN and CrN/CrCN/DLC. The first two are monolayer coatings while the last ones are nanostructured and consist of multilayer systems. In order to carry out the corresponding tribological characterization, two different approaches were selected: A laboratorial method, using micro-abrasion wear tests based on a ball-cratering configuration, and an industrial mode, analysing the wear resistance of the coated samples when inserted in a plastic injection mould. As expected, the wear phenomena are not equivalent and the results between micro-abrasion and industrial tests are not similar due to the different means used to promote the abrasion. The best wear resistance performance in the laboratorial wear tests was attained by the TiAlN monolayer coating while the best performance in the industrial wear tests was obtained by the CrN/TiAlCrSiN nanostructured multilayer coating.

  10. RESEARCH OF PROCESSES ON FORMATION AND TRIBOTECHNICAL PROPERTIES OF WEAR-RESISTANT COMPOSITE GAS THERMAL COATINGS BEING DISPERSIVELY STRENGTHENED BY SYNTHETIC DIAMONDS AND ELECTRO-CORUNDUM

    Directory of Open Access Journals (Sweden)

    O. S. Kobjakov

    2011-01-01

    Full Text Available Formation processes, tribotechnical and wear-resistant properties of composite gas thermal coatings being dispersively strengthened by synthetic diamonds and electro-corundum are investigated in the paper.

  11. Competing mechanisms in the wear resistance behavior of biomineralized rod-like microstructures

    Science.gov (United States)

    Escobar de Obaldia, Enrique; Herrera, Steven; Grunenfelder, Lessa Kay; Kisailus, David; Zavattieri, Pablo

    2016-11-01

    The remarkable mechanical properties observed in biological composite materials relative to those of their individual constituents distinguish them from common engineering materials. Some naturally occurring high-performance ceramics, like the external veneer of the Chiton (Cryptochiton stelleri) tooth, have been shown to have superior hardness and impressive abrasion resistance properties. The mechanical performance of the chiton tooth has been attributed to a hierarchical arrangement of nanostructured magnetite rods surrounded with organic material. While nanoindentation tests provide useful information about the overall performance of this biological composite, understanding the key microstructural features and energy dissipation mechanisms at small scales remains a challenging task. We present a combined experimental/numerical approach to elucidate the role of material deformation in the rods, debonding at the rod interfaces and the influence of energy dissipation mechanisms on the ability of the microstructure to distribute damage under extreme loading conditions. We employ a 3D finite element-based micromechanical model to simulate the nanoindentation tests performed in geological magnetite and cross-sections of the chiton tooth. This proposed model is capable of capturing the inelastic deformation of the rods and the failure of their interfaces, while damage, fracture and fragmentation of the mineralized rods is assessed using a probabilistic function. Our results show that these natural materials achieve their abrasion resistant properties by controlling the interface strength between rods, alleviating the tensile stress on the rods near the indentation tip and therefore decreasing the probability of catastrophic failure without significantly sacrificing resistance to penetration. The understanding of these competing energy dissipating mechanisms provides a path to the prediction of new combination of materials. In turns, these results suggest certain

  12. Effect of cryogenic treatment on wear resistance of Ti-6Al-4V alloy for biomedical applications.

    Science.gov (United States)

    Gu, Kaixuan; Wang, Junjie; Zhou, Yuan

    2014-02-01

    The effect of cryogenic treatment on wear resistance of Ti-6Al-4V alloy for biomedical applications was experimentally investigated in this paper. Cryogenic treatments with the same soaking time of 24h at different temperatures of -80°C, -140°C and -196°C were conducted and the treatments at the same temperature of -196°C were then further given different soaking time of 3h, 48h and 72h to be investigated. After cryogenic treatment, the Vickers hardness of specimens was measured. Wear resistance of Ti-6Al-4V alloy was measured by pin-on-disk wear test under dry sliding condition. The results demonstrated that the Vickers hardness increased slightly with the reduction of temperature while it increased obviously with the elongation of soaking time at -196°C. The friction coefficients of specimens cryo-treated at -196°C were lower than those of untreated and of cryo-treated at -80°C and -140°C. And the longer the soaking time is during the cryogenic treatment, the higher the friction coefficient reduction can be achieved. The obvious reduction of mass loss can be obtained at -196°C with 72h soaking. The X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to detect the microstructure and worn surface of specimens. By cryogenic treatment, the plowing in the worn surface was smoothed and shallowed, and the degree of plastic deformation in the subsurface was decreased. There was no obvious phase transformation which can be detected in the microstructure after cryogenic treatment. However, the tendency of refinement in grain size can be detected by XRD which improved the wear resistance of Ti-6Al-4V alloy. © 2013 Published by Elsevier Ltd.

  13. Self-assembled thin film of imidazolium ionic liquid on a silicon surface: Low friction and remarkable wear-resistivity

    Energy Technology Data Exchange (ETDEWEB)

    Gusain, Rashi [CSIR-Indian Institute of Petroleum, Mohkampur, Dehardun 248005 (India); Academy of Scientific and Innovative Research, New Delhi 110025 (India); Kokufu, Sho [Department of Materials Science and Engineering, Kyoto University, Kyoto 606-8501 (Japan); Bakshi, Paramjeet S. [CSIR-Indian Institute of Petroleum, Mohkampur, Dehardun 248005 (India); Utsunomiya, Toru; Ichii, Takashi; Sugimura, Hiroyuki [Department of Materials Science and Engineering, Kyoto University, Kyoto 606-8501 (Japan); Khatri, Om P., E-mail: opkhatri@iip.res.in [CSIR-Indian Institute of Petroleum, Mohkampur, Dehardun 248005 (India); Academy of Scientific and Innovative Research, New Delhi 110025 (India)

    2016-02-28

    Graphical abstract: - Highlights: • Ionic liquid thin film is deposited on a silicon surface via covalent interaction. • Chemical and morphological features of ionic liquid thin film are probed by XPS and AFM. • Ionic liquid thin film exhibited low and steady friction along with remarkable wear-resistivity. - Abstract: Imidazolium-hexafluorophosphate (ImPF{sub 6}) ionic liquid thin film is prepared on a silicon surface using 3-chloropropyltrimethoxysilane as a bifunctional chemical linker. XPS result revealed the covalent grafting of ImPF{sub 6} thin film on a silicon surface. The atomic force microscopic images demonstrated that the ImPF{sub 6} thin film is composed of nanoscopic pads/clusters with height of 3–7 nm. Microtribological properties in terms of coefficient of friction and wear-resistivity are probed at the mean Hertzian contact pressure of 0.35–0.6 GPa under the rotational sliding contact. The ImPF{sub 6} thin film exhibited low and steady coefficient of friction (μ = 0.11) along with remarkable wear-resistivity to protect the underlying silicon substrate. The low shear strength of ImPF{sub 6} thin film, the covalent interaction between ImPF{sub 6} ionic liquid thin film and underlying silicon substrate, and its regular grafting collectively reduced the friction and improved the anti-wear property. The covalently grafted ionic liquid thin film further shows immense potential to expand the durability and lifetime of M/NEMS based devices with significant reduction of the friction.

  14. Microstructure, microhardness and wear resistance of VC{sub p}/Fe surface composites fabricated in situ

    Energy Technology Data Exchange (ETDEWEB)

    Ye, Fangxia [School of Materials Science and Engineering, Xi’an University of Technology, Xi’an 710048 (China); Institute of Wear Resistant Materials, Xi’an University of Architecture and Technology, Xi’an 710055 (China); Hojamberdiev, Mirabbos [Institute of Wear Resistant Materials, Xi’an University of Architecture and Technology, Xi’an 710055 (China); Xu, Yunhua, E-mail: yunhuaxu@yahoo.com.cn [School of Materials Science and Engineering, Xi’an University of Technology, Xi’an 710048 (China); Institute of Wear Resistant Materials, Xi’an University of Architecture and Technology, Xi’an 710055 (China); Zhong, Lisheng [Institute of Wear Resistant Materials, Xi’an University of Architecture and Technology, Xi’an 710055 (China); Zhao, Nana [School of Materials Science and Engineering, Xi’an University of Technology, Xi’an 710048 (China); Li, Yaping [Institute of Wear Resistant Materials, Xi’an University of Architecture and Technology, Xi’an 710055 (China); Huang, Xing [School of Materials Science and Engineering, Xi’an University of Technology, Xi’an 710048 (China)

    2013-09-01

    Graphical The vanadium carbide particles (VC{sub p})/Fe surface composites were in situ fabricated by a technique combining infiltration casting with subsequent heat treatment. The effects of different heat treatment times on the phase evolution, microstructure, microhardness and wear resistance of the composite were studied by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), Vickers hardness tester and wear resistance testing instrument, respectively. The results show that only graphite, α-Fe and V{sub 8}C{sub 7} phases dominate in the composite after being heat treated at 1164 °C for 3 h. The amount of V{sub 8}C{sub 7} decreases gradually from the top surface of the composite to the matrix mainly composed of gray cast iron. The average microhardness of the VC{sub p}/Fe surface composites varies according to the different reaction zones as follows: 505 HV{sub 0.1} (vanadium plate), 1096 HV{sub 0.1} (composite region), and 235 HV{sub 0.1} (iron matrix). The microhardness of the composite region is four times higher than that of the iron matrix and two times higher than that of the vanadium plate. This is attributed to the formation of vanadium carbide (V{sub 2}C and V{sub 8}C{sub 7}) crystallites as reinforcement phases within the iron matrix. The VC{sub p}/Fe surface composites exhibit a good wear resistance under two-body abrasive wear test.

  15. Wear and friction of oxidation-resistant mechanical carbon graphites at 650 C in air

    Science.gov (United States)

    Allen, G. P.; Wisnader, D. W.

    1975-01-01

    Studies were conducted to determine the friction and wear properties of experimental carbon-graphites. Hemispherically tipped carbon-graphite rider specimens were tested in sliding contact with rotating Inconel X-750 disks in air. A surface speed of 1.33 m/sec, a load of 500 g, and a specimen temperature of 650 C were used. Results indicate: (1) hardness is not a major factor in determining friction and wear under the conditions of these studies. (2) Friction and wear as low as or lower than those observed for a good commercial seal material were attained with some of the experimental materials studied. (3) The inclusion of boron carbide (as an oxidation inhibitor) has a strong influence on wear rate. (4) Phosphate treatment reduces the friction coefficient when boron carbide is not present in the base material.

  16. Corrosive-wear resistance of stainless steels for the impeller of slurry pump used in zinc hydrometallurgy process

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    This paper presents corrosive-wear (C-W) behaviors of three kinds of steels under the simulating condition of traditional zinc hydrometallurgy process by using a self-made rotating disk apparatus. Result shows that pure wear loss rate is significantly larger than pure corrosion loss rate. Under this C-W condition, the ranking of C-W resistance is S2 > S3 > S1 (S1: austenite stainless steel; S2: CD-4MCu duplex stainless steel; S3:17-4PH stainless steel). S2 has excellent C-W resistance due to strong surface deformation strengthening effect of high-density dislocations of the γphase. S3 also has excellent C-W resistance owing to high hardness and strength. However, S1 does not show good C-W resistance under strong erosion of liquid-solid slurry because of its single-phase austenitic structure and very low hardness. As a result, duplex stainless steels as well as 17-4 PH stainless steel can be used as impeller candidate materials in the zinc hydrometallurgy process due to their excellent C-W resistance and lower cost.

  17. Corrosive-wear resistance of stainless steels for the impeller of slurry pump used in zinc hydrometallurgy process

    Directory of Open Access Journals (Sweden)

    Ping LI

    2005-08-01

    Full Text Available This paper presents corrosive-wear (C-W behaviors of three kinds of steels under the simulating condition of traditional zinc hydrometallurgy process by using a self-made rotating disk apparatus. Result shows that pure wear loss rate is significantly larger than pure corrosion loss rate. Under this C-W condition, the ranking of C-W resistance is S2 > S3 > S1 (S1: austenite stainless steel; S2: CD-4MCu duplex stainless steel; S3 :17-4PH stainless steel. S2 has excellent C-W resistance due to strong surface deformation strengthening effect of high-density dislocations of the γ phase. S3 also has excellent C-W resistance owing to high hardness and strength. However, S1 does not show good C-W resistance under strong erosion of liquid-solid slurry because of its single-phase austenitic structure and very low hardness. As a result, duplex stainless steels as well as 17-4 PH stainless steel can be used as impeller candidate materials in the zinc hydrometallurgy process due to their excellent C-W resistance and lower cost.

  18. Rare earth effect on the microstructure and wear resistance of Ni-based coatings

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Zhenyu [State Key Laboratory of Tribology, Tsinghua University, Beijing 100084 (China)], E-mail: zhangzhenyu@mail.tsinghua.edu.cn; Lu Xinchun [State Key Laboratory of Tribology, Tsinghua University, Beijing 100084 (China); Han Baolei [State Key Laboratory of Tribology, Tsinghua University, Beijing 100084 (China); Luo Jianbin [State Key Laboratory of Tribology, Tsinghua University, Beijing 100084 (China)

    2007-04-25

    Eight different Cr{sub 3}C{sub 2}-NiCr coatings doped with rare earth oxide were deposited with supersonic plasma spraying. Surface contact profiler, X-ray diffractometer, environmental scanning electron microscopy, multi-functional tribometer, microhardness tester were employed to investigate the microstructure and friction and wear performance of sprayed coatings. The results show that the wear volume loss of coatings doped with 2 wt.% La{sub 2}O{sub 3} and 2 wt% La{sub 2}O{sub 3} + 2wt.% CeO{sub 2} is three orders of magnitude smaller than that of the coating without rare earth, respectively, correspondingly the friction coefficient of two coatings is only two third of that of the coating without rare earth. According to the SEM worn surface observations, the wear mechanism of the coating doped with 2 wt% La{sub 2}O{sub 3} is strain crushed wear induced by plastic deformation and fatigue during the sliding process, which is distinct with abrasive wear and delamination fracture wear mechanisms of the coating without rare earth. Furthermore, rare earth can make the microstructure more compact, less porous and denser, leading to the increase of average microhardness and decrease of its fluctuation range of sprayed coatings.

  19. Influence of Induction Hardening on Wear Resistance in Case of Rolling Contact

    Directory of Open Access Journals (Sweden)

    Šofer Michal

    2016-07-01

    Full Text Available The main aim of the presented paper is to show how heat treatment, in our case the induction hardening, will affect the wear rates as well as the ratcheting evolution process beneath the contact surface in the field of line rolling contact. Used wear model is based on shear band cracking mechanism [1] and non-linear kinematic and isotropic hardening rule of Chaboche and Lemaitre. The entire numerical simulations have been realized in the C# programming language. Results from numerical simulations are subsequently compared with experimental data.

  20. Influence of Hardness, Matrix and Carbides in Combination with Nitridation on Abrasive Wear Resistance of X210Cr12 Tool Steel

    Directory of Open Access Journals (Sweden)

    Martin Orečný

    2016-10-01

    Full Text Available Materials used in abrasive wear conditions are usually selected according to their microstructure and hardness, however, other factors such as grain size, matrix saturation, carbides size and morphology are rarely considered. Therefore, the present study deals with the influence of different heat and chemical-heat treatments including their combination on abrasive wear resistance of X210Cr12 tool steel. The effects of material hardness, carbide morphology and microstructure on wear resistance after quenching and nitriding were also investigated. One sample series was quenched after austenitization at 960 °C for 20 min and tempered at 180 °C for 2 h. The second sample series was quenched from 1060 °C austenitization for 20 min and afterwards twice tempered at 530 °C for 1 h. From both the quenched and tempered states, one half of the samples was gas nitrided in NH3 atmosphere for 3 h and then diffusion annealed in N2 atmosphere for 4 h. Abrasion wear tests were performed by sliding the samples on Al2O3 paper. The samples weight loss was considered the main criterion for the wear resistance evaluation. The microstructures, nitrided layers and worn surfaces were observed using SEM microscopy. The highest abrasion wear resistance was obtained for the nitrided samples that were previously quenched from 1060 °C and tempered at 530 °C.

  1. Friction and wear behavior of electrodeposited amorphous Fe-Co-W alloy deposits

    Institute of Scientific and Technical Information of China (English)

    何凤姣; 雷惊天; 陆欣; 黄宇宁

    2004-01-01

    The microstructures, friction and wear behavior under dry sliding condition of electrodeposited amorphous Fe-Co-W alloy deposits heat treated at different temperatures were studied. A comparative study of hard chrome deposit under the same testing condition was also made. The experimental results show that the hardness and wear resistance of amorphous Fe-Co-W alloy deposits are improved with the increasing of heat treatment temperature, and reach the maximum value at 800 ℃, then decrease above 800 ℃. Under 40 N load, the wear resistance properties of the alloy deposits heat treated at 800 ℃ are superior to those of hard chrome deposit. The main wear mechanisms of amorphous Fe-Co-W alloy deposits heat treated below 600 ℃ are peeling, plastic and flowing deformation; when the deposits are heat treated above 700 ℃, they are plastic and flowing deformation. While the main wear mechanisms of hard chrome are abrasive wear, fatigue and peeling.

  2. Wear resistance and friction reduction in acrylo nitrile butadiene rubber through hybrid combination of graphite flakes and nano tungsten disulphide

    Energy Technology Data Exchange (ETDEWEB)

    Agrawal, Neha, E-mail: neha87bhu@gmail.com [Defence Material Store Research Development and Establishment (DMSRDE), DRDO, GT Road, Kanpur 208013, U.P (India); Indian Institute of Technology Bombay, Powai, Mumbai 400076, Maharashtra (India); Pandey, Akanksha; Parihar, A. S.; Mishra, A. K.; Mukhopadhyay, K.; Prasad, N. E. [Defence Material Store Research Development and Establishment (DMSRDE), DRDO, GT Road, Kanpur 208013, U.P (India); Gandhi, M. N.; Bhattacharyya, A. R. [Indian Institute of Technology Bombay, Powai, Mumbai 400076, Maharashtra (India)

    2016-05-06

    Friction and wear have considerable role in the life span of two interacting parts. Incorporation of nanofillers in polymers/elastomers matrix causes commendable changes in its tribologicalproperties. The main purpose of this work is to reduce the coefficient of friction and wear rate of Acrylo Nitrile Butadiene rubber (NBR). To achieve such objective traditionally well knownlubricants graphite(G), tungsten disulphide (WS{sub 2}) and there hybrid combination was incorporated in NBR matrix. Effect of applied load (force) and concentration of fillers on tribological properties of NBR had been studied. The filler incorporation enhanced the hardnessby 8%, showed resistance to hydraulic oil and aging effect also got improved significantly. A particular optimized concentration of NBR with hybrid combination of 2% WS{sub 2} and 4% Graphite showed minimum coefficient of friction as well as wear rate. A hypothesis could be attributed that similar lamellar structure of WS{sub 2} and Graphite along with formation of a stable nanoscale disulfide tribofilmcould result in lowering of friction. These substantially improved properties of nanoreinforced rubber materials would definitely pave promising path for plethora of potential technological applications.

  3. Comparative study of the wear resistance of Al{sub 2}O{sub 3}-coated MA956 superalloy

    Energy Technology Data Exchange (ETDEWEB)

    Canahua Loza, H.; Escudero rincon, M. L.; Ruiz Fernandez, J. [Centro Nacional de Investigaciones Metalurgicas CENIM. Madrid (Spain)

    2000-07-01

    Preoxidation of the MA956 superalloy, proposed as prosthetic biomaterial, generates a compact and inert {alpha}-alumina surface layer. The aim of this study is to assess the wear resistance provided by this alumina layer on the MA956 alloy in comparison with the same coated alloy and versus high density polyethylene. Comparative wear tests were carried out in both dry and wet conditions using the couples MA956/MA956, MA956/UHMWPE (ultra high molecular weight polyethylene) and 316LVM/UHMWPE. The results corresponding to the couples MA956/MA956, with and without alumina layer, show that the load has more significant effect than the rotation speed on the weight loss and on the roughness. On the other hand the alumina surface layer provides a clear wear protection. The weight losses of the MA956 specimen in this couple are ten times lower when testing under wet conditions than under dry conditions. The MA956/UHMWPE couple behaves much better than the 316LVM/UHMWPE, as it presents the lowest values of friction coefficient and weight losses of the MA956 specimen. These are only detectable after 70,000 cycles under a 70 MPa contact pressure. This couple offers the best guarantee of a prolonged service life for articulated parts in a prosthesis. (Author) 18 refs.

  4. Wear resistance and friction reduction in acrylo nitrile butadiene rubber through hybrid combination of graphite flakes and nano tungsten disulphide

    Science.gov (United States)

    Agrawal, Neha; Pandey, Akanksha; Parihar, A. S.; Mishra, A. K.; Gandhi, M. N.; Bhattacharyya, A. R.; Mukhopadhyay, K.; Prasad, N. E.

    2016-05-01

    Friction and wear have considerable role in the life span of two interacting parts. Incorporation of nanofillers in polymers/elastomers matrix causes commendable changes in its tribologicalproperties. The main purpose of this work is to reduce the coefficient of friction and wear rate of Acrylo Nitrile Butadiene rubber (NBR). To achieve such objective traditionally well knownlubricants graphite(G), tungsten disulphide (WS2) and there hybrid combination was incorporated in NBR matrix. Effect of applied load (force) and concentration of fillers on tribological properties of NBR had been studied. The filler incorporation enhanced the hardnessby 8%, showed resistance to hydraulic oil and aging effect also got improved significantly. A particular optimized concentration of NBR with hybrid combination of 2% WS2 and 4% Graphite showed minimum coefficient of friction as well as wear rate. A hypothesis could be attributed that similar lamellar structure of WS2 and Graphite along with formation of a stable nanoscale disulfide tribofilmcould result in lowering of friction. These substantially improved properties of nanoreinforced rubber materials would definitely pave promising path for plethora of potential technological applications.

  5. The Microstructure and Wear Resistance of a Copper Matrix Composite Layer on Copper via Nitrogen-Shielded Arc Cladding

    Directory of Open Access Journals (Sweden)

    Yinan Li

    2016-12-01

    Full Text Available A TiN and TiN·Ti2Cu reinforced copper matrix composite layer was cladded onto a T3 copper substrate to improve the anti-wear performance of copper products by means of the nitrogen-shielded gas tungsten arc cladding method (N2-GTAC. Better than the traditional preparation method of TiN, the TiN particles in the cladding layer were in situ generated using N atoms of shielding gas and Ti atoms of pre-deposited metal powders. In addition, the composite phase TiN·Ti2Cu occurred in the cladding layer, which also had a positive effect on anti-wearing. As Ti increased, the amount and grain size of TiN·Ti2Cu and TiN increased as a result. The hardness of the cladding layer increased with the increasing amount of reinforced phase generated in the layer. The hardness of the layer reached a maximum of 410 HV, which is nearly 5.1 times greater than that of copper. The TiN·Ti2Cu- and TiN-reinforced phases improved the wear resistance of the cladding layers. The cladding layer with 15 wt % Ti had the longsest launch stage (600 s and the lowest fiction coefficient (0.56.

  6. Superior Inhibitory Control and Resistance to Mental Fatigue in Professional Road Cyclists.

    Directory of Open Access Journals (Sweden)

    Kristy Martin

    Full Text Available Given the important role of the brain in regulating endurance performance, this comparative study sought to determine whether professional road cyclists have superior inhibitory control and resistance to mental fatigue compared to recreational road cyclists.After preliminary testing and familiarization, eleven professional and nine recreational road cyclists visited the lab on two occasions to complete a modified incongruent colour-word Stroop task (a cognitive task requiring inhibitory control for 30 min (mental exertion condition, or an easy cognitive task for 10 min (control condition in a randomized, counterbalanced cross-over order. After each cognitive task, participants completed a 20-min time trial on a cycle ergometer. During the time trial, heart rate, blood lactate concentration, and rating of perceived exertion (RPE were recorded.The professional cyclists completed more correct responses during the Stroop task than the recreational cyclists (705±68 vs 576±74, p = 0.001. During the time trial, the recreational cyclists produced a lower mean power output in the mental exertion condition compared to the control condition (216±33 vs 226±25 W, p = 0.014. There was no difference between conditions for the professional cyclists (323±42 vs 326±35 W, p = 0.502. Heart rate, blood lactate concentration, and RPE were not significantly different between the mental exertion and control conditions in both groups.The professional cyclists exhibited superior performance during the Stroop task which is indicative of stronger inhibitory control than the recreational cyclists. The professional cyclists also displayed a greater resistance to the negative effects of mental fatigue as demonstrated by no significant differences in perception of effort and time trial performance between the mental exertion and control conditions. These findings suggest that inhibitory control and resistance to mental fatigue may contribute to successful road cycling

  7. Increasing Wear Resistance of Titanium Alloys by Anode Plasma Electrolytic Saturation with Interstitial Elements

    Science.gov (United States)

    Belkin, P. N.; Kusmanov, S. A.; Dyakov, I. G.; Silkin, S. A.; Smirnov, A. A.

    2017-05-01

    In our previous studies, we have shown that anode plasma electrolytic saturation of titanium alloys with nitrogen and carbon can improve their tribological properties. Obtained structure containing oxide layer and solid solution of diffused element in titanium promotes the enhancement of running-in ability and the decrease in the wear rate in some special cases. In this paper, further investigations are reported regarding the tribological properties of alpha- and beta-titanium alloys in wear test against hardened steel (50 HRC) disk using pin-on-disk geometry and balls of Al2O3 (6.25 mm in diameter) or bearing steel (9.6 mm in diameter) with ball-on-plate one and normal load from 5 to 209 N. Reproducible results were obtained under testing samples treated by means of the plasma electrolytic nitriding (PEN) with the mechanical removal of the oxide layer. Friction coefficient of nitrided samples is 0.5-0.9 which is somewhat higher than that for untreated one (0.48-0.75) during dry sliding against Al2O3 ball. An increase in the sliding speed results in the polishing of nitrided samples and reduction of their wear rate by 60 times. This result is obtained for 5 min at 850 °C using PEN in electrolyte containing 5 wt.% ammonia and 10 wt.% ammonium chloride followed by quenching in solution. Optical microscope was employed to assist in the evaluation of the wear behavior. Sizes of wear tracks were measured by profilometer TR200.

  8. Effect of Ultrasonic Vibration on the Behavior of Antifriction and Wear Resistance of Al2O3/Al2O3 Ceramic Friction Pairs Under Oil Lubrication

    Science.gov (United States)

    Dong, X. Y.; Qiao, Y. L.; Zang, Y.; Cui, Q. S.

    The behavior of antifriction and wear resistance of Al2O3/Al2O3 ceramic friction pairs lubricated by four different lubrication oils under ultrasonic vibration was studied. The surface morphologies of wear scare was analyzed by metallographic microscope. The effect mechanism of ultrasonic vibration on frictional pairs under different lubrication oils was discussed. The studied results showed that, ultrasonic vibration would improve the behavior of antifriction and wear resistance of the Al2O3/Al2O3 ceramic friction pairs under various lubrication oils.The improving would be dramaticer when the viscosity of lubrication oil was low. Ultrasonic vibration decreased the friction coefficient and wear volume 12.9% and 38.7% respectively, when the lubrication oil was 6#,the viscosity of which is 39.77 mm2/s. When the lubrication oil was 150BS, the viscosity of which is 549.69 mm2/s, ultrasonic vibration made friction coefficient and wear volume decreased 4.6% and 11.6% respectively.The effect of ultrasonic vibration on the behavior of antifriction and wear resistance of Al2O3/Al2O3 ceramic friction pairs was determined by the formation and the destruction of oil film on the friction surface and the upward floatage created by ultrasonic vibration.

  9. Wear of sequentially enhanced 9-Mrad polyethylene in 10 million cycle knee simulation study.

    Science.gov (United States)

    Tsukamoto, Riichiro; Williams, Paul Allen; Shoji, Hiromu; Hirakawa, Kazuo; Yamamoto, Kengo; Tsukamoto, Mikiko; Clarke, Ian C

    2008-07-01

    Highly crosslinked polyethylene (HXPE) has been shown to be effective in reducing wear in total hip replacements. HXPE has not found widespread use in TKR, because the crosslinking inevitably leads to reductions in critical properties such as toughness and fatigue strength. Sequentially enhanced crosslinking (SXPE) have been suggested for improved wear resistance for tibial inserts with maintenance of mechanical properties and anticipated high oxidation resistance superior to conventional polyethylene (XLPE). We compared the wear of SXPE (9Mrad) to XLPE inserts (3Mrad) to 10 million cycles. Triathlon femoral condyles were identical in both. This is the first wear study of SXPE inserts. According to the power law relating irradiation dose to wear of XLPE inserts, wear of 9 Mrad inserts should be reduced by 70% compared to 3Mrad controls. The wear rates of the SXPE inserts were reduced by 86% at 10 million cycles duration, somewhat greater than predicted. The one prior investigation by the manufacturer reported a 79% wear reduction for SXPE compared to controls in a 5 million cycle simulator study in knee design and test parameters. There were important differences between the two studies. Nevertheless there clearly appeared to be a major benefit for sequentially enhanced polyethylene in tibial inserts. This combined wear reduction of 80-85% with improved oxidation resistance and retention of mechanical properties may prove beneficial for active patients who may otherwise risk high wear rates over many years of use.

  10. Influence of high sintering pressure on the microhardness and wear resistance of diamond powder and silicon carbide-based composites

    Directory of Open Access Journals (Sweden)

    Oleksandr Sergueevitch Osipov

    2004-06-01

    Full Text Available The work reported on here involved the development of several samples of "diamond-SiC" composite produced under sintering pressures of up to 9.0 GPa at temperatures of up to 1973 7K. The average size of the diamond micropowder crystals used was 40/28 µm. The sintering process was carried out in a 2500-ton hydraulic press equipped with an anvil-type high-pressure device having a toroidal work surface and a central concavity diameter of 20 mm. The microhardness and wear resistance of the samples were found to be dependent on the sintering pressure. The experimental results indicated that the maximum microhardness and minimum wear resistance coefficients of each compact were attained when the pressure applied during sintering exceeded 6.5 GPa. Based on the established values of pressure, this study served to identify the types of devices applicable for the manufacture of composite material inserts for a variety of rock drilling applications.

  11. Effect of ion nitriding on the abrasive wear resistance of ultrahigh-strength steels with different silicon contents

    Science.gov (United States)

    Riofano, R. M. Muñoz; Casteletti, L. C.; Nascente, P. A. P.

    2005-02-01

    This article studies the effect of silicon (Si) on ultrahigh-strength AISI 4340 steels in connection with the thermal treatment, as well as the influence of this element on nitriding and, consequently, abrasive wear. Four alloys with different Si contents were nitrided at 350 °C (4 and 8 h) and 500 and 550 °C (2 and 4 h) in a gas mixture of 80 vol.% H2 and 20 vol.% N2. The nitrided layers were characterized by microhardness and pin-on-disk tests, optical microscopy, scanning electron microscopy with energy-dispersive x-ray spectrometry, and x-ray diffraction (XRD). The increase in Si enhanced the tempering resistance of the steels and also improved considerably the hardness of the nitrided layers. The increase in Si produced thinner compound layers with better hardness quality and high abrasive wear resistance. XRD analysis detected a mixture of nitrides in the layers γ‧-Fe4N, ɛ-Fe2 3N, CrN, MoN, and Si3N4 with their proportions varying with the nitriding conditions.

  12. Analysis Of The Austenite Grain Growth In Low-Alloy Boron Steel With High Resistance To Abrasive Wear

    Directory of Open Access Journals (Sweden)

    Białobrzeska B.

    2015-09-01

    Full Text Available Today low-alloy steels with boron achieve high resistance to abrasive wear and high strength. These features are obtained by using advanced technology of manufacturing. This makes boron steels increasingly popular and their application more diverse. Application of these steels can extend the lifetime of very expensive machine construction in many industries such as mining, the automotive, and agriculture industries. An interesting subgroup of these materials is steel with boron intended for heat treatment. These steels are supplied by the manufacturer after cold or hot rolling so that it is possible for them to be heat treated in a suitable manner by the purchaser for its specific application. Very important factor that determines the mechanical properties of final product is austenite grain growth occurring during hot working process such us quenching or hot rolling. Investigation of the effect of heating temperature and holding time on the austenite grain size is necessary to understand the growth behavior under different conditions. This article presents the result of investigation of austenite grain growth in selected low-allow boron steel with high resistance to abrasive wear and attempts to describe the influence of chemical composition on this process.

  13. Wear and Corrosion Resistance of Fe Based Coatings by HVOF Sprayed on Gray Cast-Iron for Automotive Application

    Directory of Open Access Journals (Sweden)

    M.S. Priyan

    2014-12-01

    Full Text Available In this study, commercially available FeSiNiCr and FeBCr alloy powders were designed with suitable compositions, gas atomized and then coated on gray cast-iron substrate. The microstructures of the feed stock Fe based alloy powders and the coatings were investigated by means of optical microscopy (OM, X-Ray diffraction (XRD, Thermogravimetric analysis (TGA and Scanning Electron Microscopy (SEM. In the present study, both the coating materials experienced two-body wear mechanisms. The results showed that for loads of 0.05 N, 0.1 N and 0.2 N, the wear resistance of FeBCr coating was less than FeSiNiCr by 44 %, 40 % and 31 %, respectively. The results indicated that the coated substrates exhibited lower corrosion current densities and lower corrosion rates, when placed in 20 wt.% H2SO4 solutions. In addition, the use of optimal spraying parameters/conditions gave improvements to the corrosion resistance of the substrates that had been treated with the crystalline coating.

  14. Development of Advanced Wear and Corrosion Resistant Systems Through Laser Surface Alloying and Materials Simulations

    Energy Technology Data Exchange (ETDEWEB)

    R. P. Martukanitz and S. Babu

    2007-05-03

    Laser surfacing in the form of cladding, alloying, and modifications are gaining widespread use because of its ability to provide high deposition rates, low thermal distortion, and refined microstructure due to high solidification rates. Because of these advantages, laser surface alloying is considered a prime candidate for producing ultra-hard coatings through the establishment or in situ formation of composite structures. Therefore, a program was conducted by the Applied Research Laboratory, Pennsylvania State University and Oak Ridge National Laboratory to develop the scientific and engineering basis for performing laser-based surface modifications involving the addition of hard particles, such as carbides, borides, and nitrides, within a metallic matrix for improved wear, fatigue, creep, and corrosion resistance. This has involved the development of advanced laser processing and simulation techniques, along with the refinement and application of these techniques for predicting and selecting materials and processing parameters for the creation of new surfaces having improved properties over current coating technologies. This program has also resulted in the formulation of process and material simulation tools capable of examining the potential for the formation and retention of composite coatings and deposits produced using laser processing techniques, as well as positive laboratory demonstrations in producing these coatings. In conjunction with the process simulation techniques, the application of computational thermodynamic and kinetic models to design laser surface alloying materials was demonstrated and resulted in a vast improvement in the formulation of materials used for producing composite coatings. The methodology was used to identify materials and to selectively modify microstructures for increasing hardness of deposits produced by the laser surface alloying process. Computational thermodynamic calculations indicated that it was possible to induce the

  15. Influence of halogen irradiance on short- and long-term wear resistance of resin-based composite materials.

    LENUS (Irish Health Repository)

    Bhamra, Gurcharn S

    2009-02-01

    The Oregon Health Science University (OHSU) four-chamber oral wear simulator was used to examine the impact of halogen irradiance on the short- and long-term wear behavior of four-methacrylate resin-based composites (RBCs). The hypothesis proposed was that exacerbated wear would occur following the long-term wear of RBCs irradiated under non-optimized irradiance conditions.

  16. Abrasive wear resistance optimization of three different carbide coatings by the Taguchi method

    Energy Technology Data Exchange (ETDEWEB)

    Guer, Ali Kaya [Firat Univ., Elazig (Turkey). Dept. of Metallurgy and Materials; Kaya, Sinan [Firat Univ., Elazig (Turkey). Faculty of Technology

    2017-06-01

    In this study, FeCrC, SiC and B{sub 4}C powders were alloyed on the surface of AISI 430 ferritic stainless steel by plasma arc welding. The mass losses of the abrasive wear of the AISI 430 substrate were examined under the loads of 6, 10 and 16 N and in the distances of 10, 20 and 30 m by using Taguchi design method. The results of abrasive wear test were optimized by the minimum optimal control characteristics of the Taguchi procedure and the results were analyzed by using graphical methods. The Taguchi procedure is an important approach to achieve high quality without increasing the cost during the optimization of process parameters. The orthogonal planes of maximum effects of the controllable process parameters and minimum effects of uncontrollable process parameters were employed in the Taguchi method.

  17. Wear resistant composite structure of vitreous carbon containing convoluted fibers. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Burton, R.G.; Burton, R.A.

    1996-05-28

    Energy Related Inventions Program Number 613 was a two year program to commercialize a unique new wear material, Metal Reinforced Carbon Composite, MRCC. The program was designed to manufacture sample components of MRCC for evaluation by potential users and manufacturers. As a result of the program Burton Technologies Inc. and Rotary Power International are forming a joint company to manufacture, market and license MRCC materials to a wide range of industries.

  18. Impact of UHMWPE texture on friction and wear resistance of hip prosthesis

    Directory of Open Access Journals (Sweden)

    Eddoumy Fatima

    2013-11-01

    Full Text Available Ultra High Molecular Weight PolyEthylene (UHMWPE is a polymer widely used in hip implants (prostheses as a bearing surface against metal, because of its good mechanical properties and biocompatibility [1]. Nevertheless, the durability of such implants is limited because of failure resulting from osteolysis and aseptic loosening. These two phenomenons are due to the immune response of human body consecutive to the apparition of wear particles of UHMWPE with time.

  19. High Kinetic Energy Penetrator Shielding and High Wear Resistance Materials Fabricated with Boron Nitride Nanotubes (BNNTS) and BNNT Polymer Composites

    Science.gov (United States)

    Kang, Jin Ho (Inventor); Park, Cheol (Inventor); Sauti, Godfrey (Inventor); Smith, Michael W. (Inventor); Jordan, Kevin C. (Inventor); Lowther, Sharon E. (Inventor); Bryant, Robert George (Inventor)

    2015-01-01

    Boron nitride nanotubes (BNNTs), boron nitride nanoparticles (BNNPs), carbon nanotubes (CNTs), graphites, or combinations, are incorporated into matrices of polymer, ceramic or metals. Fibers, yarns, and woven or nonwoven mats of BNNTs are used as toughening layers in penetration resistant materials to maximize energy absorption and/or high hardness layers to rebound or deform penetrators. They can be also used as reinforcing inclusions combining with other polymer matrices to create composite layers like typical reinforcing fibers such as Kevlar.RTM., Spectra.RTM., ceramics and metals. Enhanced wear resistance and usage time are achieved by adding boron nitride nanomaterials, increasing hardness and toughness. Such materials can be used in high temperature environments since the oxidation temperature of BNNTs exceeds 800.degree. C. in air. Boron nitride based composites are useful as strong structural materials for anti-micrometeorite layers for spacecraft and space suits, ultra strong tethers, protective gear, vehicles, helmets, shields and safety suits/helmets for industry.

  20. Dureza e resistência ao desgaste da camada de ZrN formada por nitretação a plasma sobre zircônia parcialmente estabilizada com ítria Hardness and wear resistance of the ZrN layer made by plasma nitriding of yttria partially-stabilized zirconia

    Directory of Open Access Journals (Sweden)

    R. Milani

    2010-07-01

    Full Text Available Corpos-de-prova de zircônia parcialmente estabilizada com ítria foram moldados por prensagem uniaxial, sinterizados e nitretados em plasma de micro-ondas à pressão atmosférica. A camada de ZrN sobre zircônia formou-se a uma taxa de 4 µm.min-1, podendo atingir uma espessura de 500 µm. As amostras foram caracterizadas por meio de medidas de dureza e resistência ao desgaste. A superfície nitretada apresentou dureza superior e resistência ao desgaste similar ao substrato de zircônia.Samples of yttria partially-stabilized zirconia were molded by uniaxial pressing, sintered and nitrided in an atmospheric pressure microwave plasma. This procedure leads to the formation of a ZrN layer whose growth rate and thickness reached 4 µm.min-1 and 500 µm, respectively. The samples were characterized by means of hardness and wear resistance tests. The nitrided surface exhibits superior hardness and wear resistance similar to that of the zirconia substrate.

  1. Wear resistance evaluation of palm fatty acid distillate using four-ball tribotester

    Science.gov (United States)

    Golshokouh, Iman; Ani, Farid Nasir; Syahrullail, S.

    2012-06-01

    Petroleum reserves are declining nowadays while ironically petroleum is a major source of pollution despite many uses. Researchers are in effort to find an alternative to replace petroleum as a lubricant. One of the best replace sources for petroleum is bio-oil. In this paper, a comparative study of friction and wear was carried out using a fourball tester. In this research, Palm Fatty Acid Distillate (PFAD) and Jatropha oil, two well-known oils from the vegetable family oils were compared with Hydraulic mineral oil and commercial mineral Engine oil. All investigated oils in this study are used in industries as lubricants. PFAD is a product from refined crude palm oil. It exists as a light brown solid at room temperature and Jatropa oil is produced from the seeds of the Jatropha cruces, a plant that grows in marginal lands. For the wear test, the experimental research condition was comparing four kind of oils with ASTM condition in which the load applied was 392N. The sliding speed was 1200rpm under the lubricant temperature of 75 degree Celsius. The experiment was run for 3600 seconds. The experimental results demonstrated that the PFAD and Jatropha oils exhibited better performance in term of friction and wear compared to Hydraulic and Engine mineral oils.

  2. Effect of SiC Content on Microstructure and Wear Resistance of Laser Cladding SiC/Ni60A Composite Coating

    Directory of Open Access Journals (Sweden)

    ZHAO Long-zhi

    2017-03-01

    Full Text Available The SiC reinforced Ni60A alloy laser cladding coating on the 45 steel substrate was fabricated with the LDM2500-60 semiconductor laser equipment. The effect of SiC content on microstructure, dilution rate, wear resistance, friction coefficient and microhardness was investigated systematically.The results show that with the increase of SiC content, the microstructure of upper coating is refined obviously, the dilution rate, wear resistance, friction coefficient and microhardness increase firstly and then decrease;when the mass fraction of SiC is 20%, the wear resistance of the cladding coating is the best one, in which the wear loss of coating is only 0.0012g and is 1/36.3 of the matrix;the minimum friction coefficient is 0.464, the friction process is the most stable;the highest microhardness of the cladding coating is 1039.9HV0.2, which is 3.5 times of the substrate;but when the mass fraction of SiC is 25%, the microhardness and wear resistance of coating decrease.

  3. Wear and Corrosion Resistance of Thick Ti-6Al-4V Coating Deposited on Ti-6Al-4V Substrate via High-Pressure Cold Spray

    Science.gov (United States)

    Khun, N. W.; Tan, A. W. Y.; Sun, W.; Liu, E.

    2017-08-01

    Ti-6Al-4V (Ti64) coating with a thickness of about 9 mm was deposited on commercial Ti64 substrate via a high-pressure cold spray process. The microstructure, hardness, and wear and corrosion resistance of the Ti64 coating were systematically investigated. The hardness of the Ti64 coating was higher than that of the Ti64 substrate due to the cold-worked microstructure of the coating. The tribological results showed that there was no significant difference in the surface wear rates of the Ti64 coating measured on its different layers while the surface wear resistance of the Ti64 coating was lower than its cross-sectional wear resistance. The corrosion results showed that the Ti64 coating did not effectively prevent its underlying Ti64 substrate from corrosion due to the occurrence of pores in the coating microstructure. It could be concluded that the hardness and wear resistance of the Ti64 coating were comparable to those of the commercial Ti64 substrate.

  4. Measurement of the Resistance of Treated Metal Foils to Scrubbing Abrasion Using a Modified Reciprocating Wear Test

    Energy Technology Data Exchange (ETDEWEB)

    Qu, Jun [ORNL; Blau, Peter Julian [ORNL; Sikka, Vinod K [ORNL

    2007-01-01

    A reciprocating wear test method has been developed to evaluate the resistance of metal foils to scrubbing abrasion. Development included the definition of a quantitative measure of the scrubbing resistance. In order to test the ability of the new method to differentiate between surface treatments, four versions of Type 316 stainless steel foils were tested: annealed (A-NT), cold-worked (C-NT), annealed plus a case-hardened (A-T), and cold-worked plus case-hardened (C-T). Measurements were made of their scrubbing resistance using commercial kitchen scrub pads as the counterface material. Results showed that the case-hardening process significantly increased the scrubbing resistance both under dry conditions and with cleaning solutions to lubricate the contact. While this linearly-reciprocating method does not simulate the circular, overlapping motion commonly occurring in service, results indicated that the new test method could sufficiently discriminate levels of two-body abrasion behavior, and therefore can be useful for studying the effects of surface treatments on abrasion resistance.

  5. Effects of Deep Cryogenic Treatment on the Wear Resistance and Mechanical Properties of AISI H13 Hot-Work Tool Steel

    Science.gov (United States)

    Çiçek, Adem; Kara, Fuat; Kıvak, Turgay; Ekici, Ergün; Uygur, İlyas

    2015-11-01

    In this study, a number of wear and tensile tests were performed to elucidate the effects of deep cryogenic treatment on the wear behavior and mechanical properties (hardness and tensile strength) of AISI H13 tool steel. In accordance with this purpose, three different heat treatments (conventional heat treatment (CHT), deep cryogenic treatment (DCT), and deep cryogenic treatment and tempering (DCTT)) were applied to tool steel samples. DCT and DCTT samples were held in nitrogen gas at -145 °C for 24 h. Wear tests were conducted on a dry pin-on-disk device using two loads of 60 and 80 N, two sliding velocities of 0.8 and 1 m/s, and a wear distance of 1000 m. All test results showed that DCT improved the adhesive wear resistance and mechanical properties of AISI H13 steel. The formation of small-sized and uniformly distributed carbide particles and the transformation of retained austenite to martensite played an important role in the improvements in the wear resistance and mechanical properties. After cleavage fracture, the surfaces of all samples were characterized by the cracking of primary carbides, while the DCT and DCTT samples displayed microvoid formation by decohesion of the fine carbides precipitated during the cryo-tempering process.

  6. Polishability and wear resistance of splint material for oral appliances produced with conventional, subtractive, and additive manufacturing.

    Science.gov (United States)

    Huettig, Fabian; Kustermann, Achim; Kuscu, Ebru; Geis-Gerstorfer, Jürgen; Spintzyk, Sebastian

    2017-07-14

    Occlusal splints to treat bruxism are commonly made from polymethylmethacrylate (PMMA) in a manual workflow (powder-liquid technique). Today digitalization allows a machine-based manufacturing in subtractive (milling) and additive (printing) means using industrial-made PMMA or comparable resins. An in-vitro study should assess the surface finish and screen the wear resistance of conventional and industrial materials. Therefore, a total of 30 specimens made from conventionally PMMA (group C; powder-liquid, Palapress), polycarbonate ingots (group S; innoBlanc splint plus), and light-curing resin (group A; VarseoWax splint) were polished to examine the surface roughness (Ra) by profilometry and further analyzed by SEM. The specimens were loaded with a steatite ball moving 5000 times along 1cm with 5N of surface pressure under constant wetting (artificial saliva). The total height of profile (Pt) was calculated by further profilometry of the specimens. All specimen showed initially comparable Ra values ranging between 0.06 and 0.05µm (SD = 0.01) after polishing. SEM investigations revealed no visual cues for scratches or irregularities in any group. After abrasion test, the comparison of the wear depths, revealed mean Pt values of 111.4µm (SD = 18.5) in C, 85.7µm (SD = 21.5) in S, and 99.1µm (SD = 21.5) in A, whereas the mean of S was statistically different from C (p = 0.025). No signs of abrasion were found on the steatite balls. All materials showed comparable polished surfaces and a similar scale of wear. It remains questionable if the detected statistical differences are of clinical relevance, but indicates the need for tests of novel materials, especially in additive manufacturing. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Anodized porous titanium coated with Ni-CeO2 deposits for enhancing surface toughness and wear resistance

    Science.gov (United States)

    Zhou, Xiaowei; Ouyang, Chun

    2017-05-01

    In order to make large improvements of surface toughness and wear resistance for pure titanium (Ti) substrate, anodic titanium oxide (ATO) surface with nanoporous structure was coated with the Ni-CeO2 nanocomposite coatings. Regarding TiO2 barrier layer on Ti surface to inhibit its electrochemical activity, pre-treatments were successively processed with anodizing, sensitizing, activating, and then followed by electroless Ni-P film to be acted as an activated layer for electroplating Ni-CeO2 deposits. The existing Pd atoms around ATO nanopores were expected as the heterogeneous nucleation sites for supporting the growing locations of electroless Ni-P film. The innovative of interface design using porous structure was introduced for bonding pinholes to achieve a metallurgical adhesion interface between Ti substrate and surface coatings. Besides the objectives of this work were to elucidate how effects by the adding CeO2 nanoparticles on modifying microstructures and wear mechanisms of Ni-CeO2 nanocomposite coatings. Many efforts of XRD, FE-SEM, TEM and Nanoindentation tests were devoted to comparing different wear behaviors of Ni-CeO2 coatings relative to pure nickel. Results indicated that uniform-distributed Ti nanopores with an average diameter size of ∼200 nm was achieved using the Phosphate-type anodizing solution at DC 150 V. A worn surface without fatigue cracks was observed for TAO surface coated with Ni-CeO2 deposits, showing the existing Ce-rich worn products to be acted as a solid lubricant phase for making a self-healing effect on de-lamination failures. More important, this finding will be the guidelines for Ce-rich precipitations to be expected as the strengthening phase in anodized porous of Ti, Al and Mg alloys for intensifying their surface properties.

  8. Characterisation of Wear Resistant Boride Layers on a Tool Steel by Activity Controlled Pack Boronising

    DEFF Research Database (Denmark)

    Fernandes, Frederico Augusto Pires; Christiansen, Thomas Lundin; Somers, Marcel A. J.

    2015-01-01

    The present work addresses the production and characterisation of iron boride layers by pack boronising of a Vanadis 6 tool steel. The boride layers were produced at 900°C for 2h using different pack compositions in order to obtain a single-phase boride layer. The layers were characterized...... by electron microscopy, glow discharge optical emission spectroscopy, X-ray diffraction, Vickers hardness tests and wear testing with a pin-on-disc tribometer. It was found that the type of boride phases (FeB and/or Fe2B) present in the treated layer can be controlled by changing the boron activity...

  9. Sputter deposition and characterisation of hard wear-resistant Ti/TiN multilayers

    Energy Technology Data Exchange (ETDEWEB)

    Simmonds, M.C.; Swygenhoven, H. van [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1997-09-01

    Multilayered Ti/TiN thin films have been synthesized by magnetron sputter deposition. Alternating layers of Ti and TiN with layer thickness in the 5-50 nm range are sequentially deposited. The structure of the films have been characterised by atomic force microscopy (AFM), X-ray diffraction and reflection and Auger depth profiling. The mechanical properties have been investigated using pin-on-disc wear rate testing, nanoindentation determination of hardness and micro scratch testing. (author) 1 fig., 3 refs.

  10. Effect of Age-Hardening Treatment on Microstructure and Sliding Wear-Resistance Performance of WC/Cu-Ni-Mn Composite Coatings

    Science.gov (United States)

    Liu, Jun; Yang, Shuai; Liu, Kai; Gui, Chibin; Xia, Weisheng

    2017-06-01

    The Cu-Ni-Mn alloy-based hardfacing coatings reinforced by WC particles (WC/Cu-Ni-Mn) were deposited on a steel substrate by a manual oxy-acetylene weld hardfacing method. A sound interfacial junction was formed between the WC particles and the Cu-Ni-Mn alloy metal matrix binder even after the age-hardening treatment. The friction and wear behavior of the hardfacing coatings was investigated. With the introduction of WC particles, the sliding wear resistance of the WC/Cu-Ni-Mn hardfacing coatings was sharply improved: more than 200 times better than that of the age-hardening-treated Cu-Ni-Mn alloy coating. The sliding wear resistances of the as-deposited and the age-hardening-treated WC/Cu-Ni-Mn hardfacing coatings were 1.83 and 2.26 times higher than that of the commercial Fe-Cr-C hardfacing coating, which is mainly ascribed to the higher volume fraction of carbide reinforcement. Owing to the precipitation of the NiMn secondary phase in the Cu-Ni-Mn metal matrix, the age-hardening-treated coating had better wear resistance than that of the as-deposited coating. The main sliding wear mechanisms of the age-hardening-treated coatings are adhesion and abrasion.

  11. Improvement of wear resistance of AZ31 and AZ91HP by high current pulsed electron beam treatment

    Institute of Scientific and Technical Information of China (English)

    GAO Bo; HAO Sheng-zhi; DONG Chuang; TU Gan-feng

    2005-01-01

    The surface modification of magnesium alloys (AZ31 and AZ91HP) was studied by a high current pulsed electron beam(HCPEB). The results show that the cross-sectional microhardness of treated samples increases not only in the heat affected zone(HAZ), but also beyond HAZ, reaching over 250 μm. This is due to the action of quasi-static thermal stress and the shock thermal stress wave with materials, which result in its fast deformation on the surface layer and so increases microhardness. For the AZ91HP alloy, a nearly complete dissolution of the intermetallic phase Mg17Al12 is observed, and a super-saturated solid solution forms on the re-melted surface, which is due to the solute trapping effect during the fast solidification process. Measurements on sliding wear show that wear resistance is improved by approximately 5.6 and 2.4 times for the AZ31 and AZ91HP respectively, as compared with as-received samples.

  12. 强化地板液体耐磨纸性能的研究%Research on the Properties of Liquid Wear-resisting Paper for Laminate Flooring

    Institute of Scientific and Technical Information of China (English)

    黄玲玲; 肖飞; 吉军; 郭晓磊; 曹平祥

    2012-01-01

    采用耐磨微粒液相喷涂技术与装备,研究了胶种、调胶工艺、耐磨微粒与表面改性等对强化地板表面耐磨性能的影响,发现了MF性能与耐磨微粒分布均匀度密切相关,并且耐磨微粒材料、表面改性、粒径与喷涂量对强化地板耐磨转数具有影响.当三氧化二铝(Al2O3)耐磨微粒与MF的质量比为0.35~0.45时,表面改性的耐磨微粒(220目的Al2O3)能大幅度改善耐磨性能.此外,调胶工艺与耐磨纸的预固化度对耐磨性能也有不同程度的影响.%The influences of resin types, glue mixing process, wear-resisting particles and surface modification on surface abrasion resistance of laminate flooring were studied by using liquid spraying technology and relevant equipment. The results showed that: the performance of MF closely influenced the disper-sity of wear resisting material: types, surface modification, particle size and spraying amount of wear resisting materials had different influences on the product abrasion resistance: the modified A1203(220#) could significantly improve the wear-resisting properties of the product when mass ratio of the modified Al2O3to MFwas 0.35-0.45: in addition, the glue mixing process and pre-curing degree of liquid wear-resisting paper affected the abrasion value to some degree.

  13. Experimental Study of the Wear Resistance of TiC/7075 Al Matrix Composite%TIC/7075铝基复合材料的磨损实验研究

    Institute of Scientific and Technical Information of China (English)

    刘慧敏; 宋振东; 许萍; 张晶

    2011-01-01

    The TiC reinforced 7075 Al matrix composites have been fabricated by melt in situ reaction spray deposition. The microstructures of spray-deposited alloys were studied using SEM and TEM.The dry sliding wear behavior of the alloys was investigated using a pin-on-disc machine under four loads, namely 8.9, 17.8, 26.7 and 35.6N. It has been found that the wear behavior of the alloys was dependent on the TiC content in microstructure and applied load. At lower load (8.9N), with increasing TiC content, the wear rate of the alloy was decreased. At higher loads (26.7, 35.6N), spray-deposited 7075 Al alloy exhibited superior wear resistance to the TiC/7075 composites.%采用原位反应喷射沉积法制备TiC/7075铝基复合材料,并在销一盘式磨损机损上进行摩擦磨损实验研究.通过TEM观察原位TiC颗粒的分布与形貌,并利用SEM观察沉积态组织磨损表面形貌.结果表明:复合材料的耐磨性和TiC颗粒含量及载荷有关,在低载荷(8.9N)状态下,材料的耐磨性随TiC颗粒含量的增加而增强,在高载荷(26.7,35.6N)状态下,材料的耐磨性随TiC颗粒含量的增加而减小.

  14. Development of Centrifugal Cast High Speed Steel Roll with High Wear Resistance for Pre-Finishing Stands of a Hot Rod-Wire Mill

    Institute of Scientific and Technical Information of China (English)

    JIANG Zhi-qiang; FENG Xi-lan; FU Han-guang; SHA Quan-you

    2004-01-01

    The present study aims at developing high speed steel ( HSS ) as roll materials to replace traditional roll materials such as the alloy cast iron and powder metallurgical (PM) hard alloy, because lowcost alley cast iron rolls have poor wear resistance and the cost of high-quality PM hard alloy rolls is too high to be accepted by some users. By means of a centrifugal casting method, HSS rolls with excellent wear resistance have been developed. Its hardness is 65 ~ 67HRC, and its variation is smaller than 2HRC ; its impact toughness excels 15J/cm2. Using pre-finishing stands of a high-speed hot wire-rod rolling mill, the wear raze of HSS rolls per one thousand ton of steel is 0. 25mm. However, the manufacturing burden of HSS rolls is obviously lower than that of PM hard alloy rolls; it is only 30% of that of PM hard alloy rolls.

  15. Sliding Wear and Fretting Wear of DLC-Based, Functionally Graded Nanocomposite Coatings

    Science.gov (United States)

    Miyoshi, K.; Pohlchuck, B.; Street, Kenneth W.; Zabinski, J. S.; Sanders, J. H.; Voevodin, A. a.; Wu, R. L. C.

    1999-01-01

    -DLC/Ti-Ti(sub x) C(sub y)-DLC-coated AISI 440C disk and on a titanium-6 wt % aluminum-4 wt% vanadium (Ti-6Al-4V) flat, both in contact with a 9.4-mm-diameter, hemispherical Ti-6Al-4V pin. The resistance to fretting wear and damage of the a-DLC/Ti-6Al-4V materials pair was superior to that of the Ti-6Al-4V/Ti-6AI-4V materials pair.

  16. Effect of nanocrystalline TiC powder addition on the hardness and wear resistance of cast iron

    Energy Technology Data Exchange (ETDEWEB)

    Razavi, Mansour [Materials and Energy Research Center, P.O. Box 1455-4777, Tehran (Iran, Islamic Republic of)], E-mail: m-razavi@merc.ac.ir; Rahimipour, Mohammad Reza [Materials and Energy Research Center, P.O. Box 1455-4777, Tehran (Iran, Islamic Republic of); Rajabi-Zamani, Amir Hossein [Materials and Energy Research Center, P.O. Box 1455-4777, Tehran (Iran, Islamic Republic of)

    2007-04-25

    In this research, the feasibility of the addition of nanocrystalline TiC particles - synthesized via mechanical alloying - to iron matrix melt was investigated. For the preparation of TiC, impure titanium chips and carbon black were placed in a high-energy ball mill and sampled after different milling time. XRD studies showed that at milling times more than 15 h, TiC was synthesized. It was observed from the peak broadening of the diffraction patterns that the TiC crystallites were in the scale of nanometer. 0.96 wt.% TiC synthesized after 15 h was added to a 4 wt.% C cast iron melt. It was observed that this small amount of TiC was enough to improve the structure, hardness and wear resistance of the cast iron significantly.

  17. Effect of Hot Deformation on Formation and Growth of Thermal Fatigue Crack in Chromium Wear Resistant Cast Iron

    Institute of Scientific and Technical Information of China (English)

    CHANG Li-min; LIU Jian-hua

    2006-01-01

    The formation and growth of thermal fatigue crack in chromium wear resistant cast iron was investigated, and the effect of hot deformation on the crack was analyzed by means of optical microscope and scanning electron microscope and high frequency induction thermal fatigue tester. The results show that eutectic carbide is the main location and passage for initiation and extension of thermal fatigue cracks, hot deformation can improve the eutectic carbide′s morphology and distribution, inhibit the generation and propagation of thermal fatigue cracks. In the experiment, the propagation rate of thermal fatigue crack reduces with the quantity of hot deformation increasing, which was analyzed in the point view of the activation energy of crack propagation.

  18. Hardface coating systems and methods for metal alloys and other materials for wear and corrosion resistant applications

    Energy Technology Data Exchange (ETDEWEB)

    Seals, Roland D.

    2015-08-18

    The present disclosure relates generally to hardface coating systems and methods for metal alloys and other materials for wear and corrosion resistant applications. More specifically, the present disclosure relates to hardface coatings that include a network of titanium monoboride (TiB) needles or whiskers in a matrix, which are formed from titanium (Ti) and titanium diboride (TiB.sub.2) precursors by reactions enabled by the inherent energy provided by the process heat associated with coating deposition and, optionally, coating post-heat treatment. These hardface coatings are pyrophoric, thereby generating further reaction energy internally, and may be applied in a functionally graded manner. The hardface coatings may be deposited in the presence of a number of fluxing agents, beta stabilizers, densification aids, diffusional aids, and multimode particle size distributions to further enhance their performance characteristics.

  19. Hydrophobicity attainment and wear resistance enhancement on glass substrates by atmospheric plasma-polymerization of mixtures of an aminosilane and a fluorocarbon

    Science.gov (United States)

    Múgica-Vidal, Rodolfo; Alba-Elías, Fernando; Sainz-García, Elisa; Pantoja-Ruiz, Mariola

    2015-08-01

    Mixtures of different proportions of two liquid precursors were subjected to plasma-polymerization by a non-thermal atmospheric jet plasma system in a search for a coating that achieves a hydrophobic character on a glass substrate and enhances its wear resistance. 1-Perfluorohexene (PFH) was chosen as a low-surface-energy precursor to promote a hydrophobic character. Aminopropyltriethoxysilane (APTES) was chosen for its contribution to the improvement of wear resistance by the formation of siloxane bonds. The objective of this work was to determine which of the precursors' mixtures that were tested provides the coating with the most balanced enhancement of both hydrophobicity and wear resistance, given that coatings deposited with fluorocarbon-based precursors such as PFH are usually low in resistance to wear and coatings deposited with APTES are generally hydrophilic. The coatings obtained were analyzed by Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM), Fourier Transform Infra-Red (FTIR) spectroscopy, X-ray Photoelectron Spectroscopy (XPS), static Water Contact Angle (WCA) measurements, tribological ball-on-disc tests and contact profilometry. A relationship between the achievement of a hydrophobic character and the modifications to roughness and surface morphology and the incorporation of fluorocarbon groups in the surface chemistry was observed. Also, it was seen that the wear resistance was influenced by the SiOSi content of the coatings. In turn, the SiOSi content appears to be directly related to the percentage of APTES used in the mixture of precursors. The best conjunction of hydrophobicity and wear resistance in this work was found in the sample that was coated using a mixture of APTES and PFH in proportions of 75 and 25%, respectively. Its WCA (100.2 ± 7.5°) was the highest of all samples that were measured and more than three times that of the uncoated glass (31 ± 0.7°). This sample underwent a change from a hydrophilic to a

  20. Industrial scale HP-HT synthesis of hard and wear resistant c-Zr3N4

    Science.gov (United States)

    Dzivenko, Dmytro; Riedel, Ralf; Taniguchi, Takashi; Chauveau, Thierry; Zerr, Andreas

    2013-06-01

    We present a large scale high-pressure high-temperature (HP-HT) synthesis of hard and wear resistant cubic zirconium nitride having Th3P4-type structure,c-Zr3N4. This material, also available as well-adhesive coatings with exceptional wear resistance, represents a compound competitive to diamond and c-BN with respect to machining of low-carbon steels and other ferrous alloys. We obtained c-Zr3N4 powder at pressures as low as 6.5 GPa and temperatures of 1400-1600 °C from nanocrystalline Zr3N4+x precursor using a belt-type apparatus - a static HP-HT device widely employed for the commercial production of diamond and c-BN. The HP products are characterized in details by means of powder X-ray diffraction, Raman spectroscopy, scanning electron microscopy and combustion elemental analysis. In addition to major polycrystalline c-Zr3N4, we unveil the formation of a quaternary compound c-(Zr1-xTax)3 (N1-yOy)4 which indicates the possibility of doping of c-Zr3N4, thus introducing it for practical application as a multifunctional material. Moreover, we consider ways of cementing the c-Zr3N4 powders (similar to cemented tungsten carbides) which would allow economic fabrication of large bodies based on this compound. Supported by the DFG (Bonn, Germany) within SPP 1236 and by the IFR ``Paris Nord Plaine de France''.

  1. Lead-free, bronze-based surface layers for wear resistance in axial piston hydraulic pumps

    Energy Technology Data Exchange (ETDEWEB)

    Vetterick, Gregory Alan [Iowa State Univ., Ames, IA (United States)

    2010-01-01

    Concerns regarding the safety of lead have provided sufficient motivation to develop substitute materials for the surface layer on a thrust bearing type component known as a valve plate in axial piston hydraulic pumps that consists of 10% tin, 10% lead, and remainder cooper (in wt. %). A recently developed replacement material, a Cu-10Sn-3Bi (wt.%) P/M bronze, was found to be unsuitable as valve plate surface layer, requiring the development of a new alloy. A comparison of the Cu-1-Sn-10Pb and Cu-10Sn-3Bi powder metal valve plates showed that the differences in wear behavior between the two alloys arose due to the soft phase bismuth in the alloy that is known to cause both solid and liquid metal embrittlement of copper alloys.

  2. Corrosion and Wear Resistance Characterization of Environmentally Friendly Sol-gel Hybrid Nanocomposite Coating on AA5083

    Institute of Scientific and Technical Information of China (English)

    Hamed Rahimi; Reza Mozaffarinia; Akbar Hojjati Najafabadi

    2013-01-01

    Environmentally friendly organic-inorganic hybrid nanocomposite films have been developed by sol-gel method for corrosion protection of AA5083 alloy.The hybrid nanocomposite coatings have been synthesized from tetraethylorthosilicate (TEOS) and 3-glycidoxypropyltrimethoxysilane (GPTMS) precursors.The multilayer coatings were prepared by dip-coating technique.Attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy was carried out to show the formation of the Si-O-Si structural backbone of the hybrid coatings.Structure and surface morphology of the coatings were studied by optical microscopy (OM),scanning electron microscopy (SEM) and atomic force microscopy (AFM).Characterization of the coatings with respect to pencil scratch hardness,adhesive and abrasion resistance was performed.The corrosion protection performance of these coatings was examined by using cyclic potentiodynamic polarization technique in Persian Gulf water.The results revealed that crack-free films with smooth surface were obtained.With increasing the number of sol-gel coated layers,corrosion resistance increased from 81 to 419 kΩ cm2,while the abrasion wear resistance did not change significantly.However,the triple sol-gel coated layer offered excellent protection against corrosion.

  3. Characterization and wear resistance of macro-arc oxidation coating on magnesium alloy AZ91 in simulated bedy fluids

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The mechanical characteristics ofthe macro-arc oxidation(MAO) coating on Mg alloy AZ91 were examined by means of nano scratch tester.The corrosion and erosion corrosion behavior of AZ91 with and without MAO coating were investigated by using potentiodynamic electrochemical technique and micro-abrasion tribometer in simulated body fluids,respectively.The influence of HCO3-ions on the erosion corrosion was discussed.The results show that the coating and its substrate are in a pronounced bond.The MAO coating inereases1-2 orders of magnitude of the corrosion resistance of AZ91 alloy.HCO3-ions enhance the corrosion rates of the AZ91 alloys more significantly than the alloys with MAO coating.However,there exists an obvious passivation process of AZ91 without coating in the HCO3-solutions.Moreover,an MgCO3 film formed in HCO3-containing solutions leads to an enhancement in micro-wear resistance.MAO coating deteriorates the erosion corrosion resistance of AZ91 alloy due to the formation of oxidation debris resulted from the broken MAO coating.

  4. Effect of high-manganese cast steel strain hardening on the abrasion wear resistance in a mixture of SiC and water

    Directory of Open Access Journals (Sweden)

    Kalandyk B.

    2013-12-01

    Full Text Available The study attempts to determine the impact of the high-manganese cast steel strain hardening on its abrasion wear resistance in a mixture of SiC and water prepared in accordance with ASTM G75. For tests, the high-manganese cast steel containing 10.7, 17.9 and 20.02% Mn was selected. The results of microstructure examinations and abrasion wear resistance tests carried out on the material in non-hardened condition and after strain hardening with a force of 539.55kN were disclosed. Additionally, the surface of samples after a 16-hour cycle of abrasion tests was examined. Moreover, based on the obtained results, the effect of different contents of Mn in cast steel was studied, mainly in terms of its impact on the abrasion wear resistance. The results obtained on the tested materials were compared with the results obtained on the low-alloyed abrasion wear-resistant cast steel L35GSM.

  5. Effect of pressing temperature on the wear resistance of a Co-based Cr-Mo powder alloy produced by hot pressing

    Energy Technology Data Exchange (ETDEWEB)

    Somunkiran, Ilyas [Firat Univ., Elazig (Turkey). Metallurgical and Materials Engineering Dept.; Balin, Ahmet [Siirt Univ. (Turkey). Dept. of Vocational High School

    2016-02-01

    In this study, Co-based Cr-Mo powder alloy was produced at different pressing temperatures by using hot pressing technique and abrasive wear behaviors of the produced specimens were examined. Produced specimens were exposed to abrasive wear experiment using block on disc wear test device by applying a load of 50 N with 100-mesh SiC abrasive paper. Each specimen was investigated at 25, 50, 75 and 100 m. At the end of the experiment, abrasive wear results of the specimens were determined by calculating their mass losses. Microstructural properties of the specimens which were produced at different pressing temperatures were investigated by optical and SEM examinations and their wear resistances were examined by abrasive wear experiments. Consequently, it was observed that in Co-based Cr-Mo powder alloy produced by hot pressing technique; as sintering temperature increased, size of neck formations between the powder grains increased, porosity decreased and abrasive wear resistance increased. [German] In diesem Beitrag zugrunde liegenden Studie wurde eine Co-basierte Cr-Mo-Legierung mittels Heisspressens hergestellt und der Abrasivverschleisswiderstand dieser Proben untersucht. Die hergestellten Proben wurden dem Abrasivverschleissversuch durch einen Block-Scheibe-Versuchsaufbau unterzogen, wobei eine Kraft von 50 N mit einem SiC-Papier (100 mesh) verwendet wurde. Jede Probe wurde ueber eine Distanz von 25, 50, 75 und 100 m untersucht. Am Ende der jeweiligen Experimente wurden die Abrasivverschleissergebnisse ermittelt, indem die Massenverluste berechnet wurden. Die mikrostrukturellen Eigenschaften der Proben, die bei verschiedenen Presstemperaturen hergestellt wurden, wurden mittels optischer und Rasterelektronenmikroskopie bestimmt und ihr Verschleisswiderstand anhand der Verschleissversuche ermittelt. Schliesslich wurde beobachtet, dass bei steigender Sintertemperatur der heissgespressten Co-basierten Cr-Mo-Pulverlegierung die Groesse der Einschnuerungen zwischen den

  6. Effect of deep cryogenic treatment and tempering on microstructure and mechanical behaviors of a wear-resistant austempered alloyed bainitic ductile iron

    Directory of Open Access Journals (Sweden)

    Chen Liqing

    2015-01-01

    Full Text Available In this paper, the effect of deep cryogenic treatment in combination with conven- tional heat treatment process was investigated on microstructure and mechanical behaviors of alloyed bainitic ductile iron. Three processing schedules were employed to treat this alloyed ductile iron including direct tempering treatment, tempering.+deep cryogenic treatment and deep cryogenic treatment.+tempering treatments. The microstructure and mechanical behavior, especially the wear resistance, have been evaluated after treated by these three schedules. The results show that martensite microstructure can be obviously refined and the precipitation of dispersed carbides is promoted by deep cryogenic treatment at .−196 ∘C for 3 h after tempered at 450 ∘C for 2 h. In this case, the alloyed bainitic ductile iron possesses rather high hardness and wear-resistance than those processed by other two schedules. The main wear mechanism of the austempered alloyed ductile iron with deep cryogenic treatment and tempering is micro-cutting wear in association with plastic deformation wear.

  7. Effect of In-Office Carbamide Peroxide-Based Tooth Bleaching System on Wear Resistance of Silorane-Based and Methacrylate-Based Dental Composites

    Science.gov (United States)

    Hasani Tabatabaei, Masoumeh; Sheikhzadeh, Sedigheh; Ghasemi Monfared Rad, Hamidreza; Beygi, Ahmad

    2015-01-01

    Objectives: Several studies have assessed the characteristics and properties of silorane-based composites and adhesive systems. Considering the extensive application of tooth-whitening agents, possible deteriorative effects of tooth bleaching agents on these restorative materials must be studied. The aim of this study was to evaluate the effect of an in-office carbamide peroxide-based tooth bleaching agent on the wear resistance of a silorane-based and a conventional microhybrid dimethyl methacrylate-based dental composite with two different application times. Materials and Methods: Thirty cylindrical specimens were made of Z250 and P90 dental composite resins (n=15 for each composite). Samples made of each composite were divided into three groups (n=5) for immersion in an in-office bleaching agent (Opalescence® Quick 45%) for either three or eight hours or saline solution (control). Wear tests were conducted after bleaching using a pin-on disk apparatus under the load of 40N at a constant sliding speed of 0.5 ms−1 for a sliding distance of 300 m. The samples were weighed before and after the wear test. Repeated measures ANOVA was used to statistically analyze the obtained data (α=0.05). Results: There was a significant decrease in the weight of samples after the wear test (P0.05). Conclusion: Bleaching for three or eight hours using 45% carbamide peroxide had no deteriorative effect on the wear resistance of Z250 and P90 composites. PMID:27123014

  8. Thickness effects on corrosion and wear resistance properties of micro-arc discharge oxide coatings on AZ91D magnesium alloys

    Institute of Scientific and Technical Information of China (English)

    HUANG Wei-jiu; LIU Ming; LI Zhao-feng; ZENG Rong-chang

    2006-01-01

    The microarc oxidation coatings with difference thickness were synthesized on AZ91D magnesium alloy. The microstructure and phase structure of the coatings were analyzed using SEM and XRD, the tribological properties and corrosion resistance behaviour of the coatings were also investigated. The results show that the coating contains two layers, a porous outer layer and relatively dense inner layer. The microhardness of the MAO coatings is four to six times higher than that of the magnesium alloy substrate. The MAO coatings have much better wear-resistance and corrosion resistance abilities than those of magnesium alloy substrate, but possess higher friction coefficient. The results further indicate that there is an optimization thickness for corrosion and wear resistance.

  9. Effect of Friction-Induced Deformation on the Structure, Microhardness, and Wear Resistance of Austenitic Chromium—Nickel Stainless Steel Subjected to Subsequent Oxidation

    Science.gov (United States)

    Korshunov, L. G.; Chernenko, N. L.

    2016-03-01

    The effect of plastic deformation that occurs in the zone of the sliding friction contact on structural transformations in the 12Kh18N9T austenitic steel subjected to subsequent 1-h oxidation in air at temperatures of 300-800°C, as well as on its wear resistance, has been studied. It has been shown that severe deformation induced by dry sliding friction produces the two-phase nanocrystalline γ + α structure in the surface layer of the steel ~10 μm thick. This structure has the microhardness of 5.2 GPa. Subsequent oxidation of steel at temperatures of 300-500°C leads to an additional increase in the microhardness of its deformed surface layer to the value of 7.0 GPa. This is due to the active saturation of the austenite and the strain-assisted martensite (α') with the oxygen atoms, which diffuse deep into the metal over the boundaries of the γ and α' nanocrystals with an increased rate. The concentration of oxygen in the surface layer of the steel and in wear products reaches 8 wt %. The atoms of the dissolved oxygen efficiently pin dislocations in the γ and α' phases, which enhances the strength and wear resistance of the surface of the 12Kh18N9T steel. The oxidation of steel at temperatures of 550-800°C under a light normal load (98 N) results in the formation of a large number of Fe3O4 (magnetite) nanoparticles, which increase the resistance of the steel to thermal softening and its wear resistance during dry sliding friction in a pair with 40Kh13 steel. Under a heavy normal load (196 N), the toughness of 12Kh18N9T steel and, therefore, the wear resistance of its surface layer decrease due to the presence of the brittle oxide phase.

  10. Creep behavior and wear resistance of Al 5083 based hybrid composites reinforced with carbon nanotubes (CNTs) and boron carbide (B{sub 4}C)

    Energy Technology Data Exchange (ETDEWEB)

    Alizadeh, Ali [Faculty of Materials & Manufacturing Processes, Malek-e-Ashtar University of Technology, Tehran (Iran, Islamic Republic of); Abdollahi, Alireza, E-mail: alirezaabdollahi1366@gmail.com [Faculty of Materials & Manufacturing Processes, Malek-e-Ashtar University of Technology, Tehran (Iran, Islamic Republic of); Biukani, Hootan [Faculty of Engineering, South Tehran Branch, Islamic Azad University, Tehran (Iran, Islamic Republic of)

    2015-11-25

    In the current research, aluminum based hybrid composite reinforced with boron carbide (B{sub 4}C) and carbon nanotubes (CNTs) was produced by powder metallurgy method. creep behavior, wear resistance, surface roughness, and hardness of the samples were investigated. To prepare the samples, Al 5083 powder was milled with boron carbide particles and carbon nanotubes using planetary ball mill under argon atmosphere with ball-to-powder weight ratio of 10:1 for 5 h. Afterwards, the milled powders were formed by hot press process at 380{sup °}C and then were sintered at 585{sup °}C under argon atmosphere for 2 h. There was shown to be an increase in hardness values of composite with an increase in B{sub 4}C content. The micrograph of worn surfaces indicate a delamination mechanism due to the presence of CNTs and abrasion mechanism in composite containing 10 vol.%B{sub 4}C. Moreover, it was shown that increasing B{sub 4}C content increases the wear resistance by 3 times under a load of 20 N and 10 times under a load of 10 N compared to CNTs-reinforced composite. surface roughness of the composite containing 5 vol.%CNT has shown to be more than other samples. The results of creep test showed that adding carbon nanotubes increases creep rate of Al 5083 alloy; however, adding B{sub 4}C decreases its creep rate. - Highlights: • Al 5083/(CNTs + B{sub 4}C) hybrid composite was produced by powder metallurgy method. • Creep behavior, wear resistance, surface roughness, and Hardness of samples were investigated. • Addition of CNTs to Al 5083 matrix reduces alloy hardness, wear resistance and creep strength. • By addition of B{sub 4}C and composite hybridization, creep strength and wear resistance increased. • Surface roughness of Al-5 vol.%CNT has shown to be more than other samples.

  11. Erosive Wear and Wear Mechanism of in situ TiCp/Fe Composites

    Institute of Scientific and Technical Information of China (English)

    Zhaojing LIU; Zhiliang NING; Fengzhen LI; Xiurong YAO; Shanzhi REN

    2005-01-01

    The base structure of in situ TiCP/Fe composites fabricated under industrial condition was changed by different heat treatments. Erosive wear tests were carried out and the results were compared with that of wear-resistant white cast iron. The results suggest that the wear resistance of the in situ TiCp/Fe composite is higher than that of wear-resistant white cast iron under the sand erosive wear condition. The wear mechanism of the wear-resistant white cast iron was a cycle process that base surface was worn and carbides were exposed, then carbides was broken and wear pits appeared. While the wear mechanism of in situ TiCp/Fe composite was a cycle process that base surface was worn and TiC grains were exposed and dropped. The wear resistance of in situ TiCp/Fe composite was lower than that of wear-resistant white cast iron under the slurry erosive wear condition. Under such circumstance,the material was not only undergone erosive wear but also electrochemistry erosion due to the contact with water in the medium. The wear behaviours can be a combination of two kinds of wear and the sand erosive wear is worse than slurry erosive wear.

  12. THE MECHANISM OF STRUCTURE FORMATION IN SPARINGLY ALLOYED WEAR RESISTANT IRONS

    OpenAIRE

    A. I. Garost

    2012-01-01

    The results of researches of macro - and microstructure, the structure, formed at primary crystallization of abrasion-resistant irons, and peculiarities of their change in process of thermal processing are given. 

  13. 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.

  14. Influence of Plasma Transferred Arc Process Parameters on Structure and Mechanical Properties of Wear Resistive NiCrBSi-WC/Co Coatings

    Directory of Open Access Journals (Sweden)

    Eitvydas GRUZDYS

    2011-07-01

    Full Text Available Self-fluxing NiCrBSi and related coatings received considerable interest due to their good wear as well as corrosion resistance at moderate and elevated temperatures. Hard tungsten carbide (WC particles can be included in NiCrBSi for further increase of the coating hardness and abrasive wear resistance. Flame spray technique is widely used for fabrication of NiCrBSi films. However, in such a case, subsequent remelting of the deposited coatings by flame, arc discharge or high power laser beam is necessary. In present study NiCrBSi-WC/Co coatings were formed using plasma transferred arc process. By adjusting plasma parameters, such as current, plasma gas flow, shielding gas flow, a number of coatings were formed on steel substrates. Structure of the coatings was investigated using X-ray diffractometry. Microstructure of cross-sectioned coatings was examined using scanning electron microscopy. Hardness of the coating was evaluated by means of the Vickers hardness tests. Wear tests were also performed on specimens to determine resistance to abrasive wear. Acquired results allowed estimating the influence of the deposition process parameters on structure and mechanical properties of the coatings.http://dx.doi.org/10.5755/j01.ms.17.2.482

  15. Evaluation of polymerization shrinkage, polymerization shrinkage stress, wear resistance, and compressive strength of a silorane-based composite: A finite element analysis study

    Directory of Open Access Journals (Sweden)

    Suresh Mitthra

    2017-01-01

    Full Text Available Background: Understanding the mechanical properties is important in predicting the clinical behavior of composites. Finite element analysis (FEA evaluates properties of materials replicating clinical scenario. Aim: This study evaluated polymerization shrinkage and stress, wear resistance (WR, and compressive strength (CS of silorane in comparison with two methacrylate resins. Settings and Design: This study design was a numerical study using FEA. Materials and Methods: Three-dimensional (3D models of maxillary premolar with Class I cavities (2 mm depth, 4 mm length, and 2.5 mm width created and restored with silorane, nanohybrid, and microhybrid; Groups I, II, and III, respectively. Loads of 200–600 N were applied. Polymerization shrinkage was first determined by displacement produced in the X, Y, and Z planes. Maximum stress distribution due to shrinkage was calculated using AN SYS software. 3D cube models of composite resins were simulated with varying filler particle size. Similar loads were applied. WR and compressive stress were calculated: K W L/H and load/cross-sectional area, respectively. Statistical analysis done using one-way ANOVA, Kruskal–Wallis, and Tukey's honestly significant difference test (P < 0.05. Results: Polymerization shrinkage (0.99% and shrinkage stress (233.21 Mpa of silorane were less compared to microhybrid (2.14% and 472.43 Mpa and nanohybrid (2.32% and 464.88 Mpa. Silorane (7.92×/1011 μm/mm3 and nanohybrid (7.79×/1011 showed superior WR than microhybrid (1.113×/1017. There was no significant difference in compressive stress among the groups. Conclusion: Silorane exhibited less polymerization shrinkage and shrinkage stress compared to methacrylates. Silorane and nanohybrid showed greater WR compared to microhybrid. CS of all groups was similar.

  16. Surface wear resistance properties of Ta+N implanted W18Cr4V high speed steel

    Institute of Scientific and Technical Information of China (English)

    CAO Wei; LI Bing-wen; GUO Chu-wen; MAO Xin-yuan; MA Qin-qin

    2009-01-01

    High-speed steel W18Cr4V is commonly used in industries such as blade and mould manufacturers because of its high level of hardness and toughness, red-hardness and resistance. Ion implantation is an effective method to improve the wear resis-tance of W18Cr4V. In our investigation, Ta and Ta+N ion implantation was performed on W18Cr4V high-speed steel. The surface properties after implantation were evaluated by measuring friction coefficients while the carbonyl phase of the surface was ana-lyzed by X-ray diffraction analysis. It was found that the friction coefficients of the treated samples were much lower. Samples implanted with Ta+N had a lower friction coefficients than samples implanted only with Ta. This can be attributed to the formation of a new chemical compound, Fe7Ta3, on both surfaces. An even harder chemical compound, Fe2N, was formed on both sttrfaces of Ta+N implanted samples.

  17. Raising the heat and wear resistances of hardened carbon steels by friction strengthening treatment

    Science.gov (United States)

    Makarov, A. V.; Korshunov, L. G.; Malygina, I. Yu.; Solodova, I. L.

    2007-03-01

    The effect of friction treatment by a hard-alloy indenter on the microhardness and resistance to the heat-induced softening upon tempering of hardened medium-and high-carbon steels at 100-600°C is studied. The x-ray and electron microscopy methods are used to determine the causes of the increase in the heat resistance of the friction-strained steel surfaces. A comparative analysis of the effect of the hardening treatment by a hard-alloy indenter and by abrasive particles on the friction-induced heat resistance is performed for the case of high-speed friction treatment of a high-carbon laser-hardened steel.

  18. The Study of Corrosion and Wear Resistance of Copper Composite Coatings with Inclusions of Carbon Nanomaterials in the Copper Metal Matrix

    Directory of Open Access Journals (Sweden)

    Viktorija MEDELIENĖ

    2011-07-01

    Full Text Available This paper deals with the peculiarities of the behaviour of copper nanocomposite coatings with CNMs inclusions under the free corrosion conditions in the acidic medium. The parameters of corrosion current density (jcorr, anodic dissolution current density (ia and polarization resistance (Rp have been determined. In the acidic medium a stronger oxidation of nanostructured copper nanocomposites occurred. With longer immersion periods more corrosion products are formed, resulting in a increase in the polarization resistance (Rp of corrosion. Corrosion products cover the whole surface of the coatings and the corrosion rate (jcorr tends towards a steady value of 1.7×10-3 ¸ 2.1×10-3 A·cm-2 for all copper coatings studied: 1.7×10-3 A·cm-2 for both Cu and Cu-CNM1, 1.9×10-3 A·cm-2 - for Cu-CNM2 and 2.1×10-3 A·cm-2 - for Cu-CNM3 composite coatings. It has been established that nanocomposites possess a higher wear resistance as compared to that of pure copper. The damage of metal characterized as a depth scar (đ is lower. The roughness of the composites studied was found to be the essential factor affecting their wear resistance. Therefore, the wear resistance of nanocomposites is impaired when they are deposited on a hard steel substrate.http://dx.doi.org/10.5755/j01.ms.17.2.481

  19. The Study of Corrosion and Wear Resistance of Copper Composite Coatings with Inclusions of Carbon Nanomaterials in the Copper Metal Matrix

    Directory of Open Access Journals (Sweden)

    Viktorija MEDELIENĖ

    2011-07-01

    Full Text Available This paper deals with the peculiarities of the behaviour of copper nanocomposite coatings with CNMs inclusions under the free corrosion conditions in the acidic medium. The parameters of corrosion current density (jcorr, anodic dissolution current density (ia and polarization resistance (Rp have been determined. In the acidic medium a stronger oxidation of nanostructured copper nanocomposites occurred. With longer immersion periods more corrosion products are formed, resulting in a increase in the polarization resistance (Rp of corrosion. Corrosion products cover the whole surface of the coatings and the corrosion rate (jcorr tends towards a steady value of 1.7×10-3 ¸ 2.1×10-3 A·cm-2 for all copper coatings studied: 1.7×10-3 A·cm-2 for both Cu and Cu-CNM1, 1.9×10-3 A·cm-2 - for Cu-CNM2 and 2.1×10-3 A·cm-2 - for Cu-CNM3 composite coatings. It has been established that nanocomposites possess a higher wear resistance as compared to that of pure copper. The damage of metal characterized as a depth scar (đ is lower. The roughness of the composites studied was found to be the essential factor affecting their wear resistance. Therefore, the wear resistance of nanocomposites is impaired when they are deposited on a hard steel substrate.http://dx.doi.org/10.5755/j01.ms.17.2.481

  20. [Corrosion resistance and wear resistance of Ni-Cr alloy after coating titanium nitride (TiN) in oral containing fluorine environment].

    Science.gov (United States)

    Weng, Wei-Min; Yu, Wei-Qiang; Shan, Wei-Lan; Zhang, Fu-Qiang

    2010-12-01

    The aim of this study was to evaluate the corrosion resistance and wear resistance of Ni-Cr alloy after coating titanium nitride (TiN) in oral containing fluorine environment. Physical vapor deposition was established to coat titanium nitride (TiN) on the surface of dental cast Ni-Cr alloy to form TiN/Ni-Cr compound. Both Ni-Cr alloy and TiN/Ni-Cr compound were exposed to 37 degrees centigrade, artificial saliva containing 0.24% NaF. The polarization curves of the specimens were measured by PARSTAT 2273 electrochemical station to investigate its corrosion resistance. Vicker's hardness was measured by HXD-1000TMC/LCD micro-hardness tester to investigate its wear resistance. Statistical analysis was performed by SAS 8.2 software package for Student's t methods. The corrosion potential of Ni-Cr alloy was -362.407 mV, the corrosion current density was 1.568μAcm(-2),the blunt-breaking potential was 426 mV bofor TiN coating. The corrosion potential of TiN/Ni-Cr compound was -268.638 mV, the corrosion current density was 0.114μAcm(-2),the blunt-breaking potential was 1142 mV after TiN coating. Polarization curves showed TiN/Ni-Cr compound improved the corrosion potential and blunt-breaking potential, decreased the corrosion current density. The Vicker's hardness of Ni-Cr alloy was 519.75±27.27 before TiN coating, the Vicker's hardness of TiN/Ni-Cr compound was 803.24±24.64, the D-value between them was 283.49±39.34. The difference of Vicker's harnesses between Ni-Cr alloy and TiN/Ni-Cr compound had significant (Pcoating can improve the corrosion resistant to F-and the surface hardness of Ni-Cr alloy. Supported by Research Fund of Science and Technology Commission of Shanghai Municipality (Grant No.08DZ2271100), Shanghai Leading Academic Discipline Project (Grant No.S30206 ) and Research Fund of Health Bureau of Shanghai Municipality (Grant No.2009074).

  1. Wear resistance of reactive plasma sprayed and laser remelted TiB2-TiC0.3N0.7 based composite coatings against medium carbon steel

    Science.gov (United States)

    Mao, Zhengping; Wang, Jun; Sun, Baode; Bordia, Rajendra K.

    2011-01-01

    Wear resistance of reactive plasma sprayed TiB2-TiC0.3N0.7 based composite coatings and the as-sprayed coating with laser surface treatment was investigated using plate-on-plate tests. Wear tests were performed at different normal loads and sliding speeds under dry sliding conditions in air. The surface morphologies of counterparts against as-sprayed and laser remelted coatings were investigated. The microstructure and chemical composition of wear debris and coatings were studied using scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS), respectively. The results show that the wear resistance of the laser remelted coating is improved significantly due to their increased microhardness and reduced flaws. The primary wear mechanism of the remelted coating is oxidation wear and its minor wear mechanisms are grain abrasion and fatigue failure during the course of wear test. In contrast, the primary wear mechanism of the as-sprayed coating is grain abrasion at the low sliding speed (370 rpm) and fatigue failure at the high sliding speed (549 rpm). The oxidation wear mechanism is a minor contributor for the as-sprayed coating.

  2. Biofouling resistance of boron-doped diamond neural stimulation electrodes is superior to titanium nitride electrodes in vivo

    DEFF Research Database (Denmark)

    Meijs, Suzan; Alcaide, Maria; Sørensen, Charlotte;

    2016-01-01

    OBJECTIVE: The goal of this study was to assess the electrochemical properties of boron-doped diamond (BDD) electrodes in relation to conventional titanium nitride (TiN) electrodes through in vitro and in vivo measurements. APPROACH: Electrochemical impedance spectroscopy, cyclic voltammetry and ...... electrodes possess a superior biofouling resistance, which provides significantly stable electrochemical properties both in protein solution as well as in vivo compared to TiN electrodes....

  3. A method of comparing the wear resistance of various materials used for artificial teeth

    OpenAIRE

    SILVA,Claudia Maria Zarpelon; EDUARDO,José Virgílio de Paula; Milton Edson MIRANDA; BASTING, Roberta Tarkany; Olivieri, Karina Andrea Novaes

    2014-01-01

    OBJECTIVE: Abrasion resistance of three commercial brands of acrylic resin for artificial teeth, available on the domestic market (Biotone(r), Plus(r)and Vipi Dent Artiplus(r)) was evaluated by a new methodology called "Pirassununga Method ".METHODS: The Manufacturers produced the maxillary central incisor-shaped incisal resin specimens (n=27). These were embedded in chemically activated acrylic resin in an insulated metal matrix to fabricate test specimens, which were flattened on a lathe an...

  4. On the mechanism of formation of wear-resistant coatings on the friction surfaces of technical products in the presence of these drugs Tribo

    Science.gov (United States)

    Sharifullin, S. N.; Dunayev, A. V.

    2016-06-01

    Extending the service life of technical devices by exposing the surface of the friction tribo different drugs is an established fact. There are various hypotheses to explain the mechanism of formation of coatings with high wear resistance and low coefficient of friction on the mating surfaces of friction units of machines and mechanisms during their operation with the presence of drugs Tribo. All these conflicting hypotheses. The proposed technology without the wear operation of equipment using Tribo drugs differ in content and methodology of processing machinery. In this paper, an analysis of existing hypotheses formation mechanism of these coatings. The authors have their own experience in the development and application of technologies without the wear operation of equipment using Tribo drugs. This allows them to develop their own hypothesis of the mechanism of formation of coatings with high wear resistance and low coefficient of friction on the mating surfaces of friction units of machines and mechanisms during their operation with the presence of drugs Tribo.

  5. Evaluation of permanent die coatings to improve the wear resistance of die casting dies. Final project report, January 1, 1995--April 30, 1997

    Energy Technology Data Exchange (ETDEWEB)

    Shivpuri, R.

    1997-09-18

    Die Casting dies are subject to severe service conditions during the die casting operation. While these severe conditions are necessary to achieve high production rates, they cause the dies which are commonly made of H13 die steel, to suffer frequent failures. The major die failure mechanisms are erosion or washout, Heat checking, soldering and corrosion. Due to their geometrical complexity, die casting dies are very expensive (some dies cost over a million dollars), and thus a large number of parts have to be produced by a die, to justify this cost and leverage the advantages of the die casting process (high production rates, low manpower costs). A potential increase in the die service life, thus has a significant impact on the economics of the die; casting operation. There are many ways to extend die life: developing new wear resistant die materials, developing new surface treatments including coatings, improving heat treatment of existing H13 dies, using better lubricants that can protect the die material, or modifying the die geometry and process parameters to reduce the intensity of wear. Of these the use of coatings to improve the wear resistance of the die surface has shown a lot of promise. Consequently, use of coatings in the die casting industry and their wide use to decrease die wear can improve significantly the productivity of shop operations resulting in large savings in material and energy usage.

  6. Effect of Heat Treatment on the Abrasive Wear Behavior of High Chromium Iron under Dry Sliding Condition

    Directory of Open Access Journals (Sweden)

    A.A. Ayeni

    2012-06-01

    Full Text Available The effect of heat treatment on the abrasive wear behavior of high chromium cast iron (NF253AHT under dry sliding condition has been investigated. Rectangular cross sectioned samples of the alloy were produced by sand casting. After casting, the samples were machined to equal dimensions of 50 mm x 15 mm x 10 mm and heat treated by annealing, hardening and tempering. Abrasive wear tests were carried out on the samples using the pin-on-disc wear test. The tests were carried out under restricted values of speed, load and time. Within this limit, the hardened sample displayed a superior wear resistance, while the annealed sample displayed the weakest wear resistance. A graphical model (wear map displaying all the wear regimes of the alloy, which may serve as a wear predictive tool was subsequently developed from the results of the wear tests. With the exception of the as-cast and annealed specimen, all other specimens (hardened and tempered have functioned adequately in wear prone environment, but with different degree of effectiveness. Hence, the hardened and tempered samples can be used in shot blast equipments and in the grinding of minerals.

  7. Effect of laser quenching and subsequent heat treatment on the structure and wear resistance of a cemented steel 20KhN3A

    Science.gov (United States)

    Makarov, A. V.; Korshunov, L. G.; Malygina, I. Yu.; Osintseva, A. L.

    2007-05-01

    The martensite-austenite structures that are formed under the action of continuous laser irradiation in the 20KhN3A steel subjected to various regimes of cementation have been studied by metallography, electron microscopy, and X-ray diffraction. It has been established that a decrease in the amount of retained austenite in the laser-quenched structures from 40-90 to 5-35 vol % resulted from cold treatment at -196°C exerts only a small (within 10%) effect on the abrasive wear resistance of the cemented steel; the effect is negative upon microcutting and positive upon microscratching. An increase in the carbon concentration from 0.8 to 1.2 wt % in the martensite-austenite structures that are formed in the cemented steel under the action of laser irradiation and upon cold treatment leads to changes in the abrasive wear resistance by no more than 10-13%. The presence of 20-40 vol % metastable retained austenite retards the decrease in the abrasive wear resistance of the quenched steel upon subsequent low-temperature tempering. It has been shown that the laser quenching and additional cold treatment positively affect the resistance of rolling bearing units of drill bits to contact-fatigue fracture.

  8. New Wear Resistant Iron-Base Matrix Materials For The Fabrication Of Sintered Diamond Tools

    Directory of Open Access Journals (Sweden)

    Konstanty J.

    2015-06-01

    Full Text Available The possibility of the use of inexpensive iron-base powders in the production of sintered diamond tools is again explored. Ball-milled Fe-Ni-Cu-Sn-C and Fe-Mn-Cu-Sn-C powders were consolidated to a virtually pore-free condition by hot pressing at 900°C. The resultant materials are characterised by a combination of high Knoop hardness, 260-440 and yield strength, 780-1350 MPa, and resistance to abrasion. These properties can be significantly modified by changing the milling time.

  9. Amorphous metal formulations and structured coatings for corrosion and wear resistance

    Science.gov (United States)

    Farmer, Joseph C.

    2011-12-13

    A system for coating a surface comprising providing a source of amorphous metal that contains more than 11 elements and applying the amorphous metal that contains more than 11 elements to the surface by a spray. Also a coating comprising a composite material made of amorphous metal that contains more than 11 elements. An apparatus for producing a corrosion-resistant amorphous-metal coating on a structure comprises a deposition chamber, a deposition source in the deposition chamber that produces a deposition spray, the deposition source containing a composite material made of amorphous metal that contains more than 11 elements, and a system that directs the deposition spray onto the structure.

  10. Dross formation mechanism and development of wear resistant scraper in aluminum-silicon-zinc coating bath

    Science.gov (United States)

    Varadarajan, Ashok

    Steel sheet manufacturers across the globe, face a huge loss of production due to the molten metal corrosion of the pot hardware in continuous galvanizing lines. The development of steel sheet with corrosion resistant for more than 30 years using a high aluminum content zinc coating has made an impact in the construction industry. High aluminum content bath (55 wt%) causes severe corrosion of the pot hardware and causes huge repair and replacement cost with frequent stoppages. One of the main reasons for stoppages is the severe dross formation over the submerged hardware (sink roll), which results in poor coating layer over the steel sheet. Complete understanding of the mechanism of the dross formation over the submerged hardware has not yet been completely achieved. In order to establish the dross formation mechanism, an array of tests was performed. Initial inhibition of Al attack by the silicon rich layer and further formation of Fe2Al 5 layer hindering the diffusion of the Al into the substrate were observed. Also, the effect of the hydrodynamic motion of the bathe in the dross formation mechanism was established. A series of tests for efficient removal of the dross formed over the sink roll using high hardness, corrosion resistant materials were conducted at 600°C. After these tests, an efficient scraping process with a potential for energy and cost savings was developed with a better scraper material, resulting in a reduction of 75% in line stoppages.

  11. DIFFUSIVELY ALLOYED COMPOUNDS MADE OF METAL DISCARD WITH A REDUCED MELTING TEMPERATURE FOR OBTAINING WEAR RESISTANT COATINGS USING INDUCTION HARD-FACING TECHNOLOGIES

    Directory of Open Access Journals (Sweden)

    V. G. Shcherbakou

    2016-01-01

    Full Text Available The technology of obtaining diffusion doped alloys made from metal scrap is reviewed in the article. The influence of short term preprocessing at high temperature on structure formation by concentrated energy sources within the further induction deposit is reviewed. A mechanism of a contact eutectic melting in diffusion doped alloys at short term high temperature treatment is described and suggested in this work. It was shown that such kind of processing of diffusion doped alloys is a perspective way of treatment when using induction hard-facing technologies for obtaining wear resistant coatings. A resource and energy saving technology was developed for obtaining wear resistant coatings based on diffusion doped alloys from metal scrap treated using induction hard-facing process.

  12. Effect of residual stresses on the strength, adhesion and wear resistance of SiC coatings obtained by plasma-enhanced chemical vapor deposition on low alloy steel

    Energy Technology Data Exchange (ETDEWEB)

    Kattamis, T.Z. (Department of Metallurgy, Institute of Materials Science, University of Connecticut, Storrs, CT 06269-3136 (United States)); Chen, M. (Department of Metallurgy, Institute of Materials Science, University of Connecticut, Storrs, CT 06269-3136 (United States)); Skolianos, S. (Aristoteles University, Thessaloniki (Greece)); Chambers, B.V. (Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States))

    1994-11-01

    Amorphous hydrogenated silicon carbide thin coatings were deposited on AISI 4340 low alloy steel wafers and thicker steel specimens by plasma-enhanced chemical vapor deposition. The cohesion of the coating, its adhesion to the substrate and its friction coefficient were evaluated by automatic scratch testing, and its wear resistance by pin-on-disk tribometry. During annealing, the residual stress attributed to hydrogen entrapment during deposition gradually changed from compressive to tensile and its rate of increase decreased with increasing annealing time. The cohesion and adhesion failure loads and the abrasive wear resistance decreased with decreasing residual compressive stress and increasing residual tensile stress. The friction coefficient between the coating surface and a diamond stylus decreased with increasing annealing time. ((orig.))

  13. Comparison of the fracture toughness and wear resistance of indirect composites cured by conventional post curing methods and electron beam irradiation

    Directory of Open Access Journals (Sweden)

    Vaishnavi C

    2010-01-01

    Full Text Available Aim : To compare the fracture toughness and wear resistance of indirect composites cured by conventional post curing methods and electron beam irradiation. Materials and Methods : Forty specimens were randomly assigned into four groups of ten each and were subjected to various post curing methods. Fracture toughness and wear resistance tests were performed and the results were tabulated and analyzed statistically using Kruskal Wallis and Mann-Whitney U test. Results : It was found that Inlay system showed higher values followed by electron beam irradiation. Conclusion : Electron beam irradiation of dental composites gives comparable mechanical properties to other post curing systems. It can be concluded that further studies with increased radiation dose should be performed to improve the mechanical properties of indirect composites.

  14. Micro-impact testing: A novel nano-/micro-tribological tool for assessing the performance of wear-resistant coatings under impact/fatigue conditions

    Institute of Scientific and Technical Information of China (English)

    BenD.Beake; StephenR.Goodes; JamesF.Smith; AiyangZhang; JishengE.

    2001-01-01

    A novel repetitive contact technique, micro-impact testing, has been developed forcoating evaluation. Impact test results have proved a more consistent measure of coating per-formance under impact/fatigue conditions than traditional tribological methods such as scratch orpin-on-disk testing. The operating principles of the technique are described with some illustrativeresults on hard and soft coatings. The technique can provide information on impact wear resis-tance, susceptibility to brittle fracture, and strength of interfacial adhesion to substrate.

  15. Development of new corrosion-resistant and wear-resistant materials for use in aggressive hydrogen medium

    Energy Technology Data Exchange (ETDEWEB)

    Slys, I.G.; Berezanskaya, V.I.; Kossko, I.A.; Pomytkin, A.P. [National Academy of Sciences of the Ukraine, Kiev (Ukraine). Inst. for Problems of Materials Science

    2001-05-01

    Sulphidized chromium exceeds similar double-amorphous alloys with sulphur content up to 30% and chemical heat coatings by its corrosive, mechanical and antifrictional characteristics. It can be used individually or as a macroisotopic composite chromium sulphide coating, as corrosion-resistant and high-temperature tribotechnical material. The use of sulphidized chromium and composite isotropic chromium sulphide coatings for fraction units, end seals and other critical assemblies of equipment used for production, transportation and processing of oil and gas with increased content of aggressive components (such as hydrogen sulphide and carbon dioxide) can significantly improve technology and ecological safety. (Author)

  16. Effects of Y2O3 on the microstructure and wear resistance of cobalt-based alloy coatings deposited by plasma transferred arc process

    Institute of Scientific and Technical Information of China (English)

    HOU Qingyu; HUANG Zhenyi; GAO Jiasheng

    2007-01-01

    Cobalt-based alloys with different Y2O3 contents were deposited on Q235A-carbon steel using plasma transferred arc (PTA) welding machine. The effect of Y2O3 on the microstructure and wear resistance properties of the cobalt-based alloys were investigated using an optical microscope, a scanning electron microscope (SEM), X-ray diffraction (XRD), and transmission electron microscopy (TEM). It was found that a cobalt-based solid solution with a face-centered cubic crystal structure was presented accompanied by the secondary phase M7C3 with a hexagonal crystal structure in the Y2O3-free cobalt-based alloy coating. Several stacking faults exist in the cobalt-based solid solution. The addition of Y2O3leads to the existence of the Y2O3 phase in the Y2O3-modified coatings. Though stacking fault exists in the Y2O3-modified coatings, its density increases. The addition of Y2O3 can refine the microstructure and can increase the wear resistance properties when its contents are less than or equal to 0.8 wt.%. However, further increase of its contents will lead to the agglomeration of undissolved Y2O3 particles at the γ-Co grain boundary, and will lead to a coarse microstructure and lower wear resistance properties.

  17. Enhancement of toughness and wear resistance in boron nitride nanoplatelet (BNNP) reinforced Si3N4 nanocomposites

    Science.gov (United States)

    Lee, Bin; Lee, Dongju; Lee, Jun Ho; Ryu, Ho Jin; Hong, Soon Hyung

    2016-06-01

    Ceramics have superior hardness, strength and corrosion resistance, but are also associated with poor toughness. Here, we propose the boron nitride nanoplatelet (BNNP) as a novel toughening reinforcement component to ceramics with outstanding mechanical properties and high-temperature stability. We used a planetary ball-milling process to exfoliate BNNPs in a scalable manner and functionalizes them with polystyrene sulfonate. Non-covalently functionalized BNNPs were homogeneously dispersed with Si3N4 powders using a surfactant and then consolidated by hot pressing. The fracture toughness of the BNNP/Si3N4 nanocomposite increased by as much as 24.7% with 2 vol.% of BNNPs. Furthermore, BNNPs enhanced strength (9.4%) and the tribological properties (26.7%) of the ceramic matrix. Microstructural analyzes have shown that the toughening mechanisms are combinations of the pull-out, crack bridging, branching and blunting mechanisms.

  18. Non-contact evaluation of mechanical properties of electroplated wear resistant Ni-P layer from the velocity dispersion of laser SAW; Laser reiki Rayleigh ha no sokudo bunsan wo mochiita taimamo Ni-P mekkiso tokusei no hisesshoku hyoka

    Energy Technology Data Exchange (ETDEWEB)

    Morikawa, Y.; Cho, H.; Takemoto, M. [Aoyama Gakuin University, Tokyo (Japan). Faculty of Science and Engineering; Nakayama, T. [Kobe Steel Ltd., Kobe (Japan)

    1996-11-01

    We developed a new laser surface acoustic wave (SAW) system and applied this to estimate the mechanical properties of the wear-resistant Ni-P layer electroplated on a stainless steel. The velocity dispersions of Rayleigh wave of the as -plated and heat-treated Ni-P layer were obtained by the one point time domain signal processing. The Ni-P layers with excellent wear resistance produced by the heated treatment higher than 725K were found to show higher Rayleigh velocities than that of the substrate steel, while the Ni-P layer with poor wear resistance showed lower velocities. Young`s moduli of the Ni-P layer, estimated so as the computed velocity dispersion agreed with the measured one, increased with the increase of wear resistance. 10 refs., 9 figs., 2 tabs.

  19. Tribo-Mechanical Properties of HVOF Deposited Fe3Al Coatings Reinforced with TiB2 Particles for Wear-Resistant Applications

    Directory of Open Access Journals (Sweden)

    Mahdi Amiriyan

    2016-02-01

    Full Text Available This study reveals the effect of TiB2 particles on the mechanical and tribological properties of Fe3Al-TiB2 composite coatings against an alumina counterpart. The feedstock was produced by milling Fe3Al and TiB2 powders in a high energy ball mill. The high-velocity oxy-fuel (HVOF technique was used to deposit the feedstock powder on a steel substrate. The effect of TiB2 addition on mechanical properties and dry sliding wear rates of the coatings at sliding speeds ranging from 0.04 to 0.8 m·s−1 and loads of 3, 5 and 7 N was studied. Coatings made from unreinforced Fe3Al exhibited a relatively high wear rate. The Vickers hardness, elastic modulus and wear resistance of the coatings increased with increasing TiB2 content in the Fe3Al matrix. The wear mechanisms strongly depended on the sliding speed and the presence of TiB2 particles but were less dependent on the applied load.

  20. Wear-resistant and electromagnetic absorbing behaviors of oleic acid post-modified ferrite-filled epoxy resin composite coating

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Wenjie; Zang, Chongguang, E-mail: zangchongguang@bit.edu.cn; Jiao, Qingjie

    2015-03-15

    The post-modified Mn–Zn ferrite was prepared by grafting oleic acid on the surface of Mn–Zn ferrite to inhibit magnetic nanoparticle aggregation. Fourier Transform Infrared (FT-IR) spectroscopy was used to characterize the particle surfaces. The friction and electromagnetic absorbing properties of a thin coating fabricated by dispersing ferrite into epoxy resin (EP) were investigated. The roughness of the coating and water contact angle were measured using the VEECO and water contact angle meter. Friction tests were conducted using a stainless-steel bearing ball and a Rockwell diamond tip, respectively. The complex permittivity and complex permeability of the composite coating were studied in the low frequency (10 MHz–1.5 GHz). Surface modified ferrites are found to improve magnetic particles dispersion in EP resulting in significant compatibility between inorganic and organic materials. Results also indicate that modified ferrite/EP coatings have a lower roughness average value and higher water contact angle than original ferrite/EP coatings. The enhanced tribological properties of the modified ferrite/EP coatings can be seen from the increased coefficient value. The composite coatings with modified ferrite are observed to exhibit better reflection loss compared with the coatings with original ferrite. - Highlights: • The post-modified Mn-Zn ferrite was prepared by grafting oleic acid on its surface to inhibit aggregation. • The increasing in hydrophobicity and dispersion of modified coating improved compatibility between illers and polymer. • The modified fillers can decrease the friction COF of the composite coatings resulting in the enhanced resistance to wear. • The modified ferrite coatings are observed to exhibit better reflection loss compared with coatings with original ferrite.

  1. Renewable and superior thermal-resistant cellulose-based composite nonwoven as lithium-ion battery separator.

    Science.gov (United States)

    Zhang, Jianjun; Liu, Zhihong; Kong, Qingshan; Zhang, Chuanjian; Pang, Shuping; Yue, Liping; Wang, Xuejiang; Yao, Jianhua; Cui, Guanglei

    2013-01-01

    A renewable and superior thermal-resistant cellulose-based composite nonwoven was explored as lithium-ion battery separator via an electrospinning technique followed by a dip-coating process. It was demonstrated that such nanofibrous composite nonwoven possessed good electrolyte wettability, excellent heat tolerance, and high ionic conductivity. The cells using the composite separator displayed better rate capability and enhanced capacity retention, when compared to those of commercialized polypropylene separator under the same conditions. These fascinating characteristics would endow this renewable composite nonwoven a promising separator for high-power lithium-ion battery.

  2. Fe–0.4 wt.%C–6.5 wt.%Cr hardfacing coating: Microstructures and wear resistance with La{sub 2}O{sub 3} additive

    Energy Technology Data Exchange (ETDEWEB)

    Hou, Xiaoru [State Key Laboratory of Metastable Materials Science and Technology, College of Materials Science and Engineering, Yanshan University, Qinhuangdao 066004 (China); Zhao, Bin [Jiangsu Xuzhou Construction Machinery Research Institute, Xuzhou 221004 (China); Yang, Jian; Xing, Xiaolei; Zhou, Yefei; Yang, Yulin [State Key Laboratory of Metastable Materials Science and Technology, College of Materials Science and Engineering, Yanshan University, Qinhuangdao 066004 (China); Yang, Qingxiang, E-mail: qxyang@ysu.edu.cn [State Key Laboratory of Metastable Materials Science and Technology, College of Materials Science and Engineering, Yanshan University, Qinhuangdao 066004 (China)

    2014-10-30

    Highlights: • Fe–0.4 wt.%C–6.5 wt.%Cr hardfacing coatings with different La{sub 2}O{sub 3} additives were developed. • The grain size of the hardfacing coating decreases with the increase of the La{sub 2}O{sub 3} additives. • The unidirectional wear resistance of the hardfacing coating is increased with the increase of the La{sub 2}O{sub 3} additives. • The friction coefficient is decreased and the reciprocating wear resistance is increased with the increase of the La{sub 2}O{sub 3} additives. - Abstract: Flux-cored wires with different La{sub 2}O{sub 3} additives were developed. The microstructures of the hardfacing coatings were observed by optical microscopy (OM) and field emission scanning electron microscope (FESEM). The phase structures were determined by X-ray diffraction (XRD). The hardness, wear resistance and friction coefficient of the hardfacing coatings were measured by Rockwell hardness tester, unilateral abrasive belt wear testing machine and CETR reciprocating wear testing machine, respectively. At last, the worn morphologies of the hardfacing coatings were observed by FESEM. The results indicate that, the microstructures of the hardfacing coatings consist of needle-like martensite, high alloy matensite and retained austenite. With the increase of La{sub 2}O{sub 3} additive, the high alloy matensite dissolves in the matrix gradually and the amount of retained austenite is not changed basically after it is increased firstly. When La{sub 2}O{sub 3} addition is 0.70 wt.%, the grain size of the hardfacing coating is the smallest, which is 18 μm and the average hardness is the highest. Unidirectional abrasive belt wear test shows that the high alloy martensite can be as wear-resistance phase during the wear process of the hardfacing coatings. When the La{sub 2}O{sub 3} addition is 0.35 wt.%, the unidirectional wear resistance of the hardfacing coating is the highest. Reciprocating wear test shows that with the increase of the La{sub 2}O

  3. Development of wear-resistant ceramic coatings for diesel engine components. Volume 1, Coating development and tribological testing: Final report: DOE/ORNL Ceramic Technology Project

    Energy Technology Data Exchange (ETDEWEB)

    Naylor, M.G.S. [Cummins Engine Co., Inc., Columbus, IN (United States)

    1992-06-01

    The tribological properties of a variety of advanced coating materials have been evaluated under conditions which simulate the piston ring -- cylinder liner environment near top ring reversal in a heavy duty diesel engine. Coated ``ring`` samples were tested against a conventional pearlitic grey cast iron liner material using a high temperature reciprocating wear test rig. Tests were run with a fresh CE/SF 15W40lubricant at 200 and 350{degrees}C, with a high-soot, engine-tested oil at 200{degrees}C and with no lubrication at 200{degrees}C. For lowest wear under boundary lubricated conditions, the most promising candidates to emerge from this study were high velocity oxy-fuel (HVOF) Cr{sub 3} C{sub 2} - 20% NiCr and WC - 12% Co cermets, low temperature arc vapor deposited (LTAVD) CrN and plasma sprayed chromium oxides. Also,plasma sprayed Cr{sub 2}O{sub 3} and A1{sub 2}O{sub 3}-ZrO{sub 2} materials were found to give excellent wear resistance in unlubricated tests and at extremely high temperatures (450{degrees}C) with a syntheticoil. All of these materials would offer substantial wear reductions compared to the conventional electroplated hard chromium ring facing and thermally sprayed metallic coatings, especially at high temperatures and with high-soot oils subjected to degradation in diesel environments. The LTAVD CrN coating provided the lowest lubricated wear rates of all the materials evaluated, but may be too thin (4 {mu}m) for use as a top ring facing. Most of the coatings evaluated showed higher wear rates with high-soot, engine-tested oil than with fresh oil, with increases of more than a factor of ten in some cases. Generally, metallic materials were found to be much more sensitive to soot/oil degradation than ceramic and cermet coatings. Thus, decreased ``soot sensitivity`` is a significant driving force for utilizing ceramic or cermet coatings in diesel engine wear applications.

  4. Effects of Duplex Nitriding and TiN Coating Treatment on Wear Resistance, Corrosion Resistance and Biocompatibility of Ti6Al4V Alloy

    Science.gov (United States)

    Kao, W. H.; Su, Y. L.; Hsieh, Y. T.

    2017-08-01

    Ti6Al4V alloy substrates were nitrided at 900 °C. TiN coatings were then deposited on the nitrided substrates using a closed-field unbalanced magnetron sputtering system. The microstructure, hardness and adhesion properties of the TiN-N-Ti6Al4V substrates were evaluated and compared with those of an untreated Ti6Al4V sample, a nitrided Ti6Al4V sample and a TiN-coated Ti6Al4V sample, respectively. The tribological properties of the various samples were investigated by means of reciprocating sliding wear tests performed in 0.9 wt.% NaCl solution against 316L, Si3N4 and Ti6Al4V balls, respectively. In addition, the corrosion resistance was evaluated using potentiodynamic polarization tests. Finally, the biocompatibility of the samples was investigated by observing the attachment and growth of purified mouse leukemic monocyte/macrophage cells (Raw 264.7) on the sample surface after culturing periods of 24, 72 and 120 h, respectively. Overall, the results showed that the duplex nitriding/TiN coating treatment significantly improved the tribological, anti-corrosion and biocompatibility properties of the original Ti6Al4V alloy.

  5. Estudo comparativo da resistência ao desgaste abrasivo do revestimento de três ligas metálicas utilizadas na indústria, aplicadas por soldagem com arames tubulares Comparative study of the wear resistance of three metal cored wire welded coatings used in industry

    Directory of Open Access Journals (Sweden)

    Ricardo Vinícius de Melo Leite

    2009-12-01

    Full Text Available As ligas metálicas aplicadas por soldagem em superfícies, objetivando a proteção contra o desgaste e o conseqüente aumento da vida útil de peças e equipamentos, têm sido utilizadas em larga escala nas indústrias de bens de consumo e nos setores de mineração e sucroalcooleiro. O desgaste abrasivo em peças e equipamentos representa, nestas industriais, um dos principais fatores de depreciação de capital e uma importante fonte de despesas com manutenção. Para a aplicação do revestimento por soldagem, os arames tubulares têm sido uma alternativa cada vez mais viável, devido à sua alta produtividade e qualidade de solda, substituindo, em parte, o uso do eletrodo revestido. O objetivo deste trabalho é fazer um estudo comparativo da resistência ao desgaste abrasivo do revestimento aplicado por soldagem com arames tubulares autoprotegidos de três ligas metálicas utilizadas na indústria, uma do tipo Fe-Cr-C, outra do tipo Fe-Cr-C com adição de nióbio e boro e a terceira, do tipo Fe-Cr-C com adição de nióbio. Os revestimentos anti-desgaste, conhecidos como revestimento duro, foram aplicados em chapas de aço carbono, com os mesmos parâmetros e procedimentos de soldagem. Os corpos de prova foram obtidos por corte e retificação e foram submetidos a ensaios de desgaste abrasivo, em um abrasômero Roda de Borracha, conforme procedimento estabelecido pela norma ASTM G65-91. Os resultados obtidos demonstraram que a liga Fe-Cr-C com adição de Nióbio e Boro apresentou desempenho superior em relação ao desgaste abrasivo.The metal alloys deposited by welding on the components surface, with the objective of protection against wear and the consequent increase in the lifetime of parts and equipments, have been used extensively in the consumer products industry and sectors of Mining and Sugar & alcohol. The abrasive wear on parts and equipments represents one of the main depreciation factors of capital and the major source of

  6. Electrophoretic deposition and reaction-bond sintering of Al2O3/Ti composite coating: evaluation of microstructure, phase and wear resistance

    Indian Academy of Sciences (India)

    M Mahmoudi; H Maleki-Ghaleh; M Kavanlouei

    2015-04-01

    In this study, Al2O3/Ti composite coating was deposited on TiAl6V4 substrate in various compositions using the electrophoretic deposition method. After the deposition, samples were dried at room temperature then the coated samples were sintered at 1050°C for 4 h. Scanning electron microscope and X-ray diffraction analysis were used to analyse the microstructure and morphology of coatings. The friction coefficient, wear (missing volume) and hardness of coatings have been studied in comparison with uncoated sample. The results demonstrate that the density of Al2O3/Ti composite coating increased considerably after heat treatment process. Moreover, wearing resistance of TiAl6V4 alloy escalated considerably, increasing its potential for application in orthopedic implants and artificial joints.

  7. 新型中锰马氏体高强度钢的耐磨性能%Wear Resistant of New Type Medium Manganese High Strength Martensite Steel

    Institute of Scientific and Technical Information of China (English)

    孙荣民; 徐文欢; 王存宇; 邱建备; 曹文全

    2012-01-01

    利用销盘式磨料磨损试验和三体冲击磨料磨损试验研究碳质量分数分别为0.12%和0.19%新型中锰马氏体高强度钢的磨损行为,并与Hardox450钢和21C钢进行耐磨性能对比。用磨损失重量表征耐磨性能,利用LOM、SEM和XRD等设备研究材料磨料磨损机制。结果表明,新型中锰钢耐磨性能与Hardox450钢及21C钢相当。在销盘式磨料磨损试验和三体冲击磨料磨损试验中,马氏体高强钢的耐磨性能与材料的硬度呈线性关系,硬度越高,材料耐磨性越好。由于锰的添加,新型中锰钢的优点不仅在于具有锰的固溶强化特性提高耐磨性能,还在于该钢的淬透性几乎与该钢的冷却速度无关,因而该钢具有大规模工业生产的潜力。%The abrasive wear behavior of new type medium manganese high strength martensite steels with 0.12% and 0.19% carbon content were determined by the pin-on-disc abrasion test and three-body impact abrasive test,and was contrasted with steels of Hardox450 and 21C.The wear properties of the specimens were evaluated by weight loss measurements.In order to evaluate the wear mechanism of different steels,the post-test characterization of the worn surfaces were performed using LOM,SEM and XRD.The results show that the wear resistance of new type medium manganese martensite steels is comparable with the wear resistant steels of Hardox450 and 21C.The wear weight lost of the studied steel tested both in pin-on-disc abrasion and three-body impact abrasion is approximately linearly proportional to its HV hardness,i.e.,the higher the hardness,the better wear resistance of steels.Due to the addition of medium-Mn,the new typed steel assumes the advantages not only the Mn-solid strengthening to improve the wear resistance ability but its hardenability could be obtained at all cooling rate,which make the steel has the potential to be produced in steel industry.

  8. Effects of some material and experimental variables on the slurry wear characteristics of zinc-aluminum alloys

    Science.gov (United States)

    Prasad, B. K.; Modi, O. P.; Jha, A. K.; Patwardhan, A. K.

    2001-02-01

    In this study, the slurry wear behavior of a zinc-based alloy has been examined by the sample rotation method over a range of traversal speeds and distances. The influence of adding silicon to the alloy system on its wear characteristics has also been examined. The wear rate of the samples increased with increasing traversal distance initially, attained a peak, and then tended to decrease at longer distances. The initial increase in wear rate with distance was attributed to the indenting effect of the slurry constituents ( i.e., liquid droplets and the erodant particles) associated with the corrosive action of the liquid in slurry. On the contrary, factors such as entrapment of the erodant mass as well as the corrosion products in the cavities formed on the specimen surfaces could lead to the decrease in wear rate at longer traversal distances. The existence of silicon particles in the alloy microstructure led to improved wear resistance of the alloy system. This was due to the resistance offered by the hard silicon particles against the impinging action of the slurry constituents. Attainment of the wear rate peak at longer traversal distances in the case of the silicon-containing alloy over the one without the element further substantiated the superior wear resistance offered by the silicon particles. Traversal speed led to higher wear rates irrespective of the test conditions and material composition due to the more severe attack of the medium on the specimen surface. However, the presence of silicon particles in the alloy microstructure offered improved wear resistance (inverse of wear rate).

  9. Influence of heat treatment on microstructure and wear resistance of a medium-carbon-low-alloy wear-resistant steel%热处理对中碳低合金耐磨钢组织与耐磨性的影响

    Institute of Scientific and Technical Information of China (English)

    温浩宇; 马瑜; 王联波; 唐正华

    2011-01-01

    Effect of cooling modes of water,wind and air on microstructure and wear-resistant properties of a medium-carbon-low-alloy steel under same temper conditions was studied.The influence of temper temperatures on wearing properties of the steel was also investigated.The results show that the microstructure of the studied steel consist of martensite(M) or martensite plus bainite(M/B) depending on heat treatment process.The steel with M/B microstructure exhibits better temper resistance and toughness than that of the single matensite.The M/B microstructure is beneficial to improving wear-resistance of the steel.SEM analysis reveals that the main wear mechanism of the studied steel is abrasive wear with some furrows and micro-cutting on the worn surface.%研究了水冷、风冷、空冷3种冷却方式和200、250、300、350、400℃5种回火温度对中碳低合金耐磨钢的组织和耐磨粒磨损性能的影响。结果表明,经不同的冷却方式,可依次得到单相马氏体和马氏体加贝氏体的复相组织。含有贝氏体的复相组织在低温回火后有较好的抗回火软化能力和韧性,有助于耐磨性的提高。用SEM观察磨损表面,结果表明:在磨粒磨损情况下,实验用钢的磨损机理主要为塑性变形犁机制和显微切削机制。

  10. The Dry Sliding Wear Behavior of HVOF-Sprayed WC: Metal Composite Coatings

    Science.gov (United States)

    Ward, Liam P.; Pilkington, Antony

    2014-09-01

    WC-based cermet coatings containing various metallic binders such as Ni, Co, and Cr are known for their superior tribological properties, particularly abrasion resistance and enhanced surface hardness. Consequently, these systems are considered as replacements for traditional hard chrome coatings in critical aircraft components such as landing gear. The purpose of this investigation was to conduct a comparative study on the dry sliding wear behavior of three WC-based cermet coatings (WC-12Ni, WC-20Cr2C3-7Ni, and WC-10Co-4Cr), when deposited on carbon steel substrates. Ball on disk wear tests were performed on the coatings using a CSEM Tribometer (pin-on-disk) with a 6-mm ruby ball at 20 N applied load, 0.2 m/s sliding velocity, and sliding distances up to 2000 m. Analysis of both the coating wear track and worn ruby ball was performed using optical microscopy and an Alphastep-250 profilometer. The results of the study revealed both wear of the ruby ball and coated disks allowed for a comparison of both the ball wear and coating wear for the systems considered. Generally, the use of Co and Cr as a binder significantly improved the sliding wear resistance of the coating compared to Ni and/or Cr2C3.

  11. Laser surface modification of Ti6Al4V-Cu for improved microhardness and wear resistance properties

    CSIR Research Space (South Africa)

    Erinosho, MF

    2017-06-01

    Full Text Available action, particles of the titanium alloy are transferred and stuck to the tungsten carbide ball due to adhesion as a result of the heat generated. The magnitude of that adhesion depends on the load of 25N used, the speed of the rubbing ball..., Koike M, Okuno O, Oda Y. The grindability and wear of Ti-Cu alloys for dental applications. JOM. 2004;56(2):46-48. 28. Xiong D, Gao Z, Jin Z. Friction and wear properties of UHMWPE against ion implanted titanium alloy. Surface and Coatings Technology...

  12. Eye Wear

    Science.gov (United States)

    Eye wear protects or corrects your vision. Examples are Sunglasses Safety goggles Glasses (also called eyeglasses) Contact ... jobs and some sports carry a risk of eye injury. Thousands of children and adults get eye ...

  13. An Investigation on the Wear Resistance and Fatigue Behaviour of Ti-6Al-4V Notched Members Coated with Hydroxyapatite Coatings

    Directory of Open Access Journals (Sweden)

    Reza H Oskouei

    2016-02-01

    Full Text Available In this study, surface properties of Ti-6Al-4V alloy coated with hydroxyapatite coatings were investigated. Wear resistance and fatigue behaviour of samples with coating thicknesses of 10 and 50 µm as well as uncoated samples were examined. Wear experiments demonstrated that the friction factor of the uncoated titanium decreased from 0.31 to 0.06, through a fluctuating trend, after 50 cycles of wear tests. However, the friction factor of both the coated samples (10 and 50 µm gradually decreased from 0.20 to 0.12 after 50 cycles. At the end of the 50th cycle, the penetration depth of the 10 and 50 µm coated samples were 7.69 and 6.06 µm, respectively. Fatigue tests showed that hydroxyapatite coatings could improve fatigue life of a notched Ti-6Al-4V member in both low and high cycle fatigue zones. It was understood, from fractography of the fracture surfaces, that the fatigue zone of the uncoated specimens was generally smaller in comparison with that of the coated specimens. No significant difference was observed between the fatigue life of coated specimens with 10 and 50 µm thicknesses.

  14. IS ENHANCED-ECCENTRIC RESISTANCE TRAINING SUPERIOR TO TRADITIONAL TRAINING FOR INCREASING ELBOW FLEXOR STRENGTH?

    Directory of Open Access Journals (Sweden)

    Thomas W. Kaminski

    2003-06-01

    Full Text Available Protocols for strengthening muscle are important for fitness, rehabilitation, and the prevention of myotendinous injuries. In trained individuals, the optimal method of increasing strength remains unclear. The purpose of this study was to compare the effects of a traditional method of strengthening with a method that allowed for enhanced-eccentric training, on changes in elbow flexor strength in trained subjects. Thirty-nine (8 male, 31 female trained subjects with normal elbow function participated in this study. Subjects were rank-ordered according to isometric force production and randomly assigned to one of three training groups: control (CONT, traditional concentric/eccentric (TRAD, and concentric/enhanced-eccentric (NEG. The training groups completed 24 training sessions. An evaluator blinded to training group performed all testing. Mixed model ANOVA techniques were used to determine if differences existed in concentric one repetition maximum strength, and isometric force production among groups. Changes in peak and average isokinetic force production were also compared. Type 1 error was maintained at 5%. While both groups improved concentric one repetition maximum (NEG = 15.5%, TRAD = 13.8% neither training group statistically differed from changes demonstrated by the CONT group. Nor did either training group show significant improvements in isometric or isokinetic force production over the CONT group. These results do not support the superiority of enhanced-eccentric training for increasing force production in trained subjects.

  15. Monitoring and intelligent control of electrode wear based on a measured electrode displacement curve in resistance spot welding

    Science.gov (United States)

    Zhang, Y. S.; Wang, H.; Chen, G. L.; Zhang, X. Q.

    2007-03-01

    Advanced high strength steels are being increasingly used in the automotive industry to reduce weight and improve fuel economy. However, due to increased physical properties and chemistry of high strength steels, it is difficult to directly substitute these materials into production processes currently designed for mild steels. New process parameters and process-related issues must be developed and understood for high strength steels. Among all issues, endurance of the electrode cap is the most important. In this paper, electrode wear characteristics of hot-dipped galvanized dual-phase (DP600) steels and the effect on weld quality are firstly analysed. An electrode displacement curve which can monitor electrode wear was measured by a developing experimental system using a servo gun. A neuro-fuzzy inference system based on the electrode displacement curve is developed for minimizing the effect of a worn electrode on weld quality by adaptively adjusting input variables based on the measured electrode displacement curve when electrode wear occurs. A modified current curve is implemented to reduce the effects of electrode wear on weld quality using a developed neuro-fuzzy system.

  16. A Study on Fretting Wear Property of CVD SiC and Sintered SiC

    Energy Technology Data Exchange (ETDEWEB)

    Cha, Hyun-Jin; Jang, Ki-Nam; An, Ji-Hyeong; Kim, Kyu-Tae [Dongguk University, Gyeongju (Korea, Republic of)

    2015-10-15

    Silicon Carbide is broadly used as high temperature structure material because of its high temperature tolerance and superior mechanical properties. After the Fukushima nuclear power plant accident, SiC proposed as one of the alternative materials for LWR fuel cladding to provide enhanced safety margin. Grid-to-rod fretting wear-induced fuel failure is known to occur due to flow-induced vibration of the reactor core and grid to- rod gap. In this paper, wear tests for CVD SiC plate and sintered SiC tube were performed with two types of spacer grids. Wear test of corroded and non-corroded CVD SiC plates indicate that wear resistance of corroded specimen is lower than one of non-corroded specimen in contrast with zirconium alloy cladding tube. It may be affected by rough surface of corroded specimen caused by grain boundary attack.

  17. Degradation of titanium drillpipe from corrosion and wear

    Energy Technology Data Exchange (ETDEWEB)

    Ferg, T.E.; Aldrich, C.S. (Colorado School of Mines, Golden, CO (United States)); Craig, B.D. (Metallurgical Consultants Inc., Montebello (United States))

    1993-06-01

    Drilling deeper than 35,000 ft is limited by the extreme hook loads of steel drillpipe and temperature constraints of aluminum drillpipe. Titanium Alloys Ti-6Al-4V and Beta C have been proposed for use in drillpipe for wells deeper than 35,000 ft because of their high strength/weight ratios, superior high-temperature corrosion resistance, and thermal stability. Their suitability in drilling environments, however, has not been evaluated. To determine the corrosion and wear characteristics of two types of titanium-alloy drillpipe under dogleg conditions, a test cell was constructed to test titanium drillpipe joints in contact with API Spec. 5CT Grade P-110 casing in different drilling muds. Titanium-alloy pipe and Grade P-110 casing wear rates were measured, and tests showed that both titanium-alloy pipes exhibited much greater wear than did steel drillpipe in water-based mud under the same conditions. Test data showed that the total wear rate of Alloys Ti-6Al-4V and Beta C in a drilling environment is a combination of mechanical wear and corrosion.

  18. TEM analysis and wear resistance of the ceramic coatings on Q235 steel prepared by hybrid method of hot-dipping aluminum and plasma electrolytic oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Lu Lihong [State Key Laboratory of Metastable Materials Science and Technology, College of Materials Science and Engineering, Yanshan University, Qinhuangdao 066004 (China); Science and Research Department, Chinese People' s Armed Police Academy, Langfang 065000 (China); Zhang Jingwu [State Key Laboratory of Metastable Materials Science and Technology, College of Materials Science and Engineering, Yanshan University, Qinhuangdao 066004 (China); Shen Dejiu, E-mail: sdj217@ysu.edu.cn [State Key Laboratory of Metastable Materials Science and Technology, College of Materials Science and Engineering, Yanshan University, Qinhuangdao 066004 (China); Wu Lailei; Jiang Guirong [State Key Laboratory of Metastable Materials Science and Technology, College of Materials Science and Engineering, Yanshan University, Qinhuangdao 066004 (China); Li Liang [State Key Laboratory of Automotive Safety and Energy, Tsinghua University, Beijing 100084 (China)

    2012-01-25

    Highlights: Black-Right-Pointing-Pointer Transmission electron microscopy (TEM) was firstly used to analyze the phase composition of the ceramic coatings. Black-Right-Pointing-Pointer The phase composition of the ceramic coatings is mainly amorphous phase and crystal Al{sub 2}O{sub 3} oxides. Black-Right-Pointing-Pointer The cross-section micro-hardness of the treated samples was investigated, the hardness of the ceramic coatings is about HV1300. Black-Right-Pointing-Pointer The wear resistance of the PEO samples is about 3 times higher than that of the heat treated 45 steel. - Abstract: The hybrid method of PEO and hot-dipping aluminum (HDA) was employed to deposit composite ceramic coatings on the surface of Q235 steel. The composition of the composite coatings was investigated with X-ray diffraction (XRD) and transmission electron microscopy (TEM), respectively. The cross-section microstructure and micro-hardness of the treated specimens were investigated and analyzed with scanning electron microscopy (SEM) and microscopic hardness meter (MHM), respectively. The wear resistance of the ceramic coatings was investigated by a self-made rubbing wear testing machine. The results indicate that metallurgical bonding can be observed between the ceramic coatings and the steel substrate. There are many micro-pores and micro-cracks, which act as the discharge channels and result of quick and non-uniform cooling of melted sections in the plasma electrolytic oxidation ceramic coatings. The phase composition of the ceramic coatings is mainly composed of amorphous phase and crystal Al{sub 2}O{sub 3} oxides. The crystal Al{sub 2}O{sub 3} phase includes {kappa}-Al{sub 2}O{sub 3}, {theta}-Al{sub 2}O{sub 3} and {beta}-Al{sub 2}O{sub 3}. The grain size of the {kappa}-Al{sub 2}O{sub 3} crystal is quite non-uniform. The hardness of the ceramic coatings is about HV1300 and 10 times higher than that of the Q235 substrate, which was favorable to the better wear resistance of the ceramic

  19. Wear resistance of TiN(Ti2N)/Ti composite layer formed on C17200 alloy by plasma surface Ti-alloying and nitriding

    Science.gov (United States)

    Liu, L.; Shen, H. H.; Liu, X. Z.; Guo, Q.; Meng, T. X.; Wang, Z. X.; Yang, H. J.; Liu, X. P.

    2016-12-01

    The duplex treatment of plasma Ti-alloying and plasma nitriding was applied on the surface of C17200 alloy to improve its wear resistance. C17200 substrate was alloyed with Ti using double glow plasma alloying to form a Ti-alloyed layer in its surface, and then treated by plasma nitriding to make a TiN(Ti2N) alloying layer based on the Ti-alloyed surface. The microstructure and formation mechanism were studied by using GDOES, XRD and SEM. The hardness, tribological property and electrical conductivity of C17200 alloy after plasma alloying and nitriding were investigated by mean of micro-hardness tester, friction and wear testers as well as impedance analyzers. Modulus of elasticity and the adhesive strength of TiN(Ti2N)/Ti composite layer were evaluated by nano-indenter and scratch tester. The result shows that a TiN(Ti2N)-Ti-Be-Cu composite layer with a thickness of 27 μm is formed in the C17200 surface and is mainly composed of TiN, Ti2N, Cu(Ti) solid solution, etc. The composite alloying surface consists of the hard TiN(Ti2N)-rich layer on the top surface and Ti-Cu-Be diffusion layer, showing a strong adhesive strength with the C17200 substrate and a little decrease in the modulus of elasticity. A certain amount of Cu and Be together with TiN/Ti2N exists in the outmost, resulting in a better combination of wear resistance and conductive performance.

  20. The Microstructure and Wear Resistance of Fe-Cr-C-Ti Handfacing Alloy%Fe-Cr-C-Ti堆焊合金组织及耐磨性能

    Institute of Scientific and Technical Information of China (English)

    王智慧; 冯萌; 贺定勇; 陈勇; 边汉民

    2013-01-01

    采用药芯焊丝气体保护堆焊方法,在Q235钢表面制备不同Ti含量的Fe-Cr-C-Ti系堆焊层金属,利用扫描电镜(SEM)及XRD对堆焊层的组织进行了观察分析.在MLS-225型湿式橡胶轮磨粒磨损试验机上进行磨粒磨损试验,通过对磨损试样表面扫描电子显微镜观察分析并结合能谱成分分析探讨了磨损机理.结果表明,在Fe-Cr-C-Ti耐磨堆焊合金中,随着wTi的增加,合金组织中TiC硬质相增多;当w(Ti)=7.5%时,部分TiC聚集呈雪花状形貌;w(Ti)=5.5%时,合金表现出优良的抗磨损性能.%Fe-Cr-C-Ti hardfacing alloys with different Ti contents were prepared by gas-shielded flux cored arc welding on Q235 steel. The microstructures were investigated by SEM, XRD and EPMA. The abrasive wear resistance performance of the welded surfacing layers was evaluated on the MLS-225 grain-abrasion testing machine. The abrasive wear mechanics was studied on the observation of surface topography by the micro examination and energy spectrum analysis. It is indicated that with the increasing of Ti content, the content of TiC increases. The carbides distribute more symmetrical, but significantly decrease when Ti content is up to 7. 5% . The results show that the alloy with 5. 5 % Ti has better wear resistance.

  1. Abrasive Wear Map of Polymer Tapes in Sand Dust Environment

    Institute of Scientific and Technical Information of China (English)

    WU Tong-hai; DIAO Dong-feng

    2006-01-01

    To make clear the wear conditions of ATM (Automatic Teller Machine) tribosystem when servicing in Chinese sand dust environment, abrasive wear of two kinds of polymer tapes specified for ATM, PI (Polyimide) and PEN (Polyethylene-2, 6-naphthalenedicarboxylate), was investigated in simulated sand dust environment with ATM tape-scraper tribosystem under various conditions of loads and sliding distances. The surface profiles of worn tape were measured with a surface profiler in order to calculating the wear cross-section areas and the wear volumes. The specific wear rates of polymer tapes were calculated under load conditions of 0.6, 1 and 1.5 N, and wear mechanisms were investigated with optical topography photos. As main results, the specific wear rates show stage variations in the wear process and the wear resistance of polymer tape shows good relationship with the mechanical deformation factors. In consideration of the service life, four wear models are generalized according to the magnitude of specific wear rates,which include no wear, mild wear, normal wear and severe wear model and the corresponding wear mechanisms for the four wear models are discussed with typical worn topographies. Based on the wear models and corresponding wear mechanisms, the abrasive wear maps of two polymer tapes servicing in sand dust environments are concluded for its industrial applications.

  2. Effect of microstructure on the wear resistance of alumina dispersed Y{sub 2}O{sub 3}-ZrO{sub 2} ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Liang Xiaoping [Coll. of Material Science and Chemical Engineering, Tianjin Polytechnic Univ., TJ (China); Key Lab. for Advanced Ceramics and Machining Technology of Ministry of Education, Tianjin Univ., TJ (China); Yang Zhengfang; Yuan Qiming; Jin Zhengguo [Key Lab. for Advanced Ceramics and Machining Technology of Ministry of Education, Tianjin Univ., TJ (China)

    2005-07-01

    The effect of microstructure on the wear resistance of two Al{sub 2}O{sub 3} dispersed in ZrO{sub 2} matrix (ADZ) ceramics was investigated, Al{sub 2}O{sub 3} dispersed in commercially co-precipitated 3mol% Y{sub 2}O{sub 3}-doped tetragonal zirconia polycrystal (CYADZ) and Al{sub 2}O{sub 3} dispersed in mixed 3mol% Y{sub 2}O{sub 3}-doped tetragonal zirconia polycrystal (MYADZ). These materials were used as a pin sliding against a plate of polyurethane rubber (UR) in the presence of aqueous NaOH solution containing SiO{sub 2} as the abrasive medium at a sliding speed of 0.15m/s and a normal load of 100N. The results indicated that the CYADZ specimen had uniform microstructure and fine grain size, which accounted for its better abrasive wear-resistance than that of the MYADZ specimen with non-uniform microstructure and largely different grain sizes due to inhomogeneous distribution of Y{sub 2}O{sub 3}. The hardness and toughness of two ADZ specimens were close, but strength of the MYADZ specimen was lower than that of the CYADZ specimen, which indicated the defect was serious in the MYADZ specimen. The CYADZ specimen was characterized by plastic deformation and micro-ploughing, which the MYADZ specimen dominated by micro- cracking and brittle fracture. (orig.)

  3. Correlation of microstructure with hardness and wear resistance in (TiC, SiC)/stainless steel surface composites fabricated by high-energy electron-beam irradiation

    Science.gov (United States)

    Yun, Eunsub; Kim, Yong Chan; Lee, Sunghak; Kim, Nack J.

    2004-03-01

    Stainless-steel-based surface composites reinforced with TiC and SiC carbides were fabricated by high-energy electron beam irradiation. Four types of powder/flux mixtures, i.e., TiC, (Ti + C), SiC, and (Ti + SiC) powders with 40 wt. pct of CaF2 flux, were deposited evenly on an AISI 304 stainless steel substrate, which was then irradiated with an electron beam. TiC agglomerates and pores were found in the surface composite layer fabricated with TiC powders because of insufficient melting of TiC powders. In the composite layer fabricated with Ti and C powders having lower melting points than TiC powders, a number of primary TiC carbides were precipitated while very few TiC agglomerates or pores were formed. This indicated that more effective TiC precipitation was obtained from the melting of Ti and C powders than of TiC powders. A large amount of precipitates such as TiC and Cr7C3 improved the hardness, high-temperature hardness, and wear resistance of the surface composite layer two to three times greater than that of the stainless steel substrate. In particular, the surface composite fabricated with SiC powders had the highest volume fraction of Cr7C3 distributed along solidification cell boundaries, and thus showed the best hardness, high-temperature hardness, and wear resistance.

  4. 中大型耐磨铸钢件的消失模铸造%Medium and Large Wear Resistant Steel Castings by Lost Foam Casting

    Institute of Scientific and Technical Information of China (English)

    王仲珏; 傅宏江; 刘冠岳

    2012-01-01

    According to the process characteristics of lost foam casting and the alloy feature, specific structure, mechanical properties and application performance requirements of wear resistant steel castings, the common defects causes of the castings were analyzed. The method and characteristics of lost foam casting for wear resistant steel casting were introduced, and the content and main points of process design were elaborated, which can provide the references for establishing the reasonable lost foam casting process.%针对消失模铸造工艺特点和中大型耐磨铸钢件的合金特性、具体结构、力学性能和使用性能要求,分析了该类铸件常见缺陷成因.介绍了耐磨铸钢件消失模工艺设计方法和特点,阐述工艺设计内容和要点,为制定出合理的消失模铸造工艺提供借鉴.

  5. Microstructure and wear resistance of Ti-Cu-N composite coating prepared via laser cladding/laser nitriding technology on Ti-6Al-4V alloy

    Science.gov (United States)

    Yang, Yuling; Cao, Shiyin; Zhang, Shuai; Xu, Chuan; Qin, Gaowu

    2017-07-01

    Ti-Cu-N coatings with three different Cu contents on Ti-6Al-4V alloy (TC4) were obtained via laser cladding together with laser nitriding (LC/LN) technology. Phase constituents, microstructure, microhardness, and wear resistance of the coatings were investigated. The evolution of the coefficients of friction for the three coatings was measured under dry sliding conditions as a function of the revolutions until the coating failure. The results show that the coatings are mainly composed of TiN, CuTi3 and some TiO6 phases dispersed in the matrix. A good metallurgical bonding between the coating and substrate has been successfully obtained. The prepared Ti-Cu-N composite coatings almost doubly enhance the microhardness of the TC4 alloy and reduce the friction down to 1/4-1/2 of the TC4 alloy, and thus significantly improve the wear resistance. The coefficient of friction depends on the Cu content in the coating.

  6. The Study of Wear Resistance of WC Carbide-Reinforced Composite Coating Prepared by Laser Surface Alloying%激光合金化制备WC颗粒增强复合层耐磨性研究

    Institute of Scientific and Technical Information of China (English)

    王洪金; 于赟; 李小平; 孙顺平

    2012-01-01

    In order to improve the surface friction and wear properties of steel 45, prepared by laser alloying with WC particles as reinforcement of the Ni-based alloy layer to study the laser alloying technique for surface modification of materials, analysis of the microstructure of the alloy layer, hardness and wear resistance. The results showed that: laser surface alloying to obtain a uniform layer of WC particle-reinforced composites, an increase of 45 steel surface hardness and wear resistance. We can see from the morphology of wear surfaces, laser alloying layer at room temperature dry friction process, both in different degrees of abrasive wear and adhesive wear, the strengthening mechanism is mainly to strengthen the second-phase particles. The wear capacity of WC + Ni45 alloy coating was the lowest and with the best wear resistance.%通过铸造WC和Co包WC与Ni45粉末的复合添加,运用激光合金化技术在中碳钢表面制备以WC颗粒为增强相的Ni基复合层,对复合层的微观组织、硬度及耐磨性进行了测试与分析.结果表明:激光合金化技术可在中碳钢表面制备均匀的WC颗粒增强合金化层,合金层的硬度及耐磨性得到显著提高.从表面磨损形貌可知,合金层在室温干摩擦过程中,均发生不同程度的磨料磨损和粘着磨损,强化机理主要为第二相强化,WC+ Ni45制备的合金层耐磨性最佳.

  7. Wear resistance and microstructural properties of Ni–Al/h-BN/WC–Co coatings deposited using plasma spraying

    Energy Technology Data Exchange (ETDEWEB)

    Hsiao, W.T. [Materials and Chemical Research Laboratories, Industrial Technology Research Institute, Chutung 310, Taiwan (China); Su, C.Y., E-mail: cysu@ntut.edu.tw [Graduate Institute of Manufacturing Technology, National Taipei University of Technology, Taipei 106, Taiwan (China); Huang, T.S. [China Steel Corporation, Kaohsiung, Taiwan (China); Liao, W.H. [Materials and Chemical Research Laboratories, Industrial Technology Research Institute, Chutung 310, Taiwan (China); Nano Technology Laboratory, Department of Materials Engineering, National Chung Hsing University, Taichung 402, Taiwan (China)

    2013-05-15

    Hexagonal boron nitride (h-BN) and tungsten carbide cobalt (WC–Co) were added to nickel aluminum alloy (Ni–Al) and deposited as plasma sprayed coatings to improve their tribological properties. The microstructure of the coatings was analyzed using a scanning electron microscope (SEM). Following wear test, the worn surface morphologies of the coatings were analyzed using a SEM to identify their fracture modes. The results of this study demonstrate that the addition of h-BN and WC–Co improved the properties of the coatings. Ni–Al/h-BN/WC–Co coatings with high hardness and favorable lubrication properties were deposited. - Highlights: • We mixed Ni–Al, h-BN and WC–Co powders and deposited them as composite coatings. • Adding WC–Co was found to increase the hardness and reduce the wear volume loss. • Adding h-BN was found to decrease the hardness and reduce the friction coefficient. • This composite coating was shown to have improved wear properties at 850 °C.

  8. Robust Slippery Coating with Superior Corrosion Resistance and Anti-Icing Performance for AZ31B Mg Alloy Protection.

    Science.gov (United States)

    Zhang, Jialei; Gu, Changdong; Tu, Jiangping

    2017-03-29

    Biomimetic slippery liquid-infused porous surfaces (SLIPSs) are developed as a potential alternative to superhydrophobic surfaces (SHSs) to resolve the issues of poor durability in corrosion protection and susceptibility to frosting. Herein, we fabricated a double-layered SLIPS coating on the AZ31 Mg alloy for corrosion protection and anti-icing application. The porous top layer was infused by lubricant, and the compact underlayer was utilized as a corrosion barrier. The water-repellent SLIPS coating exhibits a small sliding angle and durable corrosion resistance compared with the SHS coating. Moreover, the SLIPS coating delivers durable anti-icing performance for the Mg alloy substrate, which is obviously superior to the SHS coating. Multiple barriers in the SLIPS coating, including the infused water-repellent lubricant, the self-assembled monolayers coated porous top layer, and the compact layered double hydroxide-carbonate composite underlayer, are suggested as being responsible for the enhanced corrosion resistance and anti-icing performance. The robust double-layered SLIPS coating should be of great importance to expanding the potential applications of light metals and their alloys.

  9. Is there evidence that fresh frozen plasma is superior to antithrombin administration to treat heparin resistance in cardiac surgery?

    Science.gov (United States)

    Beattie, Gwyn W; Jeffrey, Robert R

    2014-01-01

    A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was, 'in [patients with heparin resistance] is [treatment with FFP] superior [to antithrombin administration] in [achieving adequate anticoagulation to facilitate safe cardiopulmonary bypass]?' More than 29 papers were found using the reported search, of which six represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. Antithrombin (AT) binds to heparin and increases the rate at which it binds to thrombin. The levels of antithrombin in the blood are an important aspect of the heparin dose-response curve. When the activated clotting time (ACT) fails to reach a target >480, this is commonly defined as heparin resistance (HR). Heparin resistance is usually treated with a combination of supplementary heparin, fresh frozen plasma (FFP) or antithrombin III concentrate. There is a paucity of evidence on the treatment of heparin resistance with FFP, with only five studies identified, including one retrospective study, one in vitro trial and three case reports. AT has been studied more extensively with multiple studies, including a crossover trial comparing AT to supplemental heparin and a multicentre, randomized, double blind, placebo-controlled trial. Antithrombin (AT) concentrate is a safe and efficient treatment for heparin resistance to elevate the activated clotting time (ACT). It avoids the risk of transfusion-related acute lung injury (TRALI), volume overload, intraoperative time delay and viral or vCJD transmission. Antithrombin concentrates are more expensive than fresh frozen plasma and may put patients at risk of heparin rebound in the early postoperative period. Patients treated with AT have a lower risk of further FFP transfusions during their stay in hospital. We conclude that the treatment of

  10. The High performance of nanocrystalline CVD diamond coated hip joints in wear simulator test.

    Science.gov (United States)

    Maru, M M; Amaral, M; Rodrigues, S P; Santos, R; Gouvea, C P; Archanjo, B S; Trommer, R M; Oliveira, F J; Silva, R F; Achete, C A

    2015-09-01

    The superior biotribological performance of nanocrystalline diamond (NCD) coatings grown by a chemical vapor deposition (CVD) method was already shown to demonstrate high wear resistance in ball on plate experiments under physiological liquid lubrication. However, tests with a close-to-real approach were missing and this constitutes the aim of the present work. Hip joint wear simulator tests were performed with cups and heads made of silicon nitride coated with NCD of ~10 μm in thickness. Five million testing cycles (Mc) were run, which represent nearly five years of hip joint implant activity in a patient. For the wear analysis, gravimetry, profilometry, scanning electron microscopy and Raman spectroscopy techniques were used. After 0.5 Mc of wear test, truncation of the protruded regions of the NCD film happened as a result of a fine-scale abrasive wear mechanism, evolving to extensive plateau regions and highly polished surface condition (Ra<10nm). Such surface modification took place without any catastrophic features as cracking, grain pullouts or delamination of the coatings. A steady state volumetric wear rate of 0.02 mm(3)/Mc, equivalent to a linear wear of 0.27 μm/Mc favorably compares with the best performance reported in the literature for the fourth generation alumina ceramic (0.05 mm(3)/Mc). Also, squeaking, quite common phenomenon in hard-on-hard systems, was absent in the present all-NCD system.

  11. Application of PDCA in Construction of Premixed Concrete Wear-resisting Floor%论PDCA在预拌混凝土耐磨地坪施工的应用

    Institute of Scientific and Technical Information of China (English)

    张静

    2014-01-01

    文章主要论述了PDCA循环管理方法在预拌混凝土耐磨地坪施工中的应用,探讨运用PDCA循环管理方法,如何解决耐磨地坪施工中的问题。%This paper mainly discusses the application and method of PDCA circulation management in construction of pre-mixed concrete wear-resisting floor and how to solve the problem of wear-resisting floor construction.

  12. Wear performance of self-mating contact pairs of TiN and TiAlN coatings on orthopedic grade Ti-6Al-4V.

    Science.gov (United States)

    Kim, H; Kim, C Y; Kim, D W; Lee, I S; Lee, G H; Park, J C; Lee, S J; Lee, K Y

    2010-08-01

    Both titanium nitride (TiN) and titanium aluminum nitride (TiAlN) have shown great wear resistance potential in metallic medical devices as protective, hard thin film coatings. In the present study, the effects of TiN and TiAlN coating layers on the wear performance of Ti-6Al-4V were compared and analyzed. TiN and TiAlN coatings with a thickness of 3 microm were deposited by a cathodic vacuum arc ion plating technique on the surface of Ti-6Al-4V. Wear tests were conducted by using a pin-on-disk-type tribotester with a point contact self-mating pair in a linear reciprocal motion. A sliding distance of 20 mm per cycle at 1 Hz was used under a load of 15 N under ambient conditions with no lubricant. The wear resistance of TiN and TiAlN coatings is superior to that of uncoated Ti-6Al-4V at the early stage of sliding contact. Until a measurable amount of wear was detected, the number of sliding cycles of the TiAlN coating pair was longer than TiN. After the first detection of wear from the coating layers, the rate of wear of the TiN coating pairs was significantly higher than that of TiAlN (p TiN from the viewpoint of wear resistance under the test conditions used in this study.

  13. Effects of bionic units on the fatigue wear of gray cast iron surface with different shapes and distributions

    Science.gov (United States)

    Chen, Zhi-kai; Lu, Shu-chao; Song, Xi-bin; Zhang, Haifeng; Yang, Wan-shi; Zhou, Hong

    2015-03-01

    To improve the fatigue wear resistance of gray cast iron (GCI), GCI samples were modified by a laser to imitate the unique structure of some soil animals alternating between soft and hard phases; the hard phase resists the deformation and the soft phase releases the deformation. Using the self-controlled fatigue wear test method, the fatigue wear behaviors of treated and untreated samples were investigated and compared experimentally. The results show that the bionic non-smooth surface obtains a beneficial effect on improving the fatigue wear resistance of a sample, and the fatigue wear resistance of the bionic sample assembled with reticulate units (60°+0°), whose mass loss was reduced by 62%, was superior to the others. Meanwhile, a finite element (FE) was used to simulate the compression and the distributions of strain and stress on the non-smooth surface was inferred. From these results, we understood that the functions of the bionic unit such as reducing strain and stress, and also obstructing the closure and propagation of cracks were the main reasons for improving the fatigue wear property of GCI.

  14. Low-temperature growth of low friction wear-resistant amorphous carbon nitride thin films by mid-frequency, high power impulse, and direct current magnetron sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Bakoglidis, Konstantinos D., E-mail: konba@ifm.liu.se; Schmidt, Susann; Garbrecht, Magnus; Ivanov, Ivan G.; Jensen, Jens; Greczynski, Grzegorz; Hultman, Lars [Department of Physics, Chemistry and Biology (IFM), Linköping University, SE-581 83 Linköping (Sweden)

    2015-09-15

    The potential of different magnetron sputtering techniques for the synthesis of low friction and wear resistant amorphous carbon nitride (a-CN{sub x}) thin films onto temperature-sensitive AISI52100 bearing steel, but also Si(001) substrates was studied. Hence, a substrate temperature of 150 °C was chosen for the film synthesis. The a-CN{sub x} films were deposited using mid-frequency magnetron sputtering (MFMS) with an MF bias voltage, high power impulse magnetron sputtering (HiPIMS) with a synchronized HiPIMS bias voltage, and direct current magnetron sputtering (DCMS) with a DC bias voltage. The films were deposited using a N{sub 2}/Ar flow ratio of 0.16 at the total pressure of 400 mPa. The negative bias voltage, V{sub s}, was varied from 20 to 120 V in each of the three deposition modes. The microstructure of the films was characterized by high-resolution transmission electron microscopy and selected area electron diffraction, while the film morphology was investigated by scanning electron microscopy. All films possessed an amorphous microstructure, while the film morphology changed with the bias voltage. Layers grown applying the lowest substrate bias of 20 V exhibited pronounced intercolumnar porosity, independent of the sputter technique. Voids closed and dense films are formed at V{sub s} ≥ 60 V, V{sub s} ≥ 100 V, and V{sub s} = 120 V for MFMS, DCMS, and HiPIMS, respectively. X-ray photoelectron spectroscopy revealed that the nitrogen-to-carbon ratio, N/C, of the films ranged between 0.2 and 0.24. Elastic recoil detection analysis showed that Ar content varied between 0 and 0.8 at. % and increased as a function of V{sub s} for all deposition techniques. All films exhibited compressive residual stress, σ, which depends on the growth method; HiPIMS produces the least stressed films with values ranging between −0.4 and −1.2 GPa for all V{sub s}, while CN{sub x} films deposited by MFMS showed residual stresses up to −4.2

  15. Facile preparation of superamphiphobic epoxy resin/modified poly(vinylidene fluoride)/fluorinated ethylene propylene composite coating with corrosion/wear-resistance

    Science.gov (United States)

    Wang, Huaiyuan; Liu, Zhanjian; Wang, Enqun; Zhang, Xiguang; Yuan, Ruixia; Wu, Shiqi; Zhu, Yanji

    2015-12-01

    A robust superamphiphobic epoxy resin (EP)/modified poly(vinylidene fluoride) (MPVDF)/fluorinated ethylene propylene (FEP) composite coating has been prepared through the combination of chemical modification and spraying technique. Nanometer silica (SiO2, 2.5 wt.%) and carbon nanotubes (CNTs, 2.5 wt.%) were added in the coating to construct the necessary reticulate papillae structures for superamphiphobic surface. The prepared EP composite coating demonstrated high static contact angles (166°, 155°) and low sliding angles (3°, 5°) to water and glycerol, respectively. Moreover, the prepared coating can also retain superhydrophobicity under strongly acidic and alkaline conditions. The brittleness of EP can be avoided by introducing the malleable MPVDF. The wear life of the EP composite coating with 25 wt.% FEP was improved to 18 times of the pure EP coating. The increased wear life of the coating can be attributed to the designed nano/micro structures, the self-lubrication of FEP and the chemical reaction between EP and MPVDF. The anti-corrosion performance of the coatings was investigated in 3.5% NaCl solution using potentiodynamic polarization. The results showed that the prepared superamphiphobic composite coating was most effective in corrosion resistance, primarily due to the barrier effect for the diffusion of O2 and H2O molecules. It is believed that this robust superamphiphobic EP/MPVDF/FEP composite coating prepared by the facile spray method can pave a way for the large-scale application in pipeline transport.

  16. Tooth wear

    Directory of Open Access Journals (Sweden)

    Tušek Ivan

    2014-01-01

    Full Text Available Tooth wear is the loss of dental hard tissue that was not caused by decay and represents a common clinical problem of modern man. In the etiology of dental hard tissue lesions there are three dominant mechanisms that may act synergistically or separately:friction (friction, which is caused by abrasion of exogenous, or attrition of endogenous origin, chemical dissolution of dental hard tissues caused by erosion, occlusal stress created by compression and flexion and tension that leads to tooth abfraction and microfracture. Wear of tooth surfaces due to the presence of microscopic imperfections of tooth surfaces is clinically manifested as sanding veneers. Tribology, as an interdisciplinary study of the mechanisms of friction, wear and lubrication at the ultrastructural level, has defined a universal model according to which the etiopathogenesis of tooth wear is caused by the following factors: health and diseases of the digestive tract, oral hygiene, eating habits, poor oral habits, bruxism, temporomandibular disorders and iatrogenic factors. Attrition and dental erosion are much more common in children with special needs (Down syndrome. Erosion of teeth usually results from diseases of the digestive tract that lead to gastroesophageal reflux (GER of gastric juice (HCl. There are two basic approaches to the assessment of the degree of wear and dental erosion. Depending on the type of wear (erosion, attrition, abfraction, the amount of calcium that was realised during the erosive attack could be determined qualitatively and quantitatively, or changes in optical properties and hardness of enamel could be recorded, too. Abrasion of teeth (abrasio dentium is the loss of dental hard tissue caused by friction between the teeth and exogenous foreign substance. It is most commonly provoked by prosthetic dentures and bad habits, while its effect depends on the size of abrasive particles and their amount, abrasive particle hardness and hardness of tooth

  17. Biofouling resistance of boron-doped diamond neural stimulation electrodes is superior to titanium nitride electrodes in vivo

    Science.gov (United States)

    Meijs, S.; Alcaide, M.; Sørensen, C.; McDonald, M.; Sørensen, S.; Rechendorff, K.; Gerhardt, A.; Nesladek, M.; Rijkhoff, N. J. M.; Pennisi, C. P.

    2016-10-01

    Objective. The goal of this study was to assess the electrochemical properties of boron-doped diamond (BDD) electrodes in relation to conventional titanium nitride (TiN) electrodes through in vitro and in vivo measurements. Approach. Electrochemical impedance spectroscopy, cyclic voltammetry and voltage transient (VT) measurements were performed in vitro after immersion in a 5% albumin solution and in vivo after subcutaneous implantation in rats for 6 weeks. Main results. In contrast to the TiN electrodes, the capacitance of the BDD electrodes was not significantly reduced in albumin solution. Furthermore, BDD electrodes displayed a decrease in the VTs and an increase in the pulsing capacitances immediately upon implantation, which remained stable throughout the whole implantation period, whereas the opposite was the case for the TiN electrodes. Significance. These results reveal that BDD electrodes possess a superior biofouling resistance, which provides significantly stable electrochemical properties both in protein solution as well as in vivo compared to TiN electrodes.

  18. Copper Micro-Labyrinth with Graphene Skin: New Transparent Flexible Electrodes with Ultimate Low Sheet Resistivity and Superior Stability

    Directory of Open Access Journals (Sweden)

    Hak Ki Yu

    2016-09-01

    Full Text Available We have developed self-assembled copper (Cu micro-labyrinth (ML with graphene skin for transparent flexible electrodes of optoelectronic devices. The Cu ML is simply formed by heating a thin Cu film with a 100-nm thickness on a SiO2/Si substrate at 950 °C under hydrogen ambient to block the oxidation. Moreover, the Cu ML can have graphene skin at the surface by inserting carbo-hydroxyl molecules (CxHy during heating due to the catalytic decomposition of C–H bonds on the Cu surface. The Cu ML with graphene skin (Cu ML-G has superior sheet resistivity below 5 Ω/sq and mechanical flexibility without cracks at the bending radius of 0.1 cm. Although the transmittance of Cu ML-G is a little lower (70%~80% than that of conventional metallic nanowires electrodes (such as Ag, ~90% at the visible wavelength, it has good thermal stability in conductivity without any damage at 200 °C due to a micro-sized pattern and graphene skin which prohibits the surface migration of Cu atoms.

  19. The wear resistance of cobalt free hard surfaced alloys in nuclear power plant conditions. Test results; Kobolttivapaiden pinnoitteiden kulumiskestaevyys ydinvoimalaitosolosuhteissa. Koetulokset

    Energy Technology Data Exchange (ETDEWEB)

    Kosonen, A.M. [VTT Manufacturing Technology, Espoo (Finland)

    1996-09-01

    Use of cobalt containing materials is restricted in primary circuits of nuclear power plants since the cobalt is activated in the reactor core. The resulting isotope leads to increase of activity in the primary circuit. This report presents the results of the wear resistance tests of four hard facing alloys. The test method was a pin on plate test. The pins were coated with hard-facing alloys and the plates were manufactured from stainless steel. The tested materials were nickel based Stellite 6, wolfram carbide (WC), METCO 442 and cobalt based Stellite 6. Tests were carried out in simulated BWR-environment. According to the results of these tests it is not possible to get any differences between any hard facing alloys if the hardness of the plate material is much lower than that of the hard facing alloys examined. (orig.) (4 refs.).

  20. Karakterizacija WCCo/NiCrBSi prevlake otporne na habanje / Characterization of wear resistant plasma sprayed WCCo/NiCrBSi self-fluxing coatings

    Directory of Open Access Journals (Sweden)

    Mihailo R. Mrdak

    2010-04-01

    Full Text Available U radu su analizirani mikrostruktura, mehaničke i tribološke karakteristike (APS prevlake WCCoNiCrBSi koja se primenjuje za reparaciju cilindara nosne noge helikoptera. Tribološka procena prevlake određena je primenom tribometra blok-na-prstenu. Spregnuti materijalblokovi sa prevlakom ispitani su na okaljenom i poboljšanom čeličnom prstenu. Za ukupno odstojanje od 3000 m bili su konstantna brzina 0,5 m/s i opterećenje 400 N. Prednost primene ove prevlake je u značajnom produženju resursa delova uz smanjenje troškova eksploatacije i održavanja. / In this paper, the microstructural, mechanical and tribological properties of WCCoNiCrBSi thermal spray coatings, applied to repair the cylinders of helicopter nasal feet, were analyzed. The process used for coating deposition on steel substrate was the Atmospheric Plasma Spraying (APS.The plasma spray process is a procedure widely used for applying coatings with increased resistance to wear. The combination of WCCo and NiCrBSi powders produced coatings for the protection of metal parts exposed to wear abrasion, erosion and cavitation to 540°C. The WCCoNiCrBSi 50/50% powder is specially developed for the production of coatings of high cohesion and adhesive strength. The coatings are very dense, hard and smooth. Microstructures present in the layers are tungsten carbides and chromium layers that increase resistance to wear and abrasion. Powder is deposited on the substrate rugged with Al2O3. The substrates were heated at temperatures up to 200°C. Powder deposition was performed with the optimal deposition parameters The microstructure and micro hardness of the coating layer was investigated on the cross section of samples using the Pratt & Whitney standard. Micro hardness was tested using the Vickers scale with a load of 300g. The microstructure of the layers was investigated on an optical microscope (OM with a magnification of 400X. Testing of bond strength between coatings and substrates

  1. Microstructure and wear resistance of the hypereutectic Fe-Cr-C alloy hardfacing metals with different La2O3 additives

    Science.gov (United States)

    Yang, Jian; Tian, Jianjun; Hao, Feifei; Dan, Ting; Ren, Xuejun; Yang, Yulin; Yang, Qingxiang

    2014-01-01

    Hardfacing (harden-surface-welding) metal of the hypereutectic Fe-Cr-C alloy with different La2O3 additives was developed. The microstructure of the hardfacing metal was observed by optical microscopy. The phase structure was determined by X-ray diffraction. The hardness and wear resistance of the hardfacing metal were measured by hardness tester and dry sand rubber wheel abrasive tester, respectively. The worn surface morphology was observed by field emission scanning electron microscope equipped with energy dispersive X-ray spectrometry. The solidification curve of the hardfacing metal and the relationship between the content of each phase and the temperature were calculated by thermodynamics software Thermo-Calc and Jmatpro, respectively. The results indicate that, with the increase of the La2O3 additives, the dimension of the primary M7C3 carbide in the hypereutectic Fe-Cr-C alloy hardfacing metal decreases gradually. When the La2O3 additive is 0.78 wt.%, it reaches minimum, which is 11.37 μm. The amount of M7C3 carbide (including the primary carbide and the eutectic carbide) decreases firstly then increases. The hardness of the hardfacing metal increases smally, while the wear resistance of it increases firstly then decreases and reaches the most excellent when the La2O3 additive is 0.78 wt.%. The formation temperature of M7C3 carbide is higher than that of austenite in the hypereutectic Fe-Cr-C alloy hardfacing metal. Austenite precipitated in the liquid phase can improve the precipitation rate of M7C3 carbide in a certain extent. As the temperature of the molten pool drops from 870 °C to 840 °C, γ-Fe transforms into α-Fe completely, so a large number of C atoms precipitate, which promotes the growth of the M7C3 carbide in short period.

  2. Optimization of the EMS process parameters in compocasting of high-wear-resistant Al-nano-TiC composites

    Science.gov (United States)

    Shamsipour, Majid; Pahlevani, Zahra; Shabani, Mohsen Ostad; Mazahery, Ali

    2016-04-01

    Understanding of the electromagnetic stirrer (EMS) process parameters-wear relation in nanocomposite is required for further creation of tailored modifications of process in accordance with the demands for various applications. This study depicts the performance of hybrid algorithm for optimization of the parameters in EMS compocasting of nano-TiC-reinforced Al-Si alloys. Adaptive neuro-fuzzy inference system (ANFIS) coupled with particle swarm optimization (PSO) was applied to find the optimum combination of the inputs including mold temperature, mix time, impeller speed, powder temperature, cast temperature and average particle size. The optimized condition was obtained in minimization of objective function. The objective function is calculated by ANFIS and then minimized by PSO. The optimized parameters were used to produce semisolid cast aluminum matrix composites reinforced with nano-TiC particles. The optimized nanocomposites were then studied for their tribological properties.

  3. Effect of multipath laser shock processing on microhardness, surface roughness, and wear resistance of 2024-T3 Al alloy.

    Science.gov (United States)

    Kadhim, Abdulhadi; Salim, Evan T; Fayadh, Saeed M; Al-Amiery, Ahmed A; Kadhum, Abdul Amir H; Mohamad, Abu Bakar

    2014-01-01

    Laser shock processing (LSP) is an innovative surface treatment technique with high peak power, short pulse, and cold hardening for strengthening metal materials. LSP is based on the application of a high intensity pulsed laser beam (I > 1 GW/cm(2); t surface into a high temperature and density plasma that immediately develops inducing a shock wave propagating into the material. The shock wave induces plastic deformation and a residual stress distribution in the target material. In this paper we study the increase of microhardness and surface roughness with the increase of laser pulse energy in 2024-T3 Al alloy. The influence of the thickness of the confining layer (water) on microhardness and surface roughness is also studied. In addition, the effect of LSP treatment with best conditions on wear behaviors of the alloy was investigated.

  4. Study of the wear resistance of ion-plasma coatings based on titanium and aluminum and obtained by magnetron sputtering

    Science.gov (United States)

    Kachalin, G. V.; Mednikov, A. F.; Tkhabisimov, A. B.; Sidorov, S. V.

    2017-05-01

    The paper presents the results of metallographic researches and erosion tests of ion-plasma coatings (based on titanium, aluminum and their nitrides), which were formed on samples of 12Kh13 and EI961 blade steels. Erosion tests and studies of characteristics of obtained by magnetron sputtering coatings were carried out by using a set of research equipment UNU “Erosion-M” NRU “MPEI”. It was found that the formed Ti/Al-TiN/AlN coatings increase the duration of blade steels erosion wear incubation period by at least in 1.5 times and have a layered structure with thicknesses of nitride layers 1.3-1.6 μm and intermediate metallic layers 0.3-0.5 μm, with a total thickness of coatings of 10-14 μm for 12Kh13steel samples and 19-21 μm for EI961 steel samples.

  5. Preparation, characterization and wear resistance to ceramic composites Si C/Ti B{sub 2}; Elaboration, caracterisation et resistance a l`usure de composites ceramiques SiC/TiB{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Blanc, C.

    1997-12-18

    The composites Si C-Ti B{sub 2} (5,10,15% vol. Ti B{sub 2}) have been synthesized by natural and reactive sintering from Ti O{sub 2}, B{sub 4} C and phenolic resin used as carbon source, by the reaction: Ti O{sub 2} + 0.5 B{sub 4} C +1.5 C -> Ti B{sub 2} + 2 CO (1400 degrees Celsius). They have been characterized from a microstructural, mechanical and tribological point of view. The dispersion of Ti B{sub 2} particles is very homogeneous in optical microscopy and in scanning electron microscopy. The images analysis has showed that most of the particles have a size smaller than 1 {mu}m. The atomic force microscopy and the transmission electron microscopy have revealed the existence of nanometrical particles. Concerning the mechanical properties, the fracture toughness increases with the Ti B{sub 2} rate and the hardness decreases. By friction, the composite materials wear slowly than the monolithic SiC. The wear mechanisms are modified in air and in water. In air, a layer of oxidized scraps, protector if it is stable, are formed for composites while there is formation of rollers for SiC. In water, composites are polished while SiC wears by cleavages. The influence of the Ti B{sub 2} phase on the wear resistance is due to the tribo-oxidation: a lubrication can take place through the tribo-oxidation products. (O.M.) 64 refs.

  6. Mechanical and Wear Properties of SiC/Graphite Reinforced Al359 Alloy-based Metal Matrix Composite

    Directory of Open Access Journals (Sweden)

    Shubhranshu Bansal

    2015-07-01

    Full Text Available Al359 alloy was reinforced with Silicon Carbide and Silicon Carbide/Graphite particles using stir casting process. Thereafter their mechanical and wear properties were investigated. It was found that the hardness of the Al359-Silicon Carbide composite is better than Al359-Silicon Carbide-Graphite composite. The Silicon Carbide/Graphite reinforced composite exhibits a superior ultimate tensile strength against Silicon Carbide reinforced composite. The wear test was conducted at different loading, sliding velocities and sliding distances conditions. Results showed that the wear resistance of Al359 alloy increased with the reinforcement of Silicon Carbide/Graphite material for higher loading, sliding velocities and sliding distance conditions. SEM images of the worn surface of the pin were examined to study their wear mechanism.Defence Science Journal, Vol. 65, No. 4, July 2015, pp. 330-338, DOI: http://dx.doi.org/10.14429/dsj.65.8676

  7. Improved Quality Assurance Measures of Concrete Wear-resisting Floor Process%混凝土耐磨地面工艺改进质量保证措施

    Institute of Scientific and Technical Information of China (English)

    吴继刚

    2013-01-01

    This article analyses the problems in the cement floor using, and puts forward the improvement measures on concrete wear-resisting floor process.%本文分析了水泥地面使用中存在的问题,并提出对混凝土耐磨地面工艺的改进措施.

  8. Wear behaviour of laser melted an ion implanted materials.

    NARCIS (Netherlands)

    Beurs, Hans de

    1988-01-01

    The emphasis in this thesis is on the development of wear resistant materials by laser melting. Furthermore, the principle aim is to search for the dislocation characteristics common to the wear process in heterogeneous materials. ... Zie: Summary

  9. Adjusted drug treatment is superior to renal sympathetic denervation in patients with true treatment-resistant hypertension.

    Science.gov (United States)

    Fadl Elmula, Fadl Elmula M; Hoffmann, Pavel; Larstorp, Anne C; Fossum, Eigil; Brekke, Magne; Kjeldsen, Sverre E; Gjønnæss, Eyvind; Hjørnholm, Ulla; Kjaer, Vibeke N; Rostrup, Morten; Os, Ingrid; Stenehjem, Aud; Høieggen, Aud

    2014-05-01

    We aimed to investigate for the first time the blood pressure (BP)-lowering effect of renal sympathetic denervation (RDN) versus clinically adjusted drug treatment in true treatment-resistant hypertension (TRH) after excluding patients with confounding poor drug adherence. Patients with apparent TRH (n=65) were referred for RDN, and those with secondary and spurious hypertension (n=26) were excluded. TRH was defined as office systolic BP (SBP) >140 mm Hg, despite maximally tolerated doses of ≥3 antihypertensive drugs including a diuretic. In addition, ambulatory daytime SBP >135 mm Hg after witnessed intake of antihypertensive drugs was required, after which 20 patients had normalized BP and were excluded. Patients with true TRH were randomized and underwent RDN (n=9) performed with Symplicity Catheter System versus clinically adjusted drug treatment (n=10). The study was stopped early for ethical reasons because RDN had uncertain BP-lowering effect. Office SBP and diastolic BP in the drug-adjusted group changed from 160±14/88±13 mm Hg (±SD) at baseline to 132±10/77±8 mm Hg at 6 months (Pdrug-adjusted group at 6 months (P=0.002 and P=0.004, respectively), and absolute changes in SBP were larger in the drug-adjusted group (P=0.008). Ambulatory BPs changed in parallel to office BPs. Our data suggest that adjusted drug treatment has superior BP lowering effects compared with RDN in patients with true TRH. Clinical Trial Registration- URL: http://www.clinicaltrials.gov. Unique identifier: NCT01673516.

  10. Antioxidant impregnated ultra-high molecular weight polyethylene wear debris particles display increased bone remodeling and a superior osteogenic:osteolytic profile vs. conventional UHMWPE particles in a murine calvaria model.

    Science.gov (United States)

    Chen, Yu; Hallab, Nadim J; Liao, Yen-Shuo; Narayan, Venkat; Schwarz, Edward M; Xie, Chao

    2016-05-01

    Periprosthetic osteolysis remains a major limitation of long-term successful total hip replacements with ultra-high molecular weight polyethylene (UHMWPE) bearings. As intra and extracellular reactive oxygen species are know to contribute to wear debris-induced osteoclastic bone resorption and decreased osteoblastic bone formation, antioxidant doped UHMWPE has emerged as an approach to reduce the osteolytic potential of wear debris and maintain coupled bone remodeling. To test this hypothesis in vivo, we evaluated the effects of crosslinked UHMWPE wear debris particles (AltrX(™) ), versus similar wear particles made from COVERNOX(™) containing UHMWPE (AOX(™) ), in an established murine calvaria model. Eight-week-old female C57B/6 mice (n = 10/Group) received a pre-op micro-CT scan prior to surgical implantation of the UHMWPE particles (2mg), or surgery without particles (sham). Dynamic labeling was performed by intraperitoneal injection of calcein on day 7 and alizarin on day 9, and the calvaria were harvested for micro-CT and histology on day 10. Surprisingly, we found that AOX particles induced significantly more bone resorption (1.72-fold) and osteoclast numbers (1.99-fold) vs. AltrX (p UHMWPE particles have decreased osteolytic potential due to their increased osteogenic properties that support coupled bone remodeling. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:845-851, 2016.

  11. Micro-micro hierarchy replacing micro-nano hierarchy: a precisely controlled way to produce wear-resistant superhydrophobic polymer surfaces.

    Science.gov (United States)

    Huovinen, Eero; Hirvi, Janne; Suvanto, Mika; Pakkanen, Tapani A

    2012-10-16

    Superhydrophobic polymer surfaces are typically fabricated by combining hierarchical micro-nanostructures. The surfaces have a great technological potential because of their special water-repellent and self-cleaning properties. However, the poor mechanical robustness of such surfaces has severely limited their use in practical applications. This study presents a simple and swift mass production method for manufacturing hierarchically structured polymer surfaces at micrometer scale. Polypropylene surface structuring was done using injection molding, where the microstructured molds were made with a microworking robot. The effect of the micro-microstructuring on the polymer surface wettability and mechanical robustness was studied and compared to the corresponding properties of micro-nanostructured surfaces. The static contact angles of the micro-microstructured surfaces were greater than 150° and the contact angle hysteresis was low, showing that the effect of hierarchy on the surface wetting properties works equally well at micrometer scale. Hierarchically micro-microstructured polymer surfaces exhibited the same superhydrophobic wetting properties as did the hierarchically micro-nanostructured surfaces. Micro-microstructures had superior mechanical robustness in wear tests as compared to the micro-nanostructured surfaces. The new microstructuring technique offers a precisely controlled way to produce superhydrophobic wetting properties to injection moldable polymers with sufficiently high intrinsic hydrophobicity.

  12. Laser composite surfacing of A681 steel with WC + Cr + Co for improved wear resistance

    Directory of Open Access Journals (Sweden)

    Moisés Felipe Teixeira

    2017-01-01

    Full Text Available Laser surface alloying (LSA is a surface treatment technique. It involves the near surface melting by a powerful laser beam with a pre-deposited or concomitantly added alloying element along with a part of the underlying substrate to form a surface alloyed zone. In this paper, it is reported the treatment by laser surface alloying of a cold work steel ASTM A681 substrate simultaneously fed with a powder mixture of 86 wt.% WC + 8 wt.% Cr + 6 wt.% Co. It was carried out using a continuous wave λ = 1064 nm fiber-coupled diode laser with five different laser intensities – resulting in five specimens – and then studied and analyzed their microstructure, phases, composition and microhardness. One of these configurations was applied to enhance a deep drawing tool for automotive steel sheet stamping. The process modified the specimens near surface layer, from a ferritic structure into an austenitic matrix with a refined dendritic microstructure, with an enhanced surface hardness from 250 HV to ∼560 HV. The treated deep drawing tool showed remarkable wear improvement compared to a non-treated one after one thousand stamps. This result allows the process for industrial applications.

  13. Effect of Multipath Laser Shock Processing on Microhardness, Surface Roughness, and Wear Resistance of 2024-T3 Al Alloy

    Directory of Open Access Journals (Sweden)

    Abdulhadi Kadhim

    2014-01-01

    Full Text Available Laser shock processing (LSP is an innovative surface treatment technique with high peak power, short pulse, and cold hardening for strengthening metal materials. LSP is based on the application of a high intensity pulsed laser beam (I>1 GW/cm2;  t<50 ns at the interface between the metallic target and the surrounding medium (a transparent confining material, normally water forcing a sudden vaporization of the metallic surface into a high temperature and density plasma that immediately develops inducing a shock wave propagating into the material. The shock wave induces plastic deformation and a residual stress distribution in the target material. In this paper we study the increase of microhardness and surface roughness with the increase of laser pulse energy in 2024-T3 Al alloy. The influence of the thickness of the confining layer (water on microhardness and surface roughness is also studied. In addition, the effect of LSP treatment with best conditions on wear behaviors of the alloy was investigated.

  14. Simulation of flow field in symmetric multi-vane wear-resistant air flow regulating valve%对称多叶片式耐磨风量调节阀流场模拟

    Institute of Scientific and Technical Information of China (English)

    孟康; 陈旺生; 梅丹

    2012-01-01

    针对现有蝶阀存在易磨损、使用寿命短等问题,研制出一种对称多叶片式耐磨风量调节阀。利用标准κ-ε模型对该阀的流场进行了数值模拟,并与蝶阀进行了对比研究,结果表明,该阀流场分布比较均匀,无偏流现象,阀体边壁处流体速度较小,结构合理,具有较好的耐磨性能。%To solve the problems of current butterfly valves such as easiness of wearing and short service lifespan etc.,a kind of symmetric multi-vane wear-resistant air flow regulating valve was developed.The standard κ-ε model was applied to carry out the numerical simulation of the flow field,and then the simulation results was compared with that of the butterfly valve.The simulation results showed that the flow field of the symmetric multi-vane wear-resistant air flow regulating valve was distributed uniformly without flow deviation,and the flow velocity at the valve wall was low;the structure and the wear-resistance performance of the new valve were excellent.

  15. 基于数控等离子耐磨技术的综采中部槽修复%Fully mechanized coal mining central trough repair based on numerical control plasma wear resistance technology

    Institute of Scientific and Technical Information of China (English)

    李龑鹏; 丁紫阳; 王腾飞

    2015-01-01

    in order to solve the problem of mechanized coal mining central trough easy to wear and short life, numerical control plasma wear resistance technology was used to repair central trough of fully mechanized coal mining. and numerical control plasma wear resistance technology and equipment are studied and applied. The results showed that numerical control plasma wear resistance technology is suitable for the repair mechanized coal mining central trough, and this method to repair the central trough can increase the life about 2 times. Moreover, it has a good economic and social beneifts.%为了解决煤矿综采中部槽易磨损、使用寿命短的问题,采用数控等离子耐磨技术修复综采中部槽,通过对数控等离子耐磨技术及设备进行研究并应用。结果表明:数控等离子耐磨技术适合于综采中部槽的修复,且该方法修复后中部槽使用寿命提高了约2倍,具有较好的经济效益和社会效益。

  16. 多元低合金耐磨锤头制造工艺%Manufacturing Process for Complex Low-alloyed Wear-resisting Hammers

    Institute of Scientific and Technical Information of China (English)

    李正伟; 李永堂; 曹建新; 贾璐

    2013-01-01

    锤头的耐磨性和工作寿命直接影响着破碎机的工作效率和生产成本,因此锤头要求有良好的力学性能、冲击韧性和耐磨性。在分析了锤头工况和失效机理的基础上,设计了多元低合金耐磨锤头材料的化学成分,提出了铸造工艺和热处理工艺,进行了工业试验,并对试件进行了检测分析,获得了满意的结果。%The operation efficiency and production cost of crusher were directly affected by the performance and service life of hammers .Therefore ,hammers were requested to have good mechanical properties ,impact toughness and abrasive resistance .Based on the analysis of working condition of the hammers and the failure mechanism ,the chemical composition of multi-element low-alloy wear-resistant material for hammers was designed ,the program of casting process and heat treatment process were proposed ,the industrial test was carried out ,and the satisfactory results were obtained .

  17. Development and Selection of Wear Resistant Materials for Hammer Crusher%破碎机锤头耐磨材料的研制与选择

    Institute of Scientific and Technical Information of China (English)

    毛静波

    2012-01-01

    分析了近年来国内外破碎机锤头耐磨材料的研究及应用情况,指出破碎机锤头材料普遍存在的问题:硬度和韧性偏低、耐磨性差,且容易断裂。着重介绍了大型破碎机超强高锰钢锤头、耐磨合金钢锤头、高韧性合金耐磨铸铁锤头的研制和使用效果。%The development and application of wear resistant materials for hammer crusher in recent years is analyzed. It is pointed out that the common problems of hammer crusher materials are lower hardness and toughness, bad abrasion resistant and easy to fracture. The manufacture and using effects of superhigh manganese steel, wearresistant alloy steel and high toughness abrasionresistant alloy cast iron hammers for large crusher are emphasized.

  18. Influence of loading on wear resistance properties of Ti-Zr-Nb-Sn alloy for dental restoration%加载载荷对钛锆铌锡合金摩擦磨损性能的影响

    Institute of Scientific and Technical Information of China (English)

    胡欣; 李长义; 刘亚林; 李宏捷; 韩华; 张连云

    2011-01-01

    Objective:To study the influence of load on wear resistance properties of Ti-Zr-Nb-Sn alloy for dental restoration Methods: A loading wear test was performed under an artificial saliva environment at 37 ℃ by MMV-1 Vertical universal friction and wear testing machine. Ti-Zr-Nb-Sn alloy was two-body wear tested in vitro using steatite as the grinding material. Test loads were set as 20, SO and 100 N. Quality wear loss was measured by electronic balance and wear surface morphology was observed with electron microscope. Results: As loads increased, the wear loss of the Ti-Zr-Nb-Sn alloy increased. Under 20, SO and 100 N loads, the dominant wear form was abrasive wear, adhesion wear accompanied with abrasive wear, and adhesion wear respectively. Conclusions: Increasing loads could enlarge the wear loss of Ti-Zr-Nb-Sn alloy and change its dominant wear form. Serious adhesion wear occurs under high loading conditions and the lifetime of Ti-Zr-Nb-Sn alloy would therefore be shortened.%目的:探讨载荷变化对钛锆铌锡合金与滑石瓷对磨时摩擦磨损性能的影响.方法:使用MMV-1立式万能摩擦磨损试验机,以滑石瓷为对磨物,载荷设置为20、50、100 N,在37℃人工唾液润滑的试验工况下,对口腔修复用钛锆铌锡合金进行二体摩擦磨损试验.采用扫描电镜观察表面磨损形貌,电子天平得出磨损量.结果:钛锆铌锡合金与对磨物滑石瓷的磨损量随载荷的增加而增大.载荷20N,钛锆铌锡合金的磨损机制主要为磨粒磨损; 50N时,磨损机制是粘着磨损伴发磨粒磨损;100N时,钛锆铌锡合金磨损机制以粘着磨损为主.结论:载荷增加可增大钛锆铌锡合金的磨损量,导致磨损机制改变,在高载荷条件下可发生严重粘着磨损,缩短修复体的使用寿命.

  19. Microstructure and Abrasive Wear Performance of Ni-Wc Composite Microwave Clad

    Science.gov (United States)

    Bansal, Amit; Zafar, Sunny; Sharma, Apurbba Kumar

    2015-10-01

    In the present work, Ni-WC powder was deposited on mild steel substrate to develop clads through microwave hybrid heating technique. The cladding trials were carried out in an industrial microwave applicator at 1.1 kW for 540 s. The Ni-WC composite clads were characterized for microstructure and abrasive wear performance through combination of x-ray diffraction, electron and optical microscopy, microhardness, and wear tests. Phase analysis of the Ni-WC clad indicated the presence of stable carbides such as WC, W2C, Ni2W4C, and Fe6W6C. The microstructure study of the clad layer revealed the presence of a uniformly distributed interlocked WC-based reinforcement embedded in the Ni-based matrix. The average Vicker's microhardness in the clad layer was observed to be 1028 ± 90 HV, which was approximately three times the microhardness of the substrate. Abrasive wear resistance of the microwave clads was superior to the MS substrate. Abrasion was the main wear mechanism in the Ni-WC clads and the substrate samples. However, the presence of WC-based reinforcement in the composite clads reduced microcutting, resulting in enhanced wear resistance.

  20. Characterization of Al-12Si alloy and its composites in dry sliding friction and wear at elevated temperature

    Institute of Scientific and Technical Information of China (English)

    杜军; 刘耀辉; 于思荣; 王威

    2003-01-01

    Al-12Si alloy matrix composites reinforced with Al2O3 and carbon fibers respectively as well as with the two fibres were fabricated by squeeze-infiltration. The elevated temperature (about 400 ℃) friction and wear behaviors of Al-12Si alloy and its composites were investigated.The results show that the hybrid composites reinforced with Al2O3 and carbon fibres are of superior high temperature wear resistance.The critical transition temperature from mild wear to severe wear of the composites reinforced only with Al2O3 fiber is improved markedly compared with monolithic Al-12Si alloy, from 200 ℃ to 300 ℃.However, the critical transition temperature of the hybrid composites reinforced with Al2O3 and carbon fibers is improved further to 400 ℃.The reinforcing fibers have no significant effect on wear mechanisms of Al-12Si alloy.The dominant mechanisms are ploughing grooves and delamination as well as slight adhesion during mild wear regime.The subsurface consists of three regions:non-peeling delamination layer, microcrack formation and propagation zone, and unaffected zone.Whereas the dominant mechanism is shifted to severe wear when test temperature exceeds the critical transition temperature.

  1. Wear behaviour of Al 261

    Directory of Open Access Journals (Sweden)

    N. Mathan Kumar

    2016-03-01

    Full Text Available Al 2618 matrix material was mixed with the Silicon Nitride (Si3N4, Aluminium Nitride (AlN and Zirconium Boride (ZrB2 reinforced particles. AMC was synthesized successfully by the stir casting method with the various X-wt.% of reinforcements (X = 0,2,4,6,8. Tribological behaviour was studied in this composite with various temperature conditions. The working conditions were Temperature (°C, Load (N, Velocity (m/s and Sliding Distances (m. Before wear testing the mechanical behaviour has been analysed. EDAX was confirmed by the matrix material composition. The Al 2618 alloy and the reinforcement mixers were confirmed by the X-ray Diffraction analysis. Wear rate (mm3/m, Wear resistance (m/mm3, Specific Wear rate (m/Nm and Co-efficient of friction (μ were analysed with various conditions. The worn surfaces were analysed before and after wear testing by Scanning Electron Microscope (SEM. Influence of process parameters and Percentage of contribution were analysed by Taguchi and Analysis of Variance (ANOVA methods. Genetic Algorithm (GA was adopted for optimizing the best and mean of the wear rate and to identify the exact influence of input parameters.

  2. Microstructure and Wear Behaviour of Laser-Induced Thermite Reaction Al2O3 Ceramic Coatings on Pure Aluminum and AA7075 Aluminum Alloy

    Institute of Scientific and Technical Information of China (English)

    HUANG Kaijin; LIN Xin; XIE Changsheng; T M Yue

    2008-01-01

    Wear-resistant laser-induced thermite reaction Al2O3 ceramic coatings can be fabricated on pure Al and AA7075 aluminum alloy by laser cladding(one-step method)and laser cladding followed by laser re-melting(two-step method)using mixed powders CuO-Al-SiO2 in order to improve the wear properties of aluminum and aluminum alloy,respectively.The microstructure of the coatings was characterized by scanning electron microscopy(SEM)and X-ray diffraction(XRD).The wear resistance of the coatings was evaluated under dry sliding wear test condition at room temperature.Owing to the presence of hard a-Al2O3 and γ-Al2O,3phases,the coatings exhibited excellent wear resistance.In addition,the wear resistance of the coatings fabricated by two-step method is superior to that of the coatings fabricated by one-step method.

  3. Enhancement of wear and ballistic resistance of armour grade AA7075 aluminium alloy using friction stir processing

    OpenAIRE

    I. Sudhakar; V. Madhu; G. Madhusudhan Reddy; K. Srinivasa Rao

    2015-01-01

    Industrial applications of aluminium and its alloys are restricted because of their poor tribological properties. Thermal spraying, laser surfacing, electron beam welding are the most widely used techniques to alter the surface morphology of base metal. Preliminary studies reveal that the coating and layering of aluminium alloys with ceramic particles enhance the ballistic resistance. Furthermore, among aluminium alloys, 7075 aluminium alloy exhibits high strength which can be compared to tha...

  4. 离子渗氮压力对H13钢摩擦磨损性能的影响%Effect of ion nitriding pressure on wear resistance of H13 steel

    Institute of Scientific and Technical Information of China (English)

    罗顺; 林义民; 唐维学; 侯惠君

    2011-01-01

    研究了等离子渗氮压力对H13模具钢渗层组织、显微硬度和摩擦学性能的影响,对磨损后的显微形貌进行了分析,对磨损机理进行了探讨.结果表明:选择N2与H2的体积比为2∶ 1,渗氮温度为540 ℃,渗氮压力为1066 Pa的工艺条件,渗氮层厚度值最大,硬度曲线最平缓,摩擦因数低,磨损量最小,具有相对较好的耐摩擦磨损性能.%Effect of plasma nitriding pressure on nitriding layer microstructure, microhardness and wear resistance of HI3 tool steel was studied, morphologies were analyzed and wear mechanism was discussed. The results show that under the volume of nitrogen and hydrogen ratio 2: 1, nitriding temperature 540 ℃, nitriding pressure 1066 Pa, the nitriding thickness is the largest, the hardness profile is relatively flat,the friction coefficient is the lowest and the wear is the smallest, so the nitrided layer has good abrasion wear resistance.

  5. Microstructure and wear resistance of TiC carbide-reinforced composite coating prepared by laser surface alloying%激光表面合金化制备TiC颗粒增强复合材料微观结构及磨擦学性能研究

    Institute of Scientific and Technical Information of China (English)

    许长庆; 李贵江

    2008-01-01

    To strengthen the wear resistance of AISI321 stainless steel, the TiC carbide-reinforced compos-ite coating was produced by laser surface alloying. The microstructure, microhardness, and wear resistance of the composite coatings were investigated using optical microscopy, X-ray diffraction (XRD) meter, scan-ning electron microscopy (SEM), microhardness tester, and sliding wear tester. The results show that the composite coating is metallurgically bonded to the substrate and the microstructure is fine and uniform. The hardness of the composite coating is up to 400 HV, which is 2.5 times that of the substrate. Under room temperature and oil lubrication condition, the sliding wear tests indicate the friction coefficient and weight loss of the composite coating are smaller than those of substrate. The worn surface of the composite coatings is much smoother than that of the substrate, without grooves and crater. The wear resistance of the material has been greatly improved by laser surface alloying.

  6. Development of the white cast iron with niobium alloy, heat treating, to wear of the abrasive resistance; Desenvolvimento de uma liga de ferro fundido branco alto cromo com niobio, tratada termicamente, para resistencia ao desgaste abrasivo

    Energy Technology Data Exchange (ETDEWEB)

    Farah, Alessandro Fraga

    1997-07-01

    This work presents the heat treatment and abrasion tests results of a white cast iron with niobium alloy. The hardening heat treatment were made 950, 1000, 1050 e 110 deg C temperatures cooled by forced air. The tempering treatment were made at 450, 500 e 550 deg C temperatures. The heat treating alloy were compared, in the abrasive tests, with commercial alloys used as hardfacing by welding process in wear pieces. The abrasion tests was realized in pin on disk test. Additional tests were carried out for microstructural characterization to identify the different phases presents in the alloys. In a general way, the alloy studies showed the best wear rate for the heat treatments that results in higher hardness. It performance was superior than that of the commercial alloys. (author)

  7. A new methodology for predictive tool wear

    Science.gov (United States)

    Kim, Won-Sik

    turned with various cutting conditions and the results were compared with the proposed analytical wear models. The crater surfaces after machining have been carefully studied to shed light on the physics behind the crater wear. In addition, the abrasive wear mechanism plays a major role in the development of crater wear. Laser shock processing (LSP) has been applied to locally relieve the deleterious tensile residual stresses on the crater surface of a coated tool, thus to improve the hardness of the coating. This thesis shows that LSP has indeed improve wear resistance of CVD coated alumina tool inserts, which has residual stress due to high processing temperature. LSP utilizes a very short laser pulse with high energy density, which induces high-pressure stress wave propagation. The residual stresses are relieved by incident shock waves on the coating surface. Residual stress levels of LSP CVD alumina-coated carbide insert were evaluated by the X-ray diffractometer. Based on these results, LSP parameters such as number of laser pulses and laser energy density can be controlled to reduce residual stress. Crater wear shows that the wear resistance increase with LSP treated tool inserts. Because the hardness data are used to predict the wear, the improvement in hardness and wear resistance shows that the mechanism of crater wear also involves abrasive wear.

  8. Suction against resistance: a new breathing technique to significantly improve the blood flow ratio of the superior and inferior vena cava.

    Science.gov (United States)

    Gutzeit, Andreas; Roos, Justus E; Hergan, Klaus; von Weymarn, Constantin; Wälti, Stephan; Reischauer, Carolin; Froehlich, Johannes M

    2014-12-01

    Optimal contrast within the pulmonary artery is achieved by the maximum amount of contrast-enhanced blood flowing through the superior vena cava (SVC), while minimum amounts of non-contrasted blood should originate from the inferior vena cava (IVC). This study aims to clarify whether "suction against resistance" might optimise this ratio. Phase-contrast pulse sequences on a 1.5T MRI magnet were used for flow quantification (mean flow (mL/s), stroke volume (Vol) in the SVC and IVC in volunteers. Different breathing manoeuvers were analysed repeatedly: free breathing; inspiration; expiration; suction against resistance, and Valsalva. To standardise breathing commands, volunteers performed suction and Valsalva manoeuvers with an MR-compatible manometer. Suction against resistance was associated with a significant drop of the IVC/SVC flow quotient (1.63 [range 1.3-2.0] p  0.05). Suction against resistance caused a significant drop in the IVC/SVC quotient. Theoretically, this breathing manoeuver might significantly improve the enhancement characteristics of CT angiography. Suction provokes reduction in blood flow in the inferior vena cava. Ratio between the inferior and superior vena cava blood flow diminished during suction. Manometer used during breathing standardises MR phase-contrast blood flow measurements.

  9. "Bio-glues" to Enhance Slipperiness of Mucins: Improved Lubricity and Wear Resistance of Porcine Gastric Mucin (PGM) Layers Assisted by Mucoadhesion with Chitosan

    DEFF Research Database (Denmark)

    Nikogeorgos, Nikolaos; Efler, Petr; Lee, Seunghwan

    2015-01-01

    A synergetic lubricating effect between porcine gastric mucin (PGM) and chitosan based on their mucoadhesive interaction is reported at a hydrophobic interface comprised of self-mated polydimethylsiloxane (PDMS) surfaces. In acidic solution (pH 3.2) and low concentrations (0.1 mg mL- 1), the inte......A synergetic lubricating effect between porcine gastric mucin (PGM) and chitosan based on their mucoadhesive interaction is reported at a hydrophobic interface comprised of self-mated polydimethylsiloxane (PDMS) surfaces. In acidic solution (pH 3.2) and low concentrations (0.1 mg mL- 1......), the interaction of PGM with chitosan led to surface recharge and size shrinkage of their aggregates. This resulted in higher mass adsorption on the PDMS surface with increasing weight ratio of [chitosan]/[PGM + chitosan] up to 0.50. While neither PGM nor chitosan exhibited slippery characteristics, coefficient...... of friction being close to 1, their mixture improved considerably the lubricating efficiency (coefficient of friction 0.011 at optimum mixing ratio) and wear resistance of the adsorbed layers. These findings are explained by the role of chitosan as a physical crosslinker within the adsorbed PGM layers...

  10. Theoretical Analyses and Experimental Investigations of Selective Carbothermal Reactions of Vanadium-Bearing Titanomagnetite Concentrates for Preparation of Iron-Based Wear-Resistant Material

    Science.gov (United States)

    Zhang, Guangming; Feng, Keqin; Yue, Huifang

    2016-09-01

    Based on FACTSage® software, this paper focuses on the thermodynamic calculations of selective carbothermal reactions of vanadium-bearing titanomagnetite concentrates for preparing iron-based wear-resistant material directly from vanadium-bearing titanomagnetite concentrates. The calculations show that it was most likely to generate metallic iron, titanium carbide and vanadium carbide among all possible carbothermal reactions of vanadium-bearing titanomagnetite concentrates in a vacuum of 10 Pa. The equilibrium composition calculations indicate that Fe3O4 can be reduced to metallic iron by carbon above 400°C, FeTiO3 can be converted into TiC by carbon above 800°C and V2O5 can be converted into VC by carbon above 600°C in a vacuum of 10 Pa. The investigations demonstrated that the percentage of ferrous oxides reduced to metallic iron was about 96%, the conversion percentage of FeTiO3 into TiC was about 75% and the conversion percentage of V2O5 into VC was about 94% after the selective carbothermal reactions of vanadium-bearing titanomagnetite concentrates at 1300°C for 3 h in a vacuum of 10 Pa.

  11. A View on Wear Mechanism of Metallic Card Clothing

    Institute of Scientific and Technical Information of China (English)

    WU Liang; WANG Wen-qiang; NI Huai-sheng

    2008-01-01

    The wear mechanism of metallic card clothing,used in textile industry, was analyzed. A fast wear test for metallic card clothing racks was developed, which was used as collecting the wear metal particles. The failure type of card clothing was analyzed by the mean of scanning electron microscopy (SEM) and ferro-spectrum technology. The results show that the main wear mechanism of metallic card clothing is low load and high repetition interval fatigue wear caused by friction force between fiber and metal wire teeth.The appropriate quenching microstmcture, which improves the wear resistance of the metallic card clothing rack is also discussed.

  12. Corrosion and wear resistance of titanium- and aluminum-based metal matrix composites fabricated by direct metal laser deposition

    Science.gov (United States)

    Waldera, Benjamin L.

    Titanium- and Aluminum-based metal matrix composites (MMC) have shown favorable properties for aerospace applications such as airframes, reinforcement materials and joining elements. In this research, such coatings were developed by direct metal laser deposition with a powder-fed fiber coupled diode laser. The MMC formulations consisted of pure titanium and aluminum matrices with reinforcing powder blends of chromium carbide and tungsten carbide nickel alloy. Two powder formulations were investigated for each matrix material (Ti1, Ti2, Al1 and Al2). Titanium based composites were deposited onto a Ti6Al4V plate while aluminum composites were deposited onto AA 7075 and AA 5083 for Al1 and Al2, respectively. Microstructures of the MMCs were studied by optical and scanning electron microscopy. The hardness and reduced Young's modulus (Er) were assessed through depth-sensing instrumented nanoindentation. microhardness (Vickers) was also analyzed for each composite. The corrosion resistance of the MMCs were compared by monitoring open circuit potential (OCP), polarization resistance (Rp) and potentiodynamic polarization in 0.5 M NaCl to simulate exposure to seawater. The Ti-MMCs demonstrated improvements in hardness between 205% and 350% over Ti6Al4V. Al-MMCs showed improvements between 47% and 79% over AA 7075 and AA 5083. The MMCs showed an increase in anodic current density indicating the formation of a less protective surface oxide than the base metals.

  13. Effects of Graphite Additions on Microstructures and Wear Resistance of Fe-Cr-C-Nb Hardfacing Alloys

    Directory of Open Access Journals (Sweden)

    Fei HUANG

    2017-08-01

    Full Text Available Hardfacing alloys with varying amounts of graphite content were prepared on a surface of 45 steel using flux-cored wire open-arc overlaying. Testing was conducted using SEM, TEM, XRD, a Rockwell hardness apparatus and an abrasion tester to study the effect of variation of graphite content on the microstructure, hardness and abrasive resistance of the hardfacing alloy. The results show that the microstructure of the hardfacing layer consisted of martensite, austenite and NbC. As graphite content increased, martensite content increased, austenite content decreased, and the size of in situ-generated NbC particles increased. Additionally, the abrasive resistance of the hardfacing alloy, which could exceed 4 times that of the 45 steel base material, was related to the microstructure and the size of NbC particles, and generally shared the same variation trend as the hardness changes in the hardfacing layer.DOI: http://dx.doi.org/10.5755/j01.ms.23.3.16678

  14. Microstructures and Wear Resistance of the TiC-TiB2 Composite Coating Deposited by Electrical Discharge Hardening%TiC-TiB2电火花复合强化层组织与耐磨性

    Institute of Scientific and Technical Information of China (English)

    汤精明

    2012-01-01

    TiC-TiB2 composite coating was deposited by electrical discharge hardening onto the surface of 40Cr steel with using TiC and TiB2 composite rod as electrode. The composite coating structure and phase compositions were characterized by SEM and XRD, the hardness and its distribution along coating were measured on micro-hardness machine. Wear resistance of strengthen layer was evaluated on MM-200 wear experiment machine. The microstruc-tures.mechanical property and wear resistance of the TiC-TiB2 composite coating were analyzed, and the wear mechanism of strengthened layer was studied The results suggest that the major phases of the composite coating are TiB2, TiC and Fe3C, the fine crystalline structure and non-crystalline make the diffracting peak widening. The micro hardness distribution along depth of composite coating is unhomogeneous; the micro hardness value of the composite coating is about 4 times the size of the substrate. The wear mechanism of 40Cr steel is mainly attributed to micro-cutting and adhesive wear,but the wear mechanism of composite coating is mainly attributed to micro-cutting, scratch and fatigue abrasion. The results show that the change of wear mechanism between the samples induces to the hard particles and higher hardness of composite coating. Compared with the substrate, wear resistance of composite coating is 5 times higher, wear coefficient of the coating decreased by 0.12 to 0. 17 under the same wear environment.%以TiC-TiB2复合材料为电极,采用电火花表面强化技术,在40Cr钢表面制备出TiC-TiB2复合强化层.利用SEM和XRD分析了强化层的微观结构和物相,测试了强化层的硬度和耐磨性,并探讨了其磨损机理.结果表明:强化层物相主要为TiB2、TiC和Fe3C等,非晶组织和组织细化使其衍射峰宽化;强化层的显微硬度分布呈梯度变化,最高硬度值是基体硬度值的4倍多;强化层中的硬质相和较高的显微硬度改变了试样间的磨损机制,强化层

  15. Influence of silicon content and heat treatment on wear resistance of white chromium cast irons under high speed solidification conditions; Influencia del contenido de silicio y el tratamiento termico en la resistencia al desgaste de fundiciones blancas al cromo en condiciones de rapida solidificacion

    Energy Technology Data Exchange (ETDEWEB)

    Goyo, L.; Varela, A.; Verhaege, M.; Garcia, A.; Mier, J.; Moors, M.

    2012-11-01

    The influence of silicon content and heat treatment on microstructure, abrasive and dry friction wear resistance of a 3 % C, 12 % Cr cast iron, under fast solidification conditions is studied. The fast solidification condition diminishes the carbide volume and the silicon content increases their dispersion and finesses. All matrixes obtained were perlitics, whit different finesses. No intermediate transformation products were noticed. Hardness had little variation. Austenization treatment show little effectivity, with tendency to increase wear in reference to as cast and maintenance treatments. Behavior under dry friction and abrasive wear were similar under test conditions applied whit more influence of carbide morphology in the abrasive wear conditions. (Author) 32 refs.

  16. High Temperature Wear Resistance of HI3 Steel with Different Surface Treatments%不同表面处理工艺下H13钢的高温耐磨性能

    Institute of Scientific and Technical Information of China (English)

    刘英坤; 朱峰; 伍超群; 侯惠君

    2012-01-01

    首先对调质处理状态的H13钢进行了渗氮、物理气相沉积(PVD)镀膜、渗氮+PVD镀膜三种不同的表面处理,然后在UMT-3型摩擦磨损试验机上,对处理后的试样进行600℃的高温摩擦磨损试验,研究了不同工艺下H13钢的高温耐磨性能。结果表明:试样的磨损形式主要是粘着磨损+磨粒磨损,经表面处理后试样的表面硬度大幅度提高,摩擦系数大幅度降低;其中渗氮+PVD镀膜表面处理试样的高温耐磨性能最好。%First the hardened and tempered H13 steel was surface treated by three methods of nitridation, physical vapor deposition(PVD) coating, and Mtridation and PVD coating, and then the friction wear performance at high temperature of 600℃ of the specimens with different surface treatment states was studied on UMT-3 friction wear testing machine. The results indicate that the main wear forms of all speeimens were adhesion wear and abrasive particle wear. After the different surface treatments, the hardness of the H13 steel increased obviously, and the friction coefficient reduced obviously. Specimens surface treated by nitridation and PVD coating method showed the best high temperature wear resistance.

  17. Wear behaviour of epoxy resin filled with hard powders

    Science.gov (United States)

    Formisano, A.; Boccarusso, L.; Minutolo, F. Capece; Carrino, L.; Durante, M.; Langella, A.

    2016-10-01

    The development of high performance materials based on epoxy resin finds a growing number of applications in which high wear resistance is required. One major drawback in many of these applications is the relatively poor wear resistance of the epoxy resin. Therefore, in order to investigate on the possibility of increasing wear resistance of thermoset polymers filled with hard powders, sliding tests are carried out by means of a pin on disc apparatus. In particular, composite resins, constituted by an epoxy resin filled with different contents and sizes of Silicon Carbide powder, are analyzed; the wear resistance, in terms of volume loss, is measured for different abrasive counterfaces and loads.

  18. Current Statues of the Wear Resistance of Electroless Ni-P Based Alloy Plating%化学镀镍磷基合金镀层耐磨性的研究进展

    Institute of Scientific and Technical Information of China (English)

    刘宏; 卞建胜; 李莎; 张彪

    2012-01-01

    化学镀镍磷基合金镀层因硬度高、厚度均匀及耐磨性优异,在工业中得到了广泛应用.简述了化学镀镍磷基合金从二元、三元到复合镀层的发展历程,概述了化学镀镍磷基合金镀层耐磨性的影响因素——合金镀层的化学成分、镀层与基体间的结合力及镀层硬度,并从这三方面论述了改善耐磨性的方法,最后提出了在改善合金镀层耐磨性研究中存在的问题和未来的发展方向.%Electroless Ni-P based alloy platings have found extensive application in industry because of its high hardness, uniform thickness and excellent wear resistance. The development of the electroless Ni-P based alloy platings, from binary and tenary alloy coatings to composite coatings, was summarized, and the influence factors of the wear resistance were presented from the chemical composition of alloy coating, the combining power between coating and matrix and the hardness of coating, as well as current status of improving the wear resistance of electroless plated Ni-P based alloys. At last, the problem exiting in the research of improving the wear resistance of alloy coating and the future research orientation were raised.

  19. Prediction of wear rates in comminution equipment

    DEFF Research Database (Denmark)

    Jensen, Lucas Roald Dörig; Fundal, Erling; Møller, Per

    2010-01-01

    Raw material comminution equipment may be exposed to excessive wear, which makes it difficult to operate minerals processing plants continuously because lengthy and unplanned shut-downs interrupt the overall process. In general, most comminution equipment is fine-tuned to operate at low vibrations......-resistant high chromium white cast iron (21988/JN/HBW555XCr21), a heat-treated wear resistant steel (Hardox 400) and a plain carbon construction steel (S235). Quartz, which accounts for the largest wear loss in the cement industry, was chosen as abrasive. Other process parameters such as velocity (1–7 m...

  20. Comparative study of the wear resistance of Al2O3-coated MA956 superalloy

    Directory of Open Access Journals (Sweden)

    Canahua Loza, Hugo

    2000-10-01

    Full Text Available Preoxidation of the MA956 superalloy, proposed as a prosthetic biomaterial, generates a compact and inert a-alumina surface layer. The aim of this study is to assess the wear resistance provided by this alumina layer on the MA956 alloy in comparison with the same coated alloy and versus high density polyethylene. Comparative wear tests were carried out in both dry and wet conditions using the couples MA956/MA956, MA956/UHMWPE (ultra high molecular weight polyethylene and 316LVM/UHMWPE. The results corresponding to the couples MA956/MA956, with and without alumina layer, show that the load has more significant effect than the rotation speed on the weight loss and on the roughness. On the other hand the alumina surface layer provides a clear wear protection. The weight losses of the MA956 specimen in this couple are ten times lower when testing under wet conditions than under dry conditions. The MA956/UHMWPE couple behaves much better than the 316LVM/UHMWPE, as it presents the lowest values of friction coefíicient and weight losses of the MA956 specimen. These are only detectable after 70,000 cycles under a 70 MPa contact pressure. This couple offers the best guarantee of a prolonged service life for articulated parts in a prosthesis.

    La superaleación MA956, que se ha propuesto como biomaterial para prótesis osteoarticulares genera, mediante un adecuado tratamiento de preoxidación, una capa superficial, compacta e inerte, de alúmina alfa. El objetivo del presente trabajo es el estudio de la resistencia al desgaste de esta capa de alúmina, cuando se encuentra en contacto con la propia aleación recubierta y con polietileno de alta densidad. Se realizaron ensayos comparativos de desgaste, tanto en seco como en húmedo, con los pares MA956/MA956, MA956/UHMWPE (polietileno de muy elevado peso molecular y 316LVM/UHMWPE. Los resultados obtenidos con el par MA956/MA956, con y sin capa de alúmina, indican que la carga es el factor de mayor

  1. Fabrication and Wear Behavior Analysis on AlCrFeNi High Entropy Alloy Coating Under Dry Sliding and Oil Lubrication Test Conditions

    Science.gov (United States)

    Tang, Yipin; Wang, Shouren; Sun, Bin; Wang, Yan; Qiao, Yang

    2016-03-01

    In this paper, AlCrFeNi high entropy alloy coating was fabricated on the surface of Q235 steel using hot pressing sintering process. The coating has the controlled thickness size and excellent mechanical properties. Scanning electron microscopy (SEM), XRD and hardness testing method were used to study the morphology, phase structure and hardness of high entropy alloys coating. The lattice distortion plays a significant role in increasing the hardness. Coating formation mechanism caused by the element diffusion under the hot pressing effect is also discussed in the paper. Simultaneously, the dry sliding and oil lubrication wear tests, wear morphology observation and wear mechanism discussion were completed. As the result shows, AlCrFeNi high entropy alloys coating exhibits superior wear resistance either at dry sliding or oil lubrication tests owing to its hard high entropy solid solution structure.

  2. Novel High Strength Ceria-Zirconia Toughened Alumina Ceramic with Superior High Temperature Corrosion and Erosion Resistance. Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Giulio, R.; Butcher, K.

    2004-01-13

    Composite CeTZP/A1{sub 2}O{sub 3} (CeZTA) foams were developed and tested to determine their suitability as particulate filters in hot gaseous conditions generated by coal combustion in electric power plants. Exposure to these extreme corrosive conditions did not cause significant degradation in strength. Superior properties of these foams suggests they could be used for a variety of applications in environment, energy and chemical fields.

  3. Fabrication, microstructural characterization and wear characteristics of A380 alloy-alumina composites

    KAUST Repository

    Nurani, Sheikh Jaber

    2016-03-10

    To obtain better mechanical and tribological properties than aluminium alloys aluminium is reinforced with alumina particles making aluminium metal matrix composites. In this work scrap piston A380 alloy was used as the matrix alloy. Alumina particles were added by 5%, 10% and 15% into matrix alloy respectively to form desired composites by stir casting technique. Pin on disc wear testing machine with counter surface as steel disc of hardness HRC 32 and surface roughness of 0.62 μm was used to conduct the wear test. In result composites showed superior wear resistance property over A380 alloy. The effect of load, sliding speed and sliding distance on wear behaviour were also examined in this study. Wear mechanism was identified from the worn surface. Both optical and scanning electron microscope (SEM) of the composites was performed to determine the microstructures. Optical micrograph shows grain size decreases with addition of alumina particles. EDS analysis was performed to confirm the presence of α-Al matrix, primary Si particles and intermetallic. As a general method, phase compositions were analyzed by using a scanning electron microscope (SEM) equipped with an energy dispersive spectroscopy (EDS). Optical microstructures were consistent with the SEM micrographs. © 2015 IEEE.

  4. 新型填料增强复合树脂耐磨性的研究进展%Advances of new fillers in enhancing the wear resistance of dental resin composites

    Institute of Scientific and Technical Information of China (English)

    金杰; 冯丹; 张佳慧; 郭晓伟; 严敏; 朱松

    2016-01-01

    Currently, light-cured composite resin has been extensively used in dentistry, and studies about the property of such mate-rials are increasing. The resistance to wear of resin composite is an important factor that determines the clinical success. This article re-viewed the wear mechanism of resin composite, laboratory wear test methods, and new fillers having been used to improve wear per-formance.%目前光固化复合树脂广泛应用于口腔修复治疗,对其性能的研究也越来越多。复合树脂的耐磨性是决定临床疗效的重要因素。该文就复合树脂磨损机制,磨损研究实验室方法以及增强耐磨性的新型填料等方面作一综述。

  5. Wear and microstructure in fine ceramic coatings

    Energy Technology Data Exchange (ETDEWEB)

    Vijande-Diaz, R.; Belzunce, J.; Fernandez, E. (ETS de Ingenieros Industriales, Area de Ingeneria Mecanica, Gijon (Spain)); Rincon, A.; Perez, M.C. (Inst. de Fisica-Quimica ' Roco Solano' , CSIC, Madrid (Spain))

    1991-08-15

    This paper presents a study of the wear resistance of two ceramic, plasma sprayed coatings of Al{sub 2}O{sub 3} and Cr{sub 2}O{sub 3}. Tests were carried out using an LWF-1 standard machine, with lineal contact, under dry friction, abrasion and lubricant conditions. The purpose of the tests were to study how load and speed affect material wear. Results show the lower wear rate of the ceramic coating compared with the steel one, as well as how remarkably load affects wear. On the other hand, however, considering the speed ranges used, wear resistance does not depend significantly on speed. The paper proves that the wear process follows Czichos' law. At the same time, reformulation of Archard's equation allows us to quantify wear using easily measurable factors such as pressure, speed, hardness, and those factors typically featuring this type of coatings, e.g. porosity. Also, a micrographic study of the coatings carried out by means of a scanning electron microscope has evidenced three stages in the wear mechanism: (a) plastic deformation of particles; (b) crack nucleation and propagation; and (c) loosening of ceramic particles. (orig.).

  6. Análise da resistência ao desgaste de revestimento duro aplicado por soldagem em facas picadoras de cana-de-açúcar Analysis of wear resistance of hardfacing applied by welding in sugarcane shredder knife

    Directory of Open Access Journals (Sweden)

    Aldemi Coelho Lima

    2010-06-01

    cost is high due to metallic losses by wear. This paper studies the application of hardfacings by flux cored arc welding on the wear resistance of sugarcane shredder knives comparing laboratory and field-test results. Four types of consumable were used: three selfshielded flux cored wires of diameter 1.6 mm of alloys FeCrC, FeCrC+Nb and FeCrC+Ti and a covered electrode of FeCrC alloy of diameter 4.0 mm. The base metal is SAE 1020 steel. Test specimens were evaluated using rubber wheel abrasion tests (ASTM G65. Sugarcane shredder knives hardfaced in the same welding conditions were also tested on a shredder in an alcohol distillery. Wear evaluation is by mass loss. The flux cored wires were welded in short-circuit transfer mode with the same current and voltage values. The wire with Nb had the highest wear resistance in laboratory test but due to cracks and spalling had the least wear resistance in field test. The FeCrC and FeCrC+Ti wires presented the worst results in laboratory tests and the best results in field test, respectively. In comparison with the covered electrode, the FeCrC+Nb wire presented similar performance in laboratory and the FeCrC+Ti wire presented similar performance in field tests.

  7. CADI材料的热处理优化及其对耐磨性能的影响%Optimization of heat treatment and its influence on wear resistance for CADI material

    Institute of Scientific and Technical Information of China (English)

    胡小锋; 闫德胜; 戎利建

    2013-01-01

    采用正交试验对含碳化物的等温淬火球墨铸铁(CADI)的热处理工艺进行了优化,分析了热处理参数对CADI组织及耐磨性的影响.结果表明:等温淬火温度对CADI的耐磨性影响最大,较高的等温淬火温度会使奥铁体中富碳奥氏体粗化从而影响耐磨性,而较低的淬火温度则会降低韧性容易脆裂.奥氏体化温度、奥氏体化时间和等温淬火时间对CADI材料耐磨性的影响基本相当,较高的奥氏体化温度会粗化富碳奥氏体,对耐磨性不利.优化后的热处理制度为900℃奥氏体化1h,然后在280℃下盐浴保温1.5h,采用该制度处理后的CADI材料性能不低于进口商业化CADI犁铧产品的性能.%The heat treatment for carbidic austempered ductile iron (CADI) was optimized by orthogonal test and the influence of heat treatment parameters on the microstructure and wear resistance was discussed.The results show that the austempering temperature has the greatest impact on the wear resistance of CADI.While the austempering temperature is higher,the carbon enriched austenite in ausferrite will become more coarsening and decrease the wear resistance.On the contrary,the lower austempering temperature will decrease the toughness and it is easy to crack.The austenitizing temperature,austenitizing time and austempering time almost have the same influence on the wear resistance.Higher austenitizing temperature will coarsen the carbon enriched austenite and affect the wear resistance.The optimized heat treatment is austeniting at 900 ℃ for 1 h and then austempering at 280 ℃ for 1.5 h,at which the properties of CADI treated are not less than that of import and commerciatlized CADI product.

  8. Wear Characteristics of Metallic Biomaterials: A Review

    Directory of Open Access Journals (Sweden)

    Mohamed A. Hussein

    2015-05-01

    Full Text Available Metals are extensively used in a variety of applications in the medical field for internal support and biological tissue replacements, such as joint replacements, dental roots, orthopedic fixation, and stents. The metals and alloys that are primarily used in biomedical applications are stainless steels, Co alloys, and Ti alloys. The service period of a metallic biomaterial is determined by its abrasion and wear resistance. A reduction in the wear resistance of the implant results in the release of incompatible metal ions into the body that loosen the implant. In addition, several reactions may occur because of the deposition of wear debris in tissue. Therefore, developing biomaterials with high wear resistance is critical to ensuring a long life for the biomaterial. The aim of this work is to review the current state of knowledge of the wear of metallic biomaterials and how wear is affected by the material properties and conditions in terms of the type of alloys developed and fabrication processes. We also present a brief evaluation of various experimental test techniques and wear characterization techniques that are used to determine the tribological performance of metallic biomaterials.

  9. Wear resistance of artificial hip joints with poly(2-methacryloyloxyethyl phosphorylcholine) grafted polyethylene: comparisons with the effect of polyethylene cross-linking and ceramic femoral heads.

    Science.gov (United States)

    Moro, Toru; Kawaguchi, Hiroshi; Ishihara, Kazuhiko; Kyomoto, Masayuki; Karita, Tatsuro; Ito, Hideya; Nakamura, Kozo; Takatori, Yoshio

    2009-06-01

    Aseptic loosening of artificial hip joints induced by wear particles from the polyethylene (PE) liner remains the ruinous problem limiting their longevity. We reported here that grafting with a polymer, poly(2-methacryloyloxyethyl phosphorylcholine (MPC)) (PMPC), on the PE liner surface dramatically decreased the wear production under a hip joint simulator condition. We examined that the effect of properties of both PE by cross-linking and femoral head by changing the materials on wearing properties of PE. The PMPC grafting on the liners increased hydrophilicity and decreased friction torque, regardless of the cross-linking of the PE liner or the difference in the femoral head materials. During the hip joint simulator experiments (5 x 10(6) cycles of loading), cross-linking caused a decrease of wear amount and a reduction of the particle size, while the femoral head materials did not affect it. The PMPC grafting abrogated the wear production, confirmed by almost no wear of the liner surface, independently of the liner cross-linking or the femoral head material. We concluded that the PMPC grafting on the PE liner surpasses the liner cross-linking or the change of femoral head materials for extending longevity of artificial hip joints.

  10. Calculation of the Intensity of Adhesive-Fatigue Wear of Cutting Tools

    Science.gov (United States)

    Bibik, V.; Ivushkina, N.; Arhipova, D.

    2016-08-01

    On the base of kinetic equation of strength the authors suggest the method carbide tools wear intensity calculation allowing comparing wear resistance basing on tool material thermal diffusivity coefficient. The authors obtain equations of tool wear resistance dependences upon its thermal diffusivity which show close correlation between these parameters. The results of wear intensity calculations correspond well to the experimental results under the cutting rates corresponding to the region of adhesive-fatigue wear. The inserts with low thermal diffusivity coefficient are characterized by lower wear rate at the inial and normal stages of wear.

  11. Bovine colostrum is superior to enriched formulas in stimulating intestinal function and necrotising enterocolitis resistance in preterm pigs

    DEFF Research Database (Denmark)

    Møller, Hanne Kristine; Thymann, Thomas; Fink, Lisbeth Nielsen;

    2011-01-01

    ), gangliosides (Gang) or osteopontin (OPN) would improve gastrointestinal function and NEC resistance in preterm neonates. Forty-seven caesarean-delivered preterm pigs were given total parenteral nutrition for 2 d followed by 1.5 d of enteral feeding. In Expt 1, a control formula was compared with an OPN...

  12. Stacked -gene hybrids were not found to be superior to glyphosate resistant or Non-GMO corn hybrids

    Science.gov (United States)

    Seed costs of modern corn hybrids genetically modified with multiple traits for insect and herbicide resistance “stacked-gene” are in excess of $100.00 US per acre. Yields and net returns per acre along with yield component data were determined for ten hybrids, four stacked-gene, four glyphosate re...

  13. 钼铁对高锰钢自生碳化物组织与耐磨性的影响%Effects of Molybdenum on Carbide Structure and Wear Resistance of High Manganese Steel Authigenic Carbide

    Institute of Scientific and Technical Information of China (English)

    李国威; 刘立新; 韩彦朝; 李海玉

    2013-01-01

    The abrasive performance of hardfacing material was improved by hard particles (such as borides and carbides )generating in the surfacing layer using the welding metallurgy reaction by adding the second phase methods of strengthening the matrix material, such as an amount of ilmenite D256 electrode covering, ferro-vanadium, molybdenum, chromium, boron carbide, graphite and rare-earth. The surfacing layer microstructure was studied by microscopy. The effects of molybdenum iron electrode coating component on the hardness, abrasive wear and adhesive wear were studied. The results show that: the hardness and wear resistance of the cladding layer with autogenetic paniculate phase are improved. The highest hardness is 60 HRC, improved by 8 HRC than D256 electrodes, and the wear resistance improves by 1 times.%通过在D256焊条药皮中加入一定量的钛铁、钒铁、钼铁、铬铁、碳化硼、石墨和稀土,利用焊接冶金反应在堆焊层中自生成硼化物、碳化物等硬质颗粒以提高耐磨堆焊材料的抗磨粒磨损性能.本文利用金相显微镜对堆焊层显微组织进行分析,通过硬度试验、磨损试验等,研究了焊条药皮组分中钼铁的加入对堆焊层硬度及耐磨性的影响.研究结果表明:加入钼铁后,堆焊层硬度和耐磨性都有所提高,其最高硬度达到60 HRC,比D256焊条提高了8HRC,耐磨性也提高了1倍.

  14. Abrasive wear property of laser melting/deposited Ti2Ni/TiNi intermetallic alloy

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A wear resistant intermetallic alloy consisting of TiNi primary dendrites and Ti2Ni matrix was fabricated by the laser melting deposition manufacturing process. Wear resistance of Ti2Ni/TiNi alloy was evaluated on an abrasive wear tester at room temperature under the different loads. The results show that the intermetallic alloy suffers more abrasive wear attack under low wear test load of 7, 13 and 25 N than high-chromium cast-iron. However, the intermetallic alloy exhibits better wear resistance under wear test load of 49 N. Abrasive wear of the laser melting deposition Ti2Ni/TiNi alloy is governed by micro-cutting and plowing.Pseudoelasticity of TiNi plays an active role in contributing to abrasive wear resistance.

  15. Wearing gloves in the hospital

    Science.gov (United States)

    ... gloves; PPE - wearing gloves; Nosocomial infection - wearing gloves; Hospital acquired infection - wearing gloves ... Wearing gloves in the hospital helps prevent the spread of germs. This helps protect both patients and health care workers from infection.

  16. Comparative wear mapping techniques

    DEFF Research Database (Denmark)

    Alcock, J.; Sørensen, Ole Toft; Jensen, S.

    1996-01-01

    Pin-on-disc tests of tungsten carbide pins against silicon carbide discs were performed and wear rate, mechanism and friction maps constructed. Correlations were observed between the wear mode and the friction of the pin-disc interface, and between the qualitative incidence of disruptive wear...

  17. Effect of heat treatment on mechanical properties and wear resistance of Q345 aluminized steel%热处理工艺对Q345渗铝钢力学性能及耐磨性的影响

    Institute of Scientific and Technical Information of China (English)

    黄耀; 王旭明; 牛海军; 林德源; 赵金飞; 陈云祥; 刘蔚宁

    2016-01-01

    研究了不同渗铝温度及冷却方式对渗铝钢力学性能的影响,对比研究了渗铝钢、镀锌钢和原材料的耐磨特性,采用SEM及能谱仪对磨损后的物相进行了分析。力学性能结果表明:当渗铝温度降低至715~735℃时,采用空冷,可保持原材料的力学性能;耐磨失重试验表明渗铝钢的质量损失明显低于镀锌钢,其质量损失随着加载力增加而缓慢增加,当加载力从3 N增加至19 N时,渗铝钢质量损失从0.87 mg增加至2.15 mg,其最大质量损失仅为Q345的19.8%,镀锌钢的28.1%。对渗铝钢、镀锌钢和原材料磨损后的物相分析表明:渗铝钢的耐磨相为Fe-Al-O化合物,镀锌钢耐磨相为Fe-Zn合金氧化物;磨损机理分析表明,Q345的磨损主要为粘着磨损,而渗铝钢则为磨粒磨损。%Effect of different aluminizing temperature and cooling method on mechanical properties of aluminized steel were investigated, then a comparative study of wear characteristics between aluminized steel, galvanized steel and Q345 was conducted by using scanning electron microscopy (SEM) and energy dispersive spectrometer. The mechanical properties results show that when the aluminizing temperature is reduced to 715-735 ℃, mechanical properties of the raw materials can maintain by using air cooling heat-treatment. Wear weight loss test demonstrates that weight loss of aluminized steel is significantly lower than that of galvanized steel, and the weight loss increases slowly with the loading force. When the loading force increases from 3 N to 19 N, weight loss value is enhanced from 0. 87 mg to 2. 15 mg, and the maximum value is only 19. 8% of Q345 steel, 28. 1% of galvanized steel. Phase analysis of the wear of aluminized steel, galvanized steel and Q345 show that wear-resistant phase of aluminized steel is Fe-Al-O compounds, and wear-resistant phase of galvanized steel is Fe-Zn alloy oxide. Wear mechanism analysis shows that the Q345 wear mechanism is