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Sample records for abrasive wear resistance

  1. Polyurethanes from the crystalline prepolymers resistant to abrasive wear

    Domańska Agata; Boczkowska Anna; Izydorzak-Woźniak Marta; Jaegermann Zbigniew; Grądzka-Dahlke Małgorzata

    2014-01-01

    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(cyclohexyl)isocyanate (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 polyuret...

  2. Polyurethanes from the crystalline prepolymers resistant to abrasive wear

    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.

  3. The influence of boron on the abrasion wear resistance of 17%Cr white cast iron

    A study of the abrasion wear resistance of the 2.7C-17Cr-0.7Mo white cast irons with different structures alloyed with boron ranging from 0.1% to 1.3% is carried out. Eleven heat treatments were used to find the optimum treatment. Three conditions (as-cast, martensitic and austenitic) are adopted for various tests. The microstructure and three-dimensional morphology of compounds are examined by optical microscope and SEM respectively. X-ray diffractometer is employed to analyze the compound phases. A high-stress abrasive wear tests is performed with loose SiO/sub 2/ and SiC abrasives in a metal track wear tester. Another abrasive wear test is conducted with wet SiO/sub 2/ abrasives in a rubber wheel tester. The hardness and fracture toughness of these alloys was also measured. With increasing boron content fracture toughness decreases. It is noted that if the irons contained about same compound volume, the abrasion wear resistance in present wear systems are much better than the irons without boron against SiO/sub 2/ abrasives, and the toughness is equivalent to 15 Cr irons without boron. Finally, considering the wear resistance and fracture toughness, the test results would provide a basis for optimizing these properties in selecting materials for a given wear component

  4. Wear and abrasion resistance selection maps of biological materials.

    Amini, Shahrouz; Miserez, Ali

    2013-08-01

    The mechanical design of biological materials has generated widespread interest in recent years, providing many insights into their intriguing structure-property relationships. A critical characteristic of load-bearing materials, which is central to the survival of many species, is their wear and abrasion tolerance. In order to be fully functional, protective armors, dentitious structures and dynamic appendages must be able to tolerate repetitive contact loads without significant loss of materials or internal damage. However, very little is known about this tribological performance. Using a contact mechanics framework, we have constructed materials selection charts that provide general predictions about the wear performance of biological materials as a function of their fundamental mechanical properties. One key assumption in constructing these selection charts is that abrasion tolerance is governed by the first irreversible damage at the contact point. The maps were generated using comprehensive data from the literature and encompass a wide range of materials, from heavily mineralized to fully organic materials. Our analysis shows that the tolerance of biological materials against abrasion depends on contact geometry, which is ultimately correlated to environmental and selective pressures. Comparisons with experimental data from nanoindentation experiments are also drawn in order to verify our predictions. With the increasing amount of data available for biological materials also comes the challenge of selecting relevant model systems for bioinspired materials engineering. We suggest that these maps will be able to guide this selection by providing an overview of biological materials that are predicted to exhibit the best abrasion tolerance, which is of fundamental interest for a wide range of applications, for instance in restorative implants and protective devices. PMID:23643608

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

    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.

  6. Influence of alumina and titanium dioxide coatings on abrasive wear resistance of AISI 1045 steel

    Santos, A.; Remolina, A.; Marulanda, J.

    2016-02-01

    This project aims to compare the behaviour of an AISI 1045 steel's abrasive wear resistance when is covered with aluminium oxide (Al2O3) or Titanium dioxide (TiO2), of nanometric size, using the technique of thermal hot spray, which allows to directly project the suspension particles on the used substrate. The tests are performed based on the ASTM G65-04 standard (Standard Test Method for Measuring Abrasion Using the Dry Sand/Rubber Apparatus). The results show that the amount of, lost material increases linearly with the travelled distance; also determined that the thermal treatment of hardening-tempering and the alumina and titanium dioxide coatings decrease in average a 12.9, 39.6 and 29.3% respectively the volume of released material during abrasive wear test.

  7. The structure and properties of steel with different pearlite morphology and its resistance to abrasive wear

    J. Herian

    2008-06-01

    Full Text Available Purpose: The analyse of pearlite morphology changes as a result of hot rolling process and isothermal annealing.Design/methodology/approach: Physical modelling of isothermal annealing for a transition point of520-620°C was carried out using a Gleeble simulator. A scanning electron microscope was used for a quantitativeevaluation of the microstructure.Findings: The obtained test results confirm that these methods can be effectively used in shaping the pearliticstructure and properties of the steel. During numerical simulation of a ride of a rail-vehicle through a switch, theload acting on a block section being part of the vehicle structure was determined. The load values were used insimulation of the resistance to abrasive wear, which was carried out in physical simulation.Practical implications: In physical modelling of tests of resistance to abrasive wear for the steel grade R260after hot rolling and isothermal annealing it has been proved that this feature is a function of the steel structure andproperties in the given operation conditions (load and slide magnitude. Abrasive wear of the rail steel is the moreintensive, the larger the load at a constant slide is.Originality/value: An advantageous pearlitic morphology of steel (block sections with interlamellar distance inthe order of 0.12-0.13 μm, ensuring hardness of about 340-350 HB, is facilitated by a hot rolling process combinedwith isothermal annealing.

  8. The abrasive wear dependence research on chemical constitution, hardness and resistance of alloy cast steel Cr-Mo-V-Cu-Ni type

    In the work there are research program elements, alloying elements contents influence on abrasive wear for hot work. The aim of research is to define the hardness influence, resistance and contents of Cr, Mo, V on alloy cast steel abrasive wear Cr-Mo-V-Cu-Ni. (author)

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

    Białobrzeska B.; Dudziński W.

    2015-01-01

    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 h...

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

    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.

  11. Impact-abrasion and abrasion of WC-Co: wear mechanisms in severe environments

    Hawk, Jeffrey A.; Wilson, Rick D.; Osara, K. (Outokumpu Research Oy)

    2003-10-01

    Hard and super-hard materials have very good abrasive wear resistance. However, in many severe wear environments that make use of these materials, impact is a significant component of that environment. Consequently, the behavior of many of these hard materials in impact-wear conditions need to be understood with respect to the mechanisms of material removal such small scale fracture and subsequent crack growth in the carbide. This study details the behavior of several ?hard? materials in abrasion and impact-abrasion focusing on the mechanisms of material removal due to impact and abrasion.

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

    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. Development of the white cast iron with niobium alloy, heat treating, to wear of the abrasive resistance

    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)

  14. Third abrasive wear mode: is it possible?

    Ronaldo Câmara Cozza

    2014-04-01

    Full Text Available The objective of this paper is to propose an initial discussion on the characterization of a third abrasive wear mode. The results obtained in a previous work [1] under different test conditions revealed the occurrence of the superposition of the “rolling” and “grooving” abrasive wear modes. This phenomenon was denoted “micro-rolling abrasion” due to the observation that “rolling abrasion” was found to act on “grooving abrasion”.

  15. Influence of the metallic matrix ratio on the wear resistance (dry and slurry abrasion) of plasma sprayed cermet (chromia / stainless steel) coatings

    Ageorges, H.; Ctibor, Pavel; Medarhri, Z.; Touimi, S.; Fauchais, P.

    2006-01-01

    Roč. 201, č. 5 (2006), s. 2006-2011. ISSN 0257-8972 R&D Projects: GA AV ČR(CZ) 1QS200430560 Institutional research plan: CEZ:AV0Z20430508 Keywords : plasma spraying * composite coating * tribology * hardness * wear * abrasion * chromia/stainless steel Subject RIV: JH - Ceramics, Fire-Resistant Materials and Glass Impact factor: 1.559, year: 2006

  16. Analysis of polymerization time on abrasive wear of dental resins

    Eduardo Carlos Bianchi

    2010-03-01

    Full Text Available An evaluation was made of the abrasive wear of six composite thermofixed dental resins subjected to different polymerization times. The method of evaluation was based on sharpness measurements to quantify the abrasive wear resistance of the resins. To this end, a test bench was built, consisting of a rotating porcelain cylinder that wears out a resin-coated cylinder placed above it, thus causing vertical displacement of the contact as the wear progresses. The values of vertical displacement, i.e., the input variables, were read and recorded by means of a computer program to obtain the sharpness values. These data indicated that the resins displayed different behaviors as a function of the polymerization times applied, reinforcing the importance of using a practical and rapid method of analysis in order to ensure that the behavior of new materials is fully understood before they are launched on the market.

  17. Comparison of abrasion resistance of selected constructional materials

    M. Adamiak

    2009-12-01

    Full Text Available Purpose: The aim of this work was to define and compare abrasion resistance of selected constructional materials widely used in the industry. Chromium cast iron wear resistant plates were compared with typically used wear resistant plates made from Hardox 400 steel and two different, wear resistant, materials cladded by welding technologies.Design/methodology/approach: The tests of abrasive wear were conducted in accordance to procedure “A” of standard ASTM G 65 - Standard Test Method for Measuring Abrasion Using the Dry Sand/Rubber Wheel Apparatus.Findings: Abrasion resistance tests shows that the best properties among investigated samples has chromium cast iron plate. Abrasion wear resistance of this plate is two times higher than wear resistance of layer made by welding technologies and nine times higher than typical Hardox 400 steel plate.Practical implications: Application, of abrasion resistant materials, results in significant material and economy savings, due to wear and costs reduction (decreasing stop times needed to change worn parts for a new one.Originality/value: Wear plates are modern solution in regeneration of worn machines parts and also for producing a new parts which connect high wear and abrasion resistance with costs reduction.

  18. Usage of abrasion-resistant materials in agriculture

    J Votava

    2014-06-01

    Full Text Available Agricultural soil-processing machines are subject to an extensive abrasive wear. This paper analyses technical materials and their fitness to exchangeable parts of plough bottoms, such as edge-tools and whole plough cutting edges. There were tested abrasion-resistant steels with different microstructures: austenite, martensite-bainite, and carbide. Steel with the pearlite-ferrite structure was used as an etalon. Abrasion resistance tests were processed in compliance with the norm CSN 01 5084, which is a test of abrasion wear on abrasive cloth.

  19. Abrasion resistant tubular member

    A surface of a tubular member made of an austenite stainless steel having a molybdenum content of from 2 to 3% is subjected to a low temperature ionization nitriding treatment in a gas atmosphere of N2: from 5 to 15% by volume, H2: from 95 to 85% by volume, at a temperature of from 400 to 470degC to form a nitride layer. Since the low temperature ion nitriding treatment is thus applied, generation of ε phase which lowers corrosion resistance can be suppressed. That is, the hardened layer (nitride layer) is provided with abrasion resistance, while the inside can keep the inherent characteristic of the austenite stainless steel having high toughness. In addition, this can avoid the tendency of lowering corrosion resistance due to the formation of a ε phase caused by exposure to high temperature for a long time in order to increase the thickness of the nitrided layer. When the thickness of the tube is 1.3mm, the less than 130μm is enough for the nitride layer. Abrasion resistance can be improved by thus applying ion nitriding treatment to the austenite stainless steel containing molybdenum under controlled temperature and atmosphere. (N.H.)

  20. Abrasive wear response of aluminium alloy-sillimanite particle reinforced composite under low stress condition

    Singh, M. [Regional Research Laboratory (CSIR), Hoshangabad Road, Near Habibganj Naka, Bhopal 462 026 (India)]. E-mail: mulayam_singh@hotmail.com; Mondal, D.P. [Regional Research Laboratory (CSIR), Hoshangabad Road, Near Habibganj Naka, Bhopal 462 026 (India); Das, S. [Regional Research Laboratory (CSIR), Hoshangabad Road, Near Habibganj Naka, Bhopal 462 026 (India)

    2006-03-15

    The abrasive wear behaviour of aluminium alloy-sillimanite particle reinforced composite under low stress condition has been reported and the results have been compared with the corresponding matrix alloy which was produced and cast under similar conditions. The study showed that wear resistance (inverse of wear rate) of the composite was higher than the matrix alloy. The wear rate decreased with sliding distance and increased with applied load irrespective of materials. The worn surfaces and subsurfaces of the tested samples were examined in the scanning electron microscope in order to understand the material removal mechanism during low stress abrasive wear process.

  1. The Influence Of Temperature Gradient On Stereological Parameters Of Carbide Phase On Cross-Section Of Abrasive Wear Resistant Chromium Cast Iron

    Studnicki A.

    2015-09-01

    Full Text Available In the paper analysis of temperature gradient and parameters of structure on casting cross-section of abrasive wear resistant chromium cast iron at carbon content of 2,5%wt. and chromium 17%wt. with nickel and molybdenum additives are presented. The castings were made with use of special tester ϕ100mm (method of temperature gradient and derivative analysis with temperature recording in many points from thermal centre to surface (to mould of casting. Registered cooling curves were used to describe the temperature gradient on cross-section of analyzed casting. On the basis of determined curves of temperature gradient measurement fields were selected to make the quantitative studies of structure. The results of studies show significant influence of temperature gradient on quantitative parameters of chromium cast iron structure. Moreover was affirmed that exists a critical temperature gradient for which is present rapid change of quantitative parameters of chromium cast iron structure.

  2. The abrasive wear behaviour of alloy cast steel in SiC-water slurry

    R. Zapała

    2009-10-01

    Full Text Available The results of abrasive wear tests carried out in an environment of SiC-water slurry on four grades of cast steel, i.e. carbon cast steel with microadditions of vanadium, low-alloy L70H2GNM cast steel, and high-alloy L120G13 cast steels, without and with microadditions of vanadium, were discussed. Tests were carried out on a Miller machine. A measure of the abrasive wear resistance was the loss of mass in specimens during 16 hour test cycle. It has been proved that the L120G13 cast steel is definitely less resistant to abrasive wear than its L70H2GNM counterpart. On the other hand, no distinct differences in the abrasive wear resistance were noticed between the L120G13 cast steel without vanadium, and the L120G13 cast steel and carbon cast steel, both with microadditions of vanadium.

  3. Mechanical and three-body abrasive wear behaviour of PMMA/TPU blends

    The blends of poly(methyl methacrlate) (PMMA) and thermoplastic polyurethane (TPU) were prepared by a Brabender co-twin screw extruder. The mechanical and three-body abrasive wear behaviour of PMMA/TPU blends has been studied. Three-body abrasive wear tests were conducted using rubber wheel abrasion tester (RWAT) under different abrading distances at 200 rpm and 22 N load. A significant reduction in tensile strength and tensile modulus with an increase in TPU content in the blend formulation was observed. Three-body abrasive wear results indicate that the wear volume increases with increase in abrading distance for all the samples studied. However, neat PMMA showed better wear resistance as compared to PMMA/TPU blends. The worn surface features, as examined through scanning electron microscope (SEM), show matrix cracking and deep furrows in PMMA/TPU blends

  4. Effect of radiation cross-linking on the abrasive wear behaviour of polyethylenes

    Gul, Rizwan M.; Khan, Tahir I.

    2014-06-01

    This study explores the differences in the dry abrasive wear behavior of different polyethylenes, and compares the effect of radiation cross-linking on the wear behavior. Four different types of polyethylenes: LDPE, LLDPE, HDPE and UHMWPE were studied. Cross-linking was carried out by high energy electron beam with radiation dose of 200 kGy. The results show that in unirradiated state UHMWPE has excellent wear resistance, with HDPE showing comparable wear properties; both LDPE and LLDPE exhibit high wear rate. Cross-linking improves wear rate of LDPE and UHMWPE, however, the wear rate of HDPE and LLDPE increases with cross-linking.

  5. Optimization of tribological parameters in abrasive wear mode of carbon-epoxy hybrid composites

    Highlights: • Optimization of factors affecting abrasive wear of hybrid composite. • Experimental studies integrated with Taguchi based grey analysis and ANOVA. • Abrasive wear resistance improved with the addition of filler. • Wear rate depends on filler loading, grit of abrasive paper and type of filler. - Abstract: Abrasive wear performance of fabric reinforced composites filled with functional fillers is influenced by the properties of the constituents. This work is focused on identifying the factors such as filler type, filler loading, grit size of SiC paper, normal applied load and sliding distance on two-body abrasive wear behaviour of the hybrid composites. Abrasive wear tests were carried on carbon fabric reinforced epoxy composite (C-E) filled with filler alumina (Al2O3) and molybdenum disulphide (MoS2) separately in different proportions, using pin-on-disc apparatus. The experiments were planned according to Taguchi L18 orthogonal array by considering five factors, one at two levels and the remaining at three levels, affecting the abrasion process. Grey relational analysis (GRA) was employed to optimize the tribological parameters having multiple-response. Analysis of variance (ANOVA) was employed to determine the significance of factors influencing wear. Also, the comparative specific wear rates of all the composites under dry sliding and two-body abrasive wear were discussed. The analysis showed that the filler loading, grit size and filler type are the most significant factors in controlling the specific wear rate of the C-E composite. Optimal combination of the process parameters for multi performance characteristics of the composite under study is the set with filler type as MoS2, filler loading of 10 wt.%, grit size 320, load of 15 N and sliding distance of 30 m. Further, the optimal parameter setting for minimum specific wear rate, coefficient of friction and maximum hardness were corroborated with the help of scanning electron micrographs

  6. Effect of cerium on abrasive wear behaviour of hardfacing alloy

    XING Shule; YU Shengfu; DENG Yu; DAI Minghui; YU Lu

    2012-01-01

    Hardfacing alloys with different amounts of ceria were prepared by self-shielded flux cored arc welding.The abrasion tests were carried out using the dry sand-rubber wheel machine according to JB/T 7705-1995 standard.The hardness of hardfacing deposits was measured by means of HR-150AL Rockwell hardness test and the fracture toughness was measured by the indentation method.Microstructure characterization and surface analysis were made using optical microscopy,scanning electron microscopy (SEM) and energy spectrum analysis.The results showed that the wear resistance was determined by the size and distribution of the carbides,as well as by the matrix microstructure.The main wear mechanisms observed at the surfaces included micro-cutting and micro-ploughing of the matrix.The addition of ceria improved the hardness and fracture toughness of hardfacing deposits,which would increase the resistance to plastic deformation and scratch,thus the wear resistance of hardfacing alloys was improved.

  7. Two-body, dry abrasive wear of Fe/Cr/C experimental alloys - relationship between microstructure and mechanical properties

    A systematic study of abrasive wear resistance of Fe/Cr/Mn based alloys has been carried out using a two body pin-on-disc wear machine. Abrasives used were silicon carbide, alumina and quartz. The objective of this study was to evaluate the abrasive wear resistance and to investigate the relationships between microstructure, mechanical properties, and abrasive wear resistance for these experimental alloys. Several commercial alloys were also tested to provide a basis for comparison. The goal of this study was to develop information so as to improve wear resistance of these experimental alloys by means of thermal treatments. Grain-refinement by double heat treatment was carried out in this research

  8. Abrasion-resistant antireflective coating for polycarbonate

    Wydeven, T. J.

    1978-01-01

    Following plasma-polymerization technique, treatment in oxygen glow discharge further enhances abrasion resistance and transmission. Improvement in abrasion resistance was shown by measuring percentage of haze resulting from abrasion. Coating samples were analyzed for abrasion using standard fresh rubber eraser. Other tests included spectra measurements and elemental analysis with spectrometers and spectrophotometers.

  9. Three-body abrasive wear behaviour of carbon and glass fiber reinforced epoxy composites

    Three-body abrasive wear behaviour of carbon-epoxy (C-E) and glass-epoxy (G-E) composites has been investigated. The effect of abrading distance, viz., 270, 540, 810 and 1080 m and different loads of 22 and 32 N at 200 rpm have been studied. The wear volume loss and specific wear rate as a function of load and abrading distance were determined. The wear volume loss increases with increasing load/abrading distance. However, the specific wear rate decreases with increase in abrading distance and increases with the load. However, C-E composite showed better abrasion wear resistance compared to G-E composite. The worn surface features have been examined using scanning electron microscope (SEM). SEM micrographs of abraded composite specimens revealed the high percentage of broken glass fiber compared to carbon fiber and also better interfacial adhesion between epoxy and carbon fiber

  10. 低压等离子喷涂MoB/CoCr涂层的组织及耐磨性%Microstructure and Abrasive Wear Resistance of MoB/CoCr Coatings by LPPS

    陈枭; 纪岗昌; 王洪涛

    2012-01-01

    MoB/CoCr coatings were prepared by low pressure plasma spraying(I.PPS), the abrasive wear experiment was investigated. The surface and cross sectional morphologies of the MoB/CoCr coatings were observed by SEM. The properties of microhardness And bond strength of the MoB/CoCr coatings were iested. The abrasive wear properties were evaluated by MLS-225 wet sand rubber wheel tester. The results show that MoB/CoCr coatings are dense and have excellent mechanical properties with high microhardness(930HV0. 3) and bond strength(71 Mpa). The MoB/CoCr coatings have high abrasive wear resistance property.%采用低压等离子喷涂技术(LPPS)制备MoB/CoCr潦层,对涂层进行磨粒磨损试验研究.采用SEM观察涂层的表面和截面形貌,显微硬度计测试潦层的力学性能,湿式橡胶轮磨粒磨损试验机测试潦层的磨粒磨损性能.结果表明,涂层组织致密,呈层状结构;涂层具有良好的力学性能,显微硬度达到930HV0.3,结合强度在71MPa以上,具有较高的耐磨性能.

  11. Abrasive wear behaviour of bio-active glass ceramics containing apatite

    I Sevim; M K Kulekci

    2006-06-01

    In this study, abrasive wear behaviour of bio-active glass ceramic materials produced with two different processes is studied. Hot pressing process and conventional casting and controlled crystallization process were used to produce bio-active ceramics. Fracture toughness of studied material was calculated by fracture toughness equations using experimental hardness results of the bio-active glass ceramic material. Two fracture toughness equations in the literature were used to identify the wear behaviour of studied ceramics. Wear resistance results that identified with both of the equations were similar. The results showed that the abrasive wear resistance of the bio-active glass ceramics produced with hot pressing process was found to be higher than that of the ceramics produced by conventional casting and controlled crystallization process.

  12. Sliding and Abrasive Wear Behavior of WC-CoCr Coatings with Different Carbide Sizes

    Thakur, Lalit; Arora, Navneet

    2013-02-01

    This study examines the sliding and abrasive wear behaviors of high-velocity oxy-fuel (HVOF)-sprayed WC-CoCr coatings with different WC grain sizes. The HVOF coating deposition was assisted by in-flight particle temperature and velocity measurement system. The powder feedstocks and their corresponding coatings were characterized by means of XRD and Field Emission Scanning Electron Microscope analysis. Hardness, porosity, and indentation fracture toughness of these coatings were calculated and compared with each other. Sliding wear resistance of these coatings was calculated using pin-on-disk tribometer (ASTM G99-90). The two-body abrasion was quantified by sliding the samples over silicon carbide (SiC) abrasive paper bonded to a rotating flat disk of auto-polisher. The mechanism of materials' removal in both the sliding and abrasive wears was studied and discussed on microstructural investigations. It was observed that fine grain WC-CoCr cermet coating exhibits higher sliding and abrasive wear resistances as compared with conventional cermet coating.

  13. Effects of hybrid composition of LCP and glass fibres on abrasive wear of reinforced LLDPE

    S A R Hashmi; Ajay Naik; Navin Chand

    2006-02-01

    The hybrid of liquid crystalline polymer (LCP) fibres and glass fibres (GF) provide a combination of modulus and toughness to semi-crystalline linear-low-density-polyethylene (LLDPE). LCP and GF fibres reinforced composites were studied using two-body abrasion tester under different applied loads. Two sets of fibre reinforced LLDPE, 10 and 20 vol%, were investigated. The contents of LCP and glass fibres were varied as 25, 50, 75 and 100 vol% of overall volume of fibres in LLDPE. The effect of replacing glass fibre with LCP fibre on wear is reported. Wear loss increased with the applied loads and glass fibre contents in LLDPE. The replacements of glass fibres with LCP fibres improved abrasive wear resistance of composite. The composite containing 20 vol% of glass fibres in LLDPE showed the specific wear rate nearly double to that of LCP fibre reinforced LLDPE. Incorporation of LCP fibre improved wear resistance of glass fibre reinforced LLDPE. Worn surfaces were studied using SEM. Glass fibres were broken in small debris and removed easily whereas LCP fibres yielded to fibrillation during abrasive action. The overall wear rate was governed by the composition and test conditions.

  14. Comparison between PEEK and Ti6Al4V concerning micro-scale abrasion wear on dental applications.

    Sampaio, M; Buciumeanu, M; Henriques, B; Silva, F S; Souza, J C M; Gomes, J R

    2016-07-01

    In the oral cavity, abrasive wear is predictable at exposed tooth or restorative surfaces, during mastication and tooth brushing. Also, wear can occur at contacting surfaces between the Ti-based prosthetic structures and implants in presence of abrasive compounds from food or toothpaste. Thus, the aim of this work was to compare the abrasive wear resistance of PEEK and Ti6Al4V on three-body abrasion related to different hydrated silica content and loads. Surfaces of Ti6Al4V or PEEK cylinders (8mm diameter and 4mm height) were wet ground on SiC papers and then polished with 1µm diamond paste. After that, surfaces were ultrasonically cleaned in propyl alcohol for 15min and then in distilled water for 10min. Micro-scale abrasion tests were performed at 60rpm and on different normal loads (0.4, 0.8 or 1.2N) after 600 ball revolutions using suspensions with different weight contents of hydrated silica. After abrasive tests, wear scars on flat samples were measured to quantify the wear volume and characterized by scanning electron microscope (SEM) to identify the dominant wear mechanisms. Results showed a higher volume loss rate on PEEK than that recorded on Ti6Al4V,, when subjected to three-body abrasion tests involving hydrated silica suspensions. An increase in volume loss was noted on both tested materials when the abrasive content or load was increased. PEEK was characterized by less wear resistance than that on Ti6Al4V after micro-scale abrasion wear in contact with hydrated silica particles, as commonly found in toothpastes. PMID:26849309

  15. Abrasive Wear Behaviour of COPPER-SiC and COPPER-SiO2 Composites

    Umale, Tejas; Singh, Amarjit; Reddy, Y.; Khatitrkar, R. K.; Sapate, S. G.

    The present paper reports abrasive wear behaviour of copper matrix composites reinforced with silicon carbide and silica particles. Copper - SiC (12%) and Copper-SiO2 (9%) composites were prepared by powder metallurgical technique. Metallography, image analysis and hardness studies were carried out on copper composites. The abrasive wear experiments were carried out using pin on disc apparatus. The effect of sliding distance and load was studied on Copper - SiC (12%) and Copper-SiO2 (9%) composites. The abrasive wear volume loss increased with sliding distance in both the composites although the magnitude of increase was different in each case. Copper - SiC (12%) composites exhibited relatively better abrasion resistance as compared to and Copper-SiO2 (9%) composites. The abraded surfaces were observed under scanning electron microscope to study the morphology of abraded surfaces and operating wear mechanism. The analysis of wear debris particles was also carried out to substantiate the findings of the investigation.

  16. Solutionizing temperature and abrasive wear behaviour of cast Al-Si-Mg alloys

    Sharma, Rajesh [Department of Mechanical Engineering, N.I.T. Hamirpur, HP 177 005 (India); Department of Mechanical and Industrial Engineering, I.I.T., Roorkee 247 667 (India); Anesh [Department of Mechanical Engineering, N.I.T. Hamirpur, HP 177 005 (India); Department of Mechanical and Industrial Engineering, I.I.T., Roorkee 247 667 (India); Dwivedi, D.K. [Department of Mechanical and Industrial Engineering, I.I.T., Roorkee 247 667 (India)]. E-mail: dkd04fme@iitr.ernet.in

    2007-07-01

    In the present paper, the influence of solutionizing temperature during artificial age hardening treatment (T{sub 6}) of cast Al-(8, 12, 16%)Si-0.3%Mg on abrasive wear behaviour has been reported. Alloys were prepared by controlled melting and casting. Cast alloys were given artificial age hardening treatment having a sequence of solutionizing, quenching and artificial aging. All the alloys were solutionized at 450 deg. C, 480 deg. C, 510 deg. C, and 550 deg. C for 8 h followed by water quenching (30 deg. C) and aging hardening at 170 deg. C for 12 h. Abrasive wear tests were conducted against 320 grade SiC polishing papers at 5 N and 10 N normal loads. It was observed that the silicon content and solution temperature affected the wear resistance significantly. Increase in solution temperature improved the wear resistance. Hypereutectic alloy showed better wear resistance than the eutectic and hypoeutectic alloys under identical conditions. Optical microstructure study of alloys revealed that the increase in solutionizing temperature improved distribution of silicon grains. Scanning electron microscopy (SEM) of wear surface was carried out to analyze the wear mechanism.

  17. Abrasive wear: The efects of fibres size on oil palm empty fruit bunch polyester composite

    Kasolang, S.; Kalam, A.; Ahmad, M. A.; Rahman, N. A.; Suhadah, W. N.

    2012-06-01

    This paper presents an experimental investigation carried out to determine the effect of palm oil empty fruit bunch (OPEFB) fibre size in dry sliding testing of polyester composite. These composite samples were produced by mixing raw OPEFB fibre with resin. The samples were prepared at different sizes of fibre (100, 125, 180 and 250μm). Abrasion Resistance Tester (TR-600) was used to carried out abrasive wear tests in dry sliding conditions. These tests were performed at room temperature for two different loads (10 and 30N) and at a constant sliding velocity of 1.4m/s. The specific wear rates of OPEFB polyester composites were obtained. The morphology of composite surface before and after tests was also examined using 3D microscope imaging. Preliminary work on thermal distribution at the abrasive wheel point was also conducted for selected samples.

  18. Effect of the abrasive size and transformability degree on the two body abrasive wear of polycrystalline zirconia

    It was analyzed the two-body abrasive wear behavior of tetragonal zirconia polycrystals with different transformability degrees. The analyze was carried out in pin-on disk tests, by using different abrasive sizes and was complemented by monitoring the friction coefficient. The wear rate increased with the increasing of the abrasive size. The lowest transformability degree underwent the worst behavior on wear, probably associated with its low fracture toughness and the intermediate transformability presented the best behavior. The correlation between wear rate and friction coefficient characterized the presence of two distinct behaviors. (author). 14 refs., 3 figs

  19. Abrasive Wear Performance of Aluminium Modified Epoxy-Glass Fiber Composites

    Kamble, Vikram G.; Mishra, Punyapriya; Al Dabbas, Hassan A.; Panda, H. S.; Fernandez, Johnathan Bruce

    2015-07-01

    For a long time, Aluminum filled epoxies molds have been used in rapid tooling process. These molds are very economical when applied in manufacturing of low volume of plastic parts. To improve the thermal conductivity of the material, the metallic filler material is added to it and the glass fiber improves the wear resistance of the material. These two important parameters establish the life of composites. The present work reports on abrasive wear behavior of Aluminum modified epoxy and glass fiber composite with 5 wt.% and 10 wt.% of aluminum particles. Through pin on disc wear testing machine, we studied the wear behaviors of composites, and all these samples were fabricated by using hand layup process. Epoxy resin was used as matrix material which was reinforced with Glass fiber and Aluminum as filler. The composite with 5 wt.% and 10 wt.% of Al was cast with dimensions 100 × 100 × 6 mm. The specimens were machined to a size of 6 × 6 × 4 mm for abrasive testing. Abrasive tests were carried out for different grit paper sizes, i.e., 150, 320, 600 at different sliding distance, i.e., 20, 40, 60 m at different loads of 5, 10 and 15 N and at constant speed. The weight loss due to wear was calculated along with coefficient of friction. Hardness was found using Rockwell hardness machine. The SEM morphology of the worn out surface wear was analyzed to understand the wear mechanism. Results showed that the addition of Aluminum particles was beneficial for low abrasive conditions.

  20. Comparison of the abrasion wear resistance of the X40CrMoV5-1 and 55NiCrMoV7 hot work tool steel with their surface layer enriched with the ceramic powders

    L.A. Dobrzański

    2006-02-01

    Full Text Available Purpose: In the paper there are presented the results of the influence of laser remelting parameters on the properties of the surface layer of the X40CrMoV5-1 and 55NiCrMoV7 hot work steel, using the high power diode laser (HPDL.The aim of this work was to compare the abrasion wear resistance of the X40CrMoV5-1 and 55NiCrMoV7 hot work tool steel surface layers enriched with the TiC, WC and VC ceramic powders. The surface layers of hot work tool steel remelted with a diode laser beam have been metallographically examined and analyzed with the use of a hardness testing machine.Design/methodology/approach: The high power diode laser (HPDL and ceramic powders WC, VC and TiC were used. Remelting and alloying processes were carried out at the constant remelting rate and focus shape, varying the laser beam power for the alloyed test pieces in the range from 1,2 – 2,3 kW.Findings: On the basis of the wear abrasion tests carried out on 55NiCrMoV7 and X40CrMoV5-1 steels it could be ascertained that each of those steels is characterized by different resistance for the same powders and the power of the laser beam. In the case of employing 1,2 kW laser, the surface layer formed using the majority of the investigated portions undergoes a total wear during the wear-rate test which also causes the wear of the initial material. When 2,3 kW is employed, the surface layers have crack and microcrack defections which decrease the resistance to the abrasion. The smallest mass loss for 55NiCrMoV7 steel among all the analyzed cases has been observed for the surface layers alloyed with TiC powder, at the of the laser beam power of 2,3 kW and for WC powder at 1,2 kW laser beam power. For the X40CrMoV5-1 steel the smallest mass decrement has been observed for the steel alloyed with WC powder at 1,2 kW laser beam power and VC powder at 1,6 kW laser beam power.Practical implications: The investigations showed that as a result of the applied laser processing there is the

  1. Wear Resistance of Piston Sleeve Made of Layered Material Structure: MMC A356R, Anti-Abrasion Layer and FGM Interface

    Hernik Szymon

    2016-09-01

    Full Text Available The aim of this paper is the numerical analysis of the one of main part of car engine – piston sleeve. The first example is for piston sleeve made of metal matrix composite (MMC A356R. The second improved material structure is layered. Both of them are comparison to the classical structure of piston sleeve made of Cr-Ni stainless steel. The layered material structure contains the anti-abrasion layer at the inner surface of piston sleeve, where the contact and friction is highest, FGM (functionally graded material interface and the layer of virgin material on the outer surface made of A356R. The complex thermo-elastic model with Archard's condition as a wear law is proposed. The piston sleeve is modelling as a thin walled cylindrical axisymmetric shell. The coupled between the formulation of thermo-elasticity of cylindrical axisymmetric shell and the Archard’s law with functionally changes of local hardness is proposed.

  2. Comparison study on resistance to wear and abrasion of high-temperature sliding strike of laser and plasma spray layer on the stainless steel surface

    In this paper, the effect of coatings, which are formed with laser cladding and plasma spray welding on 1Cr18Ni9Ti base metal of nuclear valve seats, 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 laser-cladding layer have lower rate of spoiled products and higher rate of finished products. Their microstructure is extremely fine. They have close texture and small-size grain. Their dilution diluted by the compositions of their base metal and hot-effect on base metal are less. The hardness, toughness, and strength of the laser-cladding layers are higher. The grain size is 11-12th grade in the laser-cladding layer and 9-10th in the plasma spray layer. The width of combination zone between laser-cladding layer and substrate is 10-45 μm but that between plasma spray layer and substrate is 120-160 μm. The wear test shows that the laser layers have higher property of anti-friction, anti-scour, and high-temperature sliding strike. The wear resistance of laser-cladding layer is about one time higher than that of plasma spray welding layer

  3. Abrasive wear of railway sections of steel with a different pearlite morphology in railroad switches

    J. Herian; K. Aniołek

    2010-01-01

    Purpose: The analyse of pearlite morphology changes as a result of hot rolling process and isothermal annealing.Design/methodology/approach: Physical modelling of isothermal annealing for a transition point of 520-620°C was carried out using a Gleeble simulator. A scanning electron microscope was used for a quantitative evaluation of the microstructure. Tests of resistance to abrasive wear were carried out at the Amsler stand.Findings: The obtained test results confirm that these methods can ...

  4. Influence of the Hardfacing Welds Structure on Their Wear Resistance

    Janette Brezinová

    2016-02-01

    Full Text Available The contribution presents the research results of hardfacing metals’ resistance in conditions of abrasive wear. Two types of hardfacing electrodes with a different chemical composition were used in the creation of three layers of hardfacing metals. The chemical composition of electrodes determines the difference in a hardface deposit structure. We have investigated the influence of mixing the base metal and a filler metal and the influence of hardfacing welds structure on the resistance against abrasive wear. The results of the experiments have showed that the intensity of wear is very dependent on the parameters of wear as well as the morphology structure of hardfacing metals.

  5. Abrasive wear of railway sections of steel with a different pearlite morphology in railroad switches

    J. Herian

    2010-11-01

    Full Text Available Purpose: The analyse of pearlite morphology changes as a result of hot rolling process and isothermal annealing.Design/methodology/approach: Physical modelling of isothermal annealing for a transition point of 520-620°C was carried out using a Gleeble simulator. A scanning electron microscope was used for a quantitative evaluation of the microstructure. Tests of resistance to abrasive wear were carried out at the Amsler stand.Findings: The obtained test results confirm that these methods can be effectively used in shaping the pearlitic structure and properties of the steel.Practical implications: In physical modelling of tests of resistance to abrasive wear for the steel grade R260 after hot rolling and isothermal annealing it has been proved that this feature is a function of the steel structure and properties in the given operation conditions. The resistance to abrasive wear of steel R260 with a pearlitic structure and different pearlite morphology decreases with the increase of load and slide.Originality/value: An advantageous pearlitic morphology of steel (block sections with interlamellar distance in the order of 0.12-0.13 μm, ensuring hardness of about 340-350 HB, is facilitated by a hot rolling process combined with isothermal annealing.

  6. Comparison of the abrasion wear resistance of the X40CrMoV5-1 and 55NiCrMoV7 hot work tool steel with their surface layer enriched with the ceramic powders

    L.A. Dobrzański; E. Jonda; A. Polok

    2006-01-01

    Purpose: In the paper there are presented the results of the influence of laser remelting parameters on the properties of the surface layer of the X40CrMoV5-1 and 55NiCrMoV7 hot work steel, using the high power diode laser (HPDL).The aim of this work was to compare the abrasion wear resistance of the X40CrMoV5-1 and 55NiCrMoV7 hot work tool steel surface layers enriched with the TiC, WC and VC ceramic powders. The surface layers of hot work tool steel remelted with a diode laser beam have be...

  7. Effects of ion implantation on the abrasive wear of WC-Co

    An explanation of the improved abrasive wear resistance of ion-implanted WC-Co components has been sought. X-ray analysis is reported of scratches produced on polished implanted and non-implanted WC-Co surfaces by a single pass scratch test. It can be inferred from the results that extrusion of cobalt from a WC-Co surface under the stress of an abrading diamond is easier in the non-implanted than in the implanted case; this is the first stage of the abrasion wear process. Transmission electron diffraction of a WC-Co foil, before and after implantation by nitrogen ions, indicated the formation of Co2N microprecipitates during implantation. Precipitation hardening, hindering cobalt extrusion, is offered therefore as the explanation of the improved service life of the components. (U.K.)

  8. Aging temperature and abrasive wear behaviour of cast Al-(4%, 12%, 20%)Si-0.3% Mg alloys

    Shah, K.B. [Department of Mechanical Engineering, N.I.T. Hamirpur (HP) 177 005 (India); Kumar, Sandeep [Department of Mechanical Engineering, N.I.T. Hamirpur (HP) 177 005 (India); Dwivedi, D.K. [Department of Mechanical and Industrial Engineering, I.I.T. Roorkee 247 667 (India)]. E-mail: dkd04fme@iitr.ernet.in

    2007-07-01

    In the present paper, influence of aging temperature during artificial age hardening treatment (T {sub 6}) of cast Al-(4, 12, 20%)Si-0.3% Mg on abrasive wear behaviour has been reported. Alloys were prepared by controlled melting and casting. Cast alloys were given age hardening treatment having sequence of solutionizing, quenching and artificial aging. All the alloys were solutionized at 510 deg. C for 8 h followed by water quenching (30 deg. C) and aging hardening at 150, 170, 190, 210 and 230 deg. C for 12 h. Abrasive wear tests were conducted against of 320 grade SiC abrasive medium at 5 and 10 N normal loads. It was observed that the silicon content and aging temperature significantly affect the wear resistance. Increase in aging temperature improves the wear resistance. Hypereutectic alloy showed better wear resistance than the eutectic alloy under identical conditions. Optical microstructure study of alloys under investigation has shown that cast dendritic structure is destroyed besides the spheroidization of eutectic silicon crystals after the heat treatment. The extent of change in structure depends on aging temperature. Scanning electron microscopy (SEM) of wear surface was carried to analyze the wear mechanism.

  9. Effect of Heat Treatment on the Abrasive Wear Behavior of High Chromium Iron under Dry Sliding Condition

    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.

  10. Effect of abrasive grit size on wear of manganese-zinc ferrite under three-body abrasion

    Miyoshi, Kazuhisa

    1987-01-01

    Wear experiments were conducted using replication electron microscopy and reflection electron diffraction to study abrasion and deformed layers produced in single-crystal Mn-Zn ferrites under three-body abrasion. The abrasion mechanism of Mn-Zn ferrite changes drastically with the size of abrasive grits. With 15-micron (1000-mesh) SiC grits, abrasion of Mn-Zn ferrite is due principally to brittle fracture; while with 4- and 2-micron (4000- and 6000-mesh) SiC grits, abrasion is due to plastic deformation and fracture. Both microcracking and plastic flow produce polycrystalline states on the wear surfaces of single-crystal Mn-Zn ferrites. Coefficient of wear, total thickness of the deformed layers, and surface roughness of the wear surfaces increase markedly with an increase in abrasive grit size. The total thicknesses of the deformed layers are 3 microns for the ferrite abraded by 15-micron SiC, 0.9 microns for the ferrite abraded by 4-micron SiC, and 0.8 microns for the ferrite abraded by 1-micron SiC.

  11. 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

    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)

  12. Analysis of abrasive wear behavior of PTFE composite using Taguchi’s technique

    Yusuf Şahin

    2015-12-01

    Full Text Available Polymeric composites are widely used for structural, aerospace, and automobile sectors due to their good combination of high specific strength and specific modulus. These two main characteristics make these materials attractive, compared to conventional materials like metal or alloy ones. Some of their typical benefits include easy processing, corrosion resistance, low friction, and damping of noise and vibrations. Wear behavior of Polytetrafluoroethylenes (PTFE and its composites including glass-filled composites and carbon-filled composites are investigated using a pin-on-disc configuration. A plan of experiments in terms of Taguchi technique is carried out to acquire data in controlled way. An orthogonal array (L9 and the analysis of variance are employed to investigate the influence of process parameters on the wear of these composites. Volume loss increased with abrasive size, load, and distance. Furthermore, specific wear rate decreased with increasing grit size, load, sliding distance, whereas, slightly with compressive strength. Optimal process parameters, which minimize the volume loss, were the factor combinations of L1, G3, D1, and C3. Confirmation experiments were conducted to verify the optimal testing parameters. It was found that in terms of volume loss, there was a good agreement between the estimated and the experimental value of S/N ratio with an error of 1.604%. Moreover, abrasive size, load, and sliding distance exerted a great effect on the specific wear rate, at 51.14, 27.77, and 14.70%, respectively.

  13. The influence of heat treatnemnt on the abrasive wear resistnace of a construction and a tool steel

    M. Orečný

    2015-01-01

    Full Text Available The paper deals about the influence of heat and chemical-heat treatment of construction steel 100Cr6 and alloy steel X210Cr12, which were treated according to their corresponding norms. The steel X210Cr12 was also treated in an unconventional way. The influence of the material structures and hardness on the abrasion wear resistance was studied. The influence of nitridation was considered in a way how to increase the abrasion wear resistance and how the heat treatment affects the hardness and the quality of the nitrided layer. The nitridation with diffusion annealing of the tested materials caused a decrease and also an increase of the materials wear resistances.

  14. Abrasion, Erosion and Cavitation Erosion Wear Properties of Thermally Sprayed Alumina Based Coatings

    Ville Matikainen

    2014-01-01

    Full Text Available Thermally-sprayed alumina based materials, e.g., alumina-titania (Al2O3-TiO2, are commonly applied as wear resistant coatings in industrial applications. Properties of the coatings depend on the spray process, powder morphology, and chemical composition of the powder. In this study, wear resistant coatings from Al2O3 and Al2O3-13TiO2 powders were sprayed with plasma and high-velocity oxygen-fuel (HVOF spray processes. Both, fused and crushed, and agglomerated and sintered Al2O3-13TiO2 powders were studied and compared to pure Al2O3. The coatings were tested for abrasion, erosion, and cavitation resistances in order to study the effect of the coating structure on the wear behavior. Improved coating properties were achieved when agglomerated and sintered nanostructured Al2O3-13TiO2 powder was used in plasma spraying. Coatings with the highest wear resistance in all tests were produced by HVOF spraying from fused and crushed powders.

  15. Abrasive wear of two glass ionomer cements after simulated toothbrushing

    Márcia Furtado Antunes de Freitas

    2011-07-01

    Full Text Available Introduction and objective: Glass ionomer cement, which was first introduced in Dentistry in 1972, presents good qualities such as aesthetics, fluoride release and adhesion to dental tissues. Because of its preventive characteristics regarding to dental caries, glass ionomer cement has been used for Atraumatic Restorative Treatment (ART, as reported by Frencken and Holmgren [6], meeting the principles announced by the World Health Organization (WHO for application to large population groups without regular access to dental care. Material and methods: In this present study, the abrasive wear strength of two glass-ionomer cements (Vidrion R® and ChemFlex® was evaluated through toothbrushing machine. Classic® toothbrushes with soft bristles and Sorriso® dentifrice were also used for the study. Results: Student-t test showed significant difference between both groups, with tobs value = 9.4411 at p < 0.05. Conclusion: It can be concluded that the wear rate caused by toothbrush/dentifrice was higher for Vidrion R® (52.00 mg than ChemFlex® (5.57 mg.

  16. Abrasion, erosion and scuffing resistance of carbide and oxide ceramic thermal sprayed coatings for different applications

    Barbezat, G.; Nicoll, A. R.; Sickinger, A.

    1993-04-01

    In the area of antiwear coatings, carbide-containing coatings and oxide ceramic coatings are applied using different thermal spray processes in the form of individual layers. In many industries these coatings have become technically significant on components where wear and friction can cause critical damage in the form of abrasion, erosion and scuffing together with corrosion. Carbide-containing and ceramic coatings have been produced with different thermal spray processes for the determination of abrasive, adhesive and erosive wear resistance. Two types of abrasion test, namely an adhesion wear test and an erosion test in water at a high velocity, were used for the characterization of wear resistance under different conditions. The coatings were also characterized with regard to microstructure, composition and fracture toughness. The influence of the thermal spraying process parameters on the microstructure is presented together with the influence of the microstructure on the behavior of the coatings under simulated service conditions.

  17. Recent progress of abrasion-resistant materials: learning from nature.

    Meng, Jingxin; Zhang, Pengchao; Wang, Shutao

    2016-01-21

    Abrasion-resistant materials have attracted great attention for their broad applications in industry, biomedicine and military. However, the development of abrasion-resistant materials that have with unique features such as being lightweight and flexible remains a great challenge in order to satisfy unmet demands. The outstanding performance of natural abrasion-resistant materials motivates the development of new bio-inspired abrasion-resistant materials. This review summarizes the recent progress in the investigation of natural abrasion-resistant materials to explore their general design principles (i.e., the correlation between chemical components and structural features). Following natural design principles, several artificial abrasion-resistant materials have shown unique abrasion-resistant properties. The potential challenges in the future and possible solutions for designing bio-inspired abrasion-resistant materials are also briefly discussed. PMID:26335377

  18. A review on nozzle wear in abrasive water jet machining application

    Syazwani, H.; Mebrahitom, G.; Azmir, A.

    2016-02-01

    This paper discusses a review on nozzle wear in abrasive water jet machining application. Wear of the nozzle becomes a major problem since it may affect the water jet machining performance. Design, materials, and life of the nozzle give significance effect to the nozzle wear. There are various parameters that may influence the wear rate of the nozzle such as nozzle length, nozzle inlet angle, nozzle diameter, orifice diameter, abrasive flow rate and water pressure. The wear rate of the nozzle can be minimized by controlling these parameters. The mechanism of wear in the nozzle is similar to other traditional machining processes which uses a cutting tool. The high pressure of the water and hard abrasive particles may erode the nozzle wall. A new nozzle using a tungsten carbide-based material has been developed to reduce the wear rate and improve the nozzle life. Apart from that, prevention of the nozzle wear has been achieved using porous lubricated nozzle. This paper presents a comprehensive review about the wear of abrasive water jet nozzle.

  19. Wear characteristics of second-phase-reinforced sol-gel corundum abrasives

    The use of sol-gel technologies makes it possible to manufacture new corundum-based abrasives with superior performance in terms of grinding processes. The aim of the present work is to reveal the detailed wear mechanisms on a nanometre scale and relate them to the particular microstructure of these new materials. A commercial sol-gel corundum (Cubitron 321TM) was used. In the grinding experiments, wheels consisting of four different mixtures with 0%, 30%, 50% and 100% of sol-gel corundum were used to machine a tool steel (100Cr6V) by plane grinding. Changes to the contact zone were studied after controlled abrasion experiments on hard steel substrates using a pin-on-wheel tribometer, in single grit scratch tests and after tests of resistance to heat shock. Cross-sections through contact areas of a sol-gel grain were prepared using a focused ion beam workstation and investigated using conventional and analytical transmission electron microscopy. The results indicate that the combined effect of controlled propagation of subsurface shear cracks and plastic deformation leads to the formation of flat contact zones. On these contact zones, a nanocrystalline FeO debris layer adheres to the alumina. The results of our investigations were verified in grinding experiments and give insight into the physical reasons of the superior tribological properties of the sol-gel corundum abrasives

  20. Mechanical and Abrasive Wear Properties of Anodic Oxide Layers Formed on Aluminium

    W.Bensalah; K.Elleuch; M.Feki; M.Wery; H.F.Ayedi

    2009-01-01

    Aluminium oxide coatings were formed on aluminium substrates in oxalic acid-sulphuric acid bath. Abrasion tests of the obtained anodic layers were carried out on a pin-on-disc machine in accordance with the ISO/DP 825 specifications. The Vickers microhardness, D (HV0.2). and the abrasion weight loss, Wa (mg) were measured. Influence of oxalic acid concentration (Cox), bath temperature (T) and anodic current density (J) on D and Wa has been examined, and the sulphuric acid concentration (Caul) was maintained at 160 g.L-1. It was found that high microhardness and abrasive wear resistance of oxide layers were produced under low temperatures and high current densities with the addition of oxalic acid. The morphology and the composition of the anodic oxide layer were examined by scanning electron microscopy (SEM), atomic force microscopy (AFM), optical microscopy and glow-discharge optical emission spectroscopy (GDOES). It was found that the chemistry of the anodizing electrolyte, temperature, and current density are the controlling factors of the mechanical properties of the anodic oxide layer.

  1. Tribological properties of amorphous alloys and the role of surfaces in abrasive wear of materials

    Miyoshi, K.; Buckley, D. H.

    1982-01-01

    The research approach undertaken by the authors relative to the subject, and examples of results from the authors are reviewed. The studies include programs in adhesion, friction, and various wear mechanisms (adhesive and abrasive wear). The materials which have been studied include such ceramic and metallic materials as silicon carbide, ferrites, diamond, and amorphous alloys.

  2. Aluminium Alloy-Based Metal Matrix Composites: A Potential Material for Wear Resistant Applications

    Rupa Dasgupta

    2012-01-01

    Aluminium alloy-based metal matrix composites (AMMCs) have been by now established themselves as a suitable wear resistant material especially for sliding wear applications. However, in actual practice engineering components usually encounter combination of wear types. An attempt has been made in the present paper to highlight the effect of dispersing SiC in 2014 base alloy adopting the liquid metallurgy route on different wear modes like sliding, abrasion, erosion, and combinations of wear m...

  3. Abrasive wear of BA1055 bronze with additives of Si, Cr, Mo and/or W

    B. P. Pisarek

    2008-10-01

    Full Text Available Aluminium bronzes belong to the high-grade constructional materials applied on the put under strongly load pieces of machines, aboutgood sliding, resistant properties on corrosion both in the cast state how and after the thermal processing. It moves to them Cr and Si in the aim of the improvement of their usable proprieties. The additions Mo and/or W were not applied so far. It was worked out therefore the new kind of bronzes casting including these elements. Make additions to the Cu-Al-Fe-Ni bronze of Si, Cr, Mo and/or W in the rise of these properties makes possible. The investigations of the surface distribution of the concentration of elements in the microstructure of the studied bronze on X-ray microanalyzer were conducted. It results from conducted investigations, that in the aluminium bronze BA1055 after makes additions Si, Cr, Mo and/or W the phases of the type κFe, κNi crystallize, probably as complex silicides. Elements such as: Fe and Si dissolve first of all in phases κ, in smaller stage in the matrix of the bronze; Mn, Ni and W they dissolve in matrix and phases κ. It dissolves Cr and Mo in the larger stage in phases κ than in the matrix. The sizes of the abrasive wear were compared in the state cast multicomponentnew casting Cu-Al-Fe-Ni bronzes with the additives Cr, Mo or W with the wear of the bronze CuAl10Fe5Ni5Si. The investigations of thewear were conducted on the standard device. It results from conducted investigations, that make additions to bronze BA1055 of the additives of Si, Cr, Mo, and/or W it influences the rise of the hardness (HB of the bronze in the cast state, in the result of the enlarged quantity separates of hard phases κ, and in the consequence the decrease of the abrasive wear. The addition of molybdenum made possible obtainment of the microhardness of the phase α and γ 2 on the comparable level. From the microstructure of the bronze CuAl10Fe5Ni5MoSi is characterizes the smallest abrasive wear among

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

    Pernis, I.; J. Kasala; Žabecká, D.

    2013-01-01

    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.

  5. Wear resistant of Al{sub 2}O{sub 3}/heat-resistant steel at high temperature

    Bao Chonggao [Graduate school at Shenzhen, Tsinghua Univ., Shenzhen (China); School of Material Sci. and Eng., Xi' an Jiaotong Univ., Xi' an (China); Xing Jiandong; Gao Yimin; Wang Enze [School of Material Sci. and Eng., Xi' an Jiaotong Univ., Xi' an (China)

    2005-07-01

    The high temperature abrasive wear resistant of the composites with different Al{sub 2}O{sub 3} volume fractions, particle coating and size were investigated and the failure action of composites under different conditions at high temperature was analyzed. The results showed that the high temperature abrasive wear resistant of composite with Ni coating and wide size and 39% volume fraction of particle is the best among all composites examined. (orig.)

  6. Abrasion Resistance of as-Cast High-Chromium Cast Iron

    Pokusová Marcela

    2014-12-01

    Full Text Available High chromium cast irons are widely used as abrasion resistant materials. Their properties and wear resistance depend on carbides and on the nature of the matrix supporting these carbides. The paper presents test results of irons which contain (in wt.% 18-22 Cr and 2-5 C, and is alloyed by 1.7 Mo + 5 Ni + 2 Mn to improve the toughness. Tests showed as-cast irons with mostly austenitic matrix achieved hardness 36-53 HRC but their relative abrasion-resistance was higher than the tool steel STN 19436 heat treated on hardness 60 HRC.

  7. Multiphase Flow and Wear in the Cutting Head of Ultra-high Pressure Abrasive Water Jet

    YANG Minguan; WANG Yuli; KANG Can; YU Feng

    2009-01-01

    Abrasive water jet cutting technology is widely applied in the materials processing today and attracts great attention from scholars, but many phenomena concerned are not well understood, especially in the internal jet flow of the cutting head at the condition of ultra-high pressure. The multiphase flow in the cutting head is numerically simulated to study the abrasive motion mechanism and wear inside the cutting head at the pressure beyond 300 Mpa. Visible predictions of the particles trajectories and wear rate in the cutting head are presented. The influences of the abrasive physical properties, size of the jewel orifice and the operating pressure on the trajectories are discussed. Based on the simulation, a wear experiment is carried out under the corresponding pressures. The simulation and experimental results show that the flow in the mixing chamber is composed of the jet core zone and the disturbance zone, both affect the particles trajectories. The mixing efficiency drops with the increase of the abrasive granularity. The abrasive density determines the response of particles to the effects of different flow zones, the abrasive with medium density gives the best general performance. Increasing the operating pressure or using the jewel with a smaller orifice improves the coherency of particles trajectories but increases the wear rate of the jewel holder at the same time. Walls of the jewel holder, the entrance of the mixing chamber and the convergence part of the mixing tube are subject to wear out. The computational and experimental results give a qualitative consistency which proves that this numerical method can provide a reliable and visible cognition of the flow characteristics of ultra-high pressure abrasive water jet. The investigation is benefit for improving the machining properties of water jet cutting systems and the optimization design of the cutting head.

  8. Adhesion and wear behaviour of NCD coatings on Si3N4 by micro-abrasion tests.

    Silva, F G; Neto, M A; Fernandes, A J S; Costa, F M; Oliveira, F J; Silva, R F

    2009-06-01

    Nanocrystalline diamond (NCD) coatings offer an excellent alternative for tribological applications, preserving most of the intrinsic mechanical properties of polycrystalline CVD diamond and adding to it an extreme surface smoothness. Silicon nitride (Si3N4) ceramics are reported to guarantee high adhesion levels to CVD microcrystalline diamond coatings, but the NCD adhesion to Si3N4 is not yet well established. Micro-abrasion tests are appropriate for evaluating the abrasive wear resistance of a given surface, but they also provide information on thin film/substrate interfacial resistance, i.e., film adhesion. In this study, a comparison is made between the behaviour of NCD films deposited by hot-filament chemical vapour deposition (HFCVD) and microwave plasma assisted chemical vapour deposition (MPCVD) techniques. Silicon nitride (Si3N4) ceramic discs were selected as substrates. The NCD depositions by HFCVD and MPCVD were carried out using H2-CH4 and H2-CH4-N2 gas mixtures, respectively. An adequate set of growth parameters was chosen for each CVD technique, resulting in NCD films having a final thickness of 5 microm. A micro-abrasion tribometer was used, with 3 microm diamond grit as the abrasive slurry element. Experiments were carried out at a constant rotational speed (80 r.p.m.) and by varying the applied load in the range of 0.25-0.75 N. The wear rate for MPCVD NCD (3.7 +/- 0.8 x 10(-5) mm3 N(-1) m(-1)) is compatible with those reported for microcrystalline CVD diamond. The HFCVD films displayed poorer adhesion to the Si3N4 ceramic substrates than the MPCVD ones. However, the HFCVD films show better wear resistance as a result of their higher crystallinity according to the UV Raman data, despite evidencing premature adhesion failure. PMID:19504945

  9. Abrasion Resistance Comparison between Rotor and Ring Spun Yarn

    YANG Jian-ping; YU Chong-wen

    2002-01-01

    On the base of literature review and the analysis of yarn properties, yarn structure and some other facts, the abrasion resistance of both rotor spun yarn and ring spun yarns are discussed. The results show that with the same raw material and twist, the rotor spun yarn has lower abrasion resistance than that of ring spun yarn, because of the higher twist employed, the abrasion resistance of rotor spun yarn is higher than that of ring spun yarn.

  10. ANN & ANFIS Models for Prediction of Abrasive Wear of 3105 Aluminium Alloy with Polyurethane Coating

    H. Alimam

    2016-06-01

    Full Text Available The quest for safety and reliability has increased significantly after Industrial revolution, so is the case for coating industries. In this paper 3105 Aluminium alloy sheet is coated with organic polyurethane coating. After the implementation of coating, various processes are undergone to check its reliability under elevated conditions. ANN & ANFIS model were developed and trained with an objective to find abrasive wear during the process. ANN & ANFIS model were compared with the experimental results. It is observed that the abrasive wear of a coated specimen can be predicted accurately and precisely using ANN and ANFIS models.

  11. Mechanical and abrasive wear characterization of bidirectional and chopped E-glass fiber reinforced composite materials

    Highlights: ► Bi-directional and chopped E-glass fiber reinforced epoxy composites are fabricated. ► Three body abrasive wear behavior of fabricated composites has been assessed. ► Results are validated against existing microscopic models of Lancaster and Wang. ► Tensile strength of bi-directional E-glass fiber reinforced composites increases. ► Chopped glass fiber composites are found better in abrasive wear situations. -- Abstract: Bi-directional and chopped E-glass fiber reinforced epoxy composites are fabricated in five different (15, 20, 25, 30 and 35) wt% in an epoxy resin matrix. The mechanical characterization of these composites is performed. The three body abrasive wear behavior of fabricated composites has been assessed under different operating conditions. Abrasive wear characteristics of these composites are successfully analysed using Taguchi’s experimental design scheme and analysis of variance (ANOVA). The results obtained from these experiments are also validated against existing microscopic models of Ratner-Lancaster and Wang. It is observed that quite good linear relationships is held between specific wear rate and reciprocal of ultimate strength and strain at tensile fracture of these composites which is an indicative that the experimental results are in fair agreement with these existing models. Out of all composites fabricated it is found that tensile strength of bi-directional E-glass fiber reinforced composites increases because of interface strength enhancement. Chopped glass fiber reinforced composites are observed to perform better than bi-directional glass fiber reinforced composites under abrasive wear situations. The morphology of worn composite specimens has been examined by scanning electron microscopy (SEM) to understand about dominant wear mechanisms.

  12. The Abrasion-resistance Investigation of Rubberized Concrete

    KANG Jingfu; ZHANG Bo; LI Guangyu

    2012-01-01

    The abrasion resistance properties of rubberized concrete were comparatively studied by taking silica fume and crumb tire rubber as the additives.The abrasion tests were conducted in accordance with the Chinese standard test method DL/T 5150-2001,two recommended test methods:under water method and ring method,were used.The crumb tire rubbers with the sieve size of 8-mesh and 16-mesh were incorporated into the concrete by replacing same volume of sand and as an additive.The abrasion resistance of concrete was evaluated according to the abrasion resistance strength and the mass loss.Test results show that the addition of silica fume enhanced both compressive strength and abrasion resistance of concrete,and the addition of crumb rubber reduced the compressive strength but increased notably the abrasion resistance of the concrete.Silica fume concrete performed a better abrasion resistance than control concrete,and the rubberized concrete performed a much better abrasion resistance than silica fume concrete.The abrasion resistance of rubberized concrete increased with the increase of rubber content.

  13. Improvements of harrows wear resistance

    Warouma Arifa

    2015-01-01

    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...

  14. Abrasion Resistant Refractory Materials GB/T 23294-2009

    Yu Lingyuan

    2009-01-01

    @@ 1 Scope This standard specifies the definition, classification, technical requirements, test methods, quality appraisal procedure, packing, marking, transportation, storage, and quality certificate of abrasion resistant refractory materials. This standard is applicable to abrasion resistant refractory materials for circulating fluidized bed boilers, daily waste incinerator, industrial waste incinerator, medical waste incinerator, ordinary solid waste incinerator, hazardous waste incinerator, etc.

  15. Electrical resistivity measurements to predict abrasion resistance of rock aggregates

    Sair Kahraman; Mustafa Fener

    2008-04-01

    The prediction of Los Angeles (LA) abrasion loss from some indirect tests is useful for practical applications. For this purpose, LA abrasion, electrical resistivity, density and porosity tests were carried out on 27 different rock types. LA abrasion loss values were correlated with electrical resistivity and a good correlation between the two parameters was found. To see the effect of rock class on the correlation, regression analysis was repeated for igneous rocks, metamorphic rocks and sedimentary rocks, respectively. It was seen that correlation coefficients were increased for the rock classes. In addition, the data were divided into two groups according to porosity and density, respectively. After repeating regression analysis for these porosity and density groups, stronger correlations were obtained compared to the equation derived for all rocks. The validity of the derived equations was statistically tested and it was shown that all derived equations were significant. Finally, it can be said that all derived equations can alternatively be used for the estimation of LA abrasion loss from electrical resistivity.

  16. Modelling of structure and properties of pearlitic steel and abrasive wear of the turnout frog in the cyclic loading conditions

    J. Herian

    2011-11-01

    Full Text Available Purpose: Analysis of pearlite morphology changes as a result of hot rolling process and isothermal annealing.Design/methodology/approach: Physical modelling of isothermal annealing for a transition point of 520-620°C was carried out using a Gleeble simulator. A scanning electron microscope was used for a quantitative evaluation of the microstructure. In numerical estimations there were marked distributions of the loads and then distributions of the contact stresses and the strains in places of contact wheel-switch components. Tests of resistance to abrasive wear were carried out at the Amsler stand.Findings: The obtained test results confirm that these methods can be effectively used in shaping the pearlitic structure and properties of the steel.Practical implications: In physical modelling of tests of resistance to abrasive wear for the steel grade R260 after hot rolling and isothermal annealing it has been proved that this feature is a function of the steel structure and properties in the given operation conditions. The resistance to abrasive wear of steel R260 with a pearlitic structure and different pearlite morphology decreases with the increase of load and slide. From conducted numerical calculations result that the biggest dynamic load is in the moment of a drive of a wheel set on a frog of the turnout. The value of the vertical force depends on speed and mass of the railway vehicle.Originality/value: An advantageous pearlitic morphology of steel (block sections with interlamellar distance in the order of 0.12-0.13 μm, ensuring hardness of about 340-350 HB, is facilitated by a hot rolling process combined with isothermal annealing.

  17. EFFECT OF MICROSTRUCTURE AND MECHANICAL PROPERTIES ON WEAR RESISTANCE OF SILICON NITRIDE CERAMICS

    Pavol Švec; Alena Brusilová; Jana Kozánková

    2009-01-01

    The wear of Si3N4 ceramics with high-resistant abrasive material during friction applications was analyzed. Effects of the hot pressing parameters on the microstructures and properties of ceramic samples were evaluated. Negative influence of grain growth with increasing of the beta-Si3N4 phase ratio on wear resistance of tested materials was proved. The volume loss of separate ceramic materials during the wear tests depended mainly inversely proportional on the hardness of ceramics. Both micr...

  18. Abrasive Wear Modes in Ball-Cratering Test Conducted on Fe73Si15 Ni10Cr2 Alloy Deposited Specimen

    M.S. Priyan

    2014-03-01

    Full Text Available The objective of this study was to develop a theoretical model and associated wear mode map to identify the regimes in which two body abrasion (grooving abrasion and three body abrasion (rolling abrasion dominate in the micro-abrasive wear test (also known as the ball cratering wear test. This test is generally considered to be a three body wear test. The wear mechanisms and wear rates were investigated using diamond abrasive over a range of loads (0.05, 0.1 and 0.2 N, and slurry concentrations (0.05, 0.1, and 0.2 volume fraction abrasive. It was found that during abrasion wear, a transition from grooving to rolling wear could be identified for a load with respect to time. The critical condition for the transition between two-body and three-body abrasion was determined from a continuum mechanics model for the penetration of the abrasive particles into the surfaces of the ball and the specimen, coupled with considerations of equilibrium. Two wear modes are usually observed in this type of test: ‘rolling abrasion’ results when the abrasive particles roll on the surface of the tested specimen, while ‘grooving abrasion’ is observed when the abrasive particles slide; the type of wear mode has a significant effect on the overall behaviour of a tribological system. Wear rates of metallic samples were determined and the worn surfaces were examined by optical microscopy, SEM and Talysurf profilometry.

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

    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 of...... AISI 316, hard chromium and hardened Ni-P shows that there is no universal correlation between surface hardness and wear-corrosion loss. The possible relation between questionable passivity of Ni-P coatings and their high wear-corrosion loss rate compared to hard chromium is discussed....

  20. DEVELOPMENT OF A SOIL ABRASION TESTS AND ANALYSIS OF IMPACT OF SOILCONDITIONING OM TOOL WEAR FOR SOFTGROUND MECHANIZAED TUNNELING

    2016-01-01

    The wear issue in soft-ground tunneling using various types of shields has a major impact on machine operation, utilization, and tunneling costs. The interaction between abrasive soils and cutters, as well as other components of the machine that are involved in excavation process can cause the wear. For tool wear estimation and understanding of soil conditioning effect on wear, there is no accepted test that can address this issue clearly. The primary objective of this thesis was to develop a...

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

    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

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

    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.

  3. Improvements of harrows wear resistance

    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.

  4. Study of abrasive resistance of composites for dental restoration by ball-cratering

    Antunes, P. Vale; Ramalho, A

    2003-01-01

    Two-body abrasion occurs in the mouth whenever there is tooth-to-tooth contact. This is what most dentists call attrition. Abrasive wear may also occur when there is an abrasive slurry interposed between two surfaces, such that the two solid surfaces are not actually in contact, this is called three-body abrasion, with food acting as the abrasive agent, and occurs in the mouth during mastication. Abrasion is the key physiological wear mechanism that is present in dental materials during norma...

  5. Minimal alterations on the enamel surface by micro-abrasion: in vitro roughness and wear assessments

    Marcela Charantola Rodrigues

    2013-04-01

    Full Text Available Objective: To evaluate the in vitro changes on the enamel surface after a micro-abrasion treatment promoted by different products. Material and Methods: Fifty (50 fragments of bovine enamel (15 mm × 5 mm were randomly assigned to five groups (n=10 according to the product utilized: G1 (control= silicone polisher (TDV, G2= 37% phosphoric acid (3M/ESPE + pumice stone (SS White, G3= Micropol (DMC Equipment, G4= Opalustre (Ultradent and G5= Whiteness RM (FGM Dental Products. Roughness and wear were the responsible variables used to analyze these surfaces in four stages: baseline, 60 s and 120 s after the micro-abrasion and after polishing, using a Hommel Tester T1000 device. After the tests, a normal distribution of data was verified, with repeated ANOVA analyses (p≤0.05 which were used to compare each product in different stages. One-way ANOVA and Tukey tests were applied for individual comparisons between the products in each stage (p≤0.05. Results: Means and standard deviations of roughness and wear (µm after all the promoted stages were: G1=7.26(1.81/13.16(2.67, G2=2.02(0.62/37.44(3.33, G3=1.81(0.91/34.93(6.92, G4=1.92(0.29/38.42(0.65 and G5=1.98(0.53/33.45(2.66. At 60 seconds, all products tended to produce less surface roughness with a variable gradual decrease over time. After polishing, there were no statistically significant differences between the groups, except for G1. Independent of the product utilized, the enamel wear occurred after the micro-abrasion. Conclusions: In this in vitro study, enamel micro-abrasion presented itself as a conservative approach, regardless of the type of the paste compound utilized. These products promoted minor roughness alterations and minimal wear. The use of phosphoric acid and pumice stone showed similar results to commercial products for the micro-abrasion with regard to the surface roughness and wear.

  6. EFFECT OF MICROSTRUCTURE AND MECHANICAL PROPERTIES ON WEAR RESISTANCE OF SILICON NITRIDE CERAMICS

    Pavol Švec

    2009-04-01

    Full Text Available The wear of Si3N4 ceramics with high-resistant abrasive material during friction applications was analyzed. Effects of the hot pressing parameters on the microstructures and properties of ceramic samples were evaluated. Negative influence of grain growth with increasing of the beta-Si3N4 phase ratio on wear resistance of tested materials was proved. The volume loss of separate ceramic materials during the wear tests depended mainly inversely proportional on the hardness of ceramics. Both microcutting and microcracking mechanisms took part during the wear of Si3N4 ceramics.

  7. Wear resistance of TiAlSiN thin coatings.

    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. PMID:23447962

  8. Effect of titanium and tungsten on the structure and properties of heat-abrasion resistant steel

    The effect of Ti and W on the microstructure and properties of austenitic heat-abrasion resistant steel was studied using microstructure examinations, hardness tests, wear resistance and oxidation resistance experiments. The results indicated that the specimens containing Ti and W had a notable increase in hardness and wear resistance, but a slight decrease in oxidation resistance. The structures of specimens with Ti and W included some MC carbides, dispersedly distributed inside grains and at grain boundaries; these specimens also showed an increase in material properties. From oxidation kinetics analysis, the oxidation of austenitic heat-abrasion resistant steel specimens generally agree with parabola rule, oxidation activation energies kp1 and kp2 are calculated to be 304 and 128 kJ/mol. The oxide films composed of Cr2O3, spinelle (FeCr2O4, NiCr2O4), and some Fe3O4 were continuous and compact. Cr2O3 plays the vital role in the oxidation resistance based on the oxidation activation energy calculation

  9. Effect of titanium and tungsten on the structure and properties of heat-abrasion resistant steel

    Zhang Yan [School of Materials Science and Engineering, Zhengzhou University, 95 Wenhua Road, Zhengzhou 450002 (China)], E-mail: jessicazhang1980@126.com; Sun Yufu; Guan Shaokang [School of Materials Science and Engineering, Zhengzhou University, 95 Wenhua Road, Zhengzhou 450002 (China); Deng Xiang [Department of Materials Engineering, Henan Mechanical and Electrical Engineering College, 11 Hongli Road, Xinxiang 453002 (China); Yan Xingyi [School of Materials Science and Engineering, Zhengzhou University, 95 Wenhua Road, Zhengzhou 450002 (China)

    2008-04-15

    The effect of Ti and W on the microstructure and properties of austenitic heat-abrasion resistant steel was studied using microstructure examinations, hardness tests, wear resistance and oxidation resistance experiments. The results indicated that the specimens containing Ti and W had a notable increase in hardness and wear resistance, but a slight decrease in oxidation resistance. The structures of specimens with Ti and W included some MC carbides, dispersedly distributed inside grains and at grain boundaries; these specimens also showed an increase in material properties. From oxidation kinetics analysis, the oxidation of austenitic heat-abrasion resistant steel specimens generally agree with parabola rule, oxidation activation energies k{sub p1} and k{sub p2} are calculated to be 304 and 128 kJ/mol. The oxide films composed of Cr{sub 2}O{sub 3}, spinelle (FeCr{sub 2}O{sub 4}, NiCr{sub 2}O{sub 4}), and some Fe{sub 3}O{sub 4} were continuous and compact. Cr{sub 2}O{sub 3} plays the vital role in the oxidation resistance based on the oxidation activation energy calculation.

  10. Effect of heat treatment on strength and abrasive wear behaviour of Al6061–SiCp composites

    N R Prabhu Swamy; C S Ramesh; T Chandrashekar

    2010-02-01

    In recent years, aluminum alloy based metal matrix composites (MMC) are gaining importance in several aerospace and automobile applications. Aluminum 6061 has been used as matrix material owing to its excellent mechanical properties coupled with good formability and its wide applications in industrial sector. Addition of SiCp as reinforcement in Al6061 alloy system improves its hardness, tensile strength and wear resistance. In the present investigation Al6061–SiCp composites was fabricated by liquid metallurgy route with percentages of SiCp varying from 4 wt% to 10 wt% in steps of 2 wt%. The cast matrix alloy and its composites have been subjected to solutionizing treatment at a temperature of 530°C for 1 h followed by quenching in different media such as air, water and ice. The quenched samples are then subjected to both natural and artificial ageing. Microstructural studies have been carried out to understand the nature of structure. Mechanical properties such as microhardness, tensile strength, and abrasive wear tests have been conducted both on matrix Al6061 and Al6061–SiCp composites before and after heat treatment. However, under identical heat treatment conditions, adopted Al6061–SiCp composites exhibited better microhardness and tensile strength reduced wear loss when compared with Al matrix alloy.

  11. Abrasive wear by diesel engine coal-fuel and related particles

    Ives, L.K. [National Inst. of Standards and Technology, Gaithersburg, MD (United States)

    1994-09-01

    The purpose of the work summarized in this report was to obtain a basic understanding of the factors which are responsible for wear of the piston ring and cylinder wall surfaces in diesel engines utilizing coal-fuel. The approach included analytical studies using scanning electron microscopy and energy dispersive x-ray analyses to characterize coal-fuel and various combustion particles, and two different wear tests. The wear tests were a modified pin-on-disk test and a block-on-ring test capable of either unidirectional or reciprocating-rotational sliding. The wear tests in general were conducted with mixtures of the particles and lubricating oil. The particles studied included coal-fuel, particles resulting from the combustion of coal fuel, mineral matter extracted during the processing of coal, and several other common abrasive particle types among which quartz was the most extensively examined. The variables studied included those associated with the particles, such as particle type, size, and hardness; variables related to contact conditions and the surrounding environment; and variables related to the type and properties of the test specimen materials.

  12. Assessment of Abrasive Wear of Nanostructured WC-Co and Fe-Based Coatings Applied by HP-HVOF, Flame, and Wire Arc Spray

    Lima, C. R. C.; Libardi, R.; Camargo, F.; Fals, H. C.; Ferraresi, V. A.

    2014-10-01

    Thermal spray processes have been widely used to minimize losses caused by wear mechanisms. Sprayed deposits using conventional wire and powder materials have been long solving tribological problems in engineering equipment. More recently, the option for new different technologies and consumables like nanostructured powder materials and nanocomposite cored wires have expanded the possibilities for technical solutions. Cored wire technology allows the use of compositions that cannot be drawn into wire form like carbides in metallic matrix and high-temperature materials, thus, intensifying the use of spraying processes with low operating cost to demanding wear and corrosion applications. The objective of this work was to study the mechanical characteristics and wear performance of coatings obtained by Flame, Wire Arc, and HVOF spraying using selected nanostructured WC10Co4Cr, WC12Co, and Fe-based 140 MXC powder and wire materials. Abrasive wear performance of the coatings was determinate following the ASTM G-65 standard. Based on the results, a higher abrasive wear resistance was found for the HVOF-sprayed WC10Co4Cr nanostructured coating.

  13. Effect of the abrasive size and transformability degree on the two body abrasive wear of polycrystalline zirconia; Efeito do tamanho do abrasivo e do grau de transformabilidade no comportamento em desgaste abrasivo a dois corpos de zirconias policristalinas

    Costa, H.L.; Mello, J.D.B. de [Uberlandia Univ., MG (Brazil). Dept. de Ciencias Fisicas; Pandolfelli, V.C. [Sao Carlos Univ., SP (Brazil). Dept. de Engenharia de Materiais

    1994-12-31

    It was analyzed the two-body abrasive wear behavior of tetragonal zirconia polycrystals with different transformability degrees. The analysis was carried out in pin-on-disk tests, by using different abrasive sizes and was complemented by monitoring the friction coefficient. The wear rate increased with the increasing of the abrasive size. The lowest transformability degree underwent the worst behavior on wear, probably associated with its low fracture toughness and the intermediate transformability presented the best behavior. The correlation between wear rate and friction coefficient characterized the presence of two distinct behaviors. (author). 14 refs., 3 figs.

  14. Sliding wear resistance of iron aluminides

    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.

  15. Studies on abrasive wear of monolithic silicon nitride and a silicon carbide whisker-reinforced silicon nitride composite

    Results presented in this paper demonstrate the roles of the most important parameters that govern abrasive wear of experimental ceramics. SEM studies of the abraded surfaces evidenced two main kinds of failures: microdropping of grain(s) and powder-type wear track(s) resulting from the brittle microfracturing of parts of grain(s). There were whiskers in the surface, and whisker pullouts occurring during wear processes are believed to be the reasons for the lower wear rates of SiCw/Si3N4 composite ceramics under experimental conditions

  16. Caracterização in Situ de Propriedades Mecânicas de Materiais Resistentes ao Desgaste Abrasivo Usando o Método da Indentação In Situ Determination of Mechanical Properties of Abrasive Wear Resistant Materials Using the Indentation Method

    Hans Berns

    1997-08-01

    Full Text Available O desempenho de materiais polifásicos em sistemas tribológicos envolvendo desgaste abrasivo é função de uma série de fatores, a saber: condições de operação, características de projeto e das propriedades do abrasivo e dos microconstituintes do material utilizado. Neste trabalho são apresentados resultados de ensaios de indentação em diferentes microconstituintes e partículas duras, através dos quais as propriedades mais importantes para o fenômeno abrasivo são determinadas in situ. Dentre essas destacam-se a dureza H, a tenacidade à fratura K IC, o módulo de elasticidade E, a relação trabalho plástico / trabalho elástico Wp / We e a relação de durezas entre o microconstituinte e o agente abrasivo. Em muitas situações práticas esses sistemas encontram-se em temperaturas elevadas. Assim, neste trabalho, é também apresentada a influência da temperatura sobre algumas dessas propriedades. Os resultados obtidos mostram a grande potencialidade dessa técnica no processo de seleção e desenvolvimento de materiais resistentes ao desgaste.The wear resistance is not an intrinsic property of materials but depends on the operating conditions, design properties, type of abrasive and material properties. In this work the results of microindentation tests in different hard particles of wear resistant alloys and composites, as well as in bulk materials are presented. Continuous monitoring the load and the indenter penetration depth it is possible to obtain in situ important properties in the wear process of the alloy microconstituents. With this technique it was possible to determine the hardness H, the fracture toughness K IC, the Young modulus E and the relationship between the plastic and elastic work of deformation Wp / We. Since in many practical situations the process temperature is an important parameter, its influence on some of these properties is also considered. The results show that this technique may constitute a

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

    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.

  18. Effects of sintering temperatures on microstructure and wear resistance of iron-silica composite

    Amir, Adibah; Mamat, Othman

    2015-07-01

    Ceramic particle reinforced into metal base matrix composite has been reported to produce higher strength and wear resistance than its alloys because the ceramic phases can strongly resist abrasion. In this study the iron matrix was reinforced with two compositions of 20 and 25 wt. % fine silica particles. The compacts were produced by using powder metallurgy fabrication technique and sintered at three sintering temperatures: 1000, 1100 and 1200°C. Effects of various sintering temperatures on microstructures and the composite's wear resistance were evaluated via optical and SEM microscopy. Both compositions were also subjected to ball-on-disk wear test. The results showed the reinforcement weight fraction of 20 wt.% of silica and sintering temperature at 1100°C exhibited better result, in all aspects. It possessed higher mechanical properties, it's microstructure revealed most intact reinforcing region and it displayed higher wear resistance during wear test.

  19. Investigations on mechanical and two-body abrasive wear behaviour of glass/carbon fabric reinforced vinyl ester composites

    The aim of the research article is to study the mechanical and two-body abrasive wear behaviour of glass/carbon fabric reinforced vinyl ester composites. The measured wear volume loss increases with increase in abrading distance/abrasive particle size. However, the specific wear rate decreases with increase in abrading distance and decrease in abrasive particle size. The results showed that the highest specific wear rate is for glass fabric reinforced vinyl ester composite with a value of 10.89 x 10-11 m3/Nm and the lowest wear rate is for carbon fabric reinforced vinyl ester composite with a value of 4.02 x 10-11 m3/Nm. Mechanical properties were evaluated and obtained values are compared with the wear behaviour. The worn surface features have been examined using scanning electron microscope (SEM). Photomicrographs of the worn surfaces revealed higher percentage of broken glass fiber as compared to carbon fiber. Also better interfacial adhesion between carbon and vinyl ester in carbon reinforced vinyl ester composite was observed.

  20. Effect of Nd on microstructure and wear resistance of hypereutectic Al-20%Si alloy

    Shi, W.X. [School of Materials and Metallurgy, Northeastern University, Shenyang, Liaoning Province 110004 (China); Gao, B., E-mail: surfgao@yahoo.com.c [School of Materials and Metallurgy, Northeastern University, Shenyang, Liaoning Province 110004 (China); Tu, G.F.; Li, S.W. [School of Materials and Metallurgy, Northeastern University, Shenyang, Liaoning Province 110004 (China)

    2010-10-22

    Research highlights: Firstly, the sizes of primary silicon of hypereutectic Al-20%Si alloy after modified were apparently refined. Secondly, wear resistance of hypereutectic Al-20%Si alloy modified by Nd was significantly improved. Thirdly, the dominant wear mechanisms for the alloy before after modification were different. Finally, a new ternary Al-Si-Nd phase forms after 0.3wt.%Nd modification. - Abstract: In this paper, pure Nd was adopted to modify hypereutectic aluminum-silicon alloy (Al-20%Si). The morphology of eutectic and primary silicon phases was analyzed by OM and SEM. OM and SEM results show that pure Nd (0.3 wt.%) can significantly refine both eutectic and primary silicon of hypereutectic Al-20%Si alloy. Morphology of primary silicon was transformed from star-shaped and irregular morphology to fine polyhedral and grain size of primary silicon was refined from 80-120 {mu}m to 20-50 {mu}m. TEM results show that a new needle shape ternary phase (AlSi{sub x}Nd{sub y}) forms in modified alloy. XRD results show that three little unknown diffraction peaks appear after Nd modification and it is induced that they should be diffraction peaks of ternary AlSi{sub x}Nd{sub y} intermetallic phase in the modified alloy by analyzing both TEM and XRD results. Friction and wear resistance tests show that friction coefficient of Al-20%Si alloy decreases after Nd modification. Wear resistance of Al-20%Si alloy after 0.3 wt.%Nd modification was significantly improved as compared to the initial sample. The improvement of wear resistance was mainly attributed to change of morphology, size and distribution of eutectic silicon and primary silicon after Nd modification. The dominant wear mechanism for 0.3 wt.%Nd modified alloy was abrasive wear, adhesive wear and oxidative wear mechanism, but wear mechanism for unmodified alloy was abrasive wear and adhesive wear mechanism.

  1. Evaluation of austenitic alloys abrasive wear of FeMnAlC system; Avaliacao de desgaste abrasivo de ligas austeniticas do sistema FeMnAlC

    Souza, Allan Ribeiro de; Acselrad, Oscar [Coordenacao dos Programas de Pos-graduacao de Engenharia (COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Programa de Engenharia Metalurgica e de Materiais. Lab. de Processamento Termomecanico e Engenharia Microestrutural]. E-mail: allariba@metalmat.ufrj.br

    2003-07-01

    Alloys of the FeMnAlC system have been studied as an alternative to stainless steels applications. Such alloys, when solubilized, are non-magnetic and present an austenitic structure that can be modified by thermal treatments. In this way, a large spectrum of mechanical and physical properties can be obtained. They are oxidation-resistant alloys, and by 15 hours aging at 550 deg C mechanical strength can be as high as conventional structural alloy steels. Information concerning the performance of these alloys under wear conditions are still limited. The possibility of application in components exposed to cavitation or abrasive loads, such as pipes, pumps and drilling systems is still a subject for fundamental research, such as the one that is now reported. Samples of a FeMnAlC alloy have been submitted to different thermal processing, leading to microstructures that have been characterized by optical, transmission and atomic force microscopy and by X-ray diffraction. They were subsequently subjected to a micro-abrasion test in which the abrasive wear resistance could be determined. The results have been used to differentiate the performance of different microstructures and allowed also a comparative analysis with the performance of an AISI M2 tool steel. (author)

  2. The role of abrasion and corrosion in grinding media wear: Annual technical progress report. [Taconite; molybdenite; quartzite

    Moore, J.J.; Iwasaki, I.

    1984-06-12

    Aim of this research program is to establish the effect of mill size and batch or continuous operation on the role of corrosive and abrasive wear during mineral grinding operations. Grinding ball wear tests are being conducted on the laboratory, pilot plant and industrial scale. This report gives the results of the first year's work of the two year research program and are discussed under the following headings: Wear Tests in an 8-inch Laboratory Mill (Using Three Different Ball Chemistries for Both Taconite and Molybdenite Ore); Wear Tests in a 36-inch Batch Mill (Using High Carbon Low Alloy Steel Balls with Taconite); Mechanisms of Erosive Wear in Taconite Grinding (Using Mild Steel Balls); The Effect of Slurry Rheology on Grinding Media Wear (Using Mild Steel Balls - Quartzite Combination); and Pilot Plant continuous Grinding Tests (Using High Carbon Low Alloy Steel Balls with Taconite Ore).

  3. Microstructure and abrasive wear properties of M(Cr,Fe7C3 carbides reinforced high-chromium carbon coating produced by gas tungsten arc welding (GTAW process

    Soner BUYTOZ

    2010-01-01

    Full Text Available In the present study, high-chromium ferrochromium carbon hypereutectic alloy powder was coated on AISI 4340 steel by the gas tungsten arc welding (GTAW process. The coating layers were analyzed by optical microscopy, X-ray diffraction (XRD, field-emission scanning electron microscopy (FE-SEM, X-ray energy-dispersive spectroscopy (EDS. Depending on the gas tungsten arc welding pa-rameters, either hypoeutectic or hypereutectic microstructures were produced. Wear tests of the coatings were carried out on a pin-on-disc apparatus as function of contact load. Wear rates of the all coating layers were decreased as a function of the loading. The improvement of abrasive wear resistance of the coating layer could be attributed to the high hardness of the hypereutectic M7C3 carbides in the microstruc-ture. As a result, the microstructure of surface layers, hardness and abrasive wear behaviours showed different characteristics due to the gas tungsten arc welding parameters.

  4. Wear resistance of chromium cast iron – research and application

    A. Studnicki

    2006-04-01

    Full Text Available Purpose: A short characteristic of wear resistance chromium cast iron has been presented as well as possibilities of this material researches realization in Foundry Department have been discussed.Design/methodology/approach: Main attention was given on research process of crystallization and analysis of chromium cast iron microstructure and its resistance on erosion wears. Separate part of paper was devoted to discuss the bimetallic castings with chromium cast iron layer as well as typical applications of chromium cast iron castings in minig, proccesing, metallurgical and power industry.Findings: The new method of crystallization process research with three testers (DTA-K3 was found in the work. The method makes possible to characterize sensitivity of chromium cast iron on cooling kinetic.Research limitations/implications: DTA-K3 method can be used for research of crystallization proccess of cast materials particularly for abrasion-resisting alloy.Practical implications: Wide scope researches of chromium cast iron in Foundry Department enable extending applications its material in many industries.Originality/value: Value of the paper is the presentation of researches possibilities which undertaken in Foundry Department within the range of wear resistant materials.

  5. The influence of chemical constitution on abrasive wear of alloy cast steel Cr, Mo, V, Cu, Ni type

    In the work were presented some elements of a wide research programme of the influence of alloying element contents such as Cr, Mo, V on the abrasive wear of hot working cast steel. The dependence between the mass decrement quantity and the element contents on cast steel structure were shown. (author)

  6. Three-body abrasion on wear and frictional performance of treated betelnut fibre reinforced epoxy (T-BFRE) composite

    This work aims to investigate the wear and frictional behaviour of a new epoxy composite based on treated betelnut fibres subjected to three-body abrasion using different abrasive particle sizes (500 μm, 714 μm and 1430 μm) and sliding velocities (0.026-0.115 m s-1) at constant applied load (5 N) using a newly developed Linear Tribo Machine. The worn surfaces of the composite were studied using scanning electron microscope. The work revealed that the predominant wear mechanism of treated betelnut fibre reinforced epoxy (T-BFRE) composite sliding against grain sands was plastic deformation, pitting and pullout of betelnut fibres. The composite exhibited higher values in frictional coefficient when it was subjected against coarse sand. Besides, the abrasive wear of the composite is depending on the size of abrasive particles and sliding velocity. Higher weight loss is noticed at high sliding velocities. The specific wear rate for the composite subjected to three different sand particles follow the order of: coarse > grain > fine sands respectively.

  7. Controlled wear of vitrified abrasive materials for precision grinding applications

    M J Jackson; B Mills; M P Hitchiner

    2003-10-01

    The study of bonding hard materials such as aluminium oxide and cubic boron nitride (BN) and the nature of interfacial cohesion between these materials and glass is very important from the perspective of high precision grinding. Vitrified grinding wheels are typically used to remove large volumes of metal and to produce components with very high tolerances. It is expected that the same grinding wheel is used for both rough and finish machining operations. Therefore, the grinding wheel, and in particular its bonding system, is expected to react differently to a variety of machining operations. In order to maintain the integrity of the grinding wheel, the bonding system that is used to hold abrasive grains in place reacts differently to forces that are placed on individual bonding bridges. This paper examines the role of vitrification heat treatment on the development of strength between abrasive grains and bonding bridges, and the nature of fracture and wear in vitrified grinding wheels that are used for precision grinding applications.

  8. Advanced Wear-resistant Nanocomposites for Increased Energy Efficiency

    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.

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

    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

  10. Effect of Phenomena Accompanying Wear in Dry Corundum Abrasive on the Properties and Microstructure of Austempered Ductile Iron with Different Chemical Composition

    Myszka D.

    2015-04-01

    Full Text Available The research described in this article is a fragment in the series of published works trying to determine the applicability of new materials for parts of the mining machinery. Tests were performed on two groups of austempered ductile iron - one of which contained 1.5% Ni and 0.5% Mo, while the other contained 1.9% Ni and 0.9% Cu. Each group has been heat treated according to the three different heat treatment variants and then the material was subjected to detailed testing of mechanical properties and abrasion wear resistance, measuring also hardness and magnetic properties, and conducting microstructural examinations. The results indicated that each of the tested materials was senstive to the surface hardening effect, which resulted in high wear resistance. It has been found that high temperature of austempering, i.e. 370°C, favours high wear resistance of ductile iron containing nickel and molybdenum. Low temperature of austempering, i.e. 270°C, develops high wear resistance in ductile iron containing nickel and copper. Both these materials offer completely different mechanical properties and as such can be used for different and specific applications.

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

    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. Effect of Volume Fraction of Particle on Wear Resistance of Al2O3/Steel Composites at Elevated Temperature

    BAO Chong-gao; WANG En-ze; GAO Yi-min; XING Jian-dong

    2005-01-01

    Based on previous work,abrasive wear resistance of Al2 O3/steel composites with different Al2 O3 parti cle volume fraction (VOF) at 900 C was investigated.The experimental results showed that a suitable particle VOF is important to protect the metal matrix from wear at elevated temperature.Both too high and too low particle VOF lead to a poor abrasive wear because a bulk matrix is easily worn off by grits when it exceeds the suitable VOF and also because when VOF is low,the Al2O3 particles are easily dug out by grits during wearing as well.When the particle VOF is 39%,the wear resistance of tested composites is excellent.

  13. Interface characterization of abrasion resistant coatings co-extruded on steel substrates

    Silva, P.A.; Weber, S.; Pyzalla, A.R. [Max-Planck-Inst. fuer Eisenforschung GmbH (MPIE), Duesseldorf (Germany); Karlsohn, M.; Theisen, W. [Inst. fuer Werkstoffe, Ruhr-Univ. Bochum (Germany); Reimers, W. [Technische Univ. Berlin (Germany). Metallic Materials

    2008-11-15

    Materials with high resistance against abrasive wear are of interest for many tool applications e.g. in mining industry. A special issue is the cladding of these materials to low alloyed substrates for new protection purposes. A novel manufacturing route via direct hot extrusion of bulk steel bars and pre-sintered tool steel powders was applied. In this manner, wear resistant claddings of PM tool steels on steel substrates were obtained. The microstructures at the interfaces between the steel substrate cores and the wear resistant coatings were characterized by means of optical and scanning electron microscopy (OM and SEM/EDX) and electron-probe microanalysis (EPMA). Hardness maps and profiles, as well as tensile tests on miniaturized samples were performed to obtain mechanical properties. Concentration profiles were calculated using the commercial software DICTRA showing a good agreement with the experiments. Carbon diffuses against the concentration gradient due to a higher activity into the substrate material leading to an increase of carbide volume fractions close to the interface. The mechanical tests show a brittle fracture region with high hardness localized about 50 {mu}m away from the interface in the coating material. (orig.)

  14. Abrasive wear behaviour of conventional and large-particle tungsten carbide-based cermet coatings as a function of abrasive size and type

    Kamdi, Z.; Shipway, P.H.; Voisey, K.T.; Sturgeon, A.J.

    2011-01-01

    Abrasive wear behaviour of materials can be assessed using a wide variety of testing methods, and the relative performance of materials will tend to depend upon the testing procedure employed. In this work, two cermet type coatings have been examined, namely (i) a conventional tungsten carbide-cobalt thermally sprayed coating with a carbide size of between ∼0.3 – 5 μm and (ii) a tungsten carbide-nickel alloy weld overlay with large spherical carbides of the order of ∼50 – 140 μm in diameter (...

  15. Abrasive and sliding wear characteristics of Al-Si cast alloys before and after coating by plasma electrolytic oxidation process

    Aydin, H.; Bayram, A. [Uludag Univ., Bursa (Turkey). Dept. of Mechanical Engineering; Uguz, A. [Science Park Ulutek (Turkey)

    2008-07-01

    The wear resistance of a series of Al-Si cast alloys with 5%, 8% and 11% silicon contents have been investigated after spheroidising heat treatments, and after coating these alloys by a plasma electrolytic oxidation (PEO) process for comparison. The alloys were subjected to wear tests by using SiC and steel counterfaces. The most remarkable observation is the increase in the wear resistance of the 5% Si containing alloy against SiC counterface, which is 70 times. However, the increase in the wear resistance is 5 times in the 11% Si containing alloy under same conditions, and only about 50% increase is observed when the counterface is steel. It is argued that, coating of these alloys by plasma electrolytic oxidation improves the wear resistance more effectively if the silicon content of the alloy is low, since the silicates (or aluminosilicates) in the coating layer has deleterious effect on wear resistance. (orig.)

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

    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℃.

  17. Micro-scale abrasive wear behavior of medical implant material Ti-25Nb-3Mo-3Zr-2Sn alloy on various friction pairs.

    Wang, Zhenguo; Huang, Weijiu; Ma, Yanlong

    2014-09-01

    The micro-scale abrasion behaviors of surgical implant materials have often been reported in the literature. However, little work has been reported on the micro-scale abrasive wear behavior of Ti-25Nb-3Mo-3Zr-2Sn (TLM) titanium alloy in simulated body fluids, especially with respect to friction pairs. Therefore, a TE66 Micro-Scale Abrasion Tester was used to study the micro-scale abrasive wear behavior of the TLM alloy. This study covers the friction coefficient and wear loss of the TLM alloy induced by various friction pairs. Different friction pairs comprised of ZrO2, Si3N4 and Al2O3 ceramic balls with 25.4mm diameters were employed. The micro-scale abrasive wear mechanisms and synergistic effect between corrosion and micro-abrasion of the TLM alloy were investigated under various wear-corrosion conditions employing an abrasive, comprised of SiC (3.5 ± 0.5 μm), in two test solutions, Hanks' solution and distilled water. Before the test, the specimens were heat treated at 760°C/1.0/AC+550°C/6.0/AC. It was discovered that the friction coefficient values of the TLM alloy are larger than those in distilled water regardless of friction pairs used, because of the corrosive Hanks' solution. It was also found that the value of the friction coefficient was volatile at the beginning of wear testing, and it became more stable with further experiments. Because the ceramic balls have different properties, especially with respect to the Vickers hardness (Hv), the wear loss of the TLM alloy increased as the ball hardness increased. In addition, the wear loss of the TLM alloy in Hanks' solution was greater than that in distilled water, and this was due to the synergistic effect of micro-abrasion and corrosion, and this micro-abrasion played a leading role in the wear process. The micro-scale abrasive wear mechanism of the TLM alloy gradually changed from two-body to mixed abrasion and then to three-body abrasion as the Vickers hardness of the balls increased. PMID:25063112

  18. Abrasion test of flexible protective materials on hydraulic structures

    Xin WANG

    2014-01-01

    Full Text Available In this study, several kinds of flexible protective materials sprayed with polyurea elastomers (hereinafter referred to as polyurea elastomer protective material were adopted to meet the abrasion resistance requirement of hydraulic structures, and their abrasion resistances against the water flow with suspended load or bed load were studied systematically through tests. Natural basalt stones were adopted as the abrasive for simulation of the abrasion effect of the water flow with bed load, and test results indicate that the basalt stone is suitable for use in the abrasion resistance test of the flexible protective material. The wear process of the polyurea elastomer protective material is stable, and the wear loss is linear with the time of abrasion. If the wear thickness is regarded as the abrasion resistance evaluation factor, the abrasion resistance of the 351 pure polyurea is about twice those of pure polyurea with a high level of hardness and aliphatic polyurea, and over five times that of high-performance abrasion-resistant concrete under the abrasion of the water flow with suspended load. It is also about 50 times that of high-performance abrasion-resistant concrete under the abrasion of the water flow with bed load. Overall, the abrasion resistance of pure polyurea presented a decreasing trend with increasing hardness. Pure polyurea with a Shore hardness of D30 has the best abrasion resistance, which is 60 to 70 times that of high-performance abrasion-resistant concrete under the abrasion of the water flow with bed load, and has been recommended, among the five kinds of pure polyurea materials with different hardness, in anti-abrasion protection of hydraulic structures.

  19. Abrasion test of flexible protective materials on hydraulic structures

    Xin WANG; Shao-ze LUO; Guang-sheng LIU; Lu-chen ZHANG; Yong WANG

    2014-01-01

    In this study, several kinds of flexible protective materials sprayed with polyurea elastomers (hereinafter referred to as polyurea elastomer protective material) were adopted to meet the abrasion resistance requirement of hydraulic structures, and their abrasion resistances against the water flow with suspended load or bed load were studied systematically through tests. Natural basalt stones were adopted as the abrasive for simulation of the abrasion effect of the water flow with bed load, and test results indicate that the basalt stone is suitable for use in the abrasion resistance test of the flexible protective material. The wear process of the polyurea elastomer protective material is stable, and the wear loss is linear with the time of abrasion. If the wear thickness is regarded as the abrasion resistance evaluation factor, the abrasion resistance of the 351 pure polyurea is about twice those of pure polyurea with a high level of hardness and aliphatic polyurea, and over five times that of high-performance abrasion-resistant concrete under the abrasion of the water flow with suspended load. It is also about 50 times that of high-performance abrasion-resistant concrete under the abrasion of the water flow with bed load. Overall, the abrasion resistance of pure polyurea presented a decreasing trend with increasing hardness. Pure polyurea with a Shore hardness of D30 has the best abrasion resistance, which is 60 to 70 times that of high-performance abrasion-resistant concrete under the abrasion of the water flow with bed load, and has been recommended, among the five kinds of pure polyurea materials with different hardness, in anti-abrasion protection of hydraulic structures.

  20. Wear resistance of coke-crushing hammers

    Zupanič, Franc

    2015-01-01

    This work investigated several methods for improving the wear resistance of the 42CrMo4 tool steel used for coke-crushing hammers. The methods embraced heat treatment for obtaining different combinations of strength and ductility of the bulk steel, and surface-engineering processes comprising TiN thin-film deposition using magnetron-sputtering, nitriding and WC/Ni weld deposit surfaced by gas metal arc (GMA) method. The wear-resistance was tested under industrial conditions. Oil quenching and...

  1. Technical criteria for evaluation of wear resistance in steels

    Technical criteria of wear resistance of steels and alloys, enabling to range them according to this index without wear test performance are generalized. It is shown that a particular wear resistance criterion can be chosen for each type of wear. 9 refs.; 8 figs

  2. Structure and wear resistance of plasma sprayed coatings from composite aluminium powders with dispersion phases

    Composite aluminium powders with dispersion ceramic and ceramic-metallic phases were obtained by the mechanical alloying in the rotary-vibration mill. Parameters of obtaining powders and their microstructure and morphology were characterized. technological parameters of plasma spraying of coatings from the composite powders formed were determined. Investigation results of abrasion and erosion wear resistance of coatings are presented. The structure of coatings obtained from the composite of the powders of the Al-Ni-SiC, Al-Ti-SiC type also contains intermetallic phases formed 'in situ' reaction during thermal spraying. It has been found, that abrasion and erosion wear resistance of coatings is connected with the type and volume fraction dispersion phases strengthening the coating matrix. (author)

  3. Wear Resistant Amorphous and Nanocomposite Coatings

    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.

  4. Application of polymer-powder slurry for fabrication of abrasion resistant coatings on tool materials

    G. Matula

    2011-03-01

    Full Text Available Purpose: Development of a new generation tool materials on the basis of M2 high speed-steel or 41Cr4 steel covered with the carbides. Application of pressureless forming of powder as a manufacturing method of anti-wear coatings gives the possibility to produce this materials with relative low cost of production.Design/methodology/approach: Powder metallurgy, pressureless forming of powder, sintering, microstructure examination, X-ray dispersive energy examination, hardness examination.Findings: Putting down coatings with this method does not call for using the costly equipment for the physical or chemical deposition of coatings from the gaseous phase. Coating thickness may be easily regulated by applying the powder-binder slurry layer once or several times on the prepared substrate surface. Hardness of coatings in the sintered state is higher compared to the HS6-5-2 and 41Cr4 steels by about 400 and 700 HV respectively. It is expected that hardness of the coatings and substrate will grow after their heat treatment.Practical implications: Application of powder metallurgy and especially pressureless forming of powder to manufacturing of steel covered with anti-wear coatings gives the possibility to obtain tool materials with the relative high ductility characteristic of steel and high hardness and wear resistance typical for cemented carbides.Originality/value: One can state, based on the investigations carried out, that the pressureless forming of the powder may be used for depositing the anti-wear coatings onto the tool materials and other elements in the abrasion wear service conditions.

  5. A novel corrosion and abrasion resistant internal coating method with improved adhesion using hollow cathode PECVD (Plasma Enhanced Chemical Vapor Deposition) technology

    Boardman, B.; Boinapally, K.; Casserly, T.; Upadhyaya, D.; Gupta, M.; Dornfest, C. [SubOne Technology, Pleasanton, CA (United States)

    2008-07-01

    A new enabling technology for coating the internal surfaces of pipes with a hard, corrosion, wear resistant diamond-like-carbon (DLC) coating is described. The importance of proper surface preparation and optimized interface and adhesion layer is shown. Corrosion resistance is measured based on exposure to HCl, NaCl environments and autoclave with H{sub 2}S. Mechanical properties include high hardness, high adhesion, and excellent wear resistance including sand abrasion resistance. The coating is optimized for high hardness and deposition rate based on selection on the proper hydrocarbon precursor. This new technology enables wide spread use of DLC based coating to increase component life in applications where internal surface of pipes are exposed to corrosive and abrasive environment especially in the oil and gas industry. (author)

  6. Refractory wear resistant powder materials for metallurgy

    Powder materials on the basis of high-alloy nickel alloys containing up to 50 % (in mass) of Co, Cr, Mo, W, Ti, Nb, Al and up to 10 % refractory thermally stable compounds (oxides, carbides, nitrides, carbonitrides) have been developed. They feature a high strength, corrosion- and wear resistance at 800-1000 deg C, a satisfactory ductility at room and working temperatures, a decreased tendency towards crack formation, they are workable by cutting. 4 refs., 4 figs

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

    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.

  8. The Effect of Microstructure on the Abrasion Resistance of Low Alloyed Steels

    Xu, X.

    2016-01-01

    The thesis attempts to develop advanced high abrasion resistant steels with low hardness in combination with good toughness, processability and low alloying additions. For this purpose, a novel multi-pass dual-indenter (MPDI) scratch test approach has been developed to approach the real continuous abrasion process and unravel abrasion damage formation in construction steels, i.e. carrying out scratch tests using a large indenter with different pre-loads to generate a wide pre-scratch with sta...

  9. Wear Resistant Thermal Sprayed Composite Coatings Based on Iron Self-Fluxing Alloy and Recycled Cermet Powders

    Andrei SURŽENKOV

    2012-03-01

    Full Text Available Thermal spray and WC-Co based coatings are widely used in areas subjected to abrasive wear. Commercial  cermet thermal spray powders for HVOF are relatively expensive. Therefore applying these powders in cost-sensitive areas like mining and agriculture are hindered. Nowadays, the use of cheap iron based self-fluxing alloy powders for thermal spray is limited. The aim of this research was to study properties of composite powders based on self-fluxing alloys and recycled cermets and to examine the properties of thermally sprayed (HVOF coatings from composite powders based on iron self-fluxing alloy and recycled cermet powders (Cr3C2-Ni and WC-Co. To estimate the properties of  recycled cermet powders, the sieving analysis, laser granulometry and morphology were conducted. For deposition of coatings High Velocity Oxy-Fuel spray was used. The structure and composition of powders and coatings were estimated by SEM and XRD methods. Abrasive wear performance of coatings was determined and compared with wear resistance of coatings from commercial powders. The wear resistance of thermal sprayed coatings from self-fluxing alloy and recycled cermet powders at abrasion is comparable with wear resistance of coatings from commercial expensive spray powders and may be an alternative in tribological applications in cost-sensitive areas.DOI: http://dx.doi.org/10.5755/j01.ms.18.1.1338

  10. Modeling of Tool Wear in Vibration Assisted Nano Impact-Machining by Loose Abrasives

    Sagil James; Sundaram, Murali M.

    2014-01-01

    Vibration assisted nano impact-machining by loose abrasives (VANILA) is a novel nanomachining process that combines the principles of vibration assisted abrasive machining and tip-based nanomachining, to perform target specific nanoabrasive machining of hard and brittle materials. An atomic force microscope (AFM) is used as a platform in this process wherein nanoabrasives, injected in slurry between the workpiece and the vibrating AFM probe which is the tool, impact the workpiece and cause na...

  11. Sliding wear of cemented carbides

    Cemented carbides are known to be very hard and wear resistant and are therefor often used in applications involving surface damage and wear. The wear rate of cemented carbides is often measured in abrasion. In such tests it has been shown that the wear rate is inversely dependent on the material hardness. The sliding wear is even more of a surface phenomenon than a abrasion, making it difficult to predict friction and wear from bulk properties. This paper concentrates on the sliding wear of cemented carbides and elucidates some wear mechanisms. It is especially shown that a fragmenting wear mechanism of WC is very important for the description of wear of cemented carbides. (author)

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

    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       

  13. Microstructure, mechanical properties and wear resistance of WC/Co nanocomposites

    The microstructure, mechanical properties, abrasion and wear resistance of WC-Co nanocomposites synthesized by the spray conversion technique by McCaundlish, Kear and Kim have been investigated. The binder phase of WC-Co nanocomposites is enriched in W and C, compared to conventional cermets. Small amorphous regions exist in the binder despite the slow cooling after liquid phase sintering. Few dislocations are found in the WC grains. The increased WC content and the amorphous regions modify (i.e. strengthen) the binder phase of the composites. Vickers indentation measurements show a hardness of the nanocomposites reaching 2,310 kg/mm2. While the toughness of conventional cermets decreases with increasing hardness, the toughness does not decrease further as the WC grain size decreases from 0.7 to 0.07 microm but remains constant at 8 MPam1/2. Scratches caused by a diamond indenter are small, commensurate with their hardness. These scratches are ductile, devoid of the grain fracture that is observed with conventional materials. The abrasions resistance of nanocomposites is about double that of conventional materials, although their hardness is larger by 23% only. This is due to the lack of WC grain fragmentation and removal which takes place in conventional cermets. Sliding wear resistance of WC/Co is proportional to their hardness; no additional benefit of nanostructure is obtained. This results from the very small size of adhesive wear events in even large WC grains

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

    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.

  15. Single layer and multilayer wear resistant coatings of (Ti,Al)N: a review

    We review the status of (Ti,Al)N based coatings obtained by various physical vapor deposition (PVD) techniques and compare their properties. PVD techniques based on sputtering and cathodic arc methods are widely used to deposit wear resistant (Ti,Al)N coatings. These techniques were further modified to improve the metal ionization rate and to eliminate macrodroplets from plasma streams. We summarize manufacture of target/cathode, substrate materials for deposition of coatings, deposition parameters, and the effect of deposition parameters on the physical and mechanical properties of (Ti,Al)N coatings. It is shown that (Ti,Al)N coatings by PVD enhance the wear, thermal, and oxidation resistance of a wide variety of tool materials. We discuss the wear resistant properties of (Ti,Al)N for various machining applications as compared with coatings such as TiN, Ti(C,N) and (Ti,Zr)N. High hardness (∼28-32 GPa), relatively low residual stress (∼5 GPa), superior oxidation resistance, high hot hardness, and low thermal conductivity make (Ti,Al)N coatings most desirable in dry machining and machining of abrasive alloys at high speeds. Multicomponent coatings based on different metallic and nonmetallic elements combine the benefit of individual components leading to a further refinement of coating properties. Alloying additions such as Cr and Y drastically improve the oxidation resistance, Zr and V improve the wear resistance, whereas, Si increases the hardness and resistance to chemical reactivity of the film. Addition of boron improves the abrasive wear behavior of Ti-Al based coatings due to the formation of TiB2 and BN phases depending on the deposition conditions. Hafnium based nitrides and carbides have potential for resistance to flank and crater wear. The presence of a large number of interfaces between individual layers of a multilayered structure results in a drastic increase in hardness and strength. (Ti,Al)N multilayer super lattice coatings with lattice

  16. EFECTO DEL CONTENIDO DE CARBONO SOBRE LA RESISTENCIA AL DESGASTE ABRASIVO DE RECUBRIMIENTOS DE CrC DEPOSITADOS POR PULVERIZACIÓN CATÓDICA MAGNETRÓN EFEITO DO CONTEÚDO DE CARBONO SOBRE A RESISTÊNCIA AO DESGASTE ABRASIVO DE RECOBRIMENTOS DE CrC DEPOSITADOS POR PULVERIZAÇÃO CATÓDICA MAGNETRÃO EFFECT OF THE CARBON CONTENT IN ABRASIVE WEAR RESISTANCE OF CrC COATINGS DEPOSITED BY MAGNETRON SPUTTERING

    Maryory Astrid Gómez

    2012-12-01

    diamante. O volume das impressões de abrasão mediu-se com as imagens obtidas no microscópio interferométrico e ademais se corroborou com o cálculo do volume geométrico baseado em seções medidas com o perfilômetro. O comportamento ao desgaste abrasivo mostrou uma marcada dependência com o conteúdo de carbono. O desgaste abrasivo mais baixo obtevese para os recobrimentos com o mais alto conteúdo de carbono.Chromium carbide coatings on steel are a good candidate for applications on forming and molding dies. The high mechanical strength, chemical resistance and high temperature stability of Cr3C2 phase can be compatible with the severe abrasive wear and corrosion found in those manufacture operations. In this work chromium carbide coatings deposited by means of RF magnetron sputtering showed carbon contents between 25 % and 58 % by EDS analysis. Hardness values of these coatings were between 15 and 24 GPa, being the hardest values in the samples with carbon content in the 39-53 % range. The abrasive wear behavior of the coatings was evaluated by using a dimple grinder with diamond powder. The volume of the abrasion craters was measured from the images obtained with the interferometric microscope, and further corroborated by geometrical volume calculation based in profilometer sections that were measured. Abrasive wear behavior showed a marked dependence with carbon content. The lowest abrasive wear was obtained for the coatings with the highest carbon content.

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

    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.)

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

    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.)

  19. Correlation between Wear Resistance and Lifetime of Electrical Contacts

    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. Plasma-polymerized coating for polycarbonate: Single-layer, abrasion resistant, and antireflection

    Wydeven, Theodore

    1991-01-01

    Plasma-polymerized vinyl trimethoxy silane films were deposited on transparent polycarbonate substrates. The adherent, clear films protected the substrates from abrasion and also served as antireflection coatings. Post-treatment of the vinyl trimethoxy silane films in an oxygen glow discharge further improved their abrasion resistance. The coatings were characterized by elemental analysis of the bulk, ESCA analysis of the surface, transmission, thickness, abrasion resistance, haze, and adhesion. This patented process is currently used by the world's largest manufacturers of non-prescription sunglasses to protect the plastic glasses from scratching and thereby to increase their useful lifetime.

  1. HYDRO-ABRASIVE RESISTANCE AND MECHANICAL PROPERTIES OF CONCRETE WITH ADDED FLY ASH

    Ristić, Nenad; Grdić, Zoran; Topličić-Ćurčić, Gordana

    2015-01-01

    The durability of hydraulic engineering structures mostly depends on the resistance of their concrete surfaces to mechanical abrasion. In this paper, we study the hydro-abrasive resistance and mechanical properties of concrete in which cement is partially replaced with fly ash in various proportions. To evaluate these concretes, we measured their compressive strength, flexural strength, static modulus of elasticity, ultrasound velocity through concrete, and sclerometer rebound. The hydro-abra...

  2. Effect of pressing temperature on the wear resistance of a Co-based Cr-Mo powder alloy produced by hot pressing

    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

  3. Model criterion and basic principles of construction bank data abrasive materials durability

    О.А. Вишневський

    2006-01-01

    Full Text Available  The generalized model is created and the criterion of an abrasive wear of surfaces of materials is determined at not hard-mounted corpuscles. The principle of construction of a data bank of an abrasive wear resistance of materials of friction units is determined. 

  4. Abrasion resistance of biaxially oriented polypropylene films coated with nanocomposite hard coatings

    Wang, Jing; Zhu, Yaofeng; Fu, Yaqin

    2013-11-01

    KMnO4-treated, functionalized, biaxially oriented polypropylene (BOPP) films coated with nano-silica hybrid material were synthesized. The abrasion resistance of the films was examined using a reciprocating fabric abrasion tester. Functional groups were confirmed by Fourier-transform infrared spectroscopy. Contact angle measurements were performed on the BOPP film surface to quantify the effectiveness of the functionalization. Results indicate that the abrasion resistance and roughness of the composite film were significantly affected by the modification of the BOPP film. Water surface contact angle of the modified BOPP films decreased from 90.1° to 71.4°,when KMnO4 concentration increased from 0 M to 0.25 M. Wettability of the BOPP films clearly improved after KMnO4 treatment. Abrasion resistance of the functionalized films coated with hybrid materials improved by 27.4% compared with that of the original film.

  5. A Laser Processing Technique for Improving the Wear Resistance of Metals

    Ayers, J. D.; Schaefer, R. J.; Robey, W. P.

    1981-08-01

    This paper describes a process whereby the surface of a wide variety of metals and alloys can be impregnated with hard, wear-resisting particles. In experiments to date, particles of TiC or WC have been injected into thin laser melted surface layers of iron, nickel, titanium, aluminum, and copper base alloys. Many other metal/particle combinations appear to be feasible, for the only fundamental limitation on the process evident to date is that the metal must not exhibit an excessive vapor pressure under the conditions of laser melting. Despite the wide range of alloy compositions experimented with, the processing conditions necessary to achieve good volume fractions of carbide are surprisingly constant. This similarity in processing conditions results in part from carrying out the carbide injection under soft vacuum conditions, thus eliminating oxidation problems without introducing problems associated with the use of shielding gases. Work in progress1 has demonstrated that several of the metal/carbide combinations produced to date exhibit good resistance to abrasive wear. It is expected that resistance to most other types of wear will also be good. Preliminary results suggest that in addition to applications involving the production of wear-resisting metal surfaces, the process may be suited to the manufacture of carbide hardened cutting tools. Furthermore, the simplicity of the process recommends it for surface alloying applications.

  6. 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

    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.

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

    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.

  8. Effect of flame conditions on abrasive wear performance of HVOF sprayed nanostructured WC-12Co coatings

    WANG Yu-yue; LI Chang-jiu; MA Jian; YANG Guan-jun

    2004-01-01

    Nanostructured WC-12Co coatings were deposited by high velocity oxy-fuel (HVOF) spraying with an agglomerated powder. The effect of flame conditions on the microstructure of the nanostructured coatings was investigated. The wear properties of the coatings were characterized using a dry rubber-wheel wear test. The results show that the nanostructured WC-Co coatings consist of WC, W2C, W and an amorphous binder phase. The microstructure of the coating is significantly influenced by the ratio of oxygen flow to fuel flow. Under the lower ratio of oxygen/fuel flow, the nanostructured coating presents a relative dense microstructure and severe decarburization of WC phase occurs during spraying. With increasing ratio of oxygen/fuel flow, the bonding of WC particles in the coating becomes loose resulting from the original structure of feedstock and the decarburization of WC becomes less owing to limited heating to the powder. Both the decarburization of WC particles in spraying and the bonding among WC particles in the coatings affect the wear performance. The examination of the worn surfaces of the nanostructured coatings reveals that the dominant wear mechanisms would be spalling from the interface of WCCo splats when spray particles undergo a limited melting. While the melting state of the spray particles is improved,the dominant wear mechanisms become the plastic deformation and plowing of the matrix and spalling of WC particles from the matrix.

  9. Laboratory prediction of tire wear resistance; Tire yo zairyo no taimamosei hyokaho

    Mori, H. [Bridgestone Corp., Tokyo (Japan)

    1997-01-20

    This paper describes the present evaluation and problem on the abrasion resistance of the tread rubber in a car tyre. For the way to evaluate the abrasion in a laboratory using a rubber material unit, the abrasion test in which a slip occurs while the sample rolls as for a tyre is considered to be suitable for a tyre. The result is correlated with the abrasion of an actual car to a certain degree, but it does not also often coincide with that of an actual car. There are several points to be improved. It has been lately proposed that the abrasion mechanism is classified into E and P abrasion. The P abrasion occurs when the severity level is low. It occurs when the road surface roughness is fine and when the temperature is low. The rubber whose glass transition point is high is excellent in abrasion resistance as compared with the E abrasion. The abrasion surface in the conventional rubber abrasion test is E abrasion indicating an abrasion pattern without exception. The abrasion surface remarkably differs from the P abrasion that was observed in the tyre used actually. In other words, the major problem of a rubber abrasion test is how the P abrasion is caused. 18 refs., 10 figs.

  10. Evaluation on the fretting abrasion of heat-transfer tubes of the integrated IHX/primary sodium pump. 2. Fretting wearing analyses

    A primary sodium pump is installed in the center of an integrated component and heat transfer tubes surround the pump. Then, the pump rotation induces the vibration of heat transfer tubes and it leads the tubes to fretting wearing against support plates. Therefore, the tube wearing must be evaluated to confirm its integrity during the plant life span (60 years). This report describes the results of the tube wearing analysis by using vibration and wearing calculation models. In the first place, the vibration analysis of a pump shaft, shells, tube bundle etc. of the integrated component reveals its properties such as frequency, amplitude and vibration mode. In the second place, based on the above mentioned vibration analysis, the wearing analysis model shows the frequency and amplitude of the fretting wearing between tubes and support plates and the wearing depth of tubes. The amplitude of the pump vibration, vibration transmission paths and the contact condition between tubes and support plates especially affect the tube wearing, then the wearing evaluation needs that conservative calculation conditions must be found out by surveying these parameters. This calculation result indicates that the tube abrasion does not affect the tube integrity during the plant life time. However further evaluation by more detailed analysis and vibration and wearing tests are needed to acquire more accurate results. (author)

  11. Microstructure, microhardness and wear resistance of VCp/Fe surface composites fabricated in situ

    Graphical The vanadium carbide particles (VCp)/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 V8C7 phases dominate in the composite after being heat treated at 1164 °C for 3 h. The amount of V8C7 decreases gradually from the top surface of the composite to the matrix mainly composed of gray cast iron. The average microhardness of the VCp/Fe surface composites varies according to the different reaction zones as follows: 505 HV0.1 (vanadium plate), 1096 HV0.1 (composite region), and 235 HV0.1 (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 (V2C and V8C7) crystallites as reinforcement phases within the iron matrix. The VCp/Fe surface composites exhibit a good wear resistance under two-body abrasive wear test.

  12. Plasma polymerized coating for polycarbonate - Single layer, abrasion resistant, and antireflection

    Wydeven, T.

    1977-01-01

    Plasma polymerized vinyltrimethoxy silane films were deposited on transparent polycarbonate substrates. The adherent, clear films protected the substrates from abrasion and also served as antireflection coatings. Posttreatment of the vinyltrimethoxy silane films in an oxygen glow discharge further improved the abrasion resistance. ESCA (electron spectroscopy for chemical analysis) and IR transmission spectra of some films were recorded, and an elemental analysis of the films was obtained.

  13. Wear resistance of a metal surface modified with minerals

    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.

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

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

    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

  16. Characterization and wear- and corrosion-resistance of microarc oxidation ceramic coatings on aluminum alloy

    Wei Tongbo [State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Yan Fengyuan [State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000 (China)]. E-mail: fyyan@ns.lzb.ac.cn; Tian Jun [State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000 (China)

    2005-03-08

    Thick and hard ceramic coatings were prepared on Al-Cu-Mg alloy (2024 Al alloy) making use of microarc oxidation in an alkali-silicate electrolytic solution. The microstructure, phase composition, corrosion resistance friction and wear behaviors of the microarc oxidation coatings and the impact toughness of the impacted Al alloy blocks were investigated. Moreover, the corroded surfaces and the impacted surfaces and cross-sections of the microarc oxidation coatings were observed with a scanning electron microscope. The results show that the microarc oxidation coatings can be divided into a porous loose outer region consisting predominantly of {gamma}-Al{sub 2}O{sub 3} and Al-Si-O phase and a dense internal region consisting predominantly of {alpha}-Al{sub 2}O{sub 3}. They have excellent corrosion resistance, though the thicker coating shows somewhat poorer corrosion-resistance than the thinner one. The differences in the corrosion-resistance of the microarc oxidation coatings with different thicknesses are related to their different microstructures. The impact toughness of the Al alloy substrate is decreased after modification with the microarc oxidation coatings of extremely high hardness. This implies that the microarc oxidation coatings on the Al alloy substrate may not be suitable to impacting working condition. After abrasion away of the loose outer layer, the polished compact inner coatings possess excellent wear- and corrosion-resistance and strong adhesion to the substrate, and they show further significantly improved wear-resistance under the lubrication of a commercial 4838 lubricating oil. Namely, the friction coefficient and wear rate of the polished 100 {mu}m coating under the oil-lubricated-condition are reduced to be 1/10 and 1/1000 of that under dry sliding. The microarc oxidation coatings mainly composed of hard {alpha}-Al{sub 2}O{sub 3} could find promising application in preventing the corrosion and wear of Al alloy-based components.

  17. Investigation of improving wear performance of hypereutectic 15%Cr-2%Mo white irons

    Reda, R.; A. Nofal; Kh. Ibrahim

    2010-01-01

    This study aimed at optimizing impact toughness and abrasion wear resistance of 15%Cr-2%Mo hypereutectic abrasion-resistant white irons. The effects of dynamic solidification, niobium addition, combined action of them and heat treatment have been investigated. Investigations were performed by means of the image analyzer, scanning electron microscopy (SEM), energy-dispersive spectrometry (EDS) and X-ray diffraction. Impact toughness and abrasion wear resistance tests were conducted. Fracture a...

  18. [Improve wear resistance of UHMWPE by O+ ion implanted].

    Xiong, Dangsheng

    2003-12-01

    Ultra high molecular weight polyethylene (UHMWPE) was implanted with 450 keV and 100 keV O+ ions at dosage of 1 x 10(15)/cm2, 5 x 10(15)/cm2, 3 x 10(14)/cm2, respectively. Its wear behaviors were studied under dry friction condition and lubrication by means of distilled water using a pin-on-disk tribometer with a Si3N4 ceramic ball as a counterface. The wear surfaces were examined with SEM. The experimental results showed that the wear rate of implanted UHMWPE is lower than that of un-implanted UHMWPE under both dry and distilled friction conditions, especially for 450 keV energy and 5 x 10(15)/cm2 dose implantation. The friction coefficient of O+ ions implanted UHMWPE is higher than that of un-implanted UHMWPE under both dry and distilled friction conditions. The adhesive, plow and plastic deformation are the wearing mechanism for un-implanted UHMWPE; the fatigue and abrasive wear are that for implanted UHMWPE. PMID:14716850

  19. Selection of Heat Treatment Process and Wear Mechanism of High Wear Resistant Cast Hot-Forging Die Steel

    WEI Min-xian; WANG Shu-qi; WANG Lan; CUI Xiang-hong; CHEN Kang-min

    2012-01-01

    Dry sliding wear tests of a Cr-Mo-V cast hot-forging die steel was carried out within a load range of 50--300 N at 400℃ by a pin-on-disc high temperature wear machine. The effect of heat treatment process on wear resistance was systematically studied in order to select heat treatment processes of the steel with high wear resistance. The morphology, structure and composition were analyzed using scanning electron microscopy (SEM), X-ray diffraction (XRD) and energy dispersive spectroscopy (EDS) ; wear mechanism was also discussed. Tribo-oxide layer was found to form on worn surfaces to reduce wear under low loads, but appear inside the matrix to increase wear under high loads. The tribo-oxides were mainly consisted of Fe3O4 and Fe2O3, FeO only appeared under a high load. Oxidative mild wear, transition of mild-severe wear in oxidative wear and extrusive wear took turns to operate with increasing the load. The wear resistance strongly depended on the selection of heat treatment processes or microstructures. It was found that bainite presented a better wear resistance than martensite plus bainite duplex structure, martensite structure was of the poorest wear resistance. The wear resistance increased with increasing austenizing temperature in the range of 920 to 1 120 ℃, then decreased at up to 1 220 ℃. As for tempering temperature and microstructure, the wear resistance increased in following order: 700℃ (tempered sorbite), 200 ℃ (tempered martensite), 440 to 650 ℃ (tempered troostite). An appropriate combination of hardness, toughness, microstructural thermal stability was re- quired for a good wear resistance in high-temperature wear. The optimized heat treatment process was suggested for the cast hot-forging steel to be austenized at 1020 to 1 120 ℃, quenched in oil, then tempered at 440 to 650℃ for 2 h.

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

    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.

  1. Research in Polyurea Elastomer Material Abrasion Resistance%聚脲弹性体材料耐磨性能的探讨

    崔洪犁; 吴文文; 孟庆莉

    2014-01-01

    由不同二元醇与二异氰酸酯合成不同NCO含量的半预聚体( A组分)与端氨基聚醚、胺扩链剂等原料组成的R组分经喷涂设备喷涂成型聚脲弹性体。讨论了在不同摩擦工况下NCO含量、异氰酸酯指数、预聚物类型、耐磨助剂等对聚脲弹性体耐磨性能的影响。结果表明,不同NCO含量在不同摩擦工况下对聚脲耐磨性能的影响不同,干摩擦工况下NCO含量越高,耐磨性能越佳,湿摩擦工况下则是NCO质量分数为15%耐磨性最佳,异氰酸酯指数对聚脲耐磨性能的影响较小,使用聚四氢呋喃二元醇、TDI预聚物和耐磨助剂,可提高不同摩擦工况下聚脲的耐磨性能。%The spraying polyurea elastomer system was synthetized by A component and R component. The A component was a kind of quasi⁃prepolymer with different NCO content, synthesized by polyether diol and isocya⁃nate. The R component was composed of amino terminated polyether, amine extender and other additives. The in⁃fluence on abrasion performance under different wear conditions was discussed, such as different NCO content, iso⁃cyanate index, type of prepolymer and different wearable additives. The result was that different NCO content had different wear influence under different wear conditions. With the NCO content of the prepolymer increase, the bet⁃ter abrasion resistance the polyurea had under dry wear condition. The abrasion performance was the best when NCO content was 15% under wet wear condition. The isocyanate index had a few effects on the abrasion perform⁃ance. The application of polytetrahydrofuran diol, TDI perpolymer and wearable additives could improve the abra⁃sion resistance of polyurea under different wear conditions.

  2. 苜蓿草粉对金属材料的磨料磨损试验%Experiment of Metal Materials Abrasive Wear for Alfalfa Powder

    张炜; 吴劲锋; 马国军; 黄晓鹏

    2009-01-01

    The abrasive testing machine with operation process similar to the pelleting circular mold was used, taking the alfalfa grass powder as abrasive material. The influences of alfalfa powder on the abrasive properties of four kind of metal materials were examined, by measuring the rigidity and chemical components of the abraded surfaces and analyzing of the microstructures and surface morphologies of the abraded surfaces. It is shown that the abrasive quantities of four samples as below are orderly increased, 3Cr13, 9SiCr, 45~# steel, and HT200, some physical and chemical changes take place on the abraded surfaces, and "the soft abrasive wear" is accompanied by "the hard abrasive wear" feature due to the micro-cutting and strain fatigue.%选用与环模制粒工况相似的磨料磨损试验机,以首蓿草粉为磨料对试样进行磨料磨损试验.通过磨后表面的硬度和化学成分测定、微观结构和表面形貌观察,考察了苜蓿草粉对4种金属材料的磨料磨损.结果表明,4种材料的体积磨损量由小到大依次为3Cr13、9SiCr、45号钢、HT200,试样的磨损表面发生了物理和化学变化."软磨料磨损"中伴有"硬磨料磨损"的特征,显微切削和应变疲劳剥落为其主要磨损形式.

  3. Research of process of abrasive wear of pin surfaces in the conditions of shock loading of work of beat of grinding down

    Попов, Сергій Миколайович

    2013-01-01

    The article formulated the basic requirements for the chemical composition, structure-phase state and physical-mechanical properties of the material for parts, operating under conditions of wear by the half-fastened abrasive with local shock loads and jamming of particles. The aim of this work was to study and analyze the nature of the destruction of working objects – beaters of dispergators, and to develop recommendations as to the improvement of their operation life by optimization of techn...

  4. PLASMA NITRIDING FOR IMPROVING WEAR RESISTANCE OF CABLE BOLT

    SHAOQING NIU; SHUANGSUO YANG; YI LI

    2013-01-01

    In order to improve the wear resistance of the cable bolt and increase its life-time during operation, plasma nitriding was employed to obtain a protective nitriding layer on its surface. The microstructure, phase constitution, microhardness and wear resistance of the nitriding layer were investigated. It was shown that continuous and dense nitriding layers were formed on the surface of the samples. The microhardness of the nitrided sample was enhanced by the formation of nitriding layer, whi...

  5. Effect of Annealing Temperature on Hardness and Wear Resistance of Electroless Ni-B-Mo Coatings

    Serin, Ihsan Gökhan; Göksenli, Ali

    2015-06-01

    Formation of nickel-boron-molybdenum (Ni-B-Mo) coating on steel by electroless plating and evaluation of their morphology, hardness and tribological properties post heat treatment at different temperatures for 1 h is investigated. The 25 μm thick coating is uniform and adhesion between the substrate and coating is good. Ni-B-Mo coating was amorphous-like structure in their as-plated condition and by 400°C heat-treated coating, nickel fully crystallized and nickel borides and molybdenum carbide were formed. All coatings exhibited higher hardness than the substrate steel. Hardness values of all coatings up to 400°C did not change distinctively but decreased partly beyond 400°C. Friction coefficient reached lowest value post heat treatment at 300°C but later increased with increasing tempering temperature. Wear resistance was lowest in as-plated coating; however it reached the highest value at 300°C. Worn surface of the coatings showed the abrasive wear as the dominant wear mechanism. An additional adhesive wear mechanism was detected in coating tempered at 550°C. Moreover, our results confirmed that the molybdenum addition improved the thermal stability of the resulting coating. Therefore, Ni-B-Mo coating has potential for application in precision mould, optical parts mould or bipolar plates, where thermal stability is essential.

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

    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

  7. A level set methodology for predicting the effect of mask wear on surface evolution of features in abrasive jet micro-machining

    A previous implementation of narrow-band level set methodology developed by the authors was extended to allow for the modelling of mask erosive wear in abrasive jet micro-machining (AJM). The model permits the prediction of the surface evolution of both the mask and the target simultaneously, by representing them as a hybrid and continuous mask–target surface. The model also accounts for the change in abrasive mass flux incident to both the target surface and, for the first time, the eroding mask edge, that is brought about by the presence of the mask edge itself. The predictions of the channel surface and eroded mask profiles were compared with measurements on channels machined in both glass and poly-methyl-methacrylate (PMMA) targets at both normal and oblique incidence, using tempered steel and elastomeric masks. A much better agreement between the predicted and measured profiles was found when mask wear was taken into account. Mask wear generally resulted in wider and deeper glass target profiles and wider PMMA target profiles, respectively, when compared to cases where no mask wear was present. This work has important implications for the AJM of complex MEMS and microfluidic devices that require longer machining times. (paper)

  8. Wear resistance of micro-arc oxidation coatings on biomedical NiTi alloy

    Liu, F., E-mail: ryuufuku@hotmail.co [School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001 (China); Xu, J.L. [School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001 (China); Yu, D.Z. [Stomatological Medicine Center, Harbin Institute of Technology, Harbin 150001 (China); Wang, F.P. [Department of Applied Chemistry, Harbin Institute of Technology, Harbin 150001 (China); Zhao, L.C. [School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001 (China)

    2009-11-13

    Protective coatings were successfully formed on biomedical NiTi alloy by micro-arc oxidation (MAO) using pulsed bipolar power supply. The coating surface exhibits a typical MAO porous structure, and the coating mainly consists of O, Al, Ti and Ni, with the atomic concentration of 65.11%, 27.77%, 2.20% and 2.8%, respectively. The thickness of MAO coating is about 24.0 {mu}m when the duration time of the MAO treatment was 90 min at 400 V constant voltage treatment. XRD analysis showed that micro-arc oxidation coating is composed of {gamma}-Al{sub 2}O{sub 3} and {alpha}-Al{sub 2}O{sub 3}. The wear resistance of the coatings was investigated by ball-on-disk friction test. The microhardness of the NiTi alloy is greatly enhanced due to the formation of Al{sub 2}O{sub 3} coating after micro-arc oxidation treatment. The friction coefficient of the coated NiTi is stable at 0.85 and the wear resistance is increased by 9 times compared with uncoated NiTi. The wear mechanism transforms from abrasive-dominant for the uncoated sample to adhesive-dominant for the coated sample.

  9. Comparison of the structure and wear resistance of Al2O3 -13 wt%TiO2 coatings made by GSP and WSP plasma process with two different powders

    Ageorges, H.; Ctibor, Pavel

    2008-01-01

    Roč. 202, č. 18 (2008), s. 4362-4368. ISSN 0257-8972 R&D Projects: GA AV ČR 1QS200430560 Institutional research plan: CEZ:AV0Z20430508 Keywords : Alumina * titania * plasma spraying * wear resistance * slurry abrasion Subject RIV: JH - Ceramics, Fire-Resistant Materials and Glass Impact factor: 1.860, year: 2008

  10. Wear resistance of PM composite materials reinforced with the Ti(C,N ceramic particles

    A. Włodarczyk-Fligier

    2008-10-01

    Full Text Available Purpose: of the project was evaluation of the effect of heat treatment and of the reinforcing Ti(C,N particles in the EN AW-AlCu4Mg1(A aluminium alloy on the mechanical properties, wear resistance.Design/methodology/approach: some of the composite materials were hyperquenched for 0.5 h at the temperature of 495ºC with the subsequent cooling in water, and were quench aged next for 6 h at 200°C. Hardness tests were made on HAUSER hardness tester with the Vickers method at 10 N. Abrasion resistance wear tests were carried out with the constant number of cycles of 5000 (120 m at various loads: 4, 5, 6, 7, and 8 N. Test pieces were rinsed in the ultrasonic washer to clean them and next were weighed on the analytical balance with the accuracy of 0.0001 g to check the mass loss.Findings: Besides visible improvement of mechanical properties and wear resistance there were also observed the influence of heat treatment.Practical implications: Tested composite materials can be applied among others in automotive industry but it requires additional researches.Originality/value: It was demonstrated that the mechanical properties, as well as the wear resistance of the investigated composite materials with the EN AW-Al Cu4Mg1(A alloy matrix may be formed by the dispersion hardening with the Ti(C,N particles in various portions and by the precipitation hardening of the matrix.

  11. Influence of titanium content on wear resistance of electrolytic low-titanium eutectic Al-Si piston alloys

    Wang Jiefang; Xie Jingpei; Yan Shuqing; Liu Zhongxia; Weng Yonggang; Wang Mingxing; Song Tianfu

    2008-01-01

    The wear resistance of six kinds of the electrolytic low-titanium eutectic Al-Si piston alloys with various Ti content ranging from 0.00wt.% to 0.21wt.% has been studied. A new method of adding Ti is adopted in the electrolytic low-titanium aluminum alloy ingots. The electrolytic low-titanium eutectic AI-Si piston alloys are produced by remelting the electrolytic low-titanium aluminum alloy, crystal silicon, pure magnesium, Al-50%Cu and Al-10%Mn master alloy. The wear experiments are conducted using MM200 wear testing machine under lubricating condition. The results indicate that the better wear resistance and the less weight loss are achieved in the study for the eutectic AI-Si piston alloys with 0.08wt.%-0.12wt.% Ti content. The highest ultimate tensile strength of 135.94 MPa at 300℃ and HV141.70 hardness of the alloys are obtained at 0.12wt.% and 0.08wt.% Ti content, respectively. The wear mechanism of the eutectic Al-Si piston alloys under lubricating condition is abrasive wear.

  12. Influence of titanium content on wear resistance of electrolytic low-titanium eutectic Al-Si piston alloys

    Yan Shuqing

    2008-11-01

    Full Text Available The wear resistance of six kinds of the electrolytic low-titanium eutectic Al-Si piston alloys with various Ti content ranging from 0.00wt.% to 0.21wt.% has been studied. A new method of adding Ti is adopted in the electrolytic low-titanium aluminum alloy ingots. The electrolytic low-titanium eutectic Al-Si piston alloys are produced by remelting the electrolytic low-titanium aluminum alloy, crystal silicon, pure magnesium, Al-50%Cu and Al-10%Mn master alloy. The wear experiments are conducted using MM200 wear testing machine under lubricating condition. The results indicate that the better wear resistance and the less weight loss are achieved in the study for the eutectic Al-Si piston alloys with 0.08wt.%–0.12wt.% Ti content. The highest ultimate tensile strength of 135.94 MPa at 300℃ and HV141.70 hardness of the alloys are obtained at 0.12wt.% and 0.08wt.% Ti content, respectively. The wear mechanism of the eutectic Al-Si piston alloys under lubricating condition is abrasive wear.

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

    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. Influence of mechanical abrasion of carbon adsorbents on aerodynamic resistance of filters of system of ventilation of NPS

    Influence of mechanical abrasion of granules on aerodynamic resistance of different carbon adsorbents at conditions similar to work of filters AU-1500 is studied. The change of fractional composition of the probed adsorbents by abrasion is determined. The obtained experimental data allow making conclusion about practicability using mixture of adsorbent Norit with different fractional composition for renewal of adsorbers of ventilation system of NPS.

  15. ABOUT ABRASION RESISTANCE OF FABRICS WITH STRATEGIC DESTINATION PART I

    Adina Bucevschi; Alexandru Popa; Monica Pustianu; Erzsebet Airinei; Ionel Barbu

    2011-01-01

    This paper is part of a research agreement between "Aurel Vlaicu" University and The NationalResearch - Development Institute for Textile and Leather, Bucharest, about the relationship of interdependencebetween the yarns' characteristics and fabric's characteristics for the installation of ventilation and heating pipesof the military helicopter[5]. Fabrics for strategic areas must have certain characteristics such resistance at hightemperatures, breaking and tearing strength, shock resistance...

  16. Porous alumina based ordered nanocomposite coating for wear resistance

    Yadav, Arti; Muthukumar, M.; Bobji, M. S.

    2016-08-01

    Uniformly dispersed nanocomposite coating of aligned metallic nanowires in a matrix of amorphous alumina is fabricated by pulsed electrodeposition of copper into the pores of porous anodic alumina. Uniform deposition is obtained by controlling the geometry of the dendritic structure at the bottom of pores through stepwise voltage reduction followed by mild etching. The tribological behaviour of this nanocomposite coating is evaluated using a ball on flat reciprocating tribometer under the dry contact conditions. The nanocomposite coating has higher wear resistance compared to corresponding porous alumina coating. Wear resistant nanocomposite coating has wide applications especially in protecting the internal surfaces of aluminium internal combustion engines.

  17. Abrasive Performance of Chromium Carbide Reinforced Ni3Al Matrix Composite Cladding

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

    2009-01-01

    The Microstructure and room temperature abrasive wear resistance of chromium carbide reinforced NiM3Al matrix composite cladding at different depth on nickel base alloy were investigated. The results showed that there is a great difference in microstructure and wear resistance of the Ni3 Al matrix composite at different depth. Three kinds of tests, designed for different load and abrasive size, were used to understand the wear behaviour of this material. Under all three wear conditions, the abrasion resistance of the composite cladding at the depth of 6 mm, namely NC-M2, was much higher than that of the composite cladding at the depth of 2 mm, namely NC-M1. In addition, the wear-resistant advantage of NC-M2 was more obvious when the size of the abrasive was small. The relative wear resistance of NC-M2 increased from 1.63 times to 2.05 times when the size of the abrasive decreased from 180 μm to 50μm. The mierostructure of the composite cladding showed that the size of chromium carbide particles, which was mainly influenced by cooling rate of melting pool, was a function of distance from the interface between the coating and substrate varied gradually. The chromium carbide particles near the interface were finer than that far from inter-face, which was the main reason for the different wear resistance of the composite cladding at different depth.

  18. Wear resistance of reactive plasma sprayed and laser remelted TiB2-TiC0.3N0.7 based composite coatings against medium carbon steel

    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.

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

    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

  20. The role of fluoride and casein phosphopeptide/amorphous calcium phosphate in the prevention of erosive/abrasive wear in an in vitro model using hydrochloric acid

    Wegehaupt, F J; Attin, T.

    2010-01-01

    OBJECTIVE: To investigate the effect of various fluoride compounds and casein phosphopeptide/amorphous calcium phosphate (CPP-ACP) on the reduction of erosive/abrasive tooth wear. METHODS: Forty enamel samples were prepared from bovine lower incisors, stratified and allocated to 4 groups (1-4). Samples in group 1 remained untreated and served as negative controls. The test samples were treated for 2 min/day as follows: group 2 amine/sodium fluoride gel (pH 4.8; 12,500 ppm), group 3 sodium flu...

  1. Characterization of ion-beam-induced carbon deposition on WC-Co hard metal by microhardness, scratch and abrasive wear tests

    Diamond-like ion-beam-deposited carbon (i-C) layers were obtained on WC-Co cemented carbide using a mass-separated 12C beam at an energy of 500 eV and a deposition rate of 3 A s-1. The mechanical properties of these layers were probed using microhardness and scratch tests and abrasive wear measurements. All these tests revealed that the depositions possess an extremely high hardness and good adhesion to the substrate. In particular, a hardness of 75 GPa was obtained, which is considerably higher than that found on i-C films involving hydrogen. (orig.)

  2. Mechanical and Abrasion Resistance of Recycled Aggregates Concrete in Relation to the Cement Content

    Athanas KONIN; Mangoua David Kouadio

    2011-01-01

    This paper presents the results of an experimental investigation carried out to study the effects of cement content on the mechanical and abrasion resistance of recycled aggregates concrete. Four series of mixtures with cement content 300, 350, 400 and 450 kg/m3 were formulated. In each series, natural coarse aggregate were totally replaced with recycled aggregate that allows obtaining two types of concrete: natural aggregates concrete and recycled aggregates concrete. Compressive strength, s...

  3. Standard Test Method for Abrasion Resistance of Transparent Plastics and Coatings Using the Oscillating Sand Method

    American Society for Testing and Materials. Philadelphia

    2006-01-01

    1.1 This test method determines the resistance of transparent plastics and transparent coatings utilized in windows or viewing ports, to surface abrasion using oscillating sand. 1.2 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.

  4. ABOUT ABRASION RESISTANCE OF FABRICS WITH STRATEGIC DESTINATION PART II

    Adina Bucevschi; Alexandru Popa; Monica Pustianu; Erzsebet Airinei; Ionel Barbu

    2011-01-01

    This paper is part of a research agreement between "Aurel Vlaicu" University and The National Research - Development Institute for Textile and Leather, Bucharest, about the relationship of interdependence between the yarns' characteristics and fabric's characteristics for the installation of ventilation and heating pipesof the military helicopter[5]. Fabrics for strategic areas must have certain characteristics such resistance at high temperatures, breaking and tearing strength, shock resista...

  5. Relations of abrasion resistance and hardness of 16Cr-3C white irons with retained austenite content

    Zhiping Sun; Rulin Zuo; Cong Li; Baoluo Shen; Shengji Gao; Sijiu Huang

    2004-01-01

    The relationship between the retained austenite content of the matrix in 16Cr-3C white irons and the abrasion resistance was investigated. The results show that: (1) the abrasion resistance can be improved by sub-critical heat treatment, which could be attributed to the decrease of the retained austenite content; (2) both the abrasion resistance and hardness can be improved by controlling the retained austenite content below 20%-30% and arrive at the maximum when the retained austenite content is reduced to about 10%; (3) the abrasion resistance decreases abruptly once the retained austenite content is lower than 10%, which stems from both the in situ transformation of (Fe, Cr)23C6 to M3C carbides and the formation of pearlitic matrix.

  6. Development and Testing of Abrasion Resistant Hard Coats For Polymer Film Reflectors: Preprint

    Jorgensen, G.; Gee, R.; DiGrazia, M.

    2010-10-01

    Reflective polymer film technology can significantly reduce the cost of solar reflectors and installed Concentrated Solar Power (CSP) plants by both reduced material cost and lower weight. One challenge of polymer reflectors in the CSP environment pertains to contact cleaning methods typically used with glass mirrors. Such contact cleaning methods can scratch the surface of polymer reflectors and thereby reduce specular reflectance. ReflecTech, Inc. (a subsidiary of SkyFuel, Inc.) and the National Renewable Energy Laboratory (NREL) initiated a cooperative research and development agreement (CRADA) to devise and develop an abrasion resistant coating (ARC) suitable for deposition onto polymer based mirror film. A number of candidate ARC products were identified as candidate formulations. Industrial collaborators prepared samples having their ARCs deposited onto ReflecTech Mirror Film pre-laminated to aluminum sheet substrates. Samples were provided for evaluation and subjected to baseline (unweathered) and accelerated exposure conditions and subsequently characterized for abrasion resistance and adhesion. An advanced ARC product has been identified that exhibits outstanding initial abrasion resistance and adhesion to ReflecTech Mirror Film. These properties were also retained after exposure to the various accelerated stress conditions. This material has been successfully manufactured as a 1.5 m wide roll-to-roll construction in a production environment.

  7. Aligned composite structures for mitigation of impact damage and resistance to wear in dynamic environments

    Mulligan, Anthony C.; Rigali, Mark J.; Sutaria, Manish P.; Popovich, Dragan; Halloran, Joseph P.; Fulcher, Michael L.; Cook, Randy C.

    2005-12-13

    Fibrous monolith composites having architectures that provide increased flaw insensitivity, improved hardness, wear resistance and damage tolerance and methods of manufacture thereof are provided for use in dynamic environments to mitigate impact damage and increase wear resistance.

  8. Aligned composite structures for mitigation of impact damage and resistance to wear in dynamic environments

    Mulligan, Anthony C. (Tucson, AZ); Rigali, Mark J. (Tucson, AZ); Sutaria, Manish P. (Malden, MA); Popovich, Dragan (Redmond, WA); Halloran, Joseph P. (Tucson, AZ); Fulcher, Michael L. (Tucson, AZ); Cook, Randy C. (Tucson, AZ)

    2009-04-14

    Fibrous monolith composites having architectures that provide increased flaw insensitivity, improved hardness, wear resistance and damage tolerance and methods of manufacture thereof are provided for use in dynamic environments to mitigate impact damage and increase wear resistance.

  9. Aligned composite structures for mitigation of impact damage and resistance to wear in dynamic environments

    Rigali, Mark J.; Sutaria, Manish P.; Mulligan, Anthony C.; Popovich, Dragan

    2004-03-23

    Fibrous monolith composites having architectures that provide increased flaw insensitivity, improved hardness, wear resistance and damage tolerance and methods of manufacture thereof are provided for use in dynamic environments to mitigate impact damage and increase wear resistance.

  10. Assessment of wear resistance of tin and tin alloy coatings

    Lam, Wayne Pui-Wing

    2007-01-01

    This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University. Tin alloy coatings have traditionally been used as corrosion resistant bamens due to their inert nature and comprehensive coverage, and have seldom been considered in physically demanding applications, such as wear resistant coatings owing to misconceptions associated with the soft nature of tin metal. The alloying of tin with copper has already been shown to significantly increase its mechan...

  11. Wear properties of metal ion implanted 4140 steel

    AISI type 4140 (high tensile) steel has been implanted with tungsten and titanium using a metal vapour vacuum arc ion source. Doses in the range (1-5)x1016ionscm-2 were implanted to a depth of approximately 30nm. The relative wear resistance between non-implanted and implanted specimens has been estimated using pin-on-disc and abrasive wear tests. Implantation of titanium decreased the area of wear tracks by a factor of 5 over unimplanted steel. In some cases the steel was also hardened by a liquid carburization treatment before implantation. Abrasion tests revealed a further improvement in wear resistance on this material following ion irradiation. ((orig.))

  12. Research on the Friction and Wear Behavior at Elevated Temperature of Plasma-Sprayed Nanostructured WC-Co Coatings

    Chen, Hui; Gou, Guoqing; Tu, Mingjing; Liu, Yan

    2010-02-01

    Nanostructured and ultra-fine WC-Co coatings were prepared by plasma spray. The friction and wear behavior at elevated temperature and failure mechanism were investigated. The results indicated that the sliding wear resistance of nanostructured coating is better than that of ultra-fine coating at high temperature. The wear mechanism is different between ultra-fine coating and nanostructured coating. Brittle fracture and adhesive wear dominate in ultra-fine coating followed with abrasive wear. Toughness fracture and abrasive wear dominate in nanostructured coating followed with adhesive wear.

  13. Influence of Plasma Intensity on Wear and Erosion Resistance of Conventional and Nanometric WC-Co Coatings Deposited by APS

    Bonache, V.; Salvador, M. D.; García, J. C.; Sánchez, E.; Bannier, E.

    2011-03-01

    The effects of plasma intensity and powder particle size on wear and erosion resistance have been evaluated for WC-12 wt.%Co coatings deposited by Air Plasma Spraying. Coatings were deposited from micrometric and nanostructured powders. SEM and XRD characterization showed the presence of WC, W2C, W, and an amorphous Co-rich matrix. The performance of the different coatings was compared in sliding wear tests (ball-on-disk), under dry friction conditions. Wear debris and tracks were analyzed by SEM. The debris generated during the test was found to have a great influence on the sliding properties. Wear follows a "three-body abrasive mechanism" and is dominated by coating spallation because of sub-surface cracking. In order to evaluate erosion behavior, solid particle erosion tests were conducted. Eroded coatings were analyzed by SEM, and erosion mainly occurs by a "cracking and chipping mechanism." The study shows that wear and erosion behavior is strongly affected by plasma arc intensity.

  14. WC-Co and Cr3C2-NiCr Coatings in Low- and High-Stress Abrasive Conditions

    Kašparová, Michaela; Zahálka, František; Houdková, Šárka

    2011-03-01

    The article deals with the evaluation of abrasive wear resistance and adhesive strength of thermally sprayed coatings. The main attention was paid to differences between low- and high-stress abrasive conditions of the measuring. Conclusions include the evaluation of specific properties of the WC-Co and the Cr3C2-NiCr High Velocity Oxygen Fuel coatings and the evaluation of the changes in the behavior of the abrasive media. Mainly, the relationship between the low- and high-stress abrasion conditions and the wear mechanism in the tested materials was described. For the wear test, the abrasive media of Al2O3 and SiO2 sands were chosen. During wear tests, the volume loss of the tested materials and the surface roughness of the wear tracks were measured. The wear tracks on the tested materials and abrasive sands' morphologies were observed using Scanning Electron Microscopy. It was found that high-stress abrasive conditions change the coatings' behavior very significantly, particularly that of the Cr3C2-NiCr coating. Adhesive-cohesive properties of the coatings and relationships among individual structure particles were evaluated using tensile testing. It was found that the weak bond strength among the individual splats, structure particles, and phases plays a role in the poor wear resistance of the coatings.

  15. Microstructure and abrasive wear behavior of some Fe-Cr-C alloys; Microestrutura e resistencia ao desgaste abrasivo de algumas ligas de sistema Fe-Cr-C

    Kliauga, Andrea M.; Padilha, Angelo F. [Sao Paulo Univ., SP (Brazil). Escola Politecnica; Rotondaro, Roberto G. [Fabrica de Acos Paulista S.A., SP (Brazil)

    1992-12-31

    In this work, three Fe-Cr-C alloys were investigated. By using different complementary microstructure methods, the amount, distribution, morphology, structure and composition of different phases of these specimens were determined, their hardness and impact resistance were also measured. The results were elucidated and discussed, and a correlation between wear behaviour, wear micro mechanism, microstructure, chemical composition and heat treatment was proposed. (author). 16 refs., 6 figs., 4 tabs.

  16. Wear resistance of ion-implanted metallic materials

    The present work is devoted to the study of the effect of ion implantation on the wear resistance of materials. Steel 3 and copper cylinder specimens were irradiated with 40 keV carbon, zirconium, titanium, niobium, lead, molybdenum and chromium continuous ion beams and a 200 keV pulsed carbon ion beam with fluences of 1017 ions cm-2 and 1013 ions cm-2 respectively. The loss of mass during friction of the butt surface against the rotating disk was taken as the measure of wear. For materials irradiated with continuous ion beams the depth of the layer with increased wear resistance was about 80-100μm, which is two orders of magnitude greater than the depth of penetration of the implanted ions. In the case of ion implantation with a pulsed ion beam for a short period of time, a great amount of heat was generated. The speed of its dissipation into the bulk of a specimen depends on the thermal conductivity of the material, and hardening of the wear-surface layer starts with cooling at some speed. (orig.)

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

    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.

  18. Effect of filler type on 3-body abrasion of dental composite

    Yasini E.; Ataei M; Amini M

    2005-01-01

    Statement of Problem: The relatively poor wear resistance of dental composite in stress bearing posterior situations has restricted wider clinical application of this restorative material. Purpose: The aim of this study was to evaluate the three body abrasive wear of a dental composite based on a new filler (leucite: KAl Si2O6) and to compare it with the wear resistance of a composite based on commonly used Aluminium – Barium Silicate filler. Materials and Methods: This research was an interv...

  19. An Research on Abrasion Resistance of Muzzle Shunt Rail Gun Rail Boronized with Self-protecting B4C Paste

    HUJin-suo; CHENGShu-kang; ZHENGZhen-zhong; MAYuan; LIZhi-yuan

    2004-01-01

    Based on large numbers of experiments, together with some theoretic support such as equations related to the experiment, thermodynamic principles and so on, one useful and reasonable self-protecting boron formulation is got to reintorce the muzzle shunt rail gun rail. The preliminary friction and abrasion test results show that the formulation is acceptable and the abrasion resistance of the steel rail enhances to some extent after the surface reinforcement.

  20. An Research on Abrasion Resistance of Muzzle Shunt Rail Gun Rail Boronized with Self-protecting B4C Paste

    HU Jin-suo; CHENG Shu-kang; ZHENG Zhen-zhong; MA Yuan; LI Zhi-yuan

    2004-01-01

    Based on large numbers of experiments, together with some theoretic support such as equations related to the experiment, thermodynamic principles and so on, one useful and reasonable self-protecting boron formulation is got to reinforce the muzzle shunt rail gun rail. The preliminary friction and abrasion test results show that the formulation is acceptable and the abrasion resistance of the steel rail enhances to some extent after the surface reinforcement.

  1. Influence of Plasma Transferred Arc Process Parameters on Structure and Mechanical Properties of Wear Resistive NiCrBSi-WC/Co Coatings

    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

  2. Comparação dos valores de desgaste abrasivo e de microdureza de 13 resinas compostas usadas em odontologia através do método do disco retificado Comparing abrasive wear and microhardness of 13 dental composite resins

    Eduardo C. Bianchi

    2007-06-01

    Full Text Available Atualmente tem-se buscado simplificar a tarefa de caracterização da vida útil de restaurações dentárias realizadas por resinas compostas através de métodos laboratoriais, que são mais rápidos e não sofrem influência de variáveis pessoais inerentes às análises clínicas. Com este propósito, este trabalho apresenta uma nova metodologia de ensaio laboratorial para a avaliação do desgaste abrasivo de resinas compostas através do método do disco retificado. Realizaram-se ensaios de resistência ao desgaste abrasivo com 13 resinas compostas odontológicas e buscou-se analisar o comportamento da resistência ao desgaste abrasivo em relação à microdureza dessas resinas. Com a análise dos resultados concluiu-se que o método de discos retificados é eficiente para a obtenção da resistência ao desgaste abrasivo. Notou-se também ser extremamente pequeno o nível de correlação entre microdureza e desgaste abrasivo o que indica que cada resina composta tem características próprias e que o desgaste é dependente também de outros fatores.It is now commonplace to search for methods to assess the useful lifetime of dental restorations made of resins, which are quicker and less subjective than clinical analyses. With this purpose, this work presents a new methodology based on the grinding disk for evaluating the abrasive wear of composed resins. Resistance tests to the abrasive wear were made with 13 composed resins used as dental material, and a comparison was done with the hardness of those resins. From the data analysis, we concluded that the method of rectified disks is efficient for obtaining the resistance to the abrasive wear. Furthermore, the correlation between hardness and abrasive wear was very small, which indicates that each composed resin has its own characteristics and that the wear also depends on other factors.

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

    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.

  4. Influence of Utilization of High-Volumes of Class F Fly Ash on the Abrasion Resistance of Concrete

    William PRINCE

    2007-01-01

    Full Text Available Utilization of large volumes of fly ash in various concrete applications is a becoming a more general practice in an efforts towards using large quantities of fly ash. Around the world, Class C or Class F or both as available have been used in high volumes in cement-based materials. In India, majority of fly generated is of Class F type as per ASTM C 618. Yearly fly ash generation in India is approximately 95 million tonnes. Out of which around 15-20% is utilized in cement production and cement/concrete related activities. In order to increase its percentage utilization, an investigation was carried out to use it in concrete.In this paper, abrasion resistance of high volume fly ash (HVFA concretes made with 35, 45, 55, and 65% of cement replacement was evaluated in terms of its relation with compressive strength. Comparison was made between ordinary Portland cement and fly ash concrete. Test results indicated that abrasion resistance of concrete having cement replacement up to 35 percent was comparable to the normal concrete mix with out fly ash. Beyond 35% cement replacement, fly ash concretes exhibited slightly lower resistance to abrasion relative to non-fly ash concretes. Test results further indicated that abrasion resistance of concrete is closely related with compressive strength, and had a very good correlation between abrasion resistance and compressive strength (R2 value between 0.9018 and 0.9859 depending upon age.

  5. Hydrothermal treatment for TiN as abrasion resistant dental implant coating and its fibroblast response

    Dental implant made of pure titanium (Ti) is prone to scratch and abrasion during routine oral hygiene procedures. This results an increase in surface roughness and therefore, facilitates the adhesion of bacteria. In severe cases, this could lead to peri-implantitis. To overcome this problem, surface modification of Ti is necessary to improve its abrasion resistance. Besides, a strong implant–gingiva interface should also be guaranteed to prevent the adhesion of bacteria. In this study, titanium nitride (TiN) coating was first prepared with gas nitriding to increase surface hardness of pure the substrate. Then, the TiN was hydrothermally treated in CaCl2 solution in order to improve its soft tissue biocompatibility. The effect of hydrothermal treatment temperature on surface properties of TiN was investigated and its biocompatibility was assessed in vitro using NIH3T3 fibroblast cell. It was determined that 120 °C was the critical temperature for the hydrothermal treatment condition. Treatment below 120 °C could incorporate Ca into TiN surface, oxidize TiN surface partially and then improve the wettability while preserving its morphology and hardness. Fibroblast cell attachment and proliferation were improved and cell spreading was enhanced on hydrothermally treated specimens compared with untreated ones. Improved wettability, Ca incorporation and negative surface due to interstitial N were believed to be the main reasons. Hydrothermal treatment is expected to make TiN a promising dental implant coating with excellent abrasion resistance and good soft tissue affinity. - Highlights: • Ca was incorporated into TiN surface while not sacrificing its hardness. • Interstitial N due to oxidation promoted Ca adsorption and cell adhesion. • Hydrothermal treatment makes TiN a promising coating for dental implant

  6. Hydrothermal treatment for TiN as abrasion resistant dental implant coating and its fibroblast response

    Shi, Xingling, E-mail: shixingling1985@hotmail.com [School of Material Science and Engineering, Jiangsu University of Science and Technology, Zhenjiang 212003 (China); Department of Biomaterials, Faculty of Dental Science, Kyushu University, Fukuoka 812-8582 (Japan); Jiangsu Provincial Key Laboratory for Interventional Medical Devices, Huaiyin Institute of Technology, Huaian 223003 (China); Xu, Lingli [School of Material Science and Engineering, Jiangsu University of Science and Technology, Zhenjiang 212003 (China); Munar, Melvin L.; Ishikawa, Kunio [Department of Biomaterials, Faculty of Dental Science, Kyushu University, Fukuoka 812-8582 (Japan)

    2015-04-01

    Dental implant made of pure titanium (Ti) is prone to scratch and abrasion during routine oral hygiene procedures. This results an increase in surface roughness and therefore, facilitates the adhesion of bacteria. In severe cases, this could lead to peri-implantitis. To overcome this problem, surface modification of Ti is necessary to improve its abrasion resistance. Besides, a strong implant–gingiva interface should also be guaranteed to prevent the adhesion of bacteria. In this study, titanium nitride (TiN) coating was first prepared with gas nitriding to increase surface hardness of pure the substrate. Then, the TiN was hydrothermally treated in CaCl{sub 2} solution in order to improve its soft tissue biocompatibility. The effect of hydrothermal treatment temperature on surface properties of TiN was investigated and its biocompatibility was assessed in vitro using NIH3T3 fibroblast cell. It was determined that 120 °C was the critical temperature for the hydrothermal treatment condition. Treatment below 120 °C could incorporate Ca into TiN surface, oxidize TiN surface partially and then improve the wettability while preserving its morphology and hardness. Fibroblast cell attachment and proliferation were improved and cell spreading was enhanced on hydrothermally treated specimens compared with untreated ones. Improved wettability, Ca incorporation and negative surface due to interstitial N were believed to be the main reasons. Hydrothermal treatment is expected to make TiN a promising dental implant coating with excellent abrasion resistance and good soft tissue affinity. - Highlights: • Ca was incorporated into TiN surface while not sacrificing its hardness. • Interstitial N due to oxidation promoted Ca adsorption and cell adhesion. • Hydrothermal treatment makes TiN a promising coating for dental implant.

  7. Hydrothermal treatment for TiN as abrasion resistant dental implant coating and its fibroblast response.

    Shi, Xingling; Xu, Lingli; Munar, Melvin L; Ishikawa, Kunio

    2015-04-01

    Dental implant made of pure titanium (Ti) is prone to scratch and abrasion during routine oral hygiene procedures. This results an increase in surface roughness and therefore, facilitates the adhesion of bacteria. In severe cases, this could lead to peri-implantitis. To overcome this problem, surface modification of Ti is necessary to improve its abrasion resistance. Besides, a strong implant-gingiva interface should also be guaranteed to prevent the adhesion of bacteria. In this study, titanium nitride (TiN) coating was first prepared with gas nitriding to increase surface hardness of pure the substrate. Then, the TiN was hydrothermally treated in CaCl2 solution in order to improve its soft tissue biocompatibility. The effect of hydrothermal treatment temperature on surface properties of TiN was investigated and its biocompatibility was assessed in vitro using NIH3T3 fibroblast cell. It was determined that 120°C was the critical temperature for the hydrothermal treatment condition. Treatment below 120°C could incorporate Ca into TiN surface, oxidize TiN surface partially and then improve the wettability while preserving its morphology and hardness. Fibroblast cell attachment and proliferation were improved and cell spreading was enhanced on hydrothermally treated specimens compared with untreated ones. Improved wettability, Ca incorporation and negative surface due to interstitial N were believed to be the main reasons. Hydrothermal treatment is expected to make TiN a promising dental implant coating with excellent abrasion resistance and good soft tissue affinity. PMID:25686920

  8. Assessment of mechanical and three-body abrasive wear peculiarity of TiO$_2$- and ZnO-filled bi-directional E-glass fibre-based polyester composites

    AKANT KUMAR SINGH; SIDDHARTHA; DEEPAK

    2016-08-01

    This paper is about the development of bi-directional E-glass fibre-based polyester composites filled with zinc oxide (ZnO) and titanium dioxide (TiO$_2$) fillers, respectively. The mechanical characterization of these composites is performed. The three-body abrasive wear characteristic of fabricated composites has been assessed under different operating conditions. For this, the three-body abrasion test is done on dry abrasion test rig (TR-50)and analysed using Taguchi’s experimental design scheme and analysis of variance. The results obtained from these experiments are also validated against existing microscopic models of Ratner–Lancaster and Wang. A good linear relationship is obtained between specific wear rate and the reciprocal of ultimate strength and strain at tensile fracture of these composites. It indicates that the experimentally obtained results are in good agreement with theseexisting models. It is found that the tensile strength decreases with filler loading, while hardness, flexural strength, inter-laminar shear strength and impact strength are increased. TiO$_2$-filled composites were observed to performbetter than ZnO-filled composites under abrasive wear situations. The wear mechanism is studied in correlation with the SEM micrograph of the worn-out surface of composites. Performance optimization of composites is doneby using VIKOR method.

  9. Niobium additions in white cast irons alloyed with chromium, for applications at high load abrasive wear; Niobio em ferros fundidos brancos ligados ao cromo, para aplicacoes em desgaste abrasivo

    Guesser, Wilson Luiz; Costa, Pedro Henrique Carpinetti; Pieske, Adolar [Fundicao Tupy Ltda. (Brazil)

    1989-12-31

    The influence of niobium additions to chromium white cast irons, submitted to high load abrasive wear, is discussed. In this case, where simultaneous mechanisms of cutting and crack propagation are involved, the recommended niobium contents showed to be related to the intensity of each mechanism action. (author) 22 refs., 17 figs., 2 tabs.

  10. Checking Out Cuts, Scratches, and Abrasions

    ... Skating Crushes What's a Booger? Checking Out Cuts, Scratches, and Abrasions KidsHealth > For Kids > Checking Out Cuts, ... weren't wearing kneepads. How Do Cuts and Scratches Heal? After getting a cut, scratch, or abrasion, ...

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

    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.

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

    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.

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

    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.

  14. Laser cladding of wear resistant metal matrix composite coatings

    A number of coatings with wear-resistant properties as well as with a low friction coefficient are produced by laser cladding. The structure of these coatings is determined by required performance and realized as metal matrix composite (MMC), where solid lubricant serves as a ductile matrix (e.g. CuSn), reinforced by appropriate ceramic phase (e.g. WC/Co). One of the engineered coating with functionally graded material (FGM) structure has a dry friction coefficient 0.12. Coatings were produced by coaxial injection of powder blend into the zone of laser beam action. Metallographic and tribological examinations were carried out confirming the advanced performance of engineered coatings

  15. Titanium aluminide intermetallic alloys with improved wear resistance

    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.

  16. FIBROUS MONOLITH WEAR RESISTANT COMPONENTS FOR THE MINING INDUSTRY

    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.

  17. Micro-scale abrasion behaviour of electroless Ni-P-SiC coating on aluminium alloy

    Franco, M.; Sha, Wei; Malinov, Savko

    2014-01-01

    Electroless nickel (EN) and electroless nickel composite (ENC) coatings were deposited on aluminium alloy substrate, LM24. The micro abrasion test was conducted to study the wear behaviour of the coatings with the effect of SiC concentration. Microhardness of the coatings was tested also. The wear scars were analysed using optical microscope and scanning electron microscope (SEM). The wear resistance was found to be improved in composite coating that has higher microhardness as compared to pa...

  18. Mechanical properties and wear resistance of magnesium casting alloys

    L.A. Dobrzański

    2008-11-01

    Full Text Available Purpose: In the following paper there have been the properties of the MCMgAl12Zn1, MCMgAl9Zn1, MCMgAl6Zn1, MCMgAl3Zn1magnesium cast alloy as-cast state and after a heat treatment presented.Design/methodology/approach: A casting cycle of alloys has been carried out in an induction crucible furnace using a protective salt bath Flux 12 equipped with two ceramic filters at the melting temperature of 750±10ºC, suitable for the manufactured material. The following results concern abrasive wear, mechanical properties, light and scanning microscopy.Findings: The different heat treatment kinds employed contributed to the improvement of mechanical properties of the alloy with the slight reduction of its plastic properties.Research limitations/implications: According to the alloys characteristic, the applied cooling rate and alloy additions seems to be a good compromise for mechanical properties and microstructures, nevertheless further tests should be carried out in order to examine different cooling rates and parameters of solution treatment process and aging process.Practical implications: The concrete examples of the employment of castings from magnesium alloys in the automotive industry are elements of the pedals, dashboards, elements of seats, steering wheels, wheel bands, oil sumps, elements and housings of the gearbox, framing of doors and sunroofs, and others, etc.Originality/value: Contemporary materials should possess high mechanical properties, physical and chemical, as well as technological ones, to ensure long and reliable use. The above mentioned requirements and expectations regarding the contemporary materials are met by the non-ferrous metals alloys used nowadays, including the magnesium alloys.

  19. Tantalum-based thin film coatings for wear resistant arthroprostheses.

    Balagna, C; Faga, M G; Spriano, S

    2011-10-01

    Cobalt-chromium-molybdenum alloys with high carbon content (HC-CoCrMo) are widely used as materials for arthroprosthesis, in particular in metal-on-metal (MoM) hip joints. In spite of their good wear and corrosion resistance, production of metallic wear particles and metal ion release will occur on a large time-scale. An enhancement of the metal ion level in the patient's blood and urine is often reported in clinical data. Hypersensitivity, inflammatory response and cell necrosis can occur as consequence. So implants on young patients and women on childbearing age are not so widespread. The aim of this research is the realization of a thin film coating in order to improve the biocompatibility of Co-based alloys and to reduce debris production, ion release and citotoxicity. The innovative process consists of a thermal treatment in molten salts, in order to obtain a tantalum enriched thin film coating. Tantalum is chosen because it is considered a biocompatible metal with high corrosion resistance and low ion release. Three HC-CoCrMo alloys, produced by different manufacturing processes, are tested as substrates. The coating is a thin film of TaC or it can be composed by a multilayer of two tantalum carbides and metallic tantalum, depending on the temperature of the treatment and on the carbon content of the substrate. The thin films as well the substrates are characterized from the structural, chemical and morphological point of view. Moreover mechanical behaviour of treated and untreated materials is analyzed by means of nanohardness, scratch and ball-on-disc wear tests. The coating increases the mechanical and tribological properties of HC-CoCrMo. PMID:22400292

  20. Wear resistance of Fe-Nb-Cr-W, Nb, AISI 1020 and AISI 420 coatings produced by thermal spray wire arc

    The commercial materials 140MXC (with iron, tungsten, chrome, niobium), 530AS (AISI 1015 steel) and 560AS (AISI 420 steel) on AISI 4340 steel were deposited using thermal spray with arc. The aim of work was to evaluate the best strategy abrasive wear resistance of the system coating-substrate using the following combinations: (1) homogeneous coatings and (2) coatings depositing simultaneously 140MXC + 530AS and 140MXC + 560AS. The coatings microstructure was characterized using Optical microscopy, Scanning electron microscopy and Laser con focal microscopy. The wear resistance was evaluated through dry sand rubber wheel test (DSRW). We found that the wear resistance depends on the quantity of defects and the mechanical properties like hardness. For example, the softer coatings have the biggest wear rates and the failure mode was characterized by plastic deformation caused by particles indentation, and the other hand the failure mode at the harder materials was grooving. The details and wear mechanism of the coatings produced are described in this investigation. (Author)

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

    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.

  2. Preparation and properties of Y-TZP abrasion-resistant grinding media

    In this study a wet-chemical method was used to titrate diluted ammonia at certain pH with the mixture of ZrOCL2 · 8H2O and YCl3 solutions. High-purity ultrafine zirconia powder was prepared with this sol-gel process. The properties of the powder were identified with XRD, TEM and BET techniques. Grinding media were fabricated by isostatic pressing, followed by optimized-sintering to nearly 98% theoretical density. Some mechanical properties such as microhardness, fracture toughness, and bending strength were determined and microstructures examined. Comparison was made to indicate the superior abrasion resistance against commercial alumina grinding media (balls) and the validity of utilizing of zirconia grinding media was demonstrated

  3. The role of the microfissuration of the rock matrix in the abrasion resistance of ornamental granitic rocks

    Rodríguez-Rey, Angel; Sanchez-Delgado, Nuria; Camino, Clara; Calleja, Lope; Ruiz de Argandoña, Vicente G.; Setien, Alexia

    2015-04-01

    The microcrack density and the abrasion resistance of five ornamental granites (Albero, Gris Alba, Mondariz, Rosa Porriño and Traspieles) from Galicia (NW Spain) have been quantified as part of a research aimed to interpret the cuttability of the rocks in relation to the petrophysical properties of the rock matrix. Large blocks from the quarries have been cut with an industrial saw and the microcrack density and the abrasion resistance have been measured in two surfaces: H, parallel to the cut surface; T, perpendicular both to the cut surface and the cutting direction. Both planes are perpendicular to the rift plane, as it is known in quarry works. The microcrack density has been quantified following an stereological procedure applied to polished sections imaged under scanning electron microscopy. The magnification of the images allowed the study of microcracks as narrow as 2 microns in aperture. The density has been quantified in terms of length of microcrack traces per surface unit so possible anisotropies of the microcrack network could be detected. The obtained values are in the typical range for this type of rocks although the Traspieles granite shows a higher value due to its weathering degree (H: 5.11, T: 5.37 mm/mm2). The values measured in the two surfaces (H and T) are quite similar in four of the rocks; only the Albero granite shows a marked anisotropy (H: 2.76 T: 3.53 mm/mm2). The abrasion resistance of the rocks has been measured following the european standard EN 14157:2004 using the capon method. The rocks can be classified in two groups according to their abrasion resistance. Rosa Porriño, Gris Alba and Mondariz granites are the more resistant to abrasion with values around 16-17 mm. Albero and Traspieles granites are less resistant with values higher than 19 mm. The results show a good correlation between the microcrack density and the abrasion resistance. As can be expected the rocks with high microcrack density show low abrasion resistance. The

  4. Wear resistance and fracture mechanics of WC-Co composites

    Manufacturing of WC-Co composites using the electroless precipitation method at different sintering temperatures of 1 100, 1 250, 1 350 and 1 500 C was successfully achieved. The chemical composition of the investigated materials was 90 wt.% WC with 10 wt.% Co, and 80 wt.% WC with 20 wt.% Co. The specific density, densification, and Vickers microhardness measurements were found to increase with increased sintering temperature for both the WC-Co compositions. The composites of tungsten carbide with 10 wt.% Co had a higher specific density and Vickers microhardness measurements than those for the composites of tungsten carbide with 20 wt.% Co. Composites with WC-10 wt.% Co had better wear resistance. The stress-strain and transverse rupture strength increased monotonically with the increase in sintering temperatures, agreeing with the material hardness and wear resistance behavior. Fractographical scanning electron microscopy analysis of the fracture surface demonstrated a rough characteristic conical shape failure in the direction of the maximum shear stress. A proposed mechanism for the formation of the conical fracture surface under compression testing is presented. (orig.)

  5. Wear resistance and fracture mechanics of WC-Co composites

    Kaytbay, Saleh [Benha Univ. (Egypt). Dept. of Mechanical Engineering; El-Hadek, Medhat [Port-Said Univ. (Egypt). Dept. of Production and Mechanical Design

    2014-06-15

    Manufacturing of WC-Co composites using the electroless precipitation method at different sintering temperatures of 1 100, 1 250, 1 350 and 1 500 C was successfully achieved. The chemical composition of the investigated materials was 90 wt.% WC with 10 wt.% Co, and 80 wt.% WC with 20 wt.% Co. The specific density, densification, and Vickers microhardness measurements were found to increase with increased sintering temperature for both the WC-Co compositions. The composites of tungsten carbide with 10 wt.% Co had a higher specific density and Vickers microhardness measurements than those for the composites of tungsten carbide with 20 wt.% Co. Composites with WC-10 wt.% Co had better wear resistance. The stress-strain and transverse rupture strength increased monotonically with the increase in sintering temperatures, agreeing with the material hardness and wear resistance behavior. Fractographical scanning electron microscopy analysis of the fracture surface demonstrated a rough characteristic conical shape failure in the direction of the maximum shear stress. A proposed mechanism for the formation of the conical fracture surface under compression testing is presented. (orig.)

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

    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

  7. Improvement of wear resistance of the hot work tool steel by laser surface feeding with ceramic powders

    L.A. Dobrzański

    2013-04-01

    Full Text Available Purpose: In this paper the result of laser surface feeding or remelting is discussed. The remelted layers which were formed on the surface of the investigated hot work steel were examined and analyzed metallographically and analyzed using a hardness testing machine. The resistance research has been done on the CSM Instruments.Design/methodology/approach: In this paper the results of laser treatment techniques applied in metal surface technology are presented and discussed. There is presented laser treatment with feeding or remelting of hot work tool steel X40CrMoV5-1 with ceramic powders especially - Al2O3 and Si3N4, as well as results of laser remelting influence on structure and properties of the surface of the hot work steel, carried out using the high power diode laser (HPDL.Findings: On the basis of the wear abrasion tests carried out on hot work tool steel it could be found that each of those specimens is characterized by different resistance for the same powders and the power of the laser beam. The metallographic investigations on light microscope show that during feeding or remelting the hot work tool steel with the ceramic powder layer in the whole range of the laser power values used 1.2-2.3 kW the obtained bead face is characteristic of the high roughness, multiple pores, irregularity.Practical implications: The resistance to abrasive wear is a practical aim of this work as well as improvement of hardness as a very important properties for practical use. It is necessary to continue the research to determine feeding or remelting parameters for demanded properties of hot work tool steels surface layers. Originality/value: Laser feeding or remelting by using HPDL laser (High Power Diode Laser and selected ceramic powders can be very attractive for industries.

  8. Abrasion-resistant solgel antireflective films with a high laser-induced damage threshold for inertial confinement fusion

    Xu, Yao; Zhang, Lei; Wu, Dong; Sun, Yu Han; Huang, Zu Xing; Jiang, Xiao Dong; Wei, Xiao Feng; Li, Zhi Hong; Dong, Bao Zhong; Wu, Zhong Hua

    2005-09-01

    To prepare abrasion-resistant antireflective (AR) films for inertial confinement fusion, four solgel routes have been investigated on polysiloxane-modified and polyvinylalcohol- (PVA-) modified SiO2 sols. As confirmed with a transmissive electron microscope, different fractal structure characteristics of the modified SiO2 particles are disclosed by small-angle x-ray scattering technology. And it is these special fractal characteristics that determine the performance of AR films on the level of internal microstructure. A 29Si magic angle spinning and nuclear magnetic resonance study has been successfully applied in explaining the fractal microstructure and its relation to the laser-induced damage threshold (LIDT) of AR films. The films modified by PVA120000 or acetic acid-catalyzed polysiloxane have higher LIDTs than those films modified by PVA16000 or hydrochloride acid-catalyzed polysiloxane. The films from PVA-modified SiO2 sols have a stronger abrasion resistance but lower antireflection than those films from polysiloxane-modified SiO2 sols. In addition, the films from polysiloxane-modified SiO2 sols can possess high transmittance and high LIDT if the polysiloxane synthesis condition is appropriately chosen, but the abrasion resistance is not as good as that from PVA modification. If strong abrasion resistance is necessary, a possible resolution may be to choose a more appropriate hydrophilic polymer than PVA. If not, polysiloxane-modified silica sol can also work when polysiloxane is synthesized under acetic acid catalysis.

  9. Deposition of TiC film on titanium for abrasion resistant implant material by ion-enhanced triode plasma CVD

    Zhu Yuhe, E-mail: zyh1120@hotmail.co.jp [School of Stomatology, China Medical University, Shen Yang (China); Wang Wei; Jia Xingya [School of Stomatology, China Medical University, Shen Yang (China); Akasaka, Tsukasa [Department of Health Science, School of Dental Medicine Hokkaido University, Sapporo (Japan); Liao, Susan [School of Materials Science and Engineering, Nanyang Technological University (Singapore); Watari, Fumio [Department of Health Science, School of Dental Medicine Hokkaido University, Sapporo (Japan)

    2012-12-01

    Highlights: Black-Right-Pointing-Pointer Deposition of Titanium Carbide (TiC) layer on titanium (Ti) surface has been demonstrated by an ion-enhanced triode plasma chemical vapor deposition (CVD) method. Black-Right-Pointing-Pointer The Vickers hardness of surface carbide was more than 2000, which confirmed its high abrasion resistance. Black-Right-Pointing-Pointer Physical and mechanical properties of the deposited TiC film on Ti were investigated to examine its potential application as an abrasion resistant implant material. - Abstract: Deposition of titanium carbide (TiC) layer on titanium (Ti) surface has been demonstrated by an ion-enhanced triode plasma chemical vapor deposition (CVD) method using a TiCl{sub 4} + CH{sub 4} + H{sub 2} gas mixture. Physical and mechanical properties of the deposited TiC film on Ti were investigated to examine its potential application as an abrasion resistant implant material. X-ray diffraction (XRD) showed that the specimen was consisted of TiC and Ti. Carbide layer of about 6 {mu}m thickness was observed on the cross section of the specimen by scanning electron microscopy (SEM). The Vickers hardness of surface carbide was more than 2000, which confirmed its high abrasion resistance.

  10. Deposition of TiC film on titanium for abrasion resistant implant material by ion-enhanced triode plasma CVD

    Highlights: ► Deposition of Titanium Carbide (TiC) layer on titanium (Ti) surface has been demonstrated by an ion-enhanced triode plasma chemical vapor deposition (CVD) method. ► The Vickers hardness of surface carbide was more than 2000, which confirmed its high abrasion resistance. ► Physical and mechanical properties of the deposited TiC film on Ti were investigated to examine its potential application as an abrasion resistant implant material. - Abstract: Deposition of titanium carbide (TiC) layer on titanium (Ti) surface has been demonstrated by an ion-enhanced triode plasma chemical vapor deposition (CVD) method using a TiCl4 + CH4 + H2 gas mixture. Physical and mechanical properties of the deposited TiC film on Ti were investigated to examine its potential application as an abrasion resistant implant material. X-ray diffraction (XRD) showed that the specimen was consisted of TiC and Ti. Carbide layer of about 6 μm thickness was observed on the cross section of the specimen by scanning electron microscopy (SEM). The Vickers hardness of surface carbide was more than 2000, which confirmed its high abrasion resistance.

  11. c-axis preferential orientation of hydroxyapatite accounts for the high wear resistance of the teeth of black carp (Mylopharyngodon piceus)

    Fu, Jimin; He, Chong; Xia, Biao; Li, Yan; Feng, Qiong; Yin, Qifang; Shi, Xinghua; Feng, Xue; Wang, Hongtao; Yao, Haimin

    2016-03-01

    Biological armors such as mollusk shells have long been recognized and studied for their values in inspiring novel designs of engineering materials with higher toughness and strength. However, no material is invincible and biological armors also have their rivals. In this paper, our attention is focused on the teeth of black carp (Mylopharyngodon piceus) which is a predator of shelled mollusks like snails and mussels. Nanoscratching test on the enameloid, the outermost layer of the teeth, indicates that the natural occlusal surface (OS) has much higher wear resistance compared to the other sections. Subsequent X-ray diffraction analysis reveals that the hydroxyapatite (HAp) crystallites in the vicinity of OS possess c-axis preferential orientation. The superior wear resistance of black carp teeth is attributed to the c-axis preferential orientation of HAp near the OS since the (001) surface of HAp crystal, which is perpendicular to the c-axis, exhibits much better wear resistance compared to the other surfaces as demonstrated by the molecular dynamics simulation. Our results not only shed light on the origin of the good wear resistance exhibited by the black carp teeth but are of great value to the design of engineering materials with better abrasion resistance.

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

    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.

  13. Floor tile glass-ceramic glaze for improvement of the resistance to surface abrasion

    Gajek, M; Lis, J; Partyka, J; Wojczyk, M, E-mail: mgajek@agh.edu.pl [AGH University of Science and Technology, Faculty of Materials Science and Ceramic, al. Mickiewicza 30, 30-059 Cracow (Poland)

    2011-10-29

    The results of research aimed at the study on frits and glass-ceramic glazes for floor tiles, based on compositions located in the primary field of cordierite crystallization within the system MgO-Al{sub 2}O{sub 3}-SiO{sub 2}, have been presented. The results comprise investigations on the frits crystallization abilities, stability of the crystallizing phase under conditions of single-stage a fast firing cycle (time below 60 minutes) depending on their chemical composition and the influence of the nucleation agents. The influence of the nucleating agents namely TiO{sub 2}, ZrO{sub 2}, V{sub 2}O{sub 5} on phase composition of obtained crystalline glazes, mechanical parameters and microstructure, has been examined. The strength tests proved increased mechanical resistance of crystalline glazes. Obtained glazes are characterized by high microhardness in range 6{approx}8 GPa, as well as the increased wear resistance measured by the loss of weight below 100 mg / 55 cm{sup 2} (PN-EN ISO 10545-7). Significant increase of these parameters as compared with non-crystalline glazes, where micro-hardness values range between 5{approx}6 GPa and the wear resistance values range from 120 to 200 mg, has been proved. Starting glasses (frits) and glazes of the ternary system MgO-SiO{sub 2}-Al{sub 2}O{sub 3}, were examined with use of DTA, XRD and SEM methods.

  14. Floor tile glass-ceramic glaze for improvement of the resistance to surface abrasion

    Gajek, M.; Lis, J.; Partyka, J.; Wójczyk, M.

    2011-10-01

    The results of research aimed at the study on frits and glass-ceramic glazes for floor tiles, based on compositions located in the primary field of cordierite crystallization within the system MgO-Al2O3-SiO2, have been presented. The results comprise investigations on the frits crystallization abilities, stability of the crystallizing phase under conditions of single-stage a fast firing cycle (time below 60 minutes) depending on their chemical composition and the influence of the nucleation agents. The influence of the nucleating agents namely TiO2, ZrO2, V2O5 on phase composition of obtained crystalline glazes, mechanical parameters and microstructure, has been examined. The strength tests proved increased mechanical resistance of crystalline glazes. Obtained glazes are characterized by high microhardness in range 6~8 GPa, as well as the increased wear resistance measured by the loss of weight below 100 mg / 55 cm2 (PN-EN ISO 10545-7). Significant increase of these parameters as compared with non-crystalline glazes, where micro-hardness values range between 5~6 GPa and the wear resistance values range from 120 to 200 mg, has been proved. Starting glasses (frits) and glazes of the ternary system MgO-SiO2-Al2O3, were examined with use of DTA, XRD and SEM methods.

  15. Floor tile glass-ceramic glaze for improvement of the resistance to surface abrasion

    The results of research aimed at the study on frits and glass-ceramic glazes for floor tiles, based on compositions located in the primary field of cordierite crystallization within the system MgO-Al2O3-SiO2, have been presented. The results comprise investigations on the frits crystallization abilities, stability of the crystallizing phase under conditions of single-stage a fast firing cycle (time below 60 minutes) depending on their chemical composition and the influence of the nucleation agents. The influence of the nucleating agents namely TiO2, ZrO2, V2O5 on phase composition of obtained crystalline glazes, mechanical parameters and microstructure, has been examined. The strength tests proved increased mechanical resistance of crystalline glazes. Obtained glazes are characterized by high microhardness in range 6∼8 GPa, as well as the increased wear resistance measured by the loss of weight below 100 mg / 55 cm2 (PN-EN ISO 10545-7). Significant increase of these parameters as compared with non-crystalline glazes, where micro-hardness values range between 5∼6 GPa and the wear resistance values range from 120 to 200 mg, has been proved. Starting glasses (frits) and glazes of the ternary system MgO-SiO2-Al2O3, were examined with use of DTA, XRD and SEM methods.

  16. Effect of SiC size dimensions on the corrosion wear resistance of the electrodeposited composite coating

    Benea, L. [Dunarea de Jos Univ. of Galati, Galati (Romania); Dept. of Materials Engineering, Trento Univ., Trento (Italy); Bonora, P.L. [Dept. of Materials Engineering, Trento Univ., Trento (Italy); Borello, A. [ENEA, C. R. Casaccia, Div. Nuovi Materiali, Rome (Italy); Martelli, S. [ENEA, C. R. Frascati, Div. Fisica Applicata, Rome (Italy)

    2002-01-01

    Advances in materials' performance often require the development of composite systems, of which coated materials are one form. The abrasion and corrosion resistance of components can be greatly increased by protective coatings and this is a growing industry of considerable economic importance. This paper aims with a comparative wear corrosion study of pure nickel and Ni-SiC nano structured composite coating. All the experiments concerning the effects of the rotation speed and the applied load on the corrosion behaviour and friction coefficient were carried out using the 0.5 M Na{sub 2}SO{sub 4} neutral solution. The E{sub corr} values measured at different disc rotation speeds and different friction loads show some differences between the two types of coatings. For wear corrosion tests an apparatus constructed in the Electrochemistry Laboratory, Dept. of Materials Engineering of Trento University was used. A PMMA cell contained the test solution and a transmission shaft with the tested sample, in the shape of a disc (diameter 40 mm and height 18 mm), connected to an electrical motor. A moving rod held an alumina parallelepiped counterface and the imposing load system thus obtaining a sliding type wear system. (orig.)

  17. Preparation, characterization and wear behavior of carbon coated magnesium alloy with electroless plating nickel interlayer

    Mao, Yan; Li, Zhuguo; Feng, Kai; Guo, Xingwu; Zhou, Zhifeng; Dong, Jie; Wu, Yixiong

    2015-02-01

    Poor wear resistance of rare earth magnesium alloys has prevented them from wider application. In this study, composite coating (PVD carbon coating deposited on electroless plating nickel interlayer) is prepared to protect GW83 magnesium alloys against wear. The Ni + C composite coating has a dense microstructure, improved adhesion strength and hardness due to the effective support of Ni interlayer. The wear test result shows that the Ni + C composite coating can greatly prolong the wear life of the magnesium alloy. The wear track of the Ni + C coated magnesium alloy is obviously narrower and shows less abrasive particles as compared with the bare one. Abrasive wear is the wear mechanism of the coatings at the room temperature. In conclusion, the wear resistance of the GW83 magnesium alloy can be greatly improved by the Ni + C composite coating.

  18. Hardness and wear resistance of reaction bonded SiC-B4C composite

    Hardness and wear resistant characteristics of reaction-bonded silicon carbides with boron carbide additions are evaluated relative to those of reaction bonded silicon carbide (RBSC). The reaction-bonded SiC-B4C composites exhibit a distinctive improvement of hardness and wear resistance, indicative of high resistance against wear environment. Removal rates for the wear tests are decisively reduced by the addition of boron carbide in the composites. Controlling the amount of carbon content in the starting composition more enhances the hardness of the reaction-bonded composites. Implications concerning the partial decomposition of B4C during reaction process are considered. (orig.)

  19. Abrasion Properties of Steel Fiber Reinforced Silica Fume Concrete According to Los Angeles and Water Abrasion Tests

    Tsan-Ching CHENG

    2014-12-01

    Full Text Available The current study mainly investigated the influence of different tests on the abrasion resistance of concrete mixed with steel fibers and silica fume. The abrasion resistance was assessed at 28, 56 and 91 days on concretes with water-binder ratios of 0.35 and 0.55 where in some mixes silica fume was substituted by 5 % of cement by weight. Steel fibers of 0.5 % and 1.0 % of concrete volume were also added into the test concrete by replacement of coarse and fine aggregates. The results showed that concrete with higher compressive strength in Los Angeles abrasion tests also had better abrasion resistance. The inclusion of steel fibers into test concrete with a water-binder ratio of 0.35 resulted in a significant increase in compressive strength. This concrete also displayed better abrasion resistance and splitting tensile strength than reference concrete; in the test sample with a water-binder ratio of 0.55, the added steel fibers was unable to effectively produce cementation with the concrete. The inclusion of silica fume improved the abrasion resistance of concretes. In water abrasion testing, the abrasion resistance of concrete containing steel fiber was worse than that of concrete without steel fibers. In the water abrasion testing, the surface of steel fiber reinforced concrete was eroded by water and steel balls, and the impact caused the steel fibers to separate from the concrete and led to higher wear loss. DOI: http://dx.doi.org/10.5755/j01.ms.20.4.6460

  20. Air Abrasion

    ... delivered directly to your desktop! more... What Is Air Abrasion? Article Chapters What Is Air Abrasion? What Happens? The Pros and Cons Will I Feel Anything? Is Air Abrasion for Everyone? print full article print this ...

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

    Liu, Qiang

    2012-01-01

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

  2. FIBROUS MONOLITH WEAR RESISTANT COMPONENTS FOR THE MINING INDUSTRY

    Mark J. Rigali; Kenneth L. Knittel; Mike L. Fulcher

    2002-03-01

    During this reporting period, work continued on development of formulations using the materials identified as contenders for the fibrous monolith wear resistant components. The FM structures fabricated were: diamond/WC-Co, B{sub 4}C/WC-Co, TiB{sub 2}/WC-Co, WC-Co/Co, WC-Co/WC-Co. Results of our consolidation densification studies on these systems lead to the down-selection of WC-Co/WC-Co, WC-Co/Co and diamond/WC-Co for further development for mining applications including drill bit inserts, roof bit inserts, radial tools conical tools and wear plates (WC-Co based system only) for earth moving equipment. Prototype component fabrication focused on the fabrication of WC-Co/WC-Co FM conical tools, diamond/WC-Co coated drill bit insert prototypes. Fabrication of WC-Co/WC-Co FM insert prototypes for a grader blade is also underway. ACR plans to initiate field-testing of the drill bit insert prototypes and the grader blade insert this summer (2002). The first WC-Co/WC-Co FM conical tool prototypes were sent to Kennametal for evaluation towards the end of the current reporting period.

  3. FIBROUS MONOLITH WEAR RESISTANT COMPONENTS FOR THE MINING INDUSTRY; SEMIANNUAL

    During this reporting period, work continued on development of formulations using the materials identified as contenders for the fibrous monolith wear resistant components. The FM structures fabricated were: diamond/WC-Co, B(sub 4)C/WC-Co, TiB(sub 2)/WC-Co, WC-Co/Co, WC-Co/WC-Co. Results of our consolidation densification studies on these systems lead to the down-selection of WC-Co/WC-Co, WC-Co/Co and diamond/WC-Co for further development for mining applications including drill bit inserts, roof bit inserts, radial tools conical tools and wear plates (WC-Co based system only) for earth moving equipment. Prototype component fabrication focused on the fabrication of WC-Co/WC-Co FM conical tools, diamond/WC-Co coated drill bit insert prototypes. Fabrication of WC-Co/WC-Co FM insert prototypes for a grader blade is also underway. ACR plans to initiate field-testing of the drill bit insert prototypes and the grader blade insert this summer (2002). The first WC-Co/WC-Co FM conical tool prototypes were sent to Kennametal for evaluation towards the end of the current reporting period

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

    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...

  5. Wear resistance of composite coatings produced by thermal spraying

    Injection of refractory additions (carbides, borides, oxides etc.) into self-fluxing alloys is a well-known technique for their hardening. Nevertheless the matter of influence of refractory components on the structure and characteristics of composite coatings is not studied well enough. This paper presents the results of investigations of gas thermal coatings (plasma and detonation ones) on the base of stellite with refractory components in the form of borides such as CrB2, TiB2, (TiCr)B2. This study is concerned with the influence of refractory additions (carbides, borides, oxides) on the wear resistance sprayed coatings based on self-fluxing alloys NiCrBSi and CoCrBSi

  6. Application of ion implantation to improve the wear resistance of 52100 bearing steel

    Bearings fabricated from 52100 steel are susceptible to adhesive wear which results in reduced performance of aerospace system components. To improve the wear resistance of 52100 steel, implantation of titanium ions was performed. Ion-implanted surfaces were characterized by electron microscopy and Auger electron spectroscopy. Wear tests, using the load-friction-wear technique, showed a 24% decrease in the breakaway coefficient of friction and an 11% decrease in the saturated value for titanium-implanted specimens as well as a modification of the adhesive wear behavior. (Auth.)

  7. Micro-scale Abrasion and Medium Load Multiple Scratch Tests of PVD Coatings.

    S.Poulat; H.Sun; D.GTeer

    2004-01-01

    Micro-scale abrasion testing is widely used to determine the abrasion resistance of thin film coatings; it is a simple technique that can easily be used as part of a quality control procedure, but it has got the disadvantage of not allowing an easy study of the wear mechanisms involved: it is difficult to estimate the load applied on each abrasive particles in the contact between the loaded ball and the specimen. The possibility of using progressive loading scratch testing, a method widely used to assess the adhesion of thin film coatings, to model the abrasive wear of coatings has been studied in the past; the use of multiple scratch tests to study the wear mechanisms corresponding to a single abrasion scratch event has also been studied in the case of bulk materials (ceramics and hard metals). Two coatings, deposited by Closed Field Unbalanced Magnetron Sputter Ion Plating (CFUBMSIP) on ASP23 powder metallurgy steel substrate are chosen to be representative of the use of protective coatings in industry: titanium nitride, which is widely used to prevent tool wear, and TCL Graphit-iCTM, which is widely used as a wear resistant solid lubricant coating. The two coatings are first characterised by using a standard quality control procedure: their thickness is determined by the cap grinding method, their adhesion by progressive loading scratch. Then micro-scale abrasion tests performed with a slurry at a concentration which promotes grooving wear, and medium load multiple scratch tests performed with diamond indenters are completed; the results of these tests are analysed and compared to determine if there is any correlation between the two sets of results; the multiple scratch tests wear tracks are also observed to determine the wear mechanisms involved.

  8. Selected fretting-wear-resistant coatings for Ti-6 pct Al-4 pct V alloy

    Bill, R. C.

    1985-01-01

    The ability of several wear-resistant coatings to reduce fretting in the Ti-6Al-4V alloy is investigated. The experimental apparatus and procedures for evaluating fretting in uncoated Ti-6Al-4V alloy and in the alloy with plasma-sprayed coatings, polymer-bonded coating, and surface treatments are described. The wear volume and wear rate for the alloys are measured and compared. It is concluded that Al2O3 with 13 percent TiO2, preoxidation and nitride surface treatments, and MoS2 sputtering result in wear-resistant surfaces; however, the polyimide coating is the most wear resistant coating in both dry and moist air, and it causes the least wear to the uncoated alloy surface.

  9. Enhancement of wear resistance of ductile iron surface alloyed by stellite 6

    Research highlights: → This paper deals with the improvement of the wear resistance of ductile iron surface alloyed by stellite 6 hardfacing alloy. → The microstructure of the surface alloyed layer consisted of carbides dispersed in a Co-based solid solution matrix with dendritic structure. → The higher wear resistance of the coated sample than that of uncoated sample attributed to the hardness of the surface alloyed layer. → The dominant mechanism of the wear in the coated and uncoated samples was delamination wear. -- Abstract: This paper deals with the improvement of the wear resistance of ductile iron surface alloyed by a hypoeutectic stellite 6 alloy. In this regard, the surface alloyed layer with 3 mm thickness deposited on ductile iron using tungsten inert gas (TIG) surface processing. The microstructure, hardness and wear resistance of surface alloyed layer were investigated using optical microscopy, scanning electron microscope (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction analysis, Vickers hardness (HV0.3) and pin-on-plate tests. The results showed that the microstructure of the surface alloyed layer consisted of carbides dispersed in a Co-based solid solution matrix with dendritic structure. This microstructure was responsible for the improvement of the hardness and wear resistance of the coating. Further investigations showed that the dominant mechanism of the wear in the coated and uncoated samples was delamination wear.

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

    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.

  11. Anti-abrasive nanocoatings current and future applications

    2015-01-01

    This book provides an overview of the fabrication methods for anti-abrasive nanocoatings. The connections among fabrication parameters, the characteristics of nanocoatings and the resulting properties (i.e. nanohardness, toughness, wear rate, load-bearing ability, friction coefficient, and scratch resistance) are discussed. Size-affected mechanical properties of nanocoatings are examined, including their uses. Anti-abrasive nanocoatings, including metallic-, ceramic-, and polymeric-based layers, as well as different kinds of nanostructures, such as multi-layered nanocomposites and thin films, are reviewed. * Provides a comprehensive overview of the fabrication methods for anti-abrasive nanocoatings* Discusses the connections among fabrication parameters, the characteristics of nanocoatings and the resulting properties* Reviews advantages and drawbacks of fabrication methods for anti-abrasive nanocoatings and clarifies the place of these nanocoatings in the world of nanotechnology

  12. Surface Design and Engineering Toward Wear-Resistant, Self-Lubricating Diamond Films and Coatings

    Miyoshi, Kazuhisa

    1999-01-01

    The tribological properties of chemical-vapor-deposited (CVD) diamond films vary with the environment, possessing a Jekyll-and-Hyde character. CVD diamond has low coefficient of friction and high wear resistance in air but high coefficient of friction and low wear resistance in vacuum. Improving the tribological functionality of materials (such as achieving low friction and good wear resistance) was an aim of this investigation. Three studies on the surface design, surface engineering, and tribology of CVD diamond have shown that its friction and wear are significantly reduced in ultrahigh vacuum. The main criteria for judging whether diamond films are an effective wear-resistant, self-lubricating material were coefficient of friction and wear rate, which must be less than 0.1 and on the order of 10(exp 6) cu mm/N(dot)m, respectively. In the first study the presence of a thin film (less than 1 micron thick) of amorphous, nondiamond carbon (hydrogenated carbon, also called diamondlike carbon or DLC) on CVD diamond greatly decreased the coefficient of friction and the wear rate. Therefore, a thin DLC film on CVD diamond can be an effective wear-resistant, lubricating coating in ultrahigh vacuum. In the second study the presence of an amorphous, nondiamond carbon surface layer formed on CVD diamond by ion implantation significantly reduced the coefficient of friction and the wear rate in ultrahigh vacuum. Therefore, such surface layers are acceptable for effective self-lubricating, wear-resistant applications of CVD diamond. In the third study CVD diamond in contact with cubic boron nitride exhibited low coefficient of friction in ultra high vacuum. Therefore, this materials combination can provide an effective self-lubricating, wear-resistant couple in ultrahigh vacuum.

  13. Resistance to wear and microstructure of martensitic welds deposits for recharge

    This work studied the welding metal for a martensitic steel (alloyed to Cr, Mn, Mo, V and W), deposited with a tubular metal-cored wire with gaseous protection of 82%Ar-18%Co2 on a low carbon steel using the semi-automatic welding process. Transverse pieces were cut from the welded coupon for microstructural characterization, measurement of hardness profiles, determination of the chemical composition and wear trials. The microstructural characterization was done using optic and scanning electronic microscopes, X-rays diffraction and energy-dispersive X-ray spectroscopy and Vicker microhardness (1 kg.) was measured. The wear trials (metal-metal) were performed in an Amsler machine under pure flow conditions. Different loads were used and the reference material was a SAE 1020 steel. The temperatures for each case were measured and the weight loss curves were defined as a function of the distance run and of the load. After testing the wear surfaces and the debris were measured. The microstructure of the welded deposit mostly consists of martensite and some retained austenite, with a pattern of dendritic segregation, and a hardness on the surface of 612 HVI. A lineal variation between the weight loss and the load applied was obtained as a response to the wear. The following phenomena were observed: abrasion, plastic deformation, oxidation and adhesion to the wear surfaces, as well as a tempering effect in the condition of the biggest load. The wear mechanisms acting on both surfaces were identified (CW)

  14. Effect of sodium bicarbonate air abrasive polishing on resistance to sliding during tooth alignment and leveling: An in vitro study

    Jorge C. B. L. Filho

    2012-01-01

    Full Text Available Objective: The aim of this in vitro study was to evaluate the Resistance to Sliding (RS provided by metallic brackets and 3 types of orthodontic wires (TMA, SS and NiTi, before and after the use of sodium bicarbonate airborne particle abrasion, in an experimental model with 3 non leveled brackets. Materials and Methods: The bicarbonate airborne abrasion was applied perpendicularly to the bracket slots at a distance of 2 mm, for 5 seconds (T2 and 10 seconds (T3 on each bracket slot. In a universal testing machine, the wires were pulled through a set of 3 non leveled brackets at a cross head speed of 50 mm/min for a distance of 10 mm, and static and kinetic friction readings were registered at T1 (no airborne abrasion, T2 and T3. Results: For all tested wires, a significant RS increase between T1 and T3 (P<0.001 was seen. For SS and TMA wires, there was a statistically significant RS increase between T1 and T2 (P<0.001. Between T2 and T3, RS increase was significant for TMA (P<0.001 and NiTiwires (P<0.05. Conclusions: Sodium bicarbonate air abrasive polishing during orthodontic treatment is not recommended, once this procedure promoted a significant RS increase between the metallic brackets and all the three types of wires tested.

  15. The structure and properties of steel with different pearlite morphology and its resistance to abrasive wear

    J. Herian; K. Aniołek

    2008-01-01

    Purpose: The analyse of pearlite morphology changes as a result of hot rolling process and isothermal annealing.Design/methodology/approach: Physical modelling of isothermal annealing for a transition point of520-620°C was carried out using a Gleeble simulator. A scanning electron microscope was used for a quantitativeevaluation of the microstructure.Findings: The obtained test results confirm that these methods can be effectively used in shaping the pearliticstructure and properties of the s...

  16. Analysis of the structure of castings made from chromium white cast iron resistant to abrasive wear

    D. Kopyciński

    2009-10-01

    Full Text Available It has been proved that an addition of boron carbide and disintegrated steel scrap introduced as an inoculant to the chromium white cast iron changes the structure of castings. The said operation increases the number of crystallization nuclei for dendrites of the primary austenite. In this case, the iron particles act as substrates for the nucleation of primary austenite due to a similar crystallographic lattice. The more numerous are the dendrites of primary austenite and the structure more refined and the mechanical properties higher. Castings after B4C inoculation revealed a different structure of fine grained fracture. Primary precipitates of chromium carbide also appeared, reducing the mechanical properties of as-cast parts. Properly established heat treatment regime makes chromium iron castings regain their, originally high, mechanical properties.

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

    Guilherme Zepon; Claudio Shyinti Kiminami; Walter José Botta Filho; Claudemiro Bolfarini

    2013-01-01

    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 stai...

  18. FIBROUS MONOLITH WEAR RESISTANT COMPONENTS FOR THE MINING INDUSTRY

    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

  19. Friction and wear with a single-crystal abrasive grit of silicon carbide in contact with iron base binary alloys in oil: Effects of alloying element and its content

    Miyoshi, K.; Buckley, D. H.

    1979-01-01

    Sliding friction experiments were conducted with various iron-base binary alloys (alloying elements were Ti, Cr, Mn, Ni, Rh, and W) in contact with a rider of 0.025-millimeter-radius, single-crystal silicon carbide in mineral oil. Results indicate that atomic size and content of alloying element play a dominant role in controlling the abrasive-wear and -friction properties of iron-base binary alloys. The coefficient of friction and groove height (wear volume) general alloy decrease, and the contact pressure increases in solute content. There appears to be very good correlation of the solute to iron atomic radius ratio with the decreasing rate of coefficient of friction, the decreasing rate of groove height (wear volume), and the increasing rate of contact pressure with increasing solute content C. Those rates increase as the solute to iron atomic radius ratio increases from unity.

  20. Plasma enhanced CVD of SiOxCyHz thin film on different textile fabrics: Influence of exposure time on the abrasion resistance and mechanical properties

    In order to improve textile fabric abrasion resistance, in this work a SiOxCyHz thin film was realized by low pressure plasma chemical vapour deposition (PCVD) at room temperature, using hexamethyldisiloxane (HMDSO) as precursor compound. To test changes in the performance properties of the surface finished samples as a function of the type of the substrate, the deposition was carried out on different textile fabrics. The polymerization processes were followed by weight measurements of textile fabrics. It was found that, after PCVD, a significantly lower fabric weight loss was observed on treated samples after rubbing than on the untreated samples. The morphology, elemental composition and type of chemical bonding present in the film applied on textile fabrics were also investigated using electron scanning microscopy (SEM), energy dispersive X-ray (EDX) and infrared spectroscopy techniques (FT-IR (ATR)). The results showed a substantial enhancement of wear resistance for the surfaces modified with the presented process, while tensile and tearing strength were adversely affected.

  1. Radiation resistance evaluation of cross-linked polytetrafluoroethylene by the investigation of friction and wear behavior

    Tang, Zhongfeng; Wang, Mouhua; Zhao, Yanning; Wu, Guozhong

    2011-03-01

    Radiation resistance of cross-linked polytetrafluoroethylene (XPTFE) sheets was evaluated by measuring the friction and wear properties as well as observing the morphology after γ-irradiation in air at room temperature. The wear resistance of XPTFE was confirmed to be much higher than that of virgin PTFE. The friction coefficient of XPTFE decreased with increasing dose, whereas the wear resistance remained stable until a critical dose was reached and then decreased sharply with dose. The critical dose of wear resistance was dependent on the crosslinking density or crosslinking dose of XPTFE. The radiation resistance of XPTFE improved significantly due to the formation of three-dimensional crosslinking networks by irradiation in the molten state. In addition, morphologies of the abraded debris of virgin PTFE and XPTFE were also compared and a clear difference was observed.

  2. Nitrogen implantation of type 303 stainless steel gears for improved wear and fatigue resistance

    Fine-positioning mechanisms are responsible for accurate and reproducible control of aerospace system devices, i.e. filter grading wheels. Low wear and fatigue resistance of mechanism components, such as pinions and gears, can reduce system performance and reliability. Surface modification using ion implantation with nitrogen was used on type 303 stainless steel pinions and gears to increase tribological performance. Wear-life tests of untreated, nitrogen-implanted and nitrogen-implanted-and-annealed gears were performed in a fine-positioning mechanism under controlled environmental conditions. Wear and fatigue resistance were monitored at selected time intervals which were a percentage of the predicted failure life as determined by a numerical stress analysis. Surface analyses including scanning electron microscopy and Auger electron spectroscopy were performed to establish the wear and fatigue mechanisms and the nitrogen concentration-depth distributions respectively. Nitrogen implantation resulted in a significant improvement in both surface wear and fatigue spalling resistance over those of untreated gears. A 40% reduction in surface wear and a 44% reduction in dedendum spalling was observed. In contrast, the nitrogen-implanted-and-annealed gears showed a 46% increase in sliding wear area and an 11% increase in spall density compared with those of untreated gears, indicating that the post-implantation anneal was detrimental to wear and fatigue resistance. (orig.)

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

    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.

  4. FIBROUS MONOLITH WEAR RESISTANT COMPONENTS FOR THE MINING INDUSTRY

    Mark J. Rigali; Mike L. Fulcher; Kenneth L. Knittel

    2002-10-01

    During the reporting period, work continued on development of formulations using the materials down-selected from the initially identified contenders for the fibrous monolith wear resistant components. The FM systems studied were: WC-Co/WC-Co, WC-Co/Co, diamond/WC-Co, and Al{sub 2}O{sub 3}/Al{sub 2}O{sub 3}-TiCN. Extrudable formulations for the materials listed were developed during the first twelve months of this effort, and work during the reporting period was focused on the development of optimized binder removal processes. A two stage binder removal process was developed that resulted in prototype parts free of voids and other internal defects. In addition, changes in the binder removal atmosphere resulted in the apparent elimination of residual carbon, an important consideration when consolidating WC-Co containing systems. Using the improved binder removal processes, parts were consolidated by both sintering and hot pressing to >99% theoretical density. Samples of these materials were sent to Kyocera for mechanical evaluations. Fabrication of drill bit inserts was begun, and binder removal begun during the reporting period. A total of 24 green inserts were fabricated, and will be consolidated and delivered for field testing during the upcoming reporting period.

  5. An instrument for measuring abrasive water jet diameter

    Junkar, Mihael; Lebar, Andrej; Orbanić, Henri

    2015-01-01

    In order to improve the accuracy of abrasive water jet (AW) machining the precise value of the jet diameter has to be known. Because of an aggressive environment caused by high velocity abrasive grains, the diameter is not easily measured. That is why a measuring device consisting of a load cell and a wear resistant probe was developed. The device measures the force of the jet while it passes over the edge of the probe. If the feed rate of the jet is constant and the time needed for jet to pa...

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

    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.

  7. Design of Surface Metastable Phase-Structural Modifications For Wear-Resistant Steels by Methods of Surfacing, Plasma and Electron-Beam Treatments

    The work is devoted to the urgent problem of saving of alloying components (Ni, Mo, Nb), very scarce in Ukraine and other countries, and increasing physical, mechanical, technological and operational properties, while designing a new surfacing material. The purpose of the work is the development of the composition of economical powder-like (nickel free) wire of PP-Np-12Crl2Mn9SiTiV and- investigation of welding and surfacing characteristics for electrode-arc surfacing, surface treatment by plasma and electron beam for tool steels 150Crl2Mo and 130Crl2Vl. The structure and physical and mechanical properties of deposited meta-stable metal, capable of self-strengthening in the surface layer during the process of wearing, are due to the development of deformation induced martensite γ —♦ α' transformation (DIMT). Metallographic, duro metric, X-ray investigation were employed in the research, as well as impact energy tests and wear tests, during dry sliding friction and impact-abrasive wearing. Electrode-arc surfacing was carried out on basis of steel of St. 3 grade, in one, two and three layers, in cast-iron shot. Investigations include the changes in the panorama of microstructure of the deposited metal (alongside with various space and technological schemes), changes in hardness in horizontal and vertical directions, micro hardness of the structural components (martensite, austenite, carbides), changes in impact energy (KCU) and relative wear resistance on sliding friction and impact-abrasive wearing (η and η£i.a) depending on the temperature of quenching of 950 and 1150°C. It has been found that the deposited metal is characterized by its good alloy ability with the base metal (St. 3 steel grade), absence of pores, gas bubbles, non-metallic inclusions and hot or cold cracks. The microstructure of the deposited metal consists of martensite, meta-stable austenite and carbides of Cr23C6, TiC and VC. Depending on the temperature of quenching, number of

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

    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.

  9. Characterization and wear resistance of macro-arc oxidation coating on magnesium alloy AZ91 in simulated bedy fluids

    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.

  10. Wear Resistance of Anodic Titanium Dioxide Films Produced on Ti-6Al-4V Alloy

    María Laura Vera; Mario Roberto Rosenberger; Carlos Enrique Schvezov; Alicia Esther Ares

    2015-01-01

    Ti-6Al-4V alloy with TiO2 coating is the most commonly selected material to construct an aortic heart valve. Wear resistance is the main mechanical property to be evaluated for this purpose. In this paper, the wear resistance of TiO2 thin films obtained by anodic oxidation of Ti-6Al-4V is evaluated. Anodic oxidation was performed at 20 V to 70 V with a H2SO4 1 M electrolyte. The samples were thermally treated at 500°C for 1 h, and crystalline phases of TiO2 were obtained. The wear was perform...

  11. Improvement of wear resistance of sprayed layer on 52100 steel by friction stir processing

    Rahbar-kelishami, A.; Abdollah-zadeh, A.; Hadavi, M. M.; Seraj, R. A.; Gerlich, A. P.

    2014-10-01

    The influence of friction stir processing (FSP) on wear resistance is studied on a thermally sprayed coating in terms of microstructure and mechanical properties. A high-chromium steel coating sprayed on AISI 52100 steel has been processed, and it is shown that FSP can improve the sprayed layer wear resistance compared to the as-sprayed and quenched and tempered condition. It is suggested that improved toughness is the main contribution to wear performance rather than hardness. It is observed that FSP provides increased hardness and toughness simultaneously, while tempering of the quenched AISI 52100 steel increases toughness while hardness decreases.

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

    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...

  13. FIBROUS MONOLITH WEAR RESISTANT COMPONENTS FOR THE MINING INDUSTRY

    Mark J. Rigali; Mike L. Fulcher

    2003-03-25

    During the reporting period, work continued on development of formulations using the materials down-selected from the initially identified contenders for the fibrous monolith wear resistant components. In the previous reporting period, a two-stage binder removal process was developed that resulted in prototype parts free of voids and other internal defects. During the current reporting period, work was performed to characterize the two-stage binder removal process for WC-Co based FM material systems. Use of this process has resulted in the fabrication of defect free sintered WC-Co FM bodies, with minimal free carbon porosity and densities approaching 100% theoretical. With the elimination of free carbon porosity and other binder removal process related defects, development work focused on optimizing the densification and eliminating defects observed in WC-Co based FM consolidated by pressureless sintering. Shrinkage of the monolithic core and shell materials used in the WC-Co based FM system was measured, and differences in material shrinkage were identified as a potential cause of cell boundary cracking observed in sintered parts. Re-formulation of material blends for this system was begun, with the goal of eliminating mechanical stresses during sintering by matching the volumetric shrinkage of the core and shell materials. Thirty-three 7/8 inch drill bit inserts (WC-Co(6%)/WC-Co(16%) FM) were hot pressed during the reporting period. Six of these inserts were delivered for field-testing by Superior Rock Bit during the upcoming reporting period. In addition, Al{sub 2}O{sub 3}/Al{sub 2}O{sub 3}-TiCN FM cutting tool inserts were fabricated, and cutting tests performed.

  14. Effect of the post heat treatment on the sliding wear resistance of a nickel base coating deposited by high velocity oxyl-fuel (HVOF)

    In the present research, a nickel base coating was deposited on an AISI 1020 substrate by using high velocity oxy-fuel technique (HVOF). The coating was subsequently post heat-treated by means of an oxyacetylene flame. For the conditions evaluated in the present study, it was found that the CTT coating coating has 1,15 better wear resistance for the smaller level of the applied load and nearly 50 times for the highest level of the applied load when compared to the STT coatings. These results have been attributed to a better distribution of the hard phases, better cohesion between particles and an increase in hardness, as consequence of the post heat treatment process. A severe wear regime was found for all the samples since the wear rates presented values which were higher tan 1.10''-5 mm''3/m. For the CT T coatings, the wear mechanisms was mainly due to the adhesion and oxidation phenomena, meanwhile for the steel counterpart mechanisms such oxidation, grooving and three body abrasion were observed. (Author) 22 refs

  15. 多孔复合结合剂立方氮化硼砂轮磨损特性%Wear Behavior of Porous Composite-bonded CBN Abrasive Wheels

    陈珍珍; 徐九华; 丁文锋; 马昌玉

    2014-01-01

    针对难加工材料高效磨削砂轮难以满足高气孔率与高强度要求问题,基于氧化铝空心陶瓷球颗粒造孔与增强,开发了一种新型多孔复合结合剂立方氮化硼(Cubic boron nitride, CBN)砂轮。开展了镍基高温合金磨削试验,分别从磨削力、砂轮径向磨损量、磨损形貌过程等方面分析多孔砂轮的磨损特性,并与白刚玉砂轮进行对比。研究表明:多孔复合结合剂CBN砂轮磨削高温合金的磨削力和磨削温度均小于白刚玉砂轮;当单位材料去除率为4 mm3/(mm·s)时,多孔复合结合剂CBN砂轮的磨削比是白刚玉砂轮的6倍;多孔复合结合剂CBN砂轮磨削高温合金的磨损形式主要是磨粒磨耗磨损、磨粒及结合剂破碎磨损及黏附磨损,磨损过程伴随新磨粒与气孔的出露。相比之下,白刚玉砂轮黏附堵塞现象严重,砂轮磨损快,工件表面质量难以保证。%In order to meet the wheel requirement of high porosity and high strength for the high efficiency grinding process of difficult-to-cut materials, a new type of porous composite-bonded cubic boron nitride (CBN) abrasive wheel is developed based on alumina bubble particles as pore-forming agent. The grinding experiments are conducted on nickel-based alloy respectively with the developed porous CBN wheel and white corundum grinding wheel. The grinding forces, radial wear and wheel wear forms are measured and investigated. Results show that, the grinding forces and grinding temperatures of porous CBN wheel are smaller than that of white corundum grinding wheel, and the grinding ratio is about 6 times higher when the material remove rate is 4 mm3/(mm·s). The primary wear forms of porous composite-boned CBN wheel include abrasive abrasion wear, abrasive and bond fracture, and adhesion wear. Accompanied by the wear, new abrasives and pores are exposed. Serious wheel adhesion and loading phenomena are found during grinding with white

  16. Wear mechanism for spray deposited Al-Si/SiCp composites under dry sliding condition

    滕杰; 李华培; 陈刚

    2015-01-01

    Al-Si/15%SiCp (volume fraction) composites with different silicon contents were fabricated by spray deposition technique, and typical microstructures of these composites were studied by optical microscopy (OM). Dry sliding wear tests were carried out using a block-on-ring wear machine to investigate the effect of applied load range of 10−220 N on the wear and friction behavior of these composites sliding against SAE 52100 grade bearing steel. Scanning electron microscopy (SEM) and energy-dispersive X-ray microanalysis (EDAX) were utilized to examine the morphologies of the worn surfaces in order to observe the wear characteristics and investigate the wear mechanism. The results show that the wear behavior of these composites is dependent on the silicon content in the matrix alloy and the applied load. Al-Si/15%SiCp composites with higher silicon content exhibit better wear resistance in the applied load range. Under lower loads, the major wear mechanisms are oxidation wear and abrasive wear for all tested composites. Under higher loads, severe adhesive wear becomes the main wear mechanisms for Al-7Si/15%SiCp and Al-13Si/15%SiCp composites, while Al-20Si/15%SiCp presents a compound wear mechanism, consisting of oxidation, abrasive wear and adhesion wear.

  17. New Oxide Ceramic Developed for Superior High-Temperature Wear Resistance

    Sayir, Ali; Miyoshi, Kazuhisa; Farmer, Serene C.

    2003-01-01

    Ceramics, for the most part, do not have inherently good tribological properties. For example friction coefficients in excess of 0.7 have been reported for silicon nitride sliding on silicon nitride or on bearing steel (ref. 1). High friction is always accompanied by considerable wear. Despite their inherently poor tribological properties, the high strength and high toughness of silicon nitride (Si3N4) ceramics has led to their successful use in tribological applications (refs. 1 to 4). The upper temperature limit for the application of Si3N4 as wear-resistant material is limited by reaction with the tribological environment (ref. 3). Silicon nitride is known to produce a thin silicon dioxide film with easy shear capability that results in low friction and low wear in a moist environment (ref. 5). At elevated temperatures, the removal of the reaction product that acts as lubricant causes the friction coefficient to increase and, consequently, the wear performance to become poor. New materials are sought that will have wear resistance superior to that of Si3N4 at elevated temperatures and in harsh environments. A new class of oxide ceramic materials has been developed with potential for excellent high-temperature wear resistance. The new material consists of a multicomponent oxide with a two-phase microstructure, in which the wear resistance of the mixed oxide is significantly higher than that of the individual constituents. This is attributed to the strong constraining effects provided by the interlocking microstructures at different length scales, to the large aspect ratio of the phases, to the strong interphase bonding, and to the residual stresses. Fretting wear tests were conducted by rubbing the new ceramic material against boron carbide (B4C). The new ceramic material produced a wear track groove on B4C, suggesting significantly higher wear resistance for the oxide ceramic. The new material did not suffer from any microstructural degradation after the wear

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

    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. PMID:25115567

  19. Investigation of improving wear performance of hypereutectic 15%Cr-2%Mo white irons

    R. Reda

    2010-11-01

    Full Text Available This study aimed at optimizing impact toughness and abrasion wear resistance of 15%Cr-2%Mo hypereutectic abrasion-resistant white irons. The effects of dynamic solidification, niobium addition, combined action of them and heat treatment have been investigated. Investigations were performed by means of the image analyzer, scanning electron microscopy (SEM, energy-dispersive spectrometry (EDS and X-ray diffraction. Impact toughness and abrasion wear resistance tests were conducted. Fracture and worn surfaces were studied. Results indicated that microstructural control during solidification is the most valuable tool to attain the optimum combination between impact toughness and wear resistance in hypereutectic iron. Combined action of Nb addition and dynamic solidification improves impact toughness and wear resistance even more than the action of each individual factor. In the as-cast condition, impact toughness and abrasion resistance were increased after dynamic solidification compared to statically solidified one by 71.4% and 10%, respectively. This enhancement was increased to 114.3 % and 28.8 % by adding 2% Nb. Lower tempering temperature of 260°C exhibits better impact and abrasion resistance than the sub-critical tempering temperature of 500°C.

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

    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.

  1. Linear abrasion of a titanium superhydrophobic surface prepared by ultrafast laser microtexturing

    A novel method of fabricating titanium superhydrophobic surfaces by ultrafast laser irradiation is reported. The ultrafast laser irradiation creates self-organized microstructure superimposed with nano-scale roughness, after which a fluoropolymer coating is applied to lower the surface energy of the textured surface and achieve superhydrophobicity. The focus of this study is to investigate abrasion effects on this mechanically durable superhydrophobic surface. The mechanical durability is analyzed with linear abrasion testing and microscopy imaging. Linear abrasion tests indicate that these surfaces can resist complete microstructure failure up to 200 abrasion cycles and avoid droplet pinning up to ten abrasion cycles at 108.4 kPa applied pressure, which roughly corresponds to moderate to heavy sanding or rubbing in the presence of abrasive particles. The wear mechanisms are also investigated and the primary mechanism for this system is shown to be abrasive wear with fatigue by repeated plowing. Although these results demonstrate an advancement in mechanical durability over the majority of existing superhydrophobic surfaces, it exemplifies the challenge in creating superhydrophobic surfaces with suitable mechanical durability for harsh applications, even when using titanium. (paper)

  2. Development of new type of wear and crack resistant hardfacing electrode

    王新洪; 宋思利; 邹增大; 曲仕尧

    2004-01-01

    By using H08A bare electrode and the coating fluxes of ferrotitanium, rutile, graphite, calcium carbonate and calcium fluoride, a new type of wear and crack resistant hardfacing electrode was developed. The microstructure and wear properties of deposited layer were studied by means of scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffractometry(XRD) and wear test. The results indicate that TiC particles are produced by direct metallurgical reaction between ferrotitanium or rutile and graphite during welding process. TiC particles with sizes in the range of 3 - 5 μtm are dispersed in the matrix of lath martensite and retained austenite. The deposited layer of the new type of hardfacing electrode possesses better wear and crack resistance than that of D618 and D667 hardfacing electrodes.

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

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

    2016-05-01

    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.

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

    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.

  5. EVALUATION OF EROSIVE WEAR RESISTANCE OF TiN COATINGS BY A SLURRY JET IMPACT TEST

    Iwai, Y.; Miyajima, T.; Honda, T.; Matsubara, T.; Kanda, K; Hogmark, S

    2006-01-01

    In this paper, it is proposed to use a new type of solid particle impact test (slurry jet) to swiftly evaluate wear properties of thin, single layered or multilayered coatings. By the slurry jet, 1.2 µm alumina particles were impacted at high velocity perpendicular to thin PVD coatings of TiN deposited on high speed steel substrate materials under various substrate temperatures.Since the coatings have a much higher wear resistance than the substrate material, the wear rate increases significa...

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

    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.

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

    Mieczysław Kaczorowski; Anna Krzyńska; Paweł Skoczylas

    2011-01-01

    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 specim...

  8. The enhancement in wear resistance of W18Cr4V steel by ion implantation

    Two new methods of ion implantation were adopted in comparison with nitrogen implantation: carbon monoxide was implanted directly into W18Cr4V steel, and nitrogen was implanted into a deposited titanium film about 1000 A thick. It is shown that higher surface hardness and wear resistance have been achieved. The composition and phase structure of the implanted layer was determined in detail. The wear mechanisms were discussed

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

    Liu, Qiang

    2013-01-01

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

  10. Development of Abrasion-Resistant Coating for Solar Reflective Films. Cooperative Research and Development Final Report, CRADA Number CRD-07-247

    Gray, Matthew [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2015-10-01

    The purpose of this CRADA is to develop an abrasion-resistant coating, suitable for use on polymeric-based reflective films (e.g., the ReflecTech reflective film), that allows for improved scratch resistance and enables the use of aggressive cleaning techniques (e.g., direct contact methods like brushing) without damaging the specular reflectance properties of the reflective film.

  11. Facile fabrication of superhydrophobic surface with excellent mechanical abrasion and corrosion resistance on copper substrate by a novel method.

    Su, Fenghua; Yao, Kai

    2014-06-11

    A novel method for controllable fabrication of a superhydrophobic surface with a water contact angle of 162 ± 1° and a sliding angle of 3 ± 0.5° on copper substrate is reported in this Research Article. The facile and low-cost fabrication process is composed from the electrodeposition in traditional Watts bath and the heat-treatment in the presence of (heptadecafluoro-1,1,2,2-tetradecyl) triethoxysilane (AC-FAS). The superhydrophobicity of the fabricated surface results from its pine-cone-like hierarchical micro-nanostructure and the assembly of low-surface-energy fluorinated components on it. The superhydrophobic surface exhibits high microhardness and excellent mechanical abrasion resistance because it maintains superhydrophobicity after mechanical abrasion against 800 grit SiC sandpaper for 1.0 m at the applied pressure of 4.80 kPa. Moreover, the superhydrophobic surface has good chemical stability in both acidic and alkaline environments. The potentiodynamic polarization and electrochemical impedance spectroscopy test shows that the as-prepared superhydrophobic surface has excellent corrosion resistance that can provide effective protection for the bare Cu substrate. In addition, the as-prepared superhydrophobic surface has self-cleaning ability. It is believed that the facile and low-cost method offer an effective strategy and promising industrial applications for fabricating superhydrophobic surfaces on various metallic materials. PMID:24796223

  12. Wear Resistance of TiN Coating Prepared by Multi-arc Ion Plating on Aluminum Alloy Surface%铝合金表面多弧离子镀TiN涂层的耐磨性能

    谭银元; 潘应君

    2009-01-01

    Wear resistance of TiN coating prepared by multi-arc ion plating on ZL109 aluminum alloy surface has been examined. The results show that wear resist-ance of the ZL109 aluminum alloy with multi-arc ion plating TiN coating can be significantly improved. With applying 1N and wearing for 90min, the abrasive width of the samples without TiN coating makes ap-proximately 2 times of that with TiN coating, and av-erage frictional coefficient of the samples with TiN coating makes approximately 50% of that without coating. With applying 2N, the morphology and abra-sive width are varied as time increases. The wear mor-phology of the ZL109 alloy samples with TiN coating is characterized by adhesive abrasion in early stage and by abrasive abrasion in last stage.%采用多弧离子镀在ZL109铝合金表面进行了TiN涂层处理,并对涂层的载荷耐磨性进行了分析和讨论.结果表明,ZL109铝合金表面多弧离子镀TiN涂层后,其耐磨性得到明显提高.在1 N的载荷下,连续磨损90 min时,未镀膜试样的磨痕宽度几乎是TiN试样的2倍,镀有TiN膜试样的平均摩擦因数几乎是未镀样的50%.在2 N的载荷下,由磨痕的形貌和宽度随时间的变化可见,镀有TiN涂层的试样在磨损前期,主要以粘着磨损为主,在磨损后期以磨粒磨损为主.

  13. Mixing proportion design and construction technology of abrasion resistant concrete%抗冲磨混凝土配合比设计与施工工艺

    苏满红; 李俊华; 刘慧民

    2011-01-01

    According to the design standards of Tanghe hydropower station dam,spillway gate abrasion resistant concrete,through the on-site mixing proportion test,gained the construction technology and parameters of abrasion resistant concrete,so as to further improve the performance of concrete,provide guidance to the hydropower station dam spillway gate pier,plunge pool abrasion resistant concrete pouring construction.%针对唐河水电站重力坝、泄洪闸抗冲磨混凝土设计标准,通过现场配合比试验,取得抗冲磨混凝土施工工艺及参数,使混凝土性能得到进一步改善,为水电站大坝泄洪闸闸墩、消力池抗冲磨混凝土浇筑施工提供指导。

  14. Lubricated sliding wear behaviour of aluminium alloy composites

    J. C. Walker; Rainforth, W. M.; Jones, H.

    2005-01-01

    Interest in aluminium alloy (Al-alloy) composites as wear resistant materials continues to grow. However, the use of the popular Al-alloy-SiC composite can be limited by the abrasive nature of the SiC, leading to increased counterface wear rates. This study reports new Al-alloy composites that offer high wear resistance, to a level similar to Al-alloy-SiC. Aluminium alloy (2124, 5056) matrix composites reinforced by nominally 15 vol.% of Cr3Si, MoSi2, Ni3Al and SiC particles were prepared by ...

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

    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.

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

    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

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

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

    2010-01-01

    -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 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.......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...

  18. Plasma nitrocarburizing process - a solution to improve wear and corrosion resistance

    To prevent wear and corrosion problems in steam turbines, coatings have proved to have an advantage of isolating the component substrate from the corrosive environment with minimal changes in turbine material and design. Diffusion based coatings like plasma nitriding and plasma nitrocarburizing have been used for improving the wear and corrosion resistance of components undergoing wear during their operation. In this study plasma nitrocarburizing process was carried out on ferritic alloys like ASTM A182 Grade F22 and ATM A105 alloy steels and austenitic stainless steels like AISI 304 and AISI 316 which are used to make trim parts of control valves used for high pressure and high temperature steam lines to enhance their wear and corrosion resistance properties. The corrosion rate was measured by a potentiodynamic set up and salt spray unit in two different environments viz., tap water and 5% NaCl solutions. The Tafel plots of ferritic alloys and austenitic stainless steels show that plasma nitrocarburizing process show better corrosion resistance compared to that of the untreated steel. It was found that after plasma nitrocarburizing process the hardness of the alloy steels increased by a factor of two. The corrosion resistance of all the steels mentioned above improved in comparison to the untreated steels. This improvement can be attributed to the nitrogen and carbon incorporation in the surface of the material. This process can be also applied to components used in nuclear industries to cater to the wear and corrosion problems. (author)

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

    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.

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

    Zhang Zhiguo; Yang Chengkai; Zhang Peng; Li Wei

    2014-01-01

    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 aloys 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 aloys 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.

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

    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.

  2. Dry sliding wear behavior of Al 2219/SiCp-Gr hybrid metal matrix composites

    Basavarajappa, S.; Chandramohan, G.; Mukund, K.; Ashwin, M.; Prabu, M.

    2006-12-01

    The dry sliding wear behavior of Al 2219 alloy and Al 2219/SiCp/Gr hybrid composites are investigated under similar conditions. The composites are fabricated using the liquid metallurgy technique. The dry sliding wear test is carried out for sliding speeds up to 6 m/s and for normal loads up to 60 N using a pin on disc apparatus. It is found that the addition of SiCp and graphite reinforcements increases the wear resistance of the composites. The wear rate decreases with the increase in SiCp reinforcement content. As speed increases, the wear rate decreases initially and then increases. The wear rate increases with the increase in load. Scanning electron microscopy micrographs of the worn surface are used to predict the nature of the wear mechanism. Abrasion is the principle wear mechanism for the composites at low sliding speeds and loads. At higher loads, the wear mechanism changes to delamination.

  3. A Study of Parameters Affecting Wear Resistance of Alumina and Yttria Stabilized Zirconia Composite Coatings on Al-6061 Substrate

    N Krishnamurthy; Prashanthareddy, M. S.; H. P. Raju; H. S. Manohar

    2012-01-01

    In this investigation, a composite coating of alumina and yttria stabilized zirconia in equal proportion was developed on Al-6061 substrate using Atmospheric Plasma Spraying technique. Two commercially available powders of chemical composition Al 25Fe7Cr5Ni and Al2O330(Ni 20Al) were used as bond coats. The coating samples were subjected to abrasive wear test as per ASTM G99. From the results it was found that wear rate and coefficient of friction depend on various parameters such as microstru...

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

    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.

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

    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.

  6. Numerical Simulation of Wear Resistance of Ni-SiC Composite Coatings Deposited by Electrodeposition

    Jinwu Wang; Fafeng Xia

    2014-01-01

    In order to research effect of plating parameters on wear resistance of Ni-SiC composite coatings, Ni coatings and Ni-SiC composite coatings were synthesized on steel substrates by electrodeposition method. The results indicate that the contents of SiC particles increase with density of pulse current and on-duty ratio of pulse current increasing. The wear resistance of Ni-SiC composite coatings predicted using ANN model has the similar shapes with the measured curve and the maximum error is a...

  7. Efecto del conteo de nódulos en la resistencia al desgaste por abrasión de los hierros dúctiles austemperados. // Effect of nodules count in the abrasive wear of austempered ductile irons.

    C. J. Diez Cicero

    2009-05-01

    Full Text Available Entre los materiales metálicos de mayor demanda, la producción de hierro con grafito nodular,ocupa en la actualidad, uno de los lugares más importantes entre los hierros fundidos de altaresistencia, y con la introducción del tratamiento térmico de austemperado, aplicado a estasfundiciones, se da lugar a una nueva familia de materiales, caracterizados por su alta resistenciamecánica y elevada tenacidad, que mantienen la economía y facilidad de producción de lasfundiciones nodulares.Este trabajo, hace una valoración del comportamiento de hierros nodulares, con diferentes conteosde nódulos, a los que les fue aplicado el tratamiento de austemperado, y posteriormente se lessometió a ensayos de desgaste abrasivo.Con los resultados obtenidos, se hace un análisis de la influencia del conteo de nódulos en dichaspropiedades, así como también, de la interrelación del conteo de nódulos, con las variables detratamiento térmico utilizadas en las muestras ensayadas.Palabras claves: hierro nodular, conteo de nódulos, austemperado.__________________________________________________________________________AbstractBetween the metallic materials of greater demand, the iron production with nódular graphiteoccupies at the present time, one of the most important places between fused irons of highresistance, and with the introduction of the austemperado heat treatment of, applied to thesesmeltings, gives rise to a new family of materials, characterized by its high resistance mechanicaland elevated tenacity, that the economy and facility of production of the smeltings maintainnodulares. This work, makes a valuation of the iron behavior nodulares, with different counts fromnodules, to which the austemperado was applied treatment to them of, and later it was put underto them tests of abrasive wearing down. Of the obtained results, an analysis takes control of theinfluence of the count of nodules in these properties, as well as, of the interrelation of

  8. A wear and corrosion resistant α-ferrite toughened Fe9Cr9Si2 ternary intermetallic alloy

    Mechanical moving components working under corrosion or elevated temperature aggressive service conditions demand tribological materials having excellent combinations of wear and corrosion resistance. Most conventional high-performance wear resistant materials such as high Cr cast irons lack adequate corrosion resistance, while most corrosion resistant materials such as stainless steels are poor in resisting wear. In this paper, a novel α-ferrite toughened Fe9Cr9Si2 wear and corrosion resistant ternary intermetallic alloy was developed with a microstructure consisting of small amount of dispersive α particles well distributed in the continuous matrix of Fe9Cr9Si2 (referred as α/Fe9Cr9Si2 alloy). Corrosion properties were evaluated using the anodic polarization methods in H2SO4 and NaCl water solutions. Wear resistance was tested under room-temperature block-on-wheel dry sliding wear test conditions. Due to the unique chemical composition of both the Cr and Si highly alloyed α and the σ-phase Fe9Cr9Si2, the α/Fe9Cr9Si2 alloy exhibited outstanding corrosion resistance. Due to the excellent combination of high hardness and the strong covalent-dominant atomic bonds of σ-Fe9Cr9Si2, the excellent toughness and ductility of α and the unique chemical composition induced oxidation wear, the α-toughened Fe9Cr9Si2 σ-based alloy exhibited outstanding dry sliding wear resistance

  9. Wear Resistance of Anodic Titanium Dioxide Films Produced on Ti-6Al-4V Alloy

    María Laura Vera

    2015-03-01

    Full Text Available Ti-6Al-4V alloy with TiO2 coating is the most commonly selected material to construct an aortic heart valve. Wear resistance is the main mechanical property to be evaluated for this purpose. In this paper, the wear resistance of TiO2 thin films obtained by anodic oxidation of Ti-6Al-4V is evaluated. Anodic oxidation was performed at 20 V to 70 V with a H2SO4 1 M electrolyte. The samples were thermally treated at 500°C for 1 h, and crystalline phases of TiO2 were obtained. The wear was performed in a ball-on-flat recip‐ rocating machine with a range of loads from 1 gf to 4 gf and times between 60 s and 1200 s, using a diamond sphere as counterface. The counterface oscillates at 0.5 Hz and 4 mm in amplitude. The wear is measured using a profilometer and is calculated as the worn volume. The wear resistance of the coated samples is larger than the substrate, and increases with thickness and with crystalline coating.

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

    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.

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

    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.

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

    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.

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

    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

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

    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.

  15. Numerical Simulation of Wear Resistance of Ni-SiC Composite Coatings Deposited by Electrodeposition

    Jinwu Wang

    2014-06-01

    Full Text Available In order to research effect of plating parameters on wear resistance of Ni-SiC composite coatings, Ni coatings and Ni-SiC composite coatings were synthesized on steel substrates by electrodeposition method. The results indicate that the contents of SiC particles increase with density of pulse current and on-duty ratio of pulse current increasing. The wear resistance of Ni-SiC composite coatings predicted using ANN model has the similar shapes with the measured curve and the maximum error is about 9.6%. The wear losses decrease when current density increases from 30 to 50 A/dm2. SiC particles in Ni-SiC composite coating are much greater in number and are dispersed homogeneously in the deposit and the coating exhibited a dense structure.

  16. Application of polymer-powder slurry for fabrication of abrasion resistant coatings on tool materials

    G. Matula

    2011-01-01

    Purpose: Development of a new generation tool materials on the basis of M2 high speed-steel or 41Cr4 steel covered with the carbides. Application of pressureless forming of powder as a manufacturing method of anti-wear coatings gives the possibility to produce this materials with relative low cost of production.Design/methodology/approach: Powder metallurgy, pressureless forming of powder, sintering, microstructure examination, X-ray dispersive energy examination, hardness examination.Finding...

  17. THE INVESTIGATION OF WEAR BEHAVIOURS OF SiC(p) BASED COATINGS PRODUCED BY GTA WELDING PROCESS

    Islak, Serkan

    2009-01-01

    In this study, the silicon carbide (SiC) powder has been coated by using of GTA process on the surface of a substrate material from 45Mn5 steel. The abrasive wear behaviours of samples which had different amounts of coating powders were determined by pin-on-disc test apparatus. The effects of the formed microstructures and the production parameters on abrasive wear properties of samples in coated zone were investigated. The highest wear resistance was observed at 41.3 kJ/cm energy input, 0.44...

  18. The Effect of Silane on the Microstructure, Corrosion, and Abrasion Resistances of the Anodic Films on Ti Alloy

    Wang, Jinwei; Chen, Jiali

    2016-04-01

    Anodic oxide films on Ti-6Al-4V alloy are prepared using sodium hydroxide as the base electrolyte containing aminopropyl trimethoxysilane (APS) as an additive. Some APS undergo hydrolysis, adsorption, and chemical reaction with the TiO x to form Ti-O-Si bond as confirmed by ATR-FTIR and XPS spectra, and in turn their surface appearance and roughness are greatly changed with the addition of APS as observed by their SEM images. These amino anodic films possess much higher corrosive resistances since the formation of Ti-O-Si complex enhances the compactness of the anodic films and the existence of aminopropyl groups inside the pores provides additional blocking effects. Besides, their improvement in anti-abrasive capability is attributed to the toughening effect of the chemically bonded silanes and the lubrication functions from both the chemically bonded and physically absorbed silanes between the touched interfaces.

  19. Comparative of wear resistance of low carbon steel pack carburizing using different media

    Kharia Salman Hassan

    2015-01-01

    Full Text Available In this study, various carburizing compounds charcoal, cow bone, CaCO3 were added as energizer for the carburizing compounds in percentage of 10%. To produce another compound to pack carburized mild steel 1020 AISI for investigates the influence of these compounds on wear resistance. Many Cylindrical specimens for the adhesion wear tests were prepared from the used metal with dimensions (10x20mm according to ASTM (G99-04 specifications Three Heat Treatment process namely pack Carburizing Quenching, and Tempering were done. Firstly the mild steels specimens are carburized at 925° C for 2hr as soaking time and slow cooling in furnace then carburizing specimens were re heating to 870 °C for half hr. and water Quenching .Tempering was done at 160°C for 1 hour and air cooled. the Carburized and Tempered mild steels are subjected for different kind of test such as Adhesive Wear Test with pin on desk method, Hardness Test were taken using Vickers micro-hardness tester and optical microscope is used for microstructure examination X-ray diffraction for phases observation. The result showed that all carburizing compound were contributed in increasing wear resistance and the compound of cow bone with 10% CaCO3 as energizer had a carburizing case depth of 2.32 mm which gives the highest wear resistance while charcoal compound gives a case depth of 1.1 mm .The work shows that cow bone can be used as compounds and energizer in pack carburization of mild steel. The hardness profile plot of the 90 wt.% 10% caco3 cow bone carburized mild steel was also higher than the other compositions and this value contributed on improvements of wear resistance.

  20. THE COURSE IN TESTING THE WEARING OUT OF MUD PUMPS PARTS

    Davorin Matanović

    1989-12-01

    Full Text Available Piston and cylinder are such parts in the mud pumps which cause the greatest expences due to the work stoppage of drilling rig. To reduce so caused expences it is necessary to produce spare parts of better quality. In determining the abrasion wear resistance for chosen materials, so called dry sand/rubber wheel abrasion test as an ASTM standard has been used (the paper is published in Croatian.

  1. Development of wear and corrosion resistant surface systems; Entwicklungen von verschleiss- und korrosionsbestaendigen Oberflaechensystemen

    Ahn, H. [Technische Univ. Braunschweig (Germany). Inst. fuer Oberflaechentechnik und Plasmatechnische Werkstoffentwicklung; Pfohl, C. [Technische Univ. Braunschweig (Germany). Inst. fuer Oberflaechentechnik und Plasmatechnische Werkstoffentwicklung; Woehle, J. [Technische Univ. Braunschweig (Germany). Inst. fuer Oberflaechentechnik und Plasmatechnische Werkstoffentwicklung; Gebauer, A. [Fraunhofer-Institut fuer Schicht- und Oberflaechentechnik, Braunschweig (Germany); Biemer, S. [Technische Univ. Braunschweig (Germany). Inst. fuer Oberflaechentechnik und Plasmatechnische Werkstoffentwicklung; Bulak, A. [Technische Univ. Braunschweig (Germany). Inst. fuer Oberflaechentechnik und Plasmatechnische Werkstoffentwicklung; Menthe, E. [Technische Univ. Braunschweig (Germany). Inst. fuer Oberflaechentechnik und Plasmatechnische Werkstoffentwicklung; Rodriguez Cabeo, E. [Volkswagenwerk AG, Wolfsburg (Germany). Zentrallaboratorium; Stucky, T. [Technische Univ. Braunschweig (Germany). Inst. fuer Oberflaechentechnik und Plasmatechnische Werkstoffentwicklung

    1996-12-01

    In this study two methods are described to realize wear and corrosion resistant surface systems: plasma diffusion treatment (PDT) and plasma assisted CVD (PACVD). Plasma nitriding, plasma nitrocarburizing and plasma boriding are used to treat different kinds of substrates. The advances of PACVD and the development of low temperature PACVD and industrial applications of these techniques are explained. (orig.)

  2. Processing of Homogeneous Zirconia-Toughened Alumina Ceramics with High Dry-Sliding Wear Resistance

    Kerkwijk, Bas; Winnubst, Louis; Mulder, Elmer J.; Verweij, Henk

    1999-01-01

    The preparation of dense homogeneous zirconia-toughened alumina (ZTA) with high dry-sliding wear resistance is described. These ZTA ceramics are obtained by sintering green compacts, made by colloidal filtration of well-defined ZrO2-Al2O3 particle suspensions, for 2 h at 1400°C. The optimum solid an

  3. Corneal Abrasions

    ... eye under a light that is filtered cobalt blue. The fluorescein causes the abrasion to glow bright ... putting in or removing your contacts. Around the house, be extra careful when you use cleaning products, ...

  4. Effect of Residual Stress on the Wear Resistance of Thermal Spray Coatings

    Luo, W.; Selvadurai, U.; Tillmann, W.

    2016-01-01

    The wear resistance of thermal spray coatings mainly depends on coating properties such as the microstructure, hardness, and porosity, as well as on the residual stress in the coating. The residual stress is induced by a variety of influences e.g., temperature gradients, difference of the thermal expansion coefficient of the coating/substrate materials, and the geometry of the components. To investigate the residual stress, the impulse excitation technique was employed to measure the Young's and shear moduli. The residual stress was determined by the hole-drilling method and x-ray diffraction. Pin-on-Disk and Pin-on-Tube tests were used to investigate the wear behavior. After the wear tests, the wear volume was measured by means of a 3D-profilometer. The results show that the value of the residual stress can be modified by varying the coating thickness and the substrate geometry. The compressive stress in the HVOF-sprayed WC-Co coatings has a significant positive influence on the wear resistance whereas the tensile stress has a negative effect.

  5. Preparation, characterization and wear behavior of carbon coated magnesium alloy with electroless plating nickel interlayer

    Mao, Yan [Shanghai Key Laboratory of Materials Laser Processing and Modification, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240 (China); Li, Zhuguo, E-mail: lizg@sjtu.edu.cn [Shanghai Key Laboratory of Materials Laser Processing and Modification, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240 (China); Academician Expert Office Workstation (Jiansheng Pan), Lin’an, Zhejiang Province (China); Feng, Kai, E-mail: fengkai@sjtu.edu.cn [Shanghai Key Laboratory of Materials Laser Processing and Modification, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240 (China); Academician Expert Office Workstation (Jiansheng Pan), Lin’an, Zhejiang Province (China); Guo, Xingwu [National Engineering Research Center of Light Alloys Net Forming (LAF), School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240 (China); Zhou, Zhifeng [Department of Mechanical and Biomedical Engineering, City University of Hong Kong, Kowloon, Hong Kong (China); Dong, Jie [National Engineering Research Center of Light Alloys Net Forming (LAF), School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240 (China); Wu, Yixiong [Shanghai Key Laboratory of Materials Laser Processing and Modification, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240 (China); State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, Shanghai 200240 (China); Academician Expert Office Workstation (Jiansheng Pan), Lin’an, Zhejiang Province (China)

    2015-02-01

    Highlights: • The carbon film with nickel interlayer (Ni + C coating) is deposited on GW83. • In Ni + C composite coating the carbon coating has good adhesion with the nickel interlayer. • The wear track of Ni + C coating is narrower compared to the bare one. • The wear resistance of GW83 is greatly improved by the Ni + C coating. - Abstract: Poor wear resistance of rare earth magnesium alloys has prevented them from wider application. In this study, composite coating (PVD carbon coating deposited on electroless plating nickel interlayer) is prepared to protect GW83 magnesium alloys against wear. The Ni + C composite coating has a dense microstructure, improved adhesion strength and hardness due to the effective support of Ni interlayer. The wear test result shows that the Ni + C composite coating can greatly prolong the wear life of the magnesium alloy. The wear track of the Ni + C coated magnesium alloy is obviously narrower and shows less abrasive particles as compared with the bare one. Abrasive wear is the wear mechanism of the coatings at the room temperature. In conclusion, the wear resistance of the GW83 magnesium alloy can be greatly improved by the Ni + C composite coating.

  6. Preparation, characterization and wear behavior of carbon coated magnesium alloy with electroless plating nickel interlayer

    Highlights: • The carbon film with nickel interlayer (Ni + C coating) is deposited on GW83. • In Ni + C composite coating the carbon coating has good adhesion with the nickel interlayer. • The wear track of Ni + C coating is narrower compared to the bare one. • The wear resistance of GW83 is greatly improved by the Ni + C coating. - Abstract: Poor wear resistance of rare earth magnesium alloys has prevented them from wider application. In this study, composite coating (PVD carbon coating deposited on electroless plating nickel interlayer) is prepared to protect GW83 magnesium alloys against wear. The Ni + C composite coating has a dense microstructure, improved adhesion strength and hardness due to the effective support of Ni interlayer. The wear test result shows that the Ni + C composite coating can greatly prolong the wear life of the magnesium alloy. The wear track of the Ni + C coated magnesium alloy is obviously narrower and shows less abrasive particles as compared with the bare one. Abrasive wear is the wear mechanism of the coatings at the room temperature. In conclusion, the wear resistance of the GW83 magnesium alloy can be greatly improved by the Ni + C composite coating

  7. Tribological behavior and wear mechanism of resin-matrix contact strip against copper with electrical current

    TU Chuan-jun; CHEN Zhen-hua; CHEN Ding; YAN Hong-ge; HE Feng-yi

    2008-01-01

    The resin-matrix pantograph contact strip (RMPCS), which has excellent abrasion resistance with electrical current and friction-reducing function, was developed in view of the traditional contact strips with high maintenance cost, high wear rate with electrical current and severe damage to the copper conducting wire. The characteristics of worn surfaces, cross-section and typical elemental distributions of RMPCS were studied by scanning electron microscopy (SEM) and energy dispersion spectrometry (EDS).The wear behavior and arc discharge of RMPCS against copper were investigated with self-made electrical wear tester. The results show that the electrical current plays a critical role in determining the wear behavior, and the wear rate of the RMPCS against copper with electrical current is 2.7-5.8 times higher than the value without electrical current. The wear rate of the contact strip increases with the increase of the sliding speed and electrical current density. The main wear mechanism of RMPCS against copper without electrical current is low stress grain abrasive and slightly adhesive wear, while arc erosion wear and oxidation wear are the dominate mechanism with electrical current, which is accompanied by adhesive wear during the process of wear.

  8. Microstructural Evolution and Wear Resistance of Friction Stir-Processed AISI 52100 Steel

    Seraj, R. A.; Abdollah-zadeh, A.; Hajian, M.; Kargar, F.; Soltanalizadeh, R.

    2016-07-01

    Friction stir processing (FSP) was successfully applied on AISI 52100 steel. The influence of process parameters on the microstructure and mechanical properties of the material was evaluated. It was observed that the initial ferritic-pearlitic microstructure of the base metal is transformed to the martensitic microstructure with retained austenite in the stir zone. The results also showed that microhardness and wear resistance of the FSP samples are, respectively, at least 2 and 15 times higher than those of the base metal. The improvement of the mechanical properties of FSP samples was attributed to their microstructural characteristics. The mechanisms controlling the wear behavior of the base metal and FSP samples were also discussed.

  9. WEAR RESISTANCE AND MECHANICAL PROPERTIES OF HIGHLY CROSSLINKED UHMWPE DOPED WITH VITAMIN-E

    Oral, Ebru; Christensen, Steven D.; Malhi, Arnaz S.; Wannomae, Keith K.; Muratoglu, Orhun K.

    2006-01-01

    Our hypothesis was that cross-linked UHMWPE stabilized with vitamin-E would be wear and fatigue resistant. Acetabular liners were radiation cross-linked, doped with vitamin E and γ-sterilized. Hip simulator wear rate of vitamin E-stabilized UHMWPE was approximately 1 and 6 mg/million-cycles in clean serum and in serum with third-body bone cement particles, respectively; a four to ten-fold decrease from that of conventional UHMWPE. The ultimate strength, yield strength, elongation-at-break and...

  10. Microstructural Evolution and Wear Resistance of Friction Stir-Processed AISI 52100 Steel

    Seraj, R. A.; Abdollah-zadeh, A.; Hajian, M.; Kargar, F.; Soltanalizadeh, R.

    2016-04-01

    Friction stir processing (FSP) was successfully applied on AISI 52100 steel. The influence of process parameters on the microstructure and mechanical properties of the material was evaluated. It was observed that the initial ferritic-pearlitic microstructure of the base metal is transformed to the martensitic microstructure with retained austenite in the stir zone. The results also showed that microhardness and wear resistance of the FSP samples are, respectively, at least 2 and 15 times higher than those of the base metal. The improvement of the mechanical properties of FSP samples was attributed to their microstructural characteristics. The mechanisms controlling the wear behavior of the base metal and FSP samples were also discussed.

  11. Study on comprehensive properties of duplex austenitic surfacing alloys for impacting abrasion

    2000-01-01

    In this paper, comprehensive property crack resistance, work hardening and abrasion resistance of a series of double-phases austenitic alloys(FAW) has been studied by means of SEM, TEM and type MD-10 impacting wear test machine. FAW alloys are of middle chromium and low manganese, including Fe-Cr-Mo-C alloy,Fe-Cr-Mn-C alloy and Fe-Cr-Mn-Ni-C alloy, that are designed for working in condition of impacting abrasion resistance hardfacing.Study results show that the work hardening mechanism of FAW alloys are mainly deformation high dislocation density and dynamic carbide aging, the form of wearing is plastic chisel cutting. Adjusting the amount of carbon, nickel, manganese and other elements in austenitic phase area, the FAW alloy could fit different engineering conditions of high impacting, high temperature and so on.

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

    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.

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

    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)

  14. Effect of Inter Critical Annealing on Microstructure and Wear Behaviour of En-8 Steel

    S. Narkhede

    2012-06-01

    Full Text Available The objective of the present work is to study effect of microstructure on abrasive wear resistance of EN-8 steel which were given inter-critical annealing heat treatment. The samples were heat treated to produce dual phased structure of hard martensite islands embedded in soft ferrite matrix. The results of the indicated that abrasive wear loss increased with decrease in hardness as well as increase in grain size of initial microstructure. The wear loss also increased with applied load. The phase analysis of wear debris revealed the presence of Fe₂O₃ indicating a tendency towards oxidative mechanism. The variation in wear loss with sliding length and applied load was correlated with microstructure of the material and distribution of phases.

  15. Study on Abrasive Wear Properties of MoB/CoCr Cermet Coating%MoB/CoCr金属陶瓷涂层的磨粒磨损性能研究

    陈枭; 纪岗昌

    2012-01-01

    在310S基体表面采用低压等离子喷涂(LPPS)技术制备MoB/CoCr金属陶瓷涂层.用扫描电镜观察涂层的组织结构:测试了MoB/CoCr涂层的显微硬度和结合强度;用湿式橡胶轮磨粒磨损试验机测试涂层的磨损性能.结果显示:MoB/CoCr涂层组织为层状结构,涂层与310S基体之间、表面涂层与过渡涂层之间结合良好.MoB/CoCr涂层具有较高的硬度值和结合强度,且具有良好的抗磨粒磨损性能.%MoB/CoCr cermet coating was deposited by low pressure plasma spraying (LPPS) on 310S steel. The microstructure of the MoB/CoCr coating was observed by SEM. The microhardness and bonding strength of the MoB/CoCr coating were tested. The abrasive wear properties were evaluated by wet sand rubber wheel tester. The results show that MoB/CoCr coating is dense and has excellent combination with 310S steel substrate. MoB/CoCr coating has high hardness and excellent wear properties.

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

    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.

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

    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.

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

    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

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

    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.

  20. The properties and wear resistance of the CrN PVD coatings

    M. Polok-Rubiniec

    2008-10-01

    Full Text Available Purpose: The aim of the paper is comparison of the mechanical properties and wear resistance of the monolayer CrN PVD coatings deposited onto heat treated and plasma nitrited X37CrMoV5-1 type hot work tool steel.Design/methodology/approach: The microhardness tests of the PVD coatings were made on the dynamic ultra-microhardness tester. The surfaces’ thopography and the structure of the PVD coatings was observed on the scanning electron microscopy. The evaluation of the adhesion of coatings to the substrate was made using the scratch test. The wear and friction tests were performed on a pin-on-disc device at the room temperature and at the temperature of 500°C. The friction coefficient between the ball and disc was measured during the test.Findings: : In case of the CrN coating deposited onto the X37CrMoV5-1 nitrided hot work steel a very good adhesion has been revealed to the substrate material in comparison to the CrN coating deposited onto the heat treated hot work steel. Taking into account the results of measurements, one can state that the lowest wear at certain conditions at both room and elevated temperatures displays the CrN coating deposited onto plasma nitrited X37CrMo V5-1 hot work steel type.Practical implications: The investigation results will provide useful information to applying the plasma nitriding and the CrN PVD coatings for the improvement of the wear resistance of tools made from hot work steels.Originality/value: The paper contributes to better understanding of the structure, mechanical properties, adhesion and the wear resistance at the elevated temperature (500°C of the monolayer CrN PVD coating deposited onto the heat treated and plasma nitrited hot work tool steel.

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

    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.

  2. Comparison of the structure, properties and wear resistance of the TiN PVD coatings

    M. Polok-Rubiniec

    2008-03-01

    Full Text Available Purpose: The aim of the paper was to compare the structure, mechanical propeties, adhesion and wear resistance of the monolayer TiN PVD coatings deposited onto heat treated and plasma nitrided hot work tool steel X37CrMoV5-1.Design/methodology/approach: The microhardness tests of the PVD coatings were made with use of a dynamic ultra-microhardness tester. The topography of the surface and the structure of the PVD coatings was observed with use of scanning electron microscopy.The evaluation of the adhesion of coatings to the substrate was made with use of the scratch test. The wear and friction tests were performed with use of a pin-on-disc device at the room temperature and at the temperature of 500°C.Findings: IIn case of the TiN coating deposited onto the nitrided hot work steel X37CrMoV5-1 a very good adhesion to the substrate has been revealed in comparison with the TiN coating deposited onto the heat treated hot work steel. Taking into account the results of measurements, one can state that the lowest wear at certain conditions at both room and elevated temperatures is characteristic for the TiN coating deposited onto plasma nitrided hot work steel type X37CrMoV5-1.Practical implications: The results of the investigations provide useful information for applying the plasma nitriding and the TiN PVD coating for the improvement of the mechanical properties and wear resistance of tools made from hot work steels.Originality/value: The paper contributes to better understanding of the adhesion and wear resistance at the elevated temperature up to 500°C of the monolayer TiN PVD coating deposited onto the heat treated and plasma nitrided hot work tool steel.

  3. Wear and corrosion resistant coatings formed by microarc oxidation on TiAl alloy

    Li Xijin [Key Laboratory of Beam Technology and Material Modification of Ministry of Education, Department of Materials Science and Engineering, Beijing Normal University, Beijing 100875 (China); Cheng Guoan [Key Laboratory of Beam Technology and Material Modification of Ministry of Education, Department of Materials Science and Engineering, Beijing Normal University, Beijing 100875 (China); Institute of Low Energy Nuclear Physics, Beijing Normal University, Beijing 100875 (China)], E-mail: gacheng@bnu.edu.cn; Xue Wenbin; Zheng Ruiting [Key Laboratory of Beam Technology and Material Modification of Ministry of Education, Department of Materials Science and Engineering, Beijing Normal University, Beijing 100875 (China); Institute of Low Energy Nuclear Physics, Beijing Normal University, Beijing 100875 (China); Cheng Yunjun [Research Center of Ti-Al Intermetallic Compound, High Temperature Material Research Division, General Iron and Steel Research Institute, Beijing 100081 (China)

    2008-01-15

    Microarc oxidation is an advanced method to fabricate ceramic coatings on valve metals. The coatings up to 110 {mu}m thick were prepared on {gamma}-TiAl alloy by the alternating-current microarc oxidation in silicate electrolyte. Their structures, composition, wear resistance and corrosion resistance were evaluated by scanning electron microscopy (SEM), X-ray diffraction (XRD), ball-disc dry sliding and electrochemical polarization tests. Results showed that the dense layer of coatings was mainly composed of Al{sub 2}TiO{sub 5} and TiO{sub 2} rutile phases, while the loose layer contained a large amount of amorphous SiO{sub 2} besides Al{sub 2}TiO{sub 5} and TiO{sub 2} rutile phases. Maximum value of microhardness in the coating was about three times higher than that of TiAl substrate. The wear rate of coating was only 1/10 of TiAl substrate. Corrosion current density of the coated TiAl alloy was greatly reduced. The microarc oxidation is a promising method to improve the wear resistance and corrosion resistance of TiAl alloy.

  4. Corrosion and wear resistance study of Ni-P and Ni-P-PTFE nanocomposite coatings

    Ankita, Sharma; Singh, Ajay

    2011-09-01

    This article reports on the corrosion and wear resistance of Ni-P and Ni-P-PTFE nanocomposite coatings deposited on mild steel substrates using the electroless plating technique. The coatings were characterized by scanning electron microscopy (SEM), energy dispersive analysis of X-Ray (EDAX), and X-ray diffractometry (XRD). The coatings were smooth and had thicknesses between 7 and 23 µm. They contained Ni, P, and additionally, F, in the case of the Ni-P-PTFE films. A broadening of the Ni peak in XRD was attributed to the amorphous nature and/or fine grain size of the films. Corrosion resistance was measured using immersion and electrochemical polarization tests in 3.5% NaCl solution whereas wear resistance was determined by the pin-on-disc method. Both Ni-P and Ni-P-PTFE coatings exhibited significant improvement in corrosion (in salty media) and wear behavior. Furthermore, the addition of PTFE in the coatings showed improvement in their corrosion resistance as well as a reduction in friction coefficient. Our testing revealed that the coatings' wore out following the "adhesive type" mechanism.

  5. Wear and corrosion resistance of anti-bacterial Ti-Cu-N coatings on titanium implants

    Wu, Haibo; Zhang, Xiangyu; He, Xiaojing; Li, Meng; Huang, Xiaobo; Hang, Ruiqiang; Tang, Bin

    2014-10-01

    Anti-bacterial coatings with excellent wear and corrosion resistance play a vital role in ensuring the durability of implant materials in constant use. To this end, a novel anti-bacterial surface modification by combining magnetron sputtering with plasma nitriding was adopted in this paper to fabricate Cu-bearing Ti-based nitrides coatings (Ti-Cu-N) on titanium surface. The anti-bacterial properties of Ti-Cu-N coatings were evaluated. The microstructures and composition of the coatings were investigated by using FESEM, EDS, GDOES, XRD. The wear and corrosion resistance of the coatings were investigated. The results confirmed that an anti-bacterial Ti-Cu-N coating with a thickness of 6 μm and good adhesive strength to substrate was successfully achieved on titanium surface. As implied by XRD, the coatings were consisted of TiN, Ti2N, TiN0.3 phases. The surface micro-hardness and wear resistance of Ti-Cu-N coatings were significantly enhanced after plasma nitriding treatment. The analysis of potentiodynamic polarization curves and Nyquist plots obtained in 0.9 wt.% NaCl solution suggested that the Ti-Cu-N coatings also exhibited an excellent corrosion resistance. As mentioned above, it can be concluded that the duplex-treatment reported here was a versatile approach to develop anti-bacterial Ti-Cu-N coatings with excellent comprehensive properties on titanium implants.

  6. Effect of graphite particle size on wear property of graphite and Al2O3 reinforced AZ91D-0.8%Ce composites

    2008-01-01

    The graphite particles and Al2O3 short fibers reinforced AZ91D-0.8%Ce composites were fabricated by squeeze-infiltration technique.The researches about the effects of different graphite particle sizes on the microstructure and wear property of the composites were performed under the condition of constant contents of graphite particles and Al2O3 short fibers.The results reveal that the grain size of the composites changes less when the graphite particle size descends.Moreover,Ce enriches around the graphite particle and Al2O3 short fibers and forms Al3Ce phase with A1 element.The graphite that works as lubricant decreases the wear loss.The wear resistance of the composites increases as the graphite particle size increases.At low load the composites have similar wear loss;at high load the composite with the largest graphite particle size has the best wear resistance.The wear mechanism of all the composites at low load is abrasive wear and oxidation wear;at high load,except the composites with the particle size of 240 μm whose wear mechanism is still abrasive wear and oxicIation wear,the wear mechanism of othcrs changes to delamination wear.

  7. CrN-based wear resistant hard coatings for machining and forming tools

    Highly wear resistant multicomponent or multilayer hard coatings, based on CrN but incorporating other metals, have been developed using closed field unbalanced magnetron sputter ion plating technology. They are exploited in coated machining and forming tools cutting and forming of a wide range of materials in various application environments. These coatings are characterized by desirable properties including good adhesion, high hardness, high toughness, high wear resistance, high thermal stability and high machining capability for steel. The coatings appear to show almost universal working characteristics under operating conditions of low and high temperature, low and high machining speed, machining of ordinary materials and difficult to machine materials, and machining under lubricated and under minimum lubricant quantity or even dry conditions. These coatings can be used for cutting and for forming tools, for conventional (macro-) machining tools as well as for micromachining tools, either as a single coating or in combination with an advanced, self-lubricating topcoat.

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

    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.

  9. Wear and Corrosion Resistance of Electroless Plating Ni-P Coating on P110 Steel

    LIN Naiming; ZHOU Peng; ZOU Jiaojuan; XIE Faqin; TANG Bin

    2015-01-01

    In order to improve the surface performance and increase the lifetime of P110 oil casing tube steel during operation, electroless plating was conducted to form Ni-P coating onto its surface. The surface morphology/element distribution and phase constitution of the Ni-P coating were analyzed using scanning electron microscope (SEM) equipped with energy dispersive spectrometry (EDS) and X-ray diffraction (XRD). Tribological and electrochemical measurement tests were applied to investigate the wear and corrosion resistance of P110 steel and the Ni-P coating. The results showed that a uniform and compact, high phosphorous Ni-P coating was formed. The obtained Ni-P coating indicated certain friction-reduction effect and lower mass loss during friction-wear tests. The Ni-P coating also exhibited higher corrosion resistance in comparison with bared P110 steel. The obtained Ni-P coating has signifi cantly improved the surface performance of P110 steel.

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

    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.

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

    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.

  12. Friction and Wear Behaviors of Nanostructured Metals

    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.

  13. The friction and wear of metals and binary alloys in contact with an abrasive grit of single-crystal silicon carbide

    Miyoshi, K.; Buckley, D. H.

    1979-01-01

    Sliding friction experiments were conducted with various metals and iron-base binary alloys (alloying elements Ti, Cr, Mn, Ni, Rh, and W) in contact with single-crystal silicon carbide riders. Results indicate that the coefficient of friction and groove height (corresponding to the wear volume) decrease linearly as the shear strength of the bulk metal increases. The coefficient of friction and groove height generally decrease with an increase in solute content of binary alloys. A separate correlation exists between the solute to iron atomic radius ratio and the decreasing rates of change of coefficient of friction and groove height with increasing solute content. These rates of change are minimum at a solute to iron radius ratio of unity. They increase as the atomic ratio increases or decreases linearly from unity. The correlations indicate that atomic size is an important parameter in controlling friction and wear of alloys.

  14. Microstructure and abrasive wear properties of M(Cr,Fe)7C3 carbides reinforced high-chromium carbon coating produced by gas tungsten arc welding (GTAW) process

    Buytoz, Soner; M.Mustafa YILDIRIM

    2010-01-01

    In the present study, high-chromium ferrochromium carbon hypereutectic alloy powder was coated on AISI 4340 steel by the gas tungsten arc welding (GTAW) process. The coating layers were analyzed by optical microscopy, X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), X-ray energy-dispersive spectroscopy (EDS). Depending on the gas tungsten arc welding pa-rameters, either hypoeutectic or hypereutectic microstructures were produced. Wear tests of the coatings were c...

  15. DEVELOPMENT OF LASER CLADDING WEAR-RESISTANT COATING ON TITANIUM ALLOYS

    RUILIANG BAO; HUIJUN YU; CHUANZHONG CHEN; BIAO QI; LIJIAN ZHANG

    2006-01-01

    Laser cladding is an advanced surface modification technology with broad prospect in making wear-resistant coating on titanium alloys. In this paper, the influences of laser cladding processing parameters on the quality of coating are generalized as well as the selection of cladding materials on titanium alloys. The microstructure characteristics and strengthening mechanism of coating are also analyzed. In addition, the problems and precaution measures in the laser cladding are pointed out.

  16. Diode laser surface modification of Ti6Al4V alloy to improve erosion wear resistance

    A. Lisiecki

    2008-07-01

    Full Text Available Purpose: Purpose of this paper : The purpose of the study was to develop new laser alloying technologyproviding high erosion wear resistance of the working surfaces of blades made of titanium alloy Ti6Al4V.Design/methodology/approach: High power diode laser HPDL with a rectangular laser beam spot ofmultimode and uniform intensity of laser radiation was applied in the process of laser surface modification of thetitanium alloy Ti6Al4V. During the laser surface remelting and alloying of the titanium alloy in argon and nitrogenatmospheres, surface layers of high hardness and significantly higher erosion wear resistant, compared with thebase material of titanium alloy Ti6Al4V, were produced.Findings: The surface layers are composites of titanium nitrides participations in the titanium alloy matrix.Hardness of the surface layers and erosion wear resistance depends strongly on parameters of laser processing andon the partial pressure of nitrogen in the gas mixture of nitrogen-argon atmosphere.Research limitations/implications: The most critical parameter of the functional quality of titanium alloyblades of turbofan engine and steam turbines is the fatigue strength, therefore further investigations are required todetermine the fatigue strength and also internal stresses in the nitrided surface layers.Practical implications: The novel technology of high power diode laser surface modification of the titaniumalloy Ti6Al4V can be applied to produce erosion wear resistant and long lifetime surface layers of turbofan engineblades and steam turbine blades.Originality/value: The laser surface modification of titanium alloy by the high power diode laser with therectangular laser beam spot of multimode and uniform intensity of laser radiation is very profitable in a case oflaser surface remelting and alloying because the treated surface is heated uniformly, so uniform penetration depthand uniform thickness of the surface layer can be achieved, as opposed from

  17. Surface microhardness and wear resistance change of titanium alloy under ion nitriding

    The influence of ion implantation on the mechanical properties of titanium alloy OT-4 has been investigated. Implantation with 1016-1017 120 keV, N, Ar ions/cm2 and their mixture causes the titanium surfaces microhardness and wear resistance increase. Possible mechanisms for the change of metal surface layers as a result of ion implantation have been discussed using the results and investigations with the help of Rutherford backscattering and scanning electron microscope

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

    Chan, Chi-Wai; Lee, Seunghwan; Smith, Graham; Sarri, Gianluca; Ng, Chi-Ho; Sharba, Ahmed; Man, Hau-Chung

    2016-03-01

    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.

  19. Enhanced wear resistance of production tools and steel samples by implantation of nitrogen and carbon ions

    In recent years ion implantation has become a feasible technique for obtaining improved wear resistance of production tools. However, basic knowledge of how and in which cases ion implantation is working at its best is still needed. The present paper discusses structural and tribological investigations of carbon and nitrogen implanted steels. The nitrogen data were obtained mainly from field tests and the investigation of carbon implantations took place mainly in the laboratory. A study was made of how the tribological behaviour of implanted steels changes with different implantation parameters. The tribological laboratory investigations were carried out using pin-on-disc equipment under controlled test conditions, and deal with high dose carbon implantation (approximately (1-2)x1018 ions cm-2). The wear resistance of steels was enhanced dramatically, by up to several orders of magnitude. The field test results cover a broad range of ion implanted production tools, which showed a marked improvement in wear resistance. Nitrogen implanted tools are also compared with carbon and titanium implanted tools. (orig.)

  20. Contribution of human osteoblasts and macrophages to bone matrix degradation and proinflammatory cytokine release after exposure to abrasive endoprosthetic wear particles.

    Jonitz-Heincke, Anika; Lochner, Katrin; Schulze, Christoph; Pohle, Diana; Pustlauk, Wera; Hansmann, Doris; Bader, Rainer

    2016-08-01

    One of the major reasons for failure after total joint arthroplasty is aseptic loosening of the implant. At articulating surfaces, defined as the interface between implant and surrounding bone cement, wear particles can be generated and released into the periprosthetic tissue, resulting in inflammation and osteolysis. The aim of the present study was to evaluate the extent to which osteoblasts and macrophages are responsible for the osteolytic and inflammatory reactions following contact with generated wear particles from Ti‑6Al‑7Nb and Co‑28Cr‑6Mo hip stems. To this end, human osteoblasts and THP‑1 monocytic cells were incubated with the experimentally generated wear particles as well as reference particles (0.01 and 0.1 mg/ml) for 48 h under standard culture conditions. To evaluate the impact of these particles on the two cell types, the release of different bone matrix degrading matrix metalloproteinases (MMPs), tissue inhibitors of MMPs (TIMPs), and relevant cytokines were determined by multiplex enzyme‑linked immunosorbent assays. Following incubation with wear particles, human osteoblasts showed a significant upregulation of MMP1 and MMP8, whereas macrophages reacted with enhanced MMP3, MMP8 and MMP10 production. Moreover, the synthesis of TIMPs 1 and 2 was inhibited. The osteoblasts and macrophages also responded with modified expression of the inflammatory mediators interleukin (IL)‑6, IL‑8, monocyte chemoattractant protein‑1 and vascular endothelial growth factor. These results demonstrate that the release of wear particles affects the release of proinflammatory cytokines and has a negative impact on bone matrix formation during the first 48 h of particle exposure. Human osteoblasts are directly involved in the proinflammatory cascade of bone matrix degradation. The simultaneous activation and recruitment of monocytes/macrophages boosted osteolytic processes in the periprosthetic tissue. By the downregulation of TIMP production and the

  1. An abrasion-resistant and broadband antireflective silica coating by block copolymer assisted sol-gel method.

    Zou, Liping; Li, Xiaoguang; Zhang, Qinghua; Shen, Jun

    2014-09-01

    A double-layer broadband antireflective (AR) coating was prepared on glass substrate via sol-gel process using two kinds of acid-catalyzed TEOS-derived silica sols. The relative dense layer with a porosity of ∼10% was obtained from an as-prepared sol, while the porous layer with a porosity of ∼55% was from a modified one with block copolymer (BCP) Pluronic F127 as template which results in abundant ordered mesopores. The two layers give rise to a reasonable refractive index gradient from air to the substrate and thus high transmittance in a wide wavelength range, and both of them have the same tough skeleton despite different porosity, for which each single-layer and the double-layer coatings all behaved well in the mechanical property tests. The high transmittance and the strong ability of resisting abrasion make this coating promising for applications in some harsh conditions. In addition, the preparation is simple, low-cost, time-saving, and flexible for realizing the optical property. PMID:25117300

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

    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.

  3. Wear resistance and surface roughness of a newly devised adhesive patch for sealing smooth enamel surfaces.

    Schmidlin, Patrick R; Göhring, Till N; Roos, Malgorzata; Zehnder, Matthias

    2006-01-01

    A laboratory study assessed the wear resistance and surface roughness after chemical and mechanical wear of a newly devised adhesive patch when used as a smooth surface sealant. Forty-eight enamel discs were prepared from bovine lower central incisors. Sixteen specimens were treated with one of two sealing options: the prototype of an adhesive patch or a flowable resin. Unsealed enamel served as the positive control. Wear and surface roughness was measured at baseline and after all the samples were immersed in saliva or lactic acid (n=8 per treatment group) for up to 21 days, during which the experimental and control enamel surfaces were exposed to 10 double-stroke toothbrush cycles per day. In saliva and lactic acid, the sealed specimens showed no significant wear during the observation period (p=0.1841). Only untreated specimens exposed to lactic acid showed a significant substance loss after 14 and 21 days (p=0.0186). The patch and flowable resin showed no differences in surface roughness values at respective times (p=0.385); whereas the surface roughness of the unsealed specimens in lactic acid was significantly higher (psealant for smooth enamel surfaces. PMID:16536202

  4. Plasma spray processing of TiC-based coatings for sliding wear resistance

    Mohanty, Mahesh

    Titanium carbide-reinforced metallic coatings, produced by plasma spraying, can be used for sliding wear resistant applications. The sliding wear properties of such coatings are governed to a large extent by the strength, structure and stability of the bond interface between the carbide and the metallic phases. In the present investigation, the microstructure and sliding wear properties of plasma sprayed metal-bonded TiC coatings containing up to 90 v/o carbide have been studied. It was shown that alloying of the metallic phase improved carbide retention in TiC cermets due to better interface bonding, and increased wear resistance and lowered sliding coefficient of friction. TiC-based coatings were produced from both physically blended and synthesized feed powders. It was observed that the precursor TiC-based powder morphology and structure greatly affected the plasma sprayed coating microstructures and the resultant physical and mechanical characteristics. Physical blending of powders induced segregation during spraying, leading to somewhat lower deposit efficiencies and coating uniformity, while synthesized and alloyed titanium carbide/metal composite powders reduced problems of segregation and reactions associated with plasma spraying of physically blended powders where the TiC was in direct contact with the plasma jet. To understand oxidation effects of the environment, Ti and TiC-based coatings were produced under low pressure (VPS), air plasma (APS) and shrouded plasma sprayed conditions. APS Ti and TiC-based powders with reactive matrices suffered severe oxidation decomposition during flight, leading to poor deposition efficiencies and oxidized microstructures. High particle temperatures and cold air plasma spraying. Coating oxidation due to reactions of the particles with the surrounding air during spraying reduced coating hardness and wear resistance. TiC-with Ti or Ti-alloy matrix coatings with the highest hardness, density and wear resistance was

  5. Carbide Precipitation Behavior and Wear Resistance of a Novel Roller Steel

    Guo, Jing; Li, Qiang; Qu, Hongwei; Liu, Ligang; Yang, Qingxiang

    2013-06-01

    High speed steel, which contains more alloy elements, cannot be used to manufacture the forged work roll. Therefore, a novel roller steel was designed on the basis of W6Mo5Cr4V2 (M2) steel. In this study, the carbide precipitation behavior and wear resistance of the novel roller steel were investigated. The Fe-C isopleths were calculated by Thermo-Calc to determine the carbide types, which were precipitated at different temperatures. The phase transformation temperatures were measured by differential scanning calorimeter and then the characteristic temperatures were designed. The phase structures quenched from the characteristic temperatures were measured by x-ray diffraction and transmission electron microscopy. The typical microstructures were observed by field emission scanning electron microscopy with Energy Disperse Spectroscopy. The hardness and wear resistance of the novel roller steel were measured. The results show that the precipitation temperatures of austenite, MC, M6C, M23C6, and ferrite are 1360, 1340, 1230, 926, and 843 °C respectively. When the specimen is quenched from 1300 °C, only MC precipitates from the matrix. At 1220 °C, MC and M2C precipitate. At 1150 °C, all of MC, M2C and M6C precipitate. Relationship between mass fraction of different phases and temperature were also simulated by Thermo-Calc. The hardness of the novel roller steel is a little lower than that of M2 steel, however, the wear resistance of the novel roller steel is a little higher than that of M2 steel with the increase of wear time.

  6. Comparison of the adhesion and wear resistance of the PVD coatings

    M. Polok-Rubiniec

    2007-01-01

    Full Text Available Purpose: of the paper was comparison of the adhesion and antiwear properties of the multilayer TiN/(Ti,AlNPVD coatings deposited onto heat treated and plasma nitrited X37CrMoV5-1 type hot work tool steel.Design/methodology/approach: Hardness test of the investigated specimens from hot work steel in the heattreated state has been made using Rockwell method. The distribution of microhardness in the nitriding layermeasured using Vickers micro-hardness testing method. The evaluation of the adhesion of coatings to thesubstrate was made using the scratch test. Wear resistance tests with the pin-on-disc method were carried out onthe CSEM THT (High Temperature Tribometer device at the room temperature and at the temperature of 500˚C.The friction coefficient between the ball and disc was measured during the test.Findings: In case of the TiN/(Ti,AlN coating deposited onto the X37CrMoV5-1 nitrided hot work steel show avery good adhesion which has been revealed to the substrate material is comparison to the TiN/(Ti,AlN coatingdeposited onto heat treated hot work steel. Taking into account the results of measurements, one can state thatthe lowest wear at certain conditions in both room and elevated temperatures show TiN/(Ti,AlN deposited ontoplasma nitrited X37CrMo V5-1 hot work steel type.Practical implications: The investigation results will provide useful information to applying of the TiN/(Ti,AlNPVD coating for the improvement of wear resistance of tools made from hot work steels.Originality/value: The paper contributes to better understanding the wear resistance at the elevated temperatureto 500ºC of the multilayer TiN/(Ti,AlN PVD coating deposited onto heat treated and plasma nitrited hot worktool steel

  7. Improvement of the wear resistance of electroplated Au-Ni coatings by Zr ion bombardment of Ni-B sublayer

    The effect of bombardment of the Ni-B sublayer by Zr ion beams on the surface morphology and tribomechanical properties of Au-Ni coatings was investigated. It was found that the treatment has no significant effect on the surface roughness and grain size of the Au-Ni coatings, while it provides essential reducing of their friction coefficient and improvement of wear resistance. It is shown that increased wear resistance of these coatings was caused by their strain hardening resulted from localization of plastic strain. The optimal Zr fluence were determined that provide the maximum reduction of linear wear of the coatings

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

    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.

  9. Wear resistance of laser-deposited boride reinforced Ti-Nb-Zr-Ta alloy composites for orthopedic implants

    The inherently poor wear resistance of titanium alloys limits their application as femoral heads in femoral (hip) implants. Reinforcing the soft matrix of titanium alloys (including new generation β-Ti alloys) with hard ceramic precipitates such as borides offers the possibility of substantially enhancing the wear resistance of these composites. The present study discusses the microstructure and wear resistance of laser-deposited boride reinforced composites based on Ti-Nb-Zr-Ta alloys. These composites have been deposited using the LENSTM process from a blend of elemental Ti, Nb, Zr, Ta, and boron powders and consist of complex borides dispersed in a matrix of β-Ti. The wear resistance of these composites has been compared with that of Ti-6Al-4V ELI, the current material of choice for orthopedic femoral implants, against two types of counterfaces, hard Si3N4 and softer SS440C stainless steel. Results suggest a substantial improvement in the wear resistance of the boride reinforced Ti-Nb-Zr-Ta alloys as compared with Ti-6Al-4V ELI against the softer counterface of SS440. The presence of an oxide layer on the surface of these alloys and composites also appears to have a substantial effect in terms of enhanced wear resistance

  10. Metal-ceramic composite coatings obtained by new thermal spray technologies: Cold Gas Spray (CGS) and its wear resistance

    In this paper, composite coatings composed by an aluminum bronze metal matrix and a hard ceramic alumina phase obtained by cold spray technique were obtained in order to increase the tribological properties of the pure bronze coatings. The different processes that occur during the coating formation (hardening of the metal particles, fragmentation of the ceramic particles, shot peening on the metal substrate, etc) are described and their effects on the coating properties are studied. Wear tests consisting on Ball-on-Disk tests, abrasion Rubber Wheel tests and erosion tests as well as microhardness and adhesion tests are carried out and the results are correlated with the ceramic phase content of the coatings. It can be concluded that the hard ceramic phase increases the tribological properties with relation of the initial bronze coating. Finally, main wear mechanisms during the tribological tests are described. (Author) 21 refs.

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

    Katya Gotlib-Vainshtein

    2014-07-01

    Full Text Available 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.

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

    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.

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

    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.

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

    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). PMID:27454031

  15. Highly wear-resistant and biocompatible carbon nanocomposite coatings for dental implants.

    Penkov, Oleksiy V; Pukha, Vladimir E; Starikova, Svetlana L; Khadem, Mahdi; Starikov, Vadym V; Maleev, Maxim V; Kim, Dae-Eun

    2016-09-01

    Diamond-like carbon coatings are increasingly used as wear-protective coatings for dental implants, artificial joints, etc. Despite their advantages, they may have several weak points such as high internal stress, poor adhesive properties or high sensitivity to ambient conditions. These weak points could be overcome in the case of a new carbon nanocomposite coating (CNC) deposited by using a C60 ion beam on a Co/Cr alloy. The structure of the coatings was investigated by Raman and XPS spectroscopy. The wear resistance was assessed by using a reciprocating tribotester under the loads up to 0.4 N in both dry and wet sliding conditions. Biocompatibility of the dental implants was tested in vivo on rabbits. Biocompatibility, bioactivity and mechanical durability of the CNC deposited on a Co/Cr alloy were investigated and compared with those of bulk Co/Cr and Ti alloys. The wear resistance of the CNC was found to be 250-650 fold higher compared to the Co/Cr and Ti alloys. Also, the CNC demonstrated much better biological properties with respect to formation of new tissues and absence of negative morphological parameters such as necrosis and demineralization. Development of the CNC is expected to aid in significant improvement of lifetime and quality of implants for dental applications. PMID:27336185

  16. Structural changes in and the wear of the rock cutting element of a bulldozer during operation under the North conditions

    Vinokurov, G. G.; Yakovleva, S. P.; Kychkin, A. K.; Vasil'Eva, M. I.; Struchkov, N. F.; Fedorov, M. V.

    2009-10-01

    The phenomenon of accelerated wear of a ripper crown in a digging machine (bulldozer) under the North operating conditions is studied. The elemental composition, microstructure, microhardness of the crown metal and the wear surface relief characteristics are determined. It is found that, under complex heat-force conditions of loading during the exploitation of cryolite rocks, the metal in the active surface of the rock cutting element undergoes intense softening as a result of the formation of a secondary structure, namely, frictioninduced sorbite. As a result of an insufficient level of the wear resistance of the crown metal and its plasticization, the traces of abrasive wear become deeper and plastic impact-abrasive wear takes place.

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

    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.

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

    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

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

    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.

  20. Clinical measurement of tooth wear: tooth Wear Indices

    López Frías, J.; Castellanos Cosano, Lizett; Martín González, Jenifer; Llamas Carreras, José María; Segura-Egea, Juan J.

    2012-01-01

    Attrition, erosion, and abrasion result in alterations to the tooth and manifest as tooth wear. Each classification corresponds to a different process with specific clinical features. Classifications made so far have no accurate prevalence data because the indexes do not necessarily measure a specific etiology, or because the study populations can be diverse in age and characteristics. Tooth wears (attrition, erosion and abrasion) is perceived internationally as a growing problem. However, th...

  1. Dry Sliding Wear Behavior of a Novel 6351 Al-Al4SiC4 Composite

    Mondal, Manas Kumar; Biswas, Koushik; Saha, Atanu; Maity, Joydeep

    2015-02-01

    In this research work the dry sliding wear behavior of 6351 Al alloy and 6351 Al based composites possessing varying amount of (2-7 vol.%) in situ Al4SiC4 reinforcement was investigated at low sliding speed (1 m/s) against a hardened EN 31 disk at different loads. In general, the wear mechanism involved adhesion and microcutting abrasion. Under selected loads (9.8 and 24.5 N), the overall wear resistance increased with increasing content of Al4SiC4 particles since particles stood tall against the process of wear. Besides, strain hardening of the matrix played an additional role to provide wear resistance. Therefore, the newly developed 6351Al-Al4SiC4 composite can be used as light weight wear resistance component in industry.

  2. The Effect of Shielding Gas Composition on Microstructure and Abrasive Wear Resistance Fabricated with PTA Alloying Technique

    Çay V.V.

    2013-12-01

    Full Text Available Powierzchnie stalowe SAE 1020 były oddzielnie stopowane z wcześniej nałożonymi proszkami wysokowęglowego żelazo- chromu (FeCr, żelazo-molibdenu (FeMo i żelazo-tytanu (FeTi za pomocą techniki PTA. Dzięki zastosowaniu trzech różnych typów gazu osłonowego w trakcie procesu wytwarzania stopu, badano wpływ modyfikacji składu gazu osłonowego na mikro- strukturę, twardość i odporność na ścieranie próbek. Najbardziej jednorodną mikrostrukturę i najwyższą odporność na ścieranie otrzymuje się w środowisku gazowym, które zawiera 3% H2. Zwiększenie zawartości H2 do 5% w składzie gazu osłonowego spowodowało powstanie luk i porów w mikrostrukturze oraz spadek odporności na ścieranie. Badania dyfrakcji rentgenowskiej próbek pozwoliły zidentyfikować roztwory stałe żelazo-molibdenu i żelazo-tytanu, ferryt, austenit i martenzyt jako pierwszą fazę w ich mikrostrukturze, oraz FeC. Cr7C3, G3C2, Fe3C, Fe7C3. MoC i TiC jako drugą fazę. W związku z tym stwierdzono, że zmiany w składu gazu osłonowego w procesie stopowania wpłynęły na mikrostrukturę próbek i właściwości ścierne.

  3. Microstructure and wear resistance of the hypereutectic Fe-Cr-C alloy hardfacing metals with different La2O3 additives

    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.

  4. Sliding wear behavior of carbide coatings

    The wear rates of sliding surfaces under starved lubrication conditions are frequently controlled by the onset of scuffing or adhesive transfer resulting in scratching or galling damage mechanisms. Thermally sprayed coatings containing a high volume fraction of hard phases, such as carbides, generally exhibit good abrasion resistance. However, during sliding contact with ferrous materials, the onset of adhesive transfer can occur at relatively low combinations of temperature, sliding speed and contact pressure. Improvements may be obtained when appropriate additions of solid lubricating phases are distributed within the coating. These additions are usually accompanied by an increase in the coating porosity which may itself alter the sliding wear behavior by modifying the distribution of lubricating oil. This paper describes an investigation of the influence of coating porosity on the sliding wear behavior of two conventional carbide coatings

  5. Effect of biomimetic coupling units' morphologies on rolling contact fatigue wear resistance of steel from machine tool rolling tracks

    Yang, Wanshi; Zhou, Hong; Sun, Liang; Wang, Chuanwei; Chen, Zhikai

    2014-04-01

    The rolling contact fatigue wear resistance plays an important role on ensuring machining precision of machine tool using rolling tracks. Bio-inspired wearable surfaces with the alternated hardness were prepared on the specimen of steel material from machine tool rolling tracks by biomimetic coupling laser remelting method to imitate biological coupling principle. The microstructures and micromorphologies of bionic units in different sizes were characterized by optical microscope. The specimens with bionic units in different sizes and distributions were tested for rolling contact fatigue wear resistance. Combining the finite element analysis and the results of wear tests, a discussion on rolling contact fatigue wear was had. The specimens with bionic units had better rolling contact fatigue wear resistance than the untreated one, while the specimens with bionic units in the alternative depth's distributions present a better rolling contact fatigue wear resistance than the ones with bionic units in the single depth's distribution. It attributed to the alternative distribution made further improvement on the dispersion of depth of stress concentration.

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

    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.

  7. Scratch, wear and corrosion resistant organic inorganic hybrid materials for metals protection and barrier

    Highlights: • Polysiloxane coatings as protective barriers to delay erosion/corrosion of Fe 430 B metal substrates. • Methyl groups feature a very small steric hindrance and confer ductility to the Si–O–Si backbone. • Phenyl groups feature a larger steric hindrance, but they ensure stability and high chemical inertness. • Remarkable adhesion to the substrate, good scratch resistance and high wear endurance. • Innovative ways to design of long lasting protective barriers against corrosion and aggressive chemicals. - Abstract: Polysiloxanes are widely used as protective barriers to delay erosion/corrosion and increase chemical inertness of metal substrates. In the present work, a high molecular weight methyl phenyl polysiloxane resin was designed to manufacture a protective coating for Fe 430 B structural steel. Methyl groups feature very small steric hindrance and confer ductility to the Si–O–Si backbone of the organic inorganic hybrid resin, thus allowing the achievement of high thickness. Phenyl groups feature larger steric hindrance, but they ensure stability and high chemical inertness. Visual appearance and morphology of the coatings were studied by field emission scanning electron microscopy and contact gauge surface profilometry. Micro-mechanical response of the coatings was analyzed by instrumented progressive load scratch, while wear resistance by dry sliding linear reciprocating tribological tests. Lastly, chemical inertness and corrosion endurance of the coatings were evaluated by linear sweep voltammetry and chronoamperometry in aggressive acid environment. The resulting resins yielded protective materials, which feature remarkable adhesion to the substrate, good scratch resistance and high wear endurance, thus laying the foundations to manufacture long lasting protective barriers against corrosion and, more in general, against aggressive chemicals

  8. Comparative study of the wear resistance of Al2O3-coated MA956 superalloy

    Preoxidation of the MA956 superalloy, proposed as prosthetic biomaterial, generates a compact and inert α-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

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

    Wendler, B.G.; W. Pawlak

    2008-01-01

    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...

  10. Estimation of Wear Resistance in Acid Solution of Dental Ceramics by Neural Network

    Lisjak, D.; Čurković, L.; Živko-Babić, J.; Jakovac, M.

    2002-01-01

    It is known that exposure to acid causes damage to the glass surface. The aim of this study was to examine wear resistance, measuring the mass change of dental ceramics after contact with 10-3 mol dm-3 HCl at temperature of 50°C. Four samples of dental ceramics were analyzed: feldspatic ceramic, hydrothermal ceramic, glass ceramic for staining and glass ceramic for layering. The mass concentrations of eluted Na+, K+ and Ca2+ were determined by ion chromatography (IC) and mass concentration...

  11. Diode laser surface modification of Ti6Al4V alloy to improve erosion wear resistance

    A. Lisiecki; Klimpel, A

    2008-01-01

    Purpose: Purpose of this paper : The purpose of the study was to develop new laser alloying technologyproviding high erosion wear resistance of the working surfaces of blades made of titanium alloy Ti6Al4V.Design/methodology/approach: High power diode laser HPDL with a rectangular laser beam spot ofmultimode and uniform intensity of laser radiation was applied in the process of laser surface modification of thetitanium alloy Ti6Al4V. During the laser surface remelting and alloying of the tita...

  12. Titanium Carbides Coatings for Wear Resistant Biomedical Devices: Manufacturing and Modeling

    Deposition of Titanium Carbide coatings on Ti6Al4V substrate, through the reactive magnetron sputtering technique is here presented. The mechanical characterization of the coatings has been carried out through a set of indentation tests at different maximum applied loads. The elastic stiffness as well as the hardness of the coating-substrate system indicate that these coatings are suitable candidates for wear resistance applications in the orthopaedic field. Numerical simulation of the indentation tests allowed the identification of the constitutive parameters of the titanium carbide. Good agreement was achieved between experimental and numerical results

  13. Spark anodizing of β-Ti alloy for wear-resistant coating

    Habazaki, H.; Onodera, T.; Fushimi, K; Konno, H.; Toyotake, K.

    2007-01-01

    Spark anodizing of a bcc solid solution Ti–15% V–3% Al–3% Cr–3% Sn alloy has been performed in an alkaline electrolyte containing aluminate and phosphate using dc-biased ac anodizing to form a wear-resistant coating on the alloy. The coating consists mainly of Al2TiO5, with rutile and γ-Al2O3 being present as minor oxide phases. Depth profiles of the coating, examined by glow discharge optical emission spectroscopy, have revealed that aluminium species, highly enriched in the coating, distrib...

  14. Comparison of the structure, properties and wear resistance of the TiN PVD coatings

    M. Polok-Rubiniec; L.A. Dobrzański; K. Lukaszkowicz; M. Adamiak

    2008-01-01

    Purpose: The aim of the paper was to compare the structure, mechanical propeties, adhesion and wear resistance of the monolayer TiN PVD coatings deposited onto heat treated and plasma nitrided hot work tool steel X37CrMoV5-1.Design/methodology/approach: The microhardness tests of the PVD coatings were made with use of a dynamic ultra-microhardness tester. The topography of the surface and the structure of the PVD coatings was observed with use of scanning electron microscopy.The evaluation of...

  15. The properties and wear resistance of the CrN PVD coatings

    M. Polok-Rubiniec; L.A. Dobrzański; M. Adamiak

    2008-01-01

    Purpose: The aim of the paper is comparison of the mechanical properties and wear resistance of the monolayer CrN PVD coatings deposited onto heat treated and plasma nitrited X37CrMoV5-1 type hot work tool steel.Design/methodology/approach: The microhardness tests of the PVD coatings were made on the dynamic ultra-microhardness tester. The surfaces’ thopography and the structure of the PVD coatings was observed on the scanning electron microscopy. The evaluation of the adhesion of co...

  16. Саvitation-erosion wear resistance composite electrolytic coatings in neutral medium

    Білик, Юрій Мирославович; Стечишин, Мирослав Степанович; Мартинюк, Андрій Віталійович

    2013-01-01

    The work presented technology of wear-resistant composite electrolytic coatings on nickel base. Composite coatings containing a filler consisting of silicon carbide powders of different factions nanopowders of up to 50 nm, 5 (M5) mk, 20/28 mk, 40/50 mk and amorphous B  particle size of about 1 micron to form during the subsequent heat treatment of solid solutions. Accordingly, in the accepted designation: Ni-SiCnano; Ni-SiC5; Ni-SiC28; Ni-SiC50.To form the CEP was established setting that let...

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

    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

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

    Zhang Zhiguo; Yang Chengkai; Zhang Peng

    2014-01-01

    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, ...

  19. Reciprocating wear resistance of Al–SiC nano-composite fabricated by accumulative roll bonding process

    Highlights: • The behaviour of Al–SiC nano-composite was characterized using a pin-on-flat wear-testing machine. • Micro-hardness and reciprocating wear test were carried out. • Morphology of the worn surfaces of this nano-composite was examined. • The wear resistance of this composite increased by increasing the cycle number. - Abstract: In this work the wear behaviour of Al–SiC nano-composite, produced by accumulative roll bonding process was characterized using a pin-on-flat wear-testing machine. Hence various tests such as micro-hardness and reciprocating wear test were carried out. Morphology of the worn surfaces of this nano-composite was examined using scanning electron microscope. Experimental results have been revealed that the wear resistance of this nano-composite increased by increasing the cycle number due to SiC particles act as a solid lubricant. Also by increasing the cycle’s number the size of SiC particle becomes less than 100 nm and nano-composite was formed

  20. Assessment of exposures and potential risks to the US adult population from wear (attrition and abrasion) of gold and ceramic dental restorations.

    Richardson, G Mark; Clemow, Scott R; Peters, Rachel E; James, Kyle J; Siciliano, Steven D

    2016-01-01

    Little has been published on the chemical exposures and risks of dental restorative materials other than from dental amalgam and composite resins. Here we provide the first exposure and risk assessment for gold (Au) alloy and ceramic restorative materials. Based on the 2001-2004 US National Health and Nutrition Examination Survey (NHANES), we assessed the exposure of US adults to the components of Au alloy and ceramic dental restorations owing to dental material wear. Silver (Ag) is the most problematic component of Au alloy restorations, owing to a combination of toxicity and proportional composition. It was estimated that adults could possess an average of four tooth surfaces restored with Au alloy before exceeding, on average, the reference exposure level (REL) for Ag. Lithium (Li) is the most problematic component of dental ceramics. It was estimated that adults could possess an average of 15 tooth surfaces restored with ceramics before exceeding the REL for Li. Relative risks of chemical exposures from dental materials decrease in the following order: Amalgam>Au alloys>ceramics>composite resins. PMID:25805253

  1. Deposition of a-C:H films on UHMWPE substrate and its wear-resistance

    Xie, Dong; Liu, Hengjun; Deng, Xingrui; Leng, Y. X.; Huang, Nan

    2009-10-01

    In prosthetic hip replacements, ultrahigh molecular weight polyethylene (UHMWPE) wear debris is identified as the main factor limiting the lifetime of the artificial joints. Especially UHMWPE debris from the joint can induce tissue reactions and bone resorption that may lead to the joint loosening. The diamond like carbon (DLC) film has attracted a great deal of interest in recent years mainly because of its excellent tribological property, biocompatibility and chemically inert property. In order to improve the wear-resistance of UHMWPE, a-C:H films were deposited on UHMWPE substrate by electron cyclotron resonance microwave plasma chemical vapor deposition (ECR-PECVD) technology. During deposition, the working gases were argon and acetylene, the microwave power was set to 800 W, the biased pulsed voltage was set to -200 V (frequency 15 kHz, duty ratio 20%), the pressure in vacuum chamber was set to 0.5 Pa, and the process time was 60 min. The films were analysed by X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, nano-indentation, anti-scratch and wear test. The results showed that a typical amorphous hydrogenated carbon (a-C:H) film was successfully deposited on UHMWPE with thickness up to 2 μm. The nano-hardness of the UHMWPE coated with a-C:H films, measured at an applied load of 200 μN, was increased from 10 MPa (untreated UHMWPE) to 139 MPa. The wear test was carried out using a ball (Ø 6 mm, SiC) on disk tribometer with an applied load of 1 N for 10000 cycles, and the results showed a reduction of worn cross-sectional area from 193 μm 2 of untreated UHMWPE to 26 μm 2 of DLC coated sample. In addition the influence of argon/acetylene gas flow ratio on the growth of a-C:H films was studied.

  2. Deposition of a-C:H films on UHMWPE substrate and its wear-resistance

    Xie Dong [Key Laboratory for Advanced Technologies of Materials, Ministry of Education, School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu 610031 (China); School of Physical Science and Technology, Southwest Jiaotong University, Chengdu 610031 (China); Liu Hengjun; Deng Xingrui [Key Laboratory for Advanced Technologies of Materials, Ministry of Education, School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu 610031 (China); Leng, Y.X., E-mail: yxleng@263.net [Key Laboratory for Advanced Technologies of Materials, Ministry of Education, School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu 610031 (China); Huang Nan [Key Laboratory for Advanced Technologies of Materials, Ministry of Education, School of Materials Science and Engineering, Southwest Jiaotong University, Chengdu 610031 (China)

    2009-10-15

    In prosthetic hip replacements, ultrahigh molecular weight polyethylene (UHMWPE) wear debris is identified as the main factor limiting the lifetime of the artificial joints. Especially UHMWPE debris from the joint can induce tissue reactions and bone resorption that may lead to the joint loosening. The diamond like carbon (DLC) film has attracted a great deal of interest in recent years mainly because of its excellent tribological property, biocompatibility and chemically inert property. In order to improve the wear-resistance of UHMWPE, a-C:H films were deposited on UHMWPE substrate by electron cyclotron resonance microwave plasma chemical vapor deposition (ECR-PECVD) technology. During deposition, the working gases were argon and acetylene, the microwave power was set to 800 W, the biased pulsed voltage was set to -200 V (frequency 15 kHz, duty ratio 20%), the pressure in vacuum chamber was set to 0.5 Pa, and the process time was 60 min. The films were analysed by X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, nano-indentation, anti-scratch and wear test. The results showed that a typical amorphous hydrogenated carbon (a-C:H) film was successfully deposited on UHMWPE with thickness up to 2 {mu}m. The nano-hardness of the UHMWPE coated with a-C:H films, measured at an applied load of 200 {mu}N, was increased from 10 MPa (untreated UHMWPE) to 139 MPa. The wear test was carried out using a ball (O 6 mm, SiC) on disk tribometer with an applied load of 1 N for 10000 cycles, and the results showed a reduction of worn cross-sectional area from 193 {mu}m{sup 2} of untreated UHMWPE to 26 {mu}m{sup 2} of DLC coated sample. In addition the influence of argon/acetylene gas flow ratio on the growth of a-C:H films was studied.

  3. Deposition of a-C:H films on UHMWPE substrate and its wear-resistance

    In prosthetic hip replacements, ultrahigh molecular weight polyethylene (UHMWPE) wear debris is identified as the main factor limiting the lifetime of the artificial joints. Especially UHMWPE debris from the joint can induce tissue reactions and bone resorption that may lead to the joint loosening. The diamond like carbon (DLC) film has attracted a great deal of interest in recent years mainly because of its excellent tribological property, biocompatibility and chemically inert property. In order to improve the wear-resistance of UHMWPE, a-C:H films were deposited on UHMWPE substrate by electron cyclotron resonance microwave plasma chemical vapor deposition (ECR-PECVD) technology. During deposition, the working gases were argon and acetylene, the microwave power was set to 800 W, the biased pulsed voltage was set to -200 V (frequency 15 kHz, duty ratio 20%), the pressure in vacuum chamber was set to 0.5 Pa, and the process time was 60 min. The films were analysed by X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, nano-indentation, anti-scratch and wear test. The results showed that a typical amorphous hydrogenated carbon (a-C:H) film was successfully deposited on UHMWPE with thickness up to 2 μm. The nano-hardness of the UHMWPE coated with a-C:H films, measured at an applied load of 200 μN, was increased from 10 MPa (untreated UHMWPE) to 139 MPa. The wear test was carried out using a ball (O 6 mm, SiC) on disk tribometer with an applied load of 1 N for 10000 cycles, and the results showed a reduction of worn cross-sectional area from 193 μm2 of untreated UHMWPE to 26 μm2 of DLC coated sample. In addition the influence of argon/acetylene gas flow ratio on the growth of a-C:H films was studied.

  4. Improvement on wear resistance property of polyurethane film by compositing plasma-treated multi-walled carbon nanotubes

    Ogawa, Daisuke; Nakamura, Keiji

    2016-01-01

    We investigated the effect of plasma-treated multi-walled carbon nanotubes (CNTs) that are composited into a polyurethane (PU) film. In this journal article, we especially focused on one of mechanical properties of PU film, the wear resistance, to find how the plasma-treated CNTs give contributions to improve the resistance. Our experimental results showed that plasma-treated CNTs enhanced the wear resistance, in particular, when the CNTs treated with the plasma that was made of nitrogen-oxygen mixture gas. Then, we made measurements with infrared absorption spectroscopy to find the possible causes of the improvement. The measurement showed that the surface of the CNTs treated with nitrogen-oxygen plasma had an indication of isocyanate group, which generally hardens PU film. The plasma likely attached the functional group on CNTs, and then the CNTs added extra wear resistance of a polyurethane film.

  5. Enhanced wear resistance of ball-and-socket joints of dental implants by means of titanium gaseous nitriding.

    Gil, F J; Canedo, R; Padrós, A; Sada, E

    2002-07-01

    The aim of this research is the surface hardening of the ball-and-socket joint of dental implants by means of heat treatments in order to obtain titanium nitrides. These nitrides minimize the wear of the titanium used in prosthesis. In this paper the optimum heat treatment, the hardness and the wear resistance are described in relation to the ball-and-socket joint without heat treatment. PMID:12222756

  6. Effect of filler type on 3-body abrasion of dental composite

    Yasini E.

    2005-06-01

    Full Text Available Statement of Problem: The relatively poor wear resistance of dental composite in stress bearing posterior situations has restricted wider clinical application of this restorative material. Purpose: The aim of this study was to evaluate the three body abrasive wear of a dental composite based on a new filler (leucite: KAl Si2O6 and to compare it with the wear resistance of a composite based on commonly used Aluminium – Barium Silicate filler. Materials and Methods: This research was an interventional study done in Iran polymer institute. Five specimens were considered in each group. All ceramic IPS Empress® (Ivoclar- Vivadent ingots based on leucite crystals were ball milled, passed through an 800 sieve and used as filler. Experimental composites were prepared by mixing the silane- treated fillers with monomers (BisGMA and TEGDMA. Camphorquinone and amine were used as photoinitiator system. Degree of conversion of the light-cured and post-cured composites was measured using FTIR spectroscopy. The prepared pastes were inserted into plexy-glass mold and light cured (700 mw/cm2, 40 s. Then for maximum degree of conversion specimens were post- cured (120ºC, 5 hours. Three body abrasion wear testing was performed using a wear machine with 50 rpm rotational movement. In this machine, pumice (150 meshes was used as the third body. Weight loss of specimens in each group was measured by balance after each 50 hours. After wear testing SEM examination was made specimens in each group. The data were analyzed and compared using ANOVA and Tukey HSD tests (P<0.05. Tetric Ceram was tested as commercial composite. Results: There were significantly differences between three body abrasive wear of composites. The ranking from lowest to highest was as follows: leucite composite (19% < Tetric Ceram (22% < glass composite (28%. leucite composite showed the highest wear resistance value, propably due to the crystalliniy and hardness of filler. Conclusion

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

    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.

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

    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. Wear resistance of Fe-Nb-Cr-W, Nb, AISI 1020 and AISI 420 coatings produced by thermal spray wire arc; Resistencia al desgaste de recubrimientos Fe-Nb-Cr-W, Nb, AISI 1020 y AISI 420 producidos por proyeccion termica por arco electrico

    Lopez-Covaleda, E. A.; Mercado-Veladia, J. L.; Olaya-Florez, J. J.

    2013-07-01

    The commercial materials 140MXC (with iron, tungsten, chrome, niobium), 530AS (AISI 1015 steel) and 560AS (AISI 420 steel) on AISI 4340 steel were deposited using thermal spray with arc. The aim of work was to evaluate the best strategy abrasive wear resistance of the system coating-substrate using the following combinations: (1) homogeneous coatings and (2) coatings depositing simultaneously 140MXC + 530AS and 140MXC + 560AS. The coatings microstructure was characterized using Optical microscopy, Scanning electron microscopy and Laser con focal microscopy. The wear resistance was evaluated through dry sand rubber wheel test (DSRW). We found that the wear resistance depends on the quantity of defects and the mechanical properties like hardness. For example, the softer coatings have the biggest wear rates and the failure mode was characterized by plastic deformation caused by particles indentation, and the other hand the failure mode at the harder materials was grooving. The details and wear mechanism of the coatings produced are described in this investigation. (Author)

  10. Research on Wear Behavior of ATC Cermet Material

    ZHU Liu; LING Guo-ping; LI Jian; WANG You-wen

    2004-01-01

    By electroless chemical deposition process, a layer of metal cobalt film was coated on the surface of nano-ceramic powders of Al203 and TiC. The mixture of the two kinds of Co-coated power (about 70wt.%Al2O3-Co+30wt.%TiC-Co) was hot-pressed into ATC (Al2O3-TiC-Co8wt%) cermet samples. The wear test was carried out under dry sliding wear condition by the pin-on-disk rig. The volume-loss of the samples in three sliding pairs,ATC/Steel, ATC/SiC and ATC/artificial diamond (AD) were investigated. The wear morphologies were examined by SEM.The wear-resistance between ATC cermet and Co-cemented WC were compared. The results show that the effect of fracture toughness is better than that of hardness to the wear resistance of high hardness materials. The wear mechanisms of ATC cermet samples were found that abrasion predominated in the wear process. The wear surface of ATC cermet samples became smoother with fine asperities spalling off and the volume loss was decreased.

  11. Research on Wear Behavior of ATC Cermet Material

    ZHULiu; LINGGuo-ping; LIJian; WANGYou-wen

    2004-01-01

    By electroless chemical deposition process, a layer of metal cobalt film was coated on the surface of nano-ceramic powders of Al2O3 and TiC. The mixture of the two kinds of Co-coated power (about 70wt.% Al2O3-Co+30wt.%TiC-Co) was hot-pressed into ATC (Al2O3-TiC-Co8wt% ) cermet samples. The wear test was carried out under dry sliding wear condition by the pin-on-disk rig. The volume-loss of the samples in three sliding pairs, ATC/Steel, ATC/SiC and ATC/artificial diamond (AD) were investigated. The wear morphologies were examined by SEM. The wear-resistance between ATC cermet and Co-cemented WC were compared. The results show that the effect of fracture toughness is better than that of hardness to the wear resistance of high hardness materials. The wear mechanisms of ATC cermet samples were found that abrasion predominated in the wear process. The wear surface of ATC cermet samples became smoother with fine asperities spalling off and the volume loss was decreased.

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

    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 modified to either promote or prevent cell/biomaterial interactions. Given the favorable cell response to H-terminated USND, this material was further compared with two commonly used biocompatible metals, titanium alloy (Ti-6Al-4V) and cobalt chrome (CoCrMo). MSC adhesion and proliferation were significantly improved on USND compared with CoCrMo, although cell adhesion was greatest on Ti-6Al-4V. Comparable amounts of the pro-adhesive protein, fibronectin, were deposited from serum on the three substrates. Finally, MSCs were induced to undergo osteoblastic differentiation on the three materials, and deposition of a mineralized matrix was quantified. Similar amounts of mineral were deposited onto USND and CoCrMo, whereas mineral deposition was slightly higher on Ti-6Al-4V. When coupled with recently published wear studies, these in vitro results suggest that USND has the potential to reduce debris particle release from orthopaedic implants without compromising osseointegration. PMID:18490051

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

    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.

  14. Wear and Corrosion Resistance of Fe-Based Coatings Reinforced by TiC Particles for Application in Hydraulic Systems

    Bobzin, K.; Öte, M.; Linke, T. F.; Malik, K. M.

    2016-01-01

    Thermally sprayed Fe-based coatings reinforced by TiC particles are a cost-effective alternative to carbide coatings such as WC/CoCr, Cr3C2/NiCr, and hard chrome coatings. They feature a good wear resistance and—with sufficient amount of alloying elements like Cr and Ni—also a high corrosion resistance. In hydraulic systems, the piston is usually coated with hard chrome coatings for protection against corrosion and wear. New water-based hydraulic fluids require an adaption of the coating system. In order to investigate the wear and corrosion resistance of Fe/TiC, a novel powder consisting of a FeCr27Ni18Mo3 matrix and 34 wt.% TiC was applied by HVOF and compared to reference samples made of WC/CoCr (HVAF) and hard chrome. Besides an in-depth coating characterization (metallographic analyses, electron microprobe analyzer-EMPA), wear resistance was tested under reverse sliding in a water-based hydraulic fluid. The novel Fe/TiC coatings showed good wear protection properties, which are comparable to conventional coatings like WC/CoCr (HVAF) and electroplated hard chrome coatings. Corrosion resistance was determined by polarization in application-oriented electrolytes (hydraulic fluid at 60 °C, artificial sea water at RT). The corrosion resistance of the investigated iron-based coatings at 60 °C was superior to the references coatings for both hydraulic fluids. Selected coatings were tested in an application-oriented hydraulic test bench with HFC hydraulic fluid (water polymer solutions) showing comparably good wear and corrosion resistance as the hard chrome-coated reference.

  15. RESEARCH ON CONTAMINANT WEAR OF DISTRIBUTOR OF THE SHEARER'S MAIN PUMP

    汪茹; 荆元昌; 赵健

    1995-01-01

    Several damaged distributors of the shearer's main pump have been analyzed. Lubricated abrasive wear was found to be the cause of distributor failure. On the basis of selecting reasonably materials and surface strenthening methods of distributors, pump's function tests under the condition of contamination were performed with actual distributors. The results showed that wear resistance and contaminant wear lifetime of TIN coated high-speed steel W18Cr4V distributor is the best and TiN coating technology can be used in manufacturing of pump's distributor.

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

    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.

  17. An easy classification for dental cervical abrasions

    Madhuri Alankar Sawai

    2014-01-01

    Introduction: Tooth wear - attrition, abrasion, or erosion - are modern day problems for dentistry. It usually leads to discomfort and sensitivity especially during eating, drinking, or tooth brushing. If left untreated for a long time, it may lead to loss of vitality of tooth. Various qualitative and quantitative methods have been used in the past to describe tooth wear. However, each method has certain shortfalls. There is no ideal index that is simple and clear in its scoring criteria. The...

  18. A review of micro-scale abrasion testing

    Micro-scale abrasion (commonly referred to as 'ball cratering') is a small-scale tribological test method which can be operated on a desktop. It offers the possibility of providing a quick, cheap, localized abrasion test that can be used with small samples. In principle its operation is simple, but in practice there are issues with wear scar measurement, wear mode and its applicability to a wide variety of monolithic materials and coatings. (topical review)

  19. Impact of toothpaste slurry abrasivity and toothbrush filament stiffness on abrasion of eroded enamel - an in vitro study

    Wiegand, Annette; Schwerzmann, Martina; Sener, Beatrice; Magalhães, Ana C.; Roos, Malgorzata; Ziebolz, Dirk; Imfeld, Thomas; Attin, Thomas

    2008-01-01

    OBJECTIVE: Toothbrush abrasion is significant in the development of tooth wear, particularly when combined with erosion. This in vitro study aimed to evaluate the impact of toothpaste slurry abrasivity and toothbrush filament stiffness on abrasion of eroded enamel. MATERIAL AND METHODS: Eroded enamel samples (hydrochloric acid, pH: 2.6, 15 s) were brushed with 40 strokes in an automatic brushing machine using manual toothbrushes with different filament stiffness (filament diameter: 0.15, 0.20...

  20. Microstructure and Wear Resistance of Plasma-Sprayed Molybdenum Coating Reinforced by MoSi2 Particles

    Yan, Jianhui; He, Zheyu; Wang, Yi; Qiu, Jingwen; Wang, Yueming

    2016-08-01

    Mo coatings with or without incorporated MoSi2 were fabricated by atmospheric plasma spraying, and their microstructure, microhardness, bond strength, and wear resistance were compared. Two kinds of spray powder, i.e., pure Mo and a blend of Mo and MoSi2, were sprayed onto low-carbon steel. Microstructural analysis of the MoSi2-Mo coating showed MoSi2 homogeneously distributed in a Mo matrix. Addition of MoSi2 particles increased the microhardness of the as-sprayed Mo coating. The adhesion strength of the Mo coating was better than that of the MoSi2-Mo coating. Wear test results showed that the wear rate and friction coefficient of the two coatings increased with increasing load, and the friction coefficient of the MoSi2-Mo coating was lower than that of the Mo coating. The MoSi2-Mo composite coating exhibited better wear resistance than the Mo coating. The wear failure mechanisms of the two coatings were local plastic deformation, delamination, oxidation, and adhesion wear.

  1. A Study on Wear Resistance of HVOF-Sprayed Ni-MoS2 Self-Lubricating Composite Coatings

    Liu, Y. L.; Jeng, M. C.; Hwang, J. R.; Chang, C. H.

    2015-02-01

    Composite coating techniques are becoming increasingly popular owing to their peculiar performances. In this study, the wear resistance of thermally sprayed Ni-MoS2 composite coatings on an AISI 1020 steel substrate was investigated. Ni-MoS2 composite powder (size: 60-90 μm) containing 25 wt.% of dispersed MoS2 was prepared by electroless plating. Ni-MoS2 composite coatings were then prepared by HVOF thermal spraying. The coatings were characterized by structural, surface morphological, and compositional analyses by means of microhardness tests, SEM/EDS, XRD, and ICP-AES. For the evaluation of their anti-wear properties, the composites were subjected to ball-on-disk dry wear tests based on the ASTM G99 standard at room temperature. Experimental results showed that some of the MoS2 content dispersed in the Ni-based composite coating burnt away during the high-temperature spraying process, thereby reducing the MoS2 concentration in the coating. In the wear test, the weight loss in the Ni-MoS2 composite coating was minimal under a low load (30 N). The average wear rate of the coatings was found to be ~1/40 times that of a Ni coating, showing that the wear resistance of the composite coatings was significantly improved by MoS2 addition.

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

    Li, Ping; Qizhou CAI; Bokang WEI

    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...

  3. Effects of Si alloying and T6 treatment on mechanical properties and wear resistance of ZA27 alloys

    Rui Zhang; Guang-lei Liu; Nai-chao Si

    2016-01-01

    To improve the mechanical properties and wear resistance of ZA27 alloy, Si was introduced to the alloy, and the effect of Si alloying and T6 heat treatment on the microstructure, mechanical properties and wear resistance was investigated. The results show that with 0.55% Si, the microstructure of the alloy can be refined effectively, which leads to the increase of hardness. But the tensile strength and elongation decrease because Si undermines the integrity of the matrix. On the other hand, t...

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

    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. Ultrananocrystalline diamond film as a wear resistant and protective coating for mechanical seal applications

    Mechanical shaft seals used in pumps are critically important to the safe operation of the paper, pulp, and chemical process industry, as well as petroleum and nuclear power plants. Specifically, these seals prevent the leakage of toxic gases and hazardous chemicals to the environment and final products from the rotating equipment used in manufacturing processes. Diamond coatings have the potential to provide negligible wear, ultralow friction, and high corrosion resistance for the sliding surfaces of mechanical seals, because diamond exhibits outstanding tribological, physical, and chemical properties. However, diamond coatings produced by conventional chemical vapor deposition (CVD) exhibit high surface roughness (Ra ≥ 1 μm), which results in high wear of the seal counterface, leading to premature seal failure. To avoid this problem, we have developed an ultrananocrystalline diamond (UNCD) film formed by a unique CH4/Ar microwave plasma CVD method. This method yields extremely smooth diamond coatings with surface roughness Ra = 20-30 nm and an average grain size of 2-5 nm. We report the results of a systematic test program involving uncoated and UNCD-coated SiC shaft seals. Results confirmed that the UNCD-coated seals exhibited neither measurable wear nor any leakage during long-duration tests that took 21 days to complete. In addition, the UNCD coatings reduced the frictional torque for seal rotation by five to six times compared with the uncoated seals. This work promises to lead to rotating shaft seals with much improved service life, reduced maintenance cost, reduced leakage of environmentally hazardous materials, and increased energy savings. This technology may also have many other tribological applications involving rolling or sliding contacts.

  6. The evaluation of tribo-corrosion synergy for WC-Co hardmetals in low stress abrasion

    Gant, A.J.; Gee, M.G.; May, A.T. [National Physics Lab., Teddington (United Kingdom)

    2004-03-01

    WC-based hardmetals are materials that are widely used in applications where abrasion resistance is required. This paper describes the results of tests that were performed using a modified ASTM G65 rubber wheel test system incorporating an abrasive (silica sand) and media (sulphuric acid, deionised water, and calcium hydroxide solution). The first of these media was used in order to simulate conditions found in ash disposal equipment found in coal-fired power stations. The calcium hydroxide solution was intended to simulate conditions found in forming tools used in the manufacture of ceramic roofing tiles. Under very acidic conditions (pH 1.1), undermining of WC grains by binder dissolution appeared to be the rate-governing step in determining volume loss. Under mildly acidic conditions (pH 2.6 and 6.3) there was more evidence of WC grain fracture and correspondingly less of binder dissolution. Exposure to the alkali (pH 13 Ca(OH){sub 2} solution) caused the least wear. Results were correlated with physical and microstructural and parameters commonly used for quality assurance in the hardmetal industry. Corrosion-abrasion synergies were also evaluated using the same test rig in conjunction with the respective acidic solutions, but omitting the silica sand. These results are complemented by SEM examination of wear surfaces and of metallographically polished cross-sections of wear surfaces, and by bend strength evaluation of samples after simultaneous exposure to the various media and silica sand and the media in isolation.

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

    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. Effect of vanadium of mechanical behavior, machinability and wear resistance of aluminium grain refined by Ti+B

    It is well established that aluminum and its alloys are industrially grain refined by adding either Ti or Ti-B to improve their mechanical behavior and surface finish. In a previous paper, it was found that the grain refining efficiency of aluminum master alloys containing Ti or Ti+B was enhanced by addition of small amounts of other elements including vanadium. V. Therefore, it is anticipated that such an element will improve mechanical behavior, machinability and wear resistance of aluminum and its alloys. In this paper, the effect of vanadium addition, up to 0.3% on mechanical behavior is investigated. Machinability was assessed under different cutting conditions: speed, feed and depth of cut and finally the wear resistance was determined at different loads and speeds. The results indicated that improvement in hardness and mechanical strength were achieved by the addition of V that addition of more than 0.2%V resulted in little or no improvement. Similarly, addition of V resulted in improvement of surface quality under the different cutting conditions of speed, feed and depth of cut, and resistance to wear. However addition of more than 0.2% V resulted in increase of wear rate and change of wear mechanisms. (author)

  9. Plastic deformation wear in modified medium manganese steel

    YUAN Hai-lun

    2007-08-01

    Full Text Available A medium manganese steel with high wear-resistance, strength and toughness has been produced with addition of a complex modifier (or refining agent containing Nb, N, RE and Si-Ca. The results showed that the wear resistance, strength and toughness of the modified medium manganese steel are respectively 1.92 times, 1.45 times and 3.63 times as high as that of the referenced unmodified medium manganese steel. The plastic deformation characteristic involved in the wear mechanism of the modified medium manganese steel was investigated by means of plastic-elasticity calculation and TEM electro-microscopy. The relationship between wear resistance and yield strength of the steel was established. Since the wear volume W is proportional to the square of the loading and to the numbers of the abrasives, and inversely proportional to the square of the yield strength of the materials, the wear resistance can be substantially improved by the enhancement of yield strength of the materials. The calculation results generally agreed with the experimental results.

  10. Residual stress and wear resistance of WC particle reinforced Ni-based coating%W C颗粒增强 Ni基涂层的残余应力及耐磨性能

    郭华锋; 李菊丽; 孙涛; 杨海峰

    2014-01-01

    Microstructure of WC particle reinforced Ni-based plasma-sprayed coating was observed by scanning electron microscope (SEM). Surface residual stress of the coating with different WC content and the bonding layer were tested by X -ray diffraction ( XRD) method. Microhardness and wear mechanism of the coating were studied by friction and wear test machine and confocal laser scanning microscope .The results show that the surface residual stress of the coatings are compressive stress and decreased with the increase of WC content .However, residual stress increase with the increase of thickness of coatings and when thickness is 1000 μm, the coating appears delamination failure . The thermal stress is the largest contributive factor to residual stress of the bonding layer .A certain amplitude of compressive stress is beneficial to improve abrasion resistance of the coating .The wear loss of the coating is only about 0.135 times of that of the substrate under the same loading .The wear mechanism of the coating is mainly abrasive wear .%用扫描电子显微镜( SEM)观察了等离子喷涂WC颗粒增强Ni涂层的显微结构,用X射线衍射法( XRD)测试了不同WC含量下涂层及粘结层表面残余应力,利用摩擦磨损试验机和共聚焦激光扫描显微镜研究了涂层的磨损机制。结果表明:涂层表面残余应力为压应力,且随着WC含量的增加先增大后减小,随着涂层厚度的增加而增大,厚度为1000μm时出现分层失效,热应力对粘结层残余应力的贡献最大。一定幅值的压应力有利于涂层耐磨性的提高,同载荷下磨损量仅为基体的0.135倍,涂层磨损机制主要为磨粒磨损。

  11. Wear properties of Fe-Cr-C and B{sub 4}C powder coating on AISI 316 stainless steel analyzed by the Taguchi method

    Gur, Ali Kaya; Ozay, Cetin; Orhan, Ayhan; Buytoz, Soner; Caligulu, Ugur; Yigitturk, Necmettin [Firat Univ., Elazig (Turkey). Faculty of Technical Education

    2014-06-01

    In this study, the plasma arc welded cladding of FeCrC and B{sub 4}C powder mixtures alloyed with 70 wt.-% Cr on the surface of AISI 316 stainless steel was investigated. Application of the Taguchi method revealed respective effects on the abrasive wear resistance of the cladding layer on the stainless steel. The abrasive wear behaviour of the AISI 316 stainless steel surfaces coated with Fe-Cr-C and with 10 wt.-%, 15 wt.-%, 20 wt.-%, and 25 wt.-% B{sub 4}C was investigated by using four loads and four distances for the 220 mesh SiC abrasive. Results were analyzed by variance analysis using ANOVA, and effects of parameters on the wear rate were determined as percentage rate. Furthermore, the error ratio was statistically evaluated. The experimental results were analyzed by the respective analysis of means and variance which is discussed in detail. (orig.)

  12. Surface Design and Engineering Toward Wear-Resistant, Self-Lubricant Diamond Films and Coatings. Chapter 10

    Miyoshi, Kazuhisa

    1999-01-01

    This chapter describes three studies on the surface design, surface engineering, and tribology of chemical-vapor-deposited (CVD) diamond films and coatings toward wear-resistant, self-lubricating diamond films and coatings. Friction mechanisms and solid lubrication mechanisms of CVD diamond are stated. Effects of an amorphous hydrogenated carbon on CVD diamond, an amorphous, nondiamond carbon surface layer formed on CVD diamond by carbon and nitrogen ion implantation, and a materials combination of cubic boron nitride and CVD diamond on the adhesion, friction, and wear behaviors of CVD diamond in ultrahigh vacuum are described. How surface modification and the selected materials couple improved the tribological functionality of coatings, giving low coefficient of friction and good wear resistance, is explained.

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

    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.

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

    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.

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

    Kang, Minwoo; Lee, Young-Kook

    2016-04-01

    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.

  16. Wear resistance of nano- and micro-crystalline diamond coatings onto WC-Co with Cr/CrN interlayers

    Polini, Riccardo [Dipartimento di Scienze e Tecnologie Chimiche, Universita di Roma Tor Vergata, Via della Ricerca Scientifica, 1, Rome, 00133 (Italy); Barletta, Massimiliano, E-mail: barletta@ing.uniroma2.i [Dipartimento di Ingegneria Meccanica, Universita di Roma Tor Vergata, Via del Politecnico, 1, Rome, 00133 (Italy); Cristofanilli, Giacomo [Dipartimento di Scienze e Tecnologie Chimiche, Universita di Roma Tor Vergata, Via della Ricerca Scientifica, 1, Rome, 00133 (Italy)

    2010-12-30

    Cr/CrN bi-layers have been used recently to promote the growth of high quality Hot Filament Chemical Vapour Deposition (HFCVD) diamond coatings onto Co-cemented tungsten carbide (WC-6 wt.%Co) substrates. In the present investigation, the influence of the crystalline size of the diamond coatings on their wear endurance is looked into. Nano- (NDC) and micro-crystalline Diamond Coatings (MDC) were deposited by HFCVD onto untreated and Fluidized Bed (FB) treated Cr/CrN interlayers. NDCs, characterized by a cauliflower-like morphology, showed improved wear resistance. However, the superimposition of NDCs onto Cr/CrN interlayers micro-corrugated by FB treatment was found to be the most promising choice, leading to the formation of highly adherent and wear resistant coatings.

  17. Avaliação da resistência ao desgaste de aços inoxidáveis endurecíveis por precipitação nitretados Wear resistance evaluation of nitrided precipitation hardening stainless steels

    Luiz Carlos Casteletti

    2010-03-01

    Full Text Available A nitretação por plasma consiste num tratamento efetivo para o aumento das durezas superficiais dos aços inoxidáveis, podendo ser realizada em temperaturas inferiores às usadas nos processos convencionais, evitando-se assim, a formação de nitretos de cromo, que prejudicariam a resistência à corrosão do material. Os aços inoxidáveis endurecíveis por precipitação foram desenvolvidos após a Segunda Guerra Mundial em decorrência das necessidades da indústria aeroespacial, que necessitava de materiais resistentes à corrosão em temperaturas mais elevadas. Nesse trabalho, foi produzido um aço inoxidável endurecível por precipitação com uso de Nb e um aço comercial PH 13-8Mo endurecível por precipitados à base de Cu, para fins de comparação em termos de produção de camadas nitretadas e de resistências ao desgaste abrasivo. O Nb mostrou-se um eficiente formador de precipitados endurecedores do aço, com o pico de dureza ocorrendo em poucos minutos de tratamento. Nos dois aços, obtiveram-se camadas nitretadas com boa uniformidade. A resistência ao desgaste do aço com Nb nitretado foi muito superior à do aço PH 13-8Mo também nitretado.Plasma nitriding is an effective treatment to increase the surface hardness of stainless steel and may be performed in temperatures below those used in conventional nitriding procedures, thereby avoiding the formation of chromium nitrides that would deteriorate the corrosion resistance of the material. The precipitation hardened stainless steels were developed after the Second World War as a result of the needs of the aerospace industry, which needed materials resistant to corrosion at higher temperatures. In this research, a precipitation hardening Nb stainless steel and a PH 13-8Mo precipitation hardened stainless steels with Cu were produced, for purposes of comparison in terms of the production of nitrided layers and abrasive wear resistances. Nb proved to be an effective hardening

  18. Design and Preparation of SiO2/TiO2/SiO2-TiO2 Antireflective Coatings with Excellent Abrasion-resistance and Transmittance via Sol-Gel Process

    YE Long-Qiang, ZHANG Qing-Hua, ZHANG Yu-Lu, ZHANG Xin-Xiang, JIANG Bo

    2012-08-01

    Full Text Available Triple-layer broadband antireflective (AR coatings with excellent abrasion-resistance and transmittance were designed using the theory of optical coating design. And the designed coatings were prepared on K9 glass via Sol-Gel process in this work. SiO2 and TiO2 sols were prepared using tetraethylorthosilicate (TEOS and titanium tetraisopropoxide (TTIP as precursors, respectively, and hydrochloric acid as catalyst. It is found that the average transmittance of the AR coatings over the entire visible region can reach 98.7%, which is 7.1% higher than that at the blank K9 glass. Moreover the transmittance of the AR coating does not obviously decrease after abrasion test, showing the excellent abrasion-resistance of the AR coatings. Hexamethyldisiloxane (HMDS is further used to modify the surface of the AR coatings, which greatly improves the hydrophobicity of the coatings, and thus gives the AR coatings excellent environmental resistance.

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

    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. PMID:19423603

  20. Enhancing Fracture and Wear Resistance of Dentures/Overdentures Utilizing Digital Technology: A Case Series Report.

    Afify, Ahmed; Haney, Stephan

    2016-08-01

    Since it was first introduced into the dental world, computer-aided design/computer-aided manufacturing (CAD/CAM) technology has improved dramatically in regards to both data acquisition and fabrication abilities. CAD/CAM is capable of providing well-fitting intra- and extraoral prostheses when sound guidelines are followed. As CAD/CAM technology encompasses both surgical and prosthetic dental applications as well as fixed and removable aspects, it could improve the average quality of dental prostheses compared with the results obtained by conventional manufacturing methods. The purpose of this article is to provide an introduction into the methods in which this technology may be used to enhance the wear and fracture resistance of dentures and overdentures. This article will also showcase two clinical reports in which CAD/CAM technology has been implemented. PMID:26916680

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

    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.

  2. Avaliação do desgaste abrasivo causado pelas cerâmicas Duceram e Vita em resinas compostas pelo método do disco retificado Evaluation of the abrasive wear caused by the ceramics Duceram and Vita in composite resins by the method of the ground disk

    T. V. França

    2004-06-01

    Full Text Available O presente trabalho apresenta uma metodologia confiável e de execução rápida para a avaliação do desgaste abrasivo entre as cerâmicas Duceram e Vita nas resinas compostas Z-100 e Charisma. Estes materiais são amplamente utilizados nos consultórios e clínicas dentais para restaurações funcionais e estéticas dos dentes. Para avaliar o desgaste abrasivo entre os materiais, um disco dinâmico revestido com porcelana foi utilizado sobre um disco estático revestido com resina. Os resultados indicaram que a cerâmica Vita apresenta desgaste inferior a Duceram nas resinas analisadas.This work presents a fast and trustworthy methodology for the evaluation of the abrasive wear between the ceramics Duceram and Vita and the composites resins Z-100 and Charisma. These materials are widely used in dental clinics to restoration of function and aesthetics of the teeth. To evaluate the abrasive wear between the materials, a dynamic disk covered with ceramic was used contrary to a static disk covered with resin. The results showed that Vita presents an inferior wear against Duceram in the resins tested.

  3. Wear behavior of nanostructured Al/Al2O3 composite fabricated via accumulative roll bonding (ARB) process

    Highlights: • ARB process led to the increase in wear weight loss of the samples. • Wear resistance was decreased with the increase in the number of ARB cycles. • At the higher number of ARB cycles, delamination was the dominant wear mechanism. • In the composite sample, both delamination and spalling mechanisms occurred. • Intense Rotated Cube texture of composite helped crack nucleation and propagation. - Abstract: In the present work, wear behavior of nanostructured aluminum and composite performed by accumulative roll bonding (ARB) process was investigated. The wear characteristics were studied by scanning electron microscopy (SEM) equipped with energy dispersive spectroscopy (EDS). Also, transmission electron microscopy (TEM) and crystallographic texture investigations were performed. The results indicated that the ARB process led to the decrease in wear resistance of the monolithic and composite samples compared with as-received aluminum strip. The adhesive, abrasive and delaminating wear mechanisms occurred in the monolithic and composite samples simultaneously. At higher number of ARB cycles, delamination was the dominant wear mechanism. It was found that the surface damage of the composite was more extensive than that of the monolithic sample due to the occurrence of spalling mechanism. It was suggested that the intense Rotated Cube {0 0 1}〈1 1 0〉 texture component of composite helped to crack nucleation and propagation greatly. The role of delamination and especially, spalling in decreasing the wear resistance of composite was very important such that it eliminated the role of reinforcing particles and grain size on the wear resistance

  4. Laser-Assisted Cold-Sprayed Corrosion- and Wear-Resistant Coatings: A Review

    Olakanmi, E. O.; Doyoyo, M.

    2014-06-01

    Laser-assisted cold spray (LACS) process will be increasingly employed for depositing coatings because of its unique advantages: solid-state deposition of dense, homogeneous, and pore-free coatings onto a range of substrates; and high build rate at reduced operating costs without the use of expensive heating and process inert gases. Depositing coatings with excellent performance indicators via LACS demands an accurate knowledge and control of processing and materials' variables. By varying the LACS process parameters and their interactions, the functional properties of coatings can be manipulated. Moreover, thermal effect due to laser irradiation and microstructural evolution complicate the interpretation of LACS mechanical deformation mechanism which is essential for elucidating its physical phenomena. In order to provide a basis for follow-on-research that leads to the development of high-productivity LACS processing of coatings, this review focuses on the latest developments in depositing corrosion- and wear-resistant coatings with the emphasis on the composition, structure, and mechanical and functional properties. Historical developments and fundamentals of LACS are addressed in an attempt to describe the physics behind the process. Typical technological applications of LACS coatings are also identified. The investigations of all process sequences, from laser irradiation of the powder-laden gas stream and the substrate, to the impingement of thermally softened particles on the deposition site, and subsequent further processes, are described. Existing gaps in the literature relating to LACS-dependent microstructural evolution, mechanical deformation mechanisms, correlation between functional properties and process parameters, processing challenges, and industrial applications have been identified in order to provide insights for further investigations and innovation in LACS deposition of wear- and corrosion-resistant coatings.

  5. Improved wear resistance of Al-15Si alloy with a high current pulsed electron beam treatment

    Hao, Y. [School of Materials and Metallurgy, Northeastern University, Shenyang 110004 (China); Gao, B., E-mail: surfgao@yahoo.com.cn [School of Materials and Metallurgy, Northeastern University, Shenyang 110004 (China); Tu, G.F.; Li, S.W. [School of Materials and Metallurgy, Northeastern University, Shenyang 110004 (China); Dong, C. [Key Laboratory of the Ministry of Education of Materials Modification by Laser, Ion and Electron Beams, Dalian University of Technology, Dalian 116024 (China); Zhang, Z.G. [School of Materials and Metallurgy, Northeastern University, Shenyang 110004 (China)

    2011-07-01

    Highlights: > Firstly, Raman spectra are used to research the variation of Si structure before and after HCPEB treatment for the first time. > Secondly, a fine structure, namely the precipitation of nanocrystalline Si particles, is formed in the surface layer of the HCPEB-treated sample. > Thirdly, the relative wear resistance of an Al-15Si alloy surface is effectively enhanced by a factor of 9 after 15 pulse treatment. - Abstract: A hypereutectic Al-15Si alloy (Si 15 wt.%, Al balance) was irradiated by high current pulsed electron beam (HCPEB). The HCPEB treatment causes ultra-rapid heating, melting and cooling at the top surface layer. As a result, the special 'halo' microstructure centering on the primary Si phase is formed on the surface due to interdiffusion of Al and Si elements. The composition of the 'halo' microstructure is distributed continuously from the center to the edge of the 'halo'. Compared to an untreated matrix, the remelted layer underneath the surface presents single contrast because of the compositional homogeneity after HCPEB treatment. The thickness of the remelted layer increases slightly from 4.4 {mu}m (5 pulses) to 5.6 {mu}m (25 pulses). HCPEB treatment broadens and shifts the diffraction peaks of Al and Si. The lattice parameters of Al decreases due to the formation of a supersaturated solid solution of Al in the melted layer. Through analysis of Raman spectra and transmission electron microscopy (TEM), the amorphous Si (a-Si) and nanocrystalline Si are formed in the near-surface region under multiple bombardments of HCPEB. The relative wear resistance of a 15-pulse sample is effectively improved by a factor of 9, which can be attributed to the formation of metastable structures.

  6. Improved wear resistance of functional diamond like carbon coated Ti-6Al-4V alloys in an edge loading conditions.

    Choudhury, Dipankar; Lackner, Jürgen M; Major, Lukasz; Morita, Takehiro; Sawae, Yoshinori; Bin Mamat, Azuddin; Stavness, Ian; Roy, Chanchal K; Krupka, Ivan

    2016-06-01

    This study investigates the durability of functional diamond-like carbon (DLC) coated titanium alloy (Ti-6Al-4V) under edge loading conditions for application in artificial hip joints. The multilayered (ML) functional DLC coatings consist of three key layers, each of these layers were designed for specific functions such as increasing fracture strength, adapting stress generation and enhancing wear resistance. A 'ball-on-disk' multi-directional wear tester was used in the durability test. Prior to the wear testing, surface hardness, modulus elasticity and Raman intensity were measured. The results revealed a significant wear reduction to the DLC coated Ti-6Al-4V disks compared to that of non-coated Ti-6Al-4V disks. Remarkably, the counterpart Silicon Nitride (Si3N4) balls also yielded lowered specific wear rate while rubbed against the coated disks. Hence, the pairing of a functional multilayered DLC and Si3N4 could be a potential candidate to orthopedics implants, which would perform a longer life-cycle against wear caused by edge loading. PMID:27085502

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

    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.

  8. 铌对喷射成形 M3∶2高速钢组织和耐磨性的影响%Effect of Nb on microstructure and wear resistance of spray-formed M 3∶2 high speed steel

    张程; 黄进峰; 吴健安; 连勇; 王和斌; 张济山; 李书开; 王宏亮

    2016-01-01

    研究了Nb对喷射成形高速钢M 3∶2组织和硬度的影响,并对含Nb喷射成形高速钢在不同温度下的摩擦行为进行了研究。结果表明,Nb可以使一次MC型碳化物变得更细小、球形度更好,M2 C片层厚度变薄,有利于高速钢回火过程中的二次析出,提高其回火硬度。0.5%Nb的添加可显著提高喷射成形M3∶2高速钢的耐磨性。常温(20℃)时高速钢的磨损机制主要为磨粒磨损;中温(300℃)时,磨损机制则以粘着磨损为主,氧化磨损增加;高温(500℃)时,主要以氧化磨损为主。%Effect of niobium on microstructure and hardness of spray formed M3∶2 high speed steel was investigated. And the wear behavior of M3∶2 high speed steel with Nb at different temperature is also discussed.The results show that the addition of niobium can make MC carbides smaller and more spherical, and M2 C lamellar more thinner, which is helpful for secondary precipitation of high speed steel during tempering and improving the hardness after tempering.With the temperature increased, the M3-0.5Nb high speed steel presents better wear resistance than that of the M3 steel.Wear mechanism of the high speed steels is depends on the temperature.At room temperature, abrasive wear dominates;near 300℃, it transfer to adhesive wear, and the oxidation wear gradually increases.At higher temperature, near 500℃, the wear mechanism is oxidation wear accompanied with some abrasive wear and adhesive wear.

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

    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.

  10. New Rock Abrasivity Test Method for Tool Life Assessments on Hard Rock Tunnel Boring: The Rolling Indentation Abrasion Test (RIAT)

    Macias, F. J.; Dahl, F.; Bruland, A.

    2016-05-01

    The tunnel boring machine (TBM) method has become widely used and is currently an important presence within the tunnelling industry. Large investments and high geological risk are involved using TBMs, and disc cutter consumption has a great influence on performance and cost, especially in hard rock conditions. Furthermore, reliable cutter life assessments facilitate the control of risk as well as avoiding delays and budget overruns. Since abrasive wear is the most common process affecting cutter consumption, good laboratory tests for rock abrasivity assessments are needed. A new abrasivity test method by rolling disc named Rolling Indentation Abrasion Test (RIAT) has been developed. The goal of the new test design and procedure is to reproduce wear behaviour on hard rock tunnel boring in a more realistic way than the traditionally used methods. Wear by rolling contact on intact rock samples is introduced and several rock types, covering a wide rock abrasiveness range, have been tested by RIAT. The RIAT procedure indicates a great ability of the testing method to assess abrasive wear on rolling discs. In addition and to evaluate the newly developed RIAT test method, a comprehensive laboratory testing programme including the most commonly used abrasivity test methods and the mineral composition were carried out. Relationships between the achieved results from conventional testing and RIAT results have been analysed.

  11. Wear resistance and electronic structure of cutting tool materials on a basis carbides of tungsten and titanium

    The tool materials durability problem, in particular shock and wear resistance, has allowed to formulate a set of requirements and also to stablish the dependence between physical properties and wear. However, for understanding the nature of the process, for example determining the tribological property of the cutting tool, it is necessary to consider the atom interactions in a crystal. A theoretical study of the physical properties of cutting tool materials (W-Ti-C) with varying concentration of titanium is presented. Total and partial local electronic density for each atom in such hard solutions were calculated. (nevyjel)

  12. Influence of titanium content on wear resistance of electrolytic low-titanium eutectic Al-Si piston alloys

    Yan Shuqing; Xie Jingpei; Wang Jiefang

    2008-01-01

    The wear resistance of six kinds of the electrolytic low-titanium eutectic Al-Si piston alloys with various Ti content ranging from 0.00wt.% to 0.21wt.% has been studied. A new method of adding Ti is adopted in the electrolytic low-titanium aluminum alloy ingots. The electrolytic low-titanium eutectic Al-Si piston alloys are produced by remelting the electrolytic low-titanium aluminum alloy, crystal silicon, pure magnesium, Al-50%Cu and Al-10%Mn master alloy. The wear experiments are conducte...

  13. Effects of methane plasma ion implantation on the microstructure and wear resistance of NiTi shape memory alloys

    This paper reports the surface characterization, microhardness and fretting wear behavior of methane-plasma-modified NiTi as well as those control samples. Auger electron spectroscopy (AES), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy were used for surface characterization. It is found that the hardness of methane-treated samples is highly improved with surface modification due to the contribution from titanium oxides, titanium carbide and organic titanium compounds. A new modified Archard's equation is used to describe the relationship between pseudoelasticity, hardness and wear resistance. This study provides an understanding of the interplay between surface microstructure and mechanical properties of methane-treated NiTi

  14. Dry sliding wear behavior and corrosion resistance of NiCrBSi coating deposited by activated combustion-high velocity air fuel spray process

    NiCrBSi is a Ni-based superalloy widely used to obtain high wear and corrosion resistant coatings. This Ni-based alloy coating has been deposited onto 0Cr13Ni5Mo stainless steel using the AC-HVAF technique. The structure and morphologies of the Ni-based coatings were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy-dispersive spectrometer (EDS). The wear resistance and corrosion resistance were studied. The tribological behaviors were evaluated using a HT-600 wear test rig. The wear resistance of the Ni-based coating was shown to be higher than that of the 0Cr13Ni5Mo stainless steel because Fe3B, with high hardness, was distributed in the coating so the dispersion strengthening in the Ni-based coating was obvious and this increased the wear resistance of the Ni-based coating in a dry sliding wear test. Under the same conditions, the worn volume of 0Cr13Ni5Mo stainless steel was 4.1 times greater than that of the Ni-based coating. The wear mechanism is mainly fatigue wear. A series of the electrochemical tests was carried out in a 3.5 wt.% NaCl solution in order to examine the corrosion behavior. The mechanisms for corrosion resistance are discussed.

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

    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.

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

    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. PMID:23642807

  17. Mechanical properties and wear resistance of ion-beam-assisted sputter-deposited NiTi(N) coatings

    Thin films are deposited on an austenitic type 304L stainless steel using the sputtering of an Ni49Ti51 target with 1.5 keV N+ ions. The influence of a simultaneous 160 keV Ar+ implantation on hardness and wear resistance is studied. Hardness is measured with a nanoindenter. N+ reactive sputtering forms a coating harder than the substrate. The hardness increases by 80% when the eposit is ion beam assisted. Transmission electron microscopy analyses of the thin films reveal that the N+ sputtered films present a large content of nitrogen which forms with titanium strong disorganized metal-metalloid Ti-N bonds; when ion implantation is simultaneously used, very tiny crystalline TiN precipitates embedded in an amorphous matrix are observed. This could explain the increase in hardness. The simultaneous ion irradiation would favour TiN precipitation through an enhanced diffusion mechanism in the cascades. Subsequent wear resistance of these coatings is measured through three-dimensional profile analyses of the wear tracks obtained after tests performed on a pin-on-disc machine. It is shown that sputtered NiTi(N) coatings largely increase the wear resistance. When the deposit is ion beam assisted, the improvement is much more pronounced; it can be related to either the increase in the hardness or the ion beam mixing of the interface, or both these processes. The influence of the coating thickness and the ratio of the implanted ions to the deposited atoms are also studied. (orig.)

  18. Splitting strength and abrasion resistance of concrete paving blocks as a function of dry bulk specific gravity and ultrasonic pulse velocity

    Haktanir, T.

    2005-06-01

    Full Text Available Artificial Portland cement concrete paving blocks are widely used in many countries. These paving blocks come in a variety of designs with names such as "Interlocking" and "Italian Flower", and are manufactured with special machinery using rather high quality concrete having a compressive strength of about 50 MPa. Concrete blocks are employed instead of natural cobble stones for essentially economic reasons. The laboratoiy equipment required to measure paving block splitting strength and abrasion resistance, two of the chief properties to be tested in quality checks, is costly and the tests are time-consuming and labour-intensive. The present paper reports on a detailed experimental study performed to relate the splitting strength and abrasion resistance of concrete paving blocks to "dry bulk specific gravity" (DBSG and "ultrasonic pulse velocity" (UPV, respectively. Statistically significant regression equations describing the dependence of splitting strength on DBSG and abrasion resistance on UPV were obtained with data from random samples of material provided by seven different manufacturers.

    RESUMEN Los bloques para pavimentos (adoquines elaborados con hormigón se utilizan habitualmente en numerosos países. Estos bloques de pavimentación se diseñan de diversas formas, como por ejemplo "Entrelazado " ("Interlocking " o "Flor Italiana " ("Italian Flower"; se fabrican con maquinaria especial y con frecuencia se utiliza hormigón de la más alta calidad, con resistencia a la compresión de alrededor de 50 MPa. La razón de utilizar bloques de hormigón en lugar de bloques de piedra natural es básicamente económica. Los equipos de laboratorio necesarios para medir la resistencia a la compresión y a la abrasión -dos de las propiedades más importantes para determinar la calidad de los bloques en estudio- son costosos y los ensayos requieren tiempo y mano de obra considerables. En el presente trabajo se exponen ensayos experimentales

  19. Fabrication of wear-resistant silicon microprobe tips for high-speed surface roughness scanning devices

    Wasisto, Hutomo Suryo; Yu, Feng; Doering, Lutz; Völlmeke, Stefan; Brand, Uwe; Bakin, Andrey; Waag, Andreas; Peiner, Erwin

    2015-05-01

    Silicon microprobe tips are fabricated and integrated with piezoresistive cantilever sensors for high-speed surface roughness scanning systems. The fabrication steps of the high-aspect-ratio silicon microprobe tips were started with photolithography and wet etching of potassium hydroxide (KOH) resulting in crystal-dependent micropyramids. Subsequently, thin conformal wear-resistant layer coating of aluminum oxide (Al2O3) was demonstrated on the backside of the piezoresistive cantilever free end using atomic layer deposition (ALD) method in a binary reaction sequence with a low thermal process and precursors of trimethyl aluminum and water. The deposited Al2O3 layer had a thickness of 14 nm. The captured atomic force microscopy (AFM) image exhibits a root mean square deviation of 0.65 nm confirming the deposited Al2O3 surface quality. Furthermore, vacuum-evaporated 30-nm/200-nm-thick Au/Cr layers were patterned by lift-off and served as an etch mask for Al2O3 wet etching and in ICP cryogenic dry etching. By using SF6/O2 plasma during inductively coupled plasma (ICP) cryogenic dry etching, micropillar tips were obtained. From the preliminary friction and wear data, the developed silicon cantilever sensor has been successfully used in 100 fast measurements of 5- mm-long standard artifact surface with a speed of 15 mm/s and forces of 60-100 μN. Moreover, the results yielded by the fabricated silicon cantilever sensor are in very good agreement with those of calibrated profilometer. These tactile sensors are targeted for use in high-aspect-ratio microform metrology.

  20. Machinability and scratch wear resistance of carbon-coated WC inserts

    Highlights: • Cemented WC inserts were coated with carbon by CVD. • The deposits were either loosely held MWCNTs or adherent carbides. • Co-efficient of friction (ramp load; 1–13 N); 0.2 and 0.1 μ, respectively, for the uncoated and carbide-coated inserts. • The carbide-coated insert exhibited better machinability and surface finish than a commercial TiCN-coated insert. - Abstract: In this work, cemented tungsten carbide (WC) inserts were coated with nanocarbons/carbides by chemical vapor deposition (CVD) and their machinability and scratch wear resistance were investigated. The hardness and surface conditions of the WC substrate were studied before and after coating. The CVD-generated nanocarbons on the insert surfaces were examined by SEM, FE-SEM and TEM. The electron microscopic images revealed that the carbons generated were multi-walled carbon nanotubes (MWCNTs) or carbides depending on the experimental conditions. In both the cases, the cutting edges of the inserts had dense deposits. Scratch wear test with the coated inserts showed that the co-efficient of friction was 0.1 μ as against 0.2 μ for the uncoated inserts under a ramp load of 1–13 N. The machinability characteristics of commercially available TiCN-coated inserts and the carbon-coated WC inserts were compared by using a CNC machine and a Rapid I vision inspection system. It was found that the carbide-coated inserts exhibited machinability with better surface finish comparable to that of the TiCN-coated inserts while the MWCNT-coated inserts showed inferior adhesion properties

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

    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.

  2. Structure and wear resistance of Ti and TiAl surfaces implanted with B, C, N, O

    The composition and the structure of as-implanted and of worn surfaces were determined by means of Rutherford Backscattering Spectrometry, Nuclear Reaction Analysis, Secondary Ion Mass Spectroscopy and transmission electron microscopy. The structural transformations during implantation were often different to those previously reported and new compounds were obtained. The main factor of wear for all films was a local cracking induced by the sinking of a more plastic substrate. When the latter was pure Ti, oxygen diffusion through these cracks and adhesion between stripped areas of Ti and the friction counterpart enhanced the wear process. The contamination of Ti nitrides with O, either during implantation or friction, appeared as another important parameter contributing to the reduction of their wear resistance. Otherwise the kinetics were in the ratio of films hardness. (author)

  3. Abrasion and deformed layer formation of manganese-zinc ferrite in sliding contact with lapping tapes

    Miyoshi, K.; Buckley, D. H.; Tanaka, K.

    1986-01-01

    Wear experiments were conducted using replication electron microscopy and reflection electron diffraction to study abrasion and the deformed layers produced in single-crystal Mn-Zn ferrite simulated heads during contact with lapping tapes. The crystaline state of the head is changed drastically during the abrasion process. Crystalline states ranging from nearly amorphous to highly textured polycrystalline can be produced on the wear surface of a single-crystal Mn-Zn ferrite head. The total thickness of the deformed layer was approximately 0.8 microns. This thickness increased as the load and abrasive grit size increased. The anisotropic wear of the ferrite was found to be inversely proportional to the hardness of the wear surface. The wear was lower in the order 211 111 10 0110. The wear of the ferrite increased markedly with an increase in sliding velocity and abrasive grit size.

  4. Microstructure and wear resistance of the hypereutectic Fe–Cr–C alloy hardfacing metals with different La{sub 2}O{sub 3} additives

    Yang, Jian [State Key Laboratory of Metastable Materials Science and Technology, College of Materials Science and Engineering, Yanshan University, Qinhuangdao 066004 (China); Tian, Jianjun [Beijing Beiye Functional Materials Co., Ltd., Beijing 100192 (China); Hao, Feifei; Dan, Ting [Capital Aerospace Machinery Corporation, Beijing 100076 (China); Ren, Xuejun [School of Engineering, Liverpool John Moores University, Liverpool L3 3AF (United Kingdom); 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)

    2014-01-15

    Hardfacing (harden-surface-welding) metal of the hypereutectic Fe–Cr–C alloy with different La{sub 2}O{sub 3} 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 La{sub 2}O{sub 3} additives, the dimension of the primary M{sub 7}C{sub 3} carbide in the hypereutectic Fe–Cr–C alloy hardfacing metal decreases gradually. When the La{sub 2}O{sub 3} additive is 0.78 wt.%, it reaches minimum, which is 11.37 μm. The amount of M{sub 7}C{sub 3} 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 La{sub 2}O{sub 3} additive is 0.78 wt.%. The formation temperature of M{sub 7}C{sub 3} 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 M{sub 7}C{sub 3} 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 M{sub 7}C{sub 3} carbide in short period.

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

    常立民; 刘建华; 张瑞军; 王继东

    2004-01-01

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

  6. Wear property of high-resistivity carbon brushes made with and without MoS2 in variable humidity

    HU Zhong-liang; CHEN Zhen-hua; XIA Jin-tong; DING Guo-yun

    2008-01-01

    Four kinds of high-resistivity carbon brushes with MoS2 contents of 0%, 2%, 4% and 6% (mass fraction) were prepared, respectively. Wear tests of brushes were conducted on an alternate current(AC) motor. Scanning electron microscopy(SEM) and energy dispersive X-ray analysis(EDS) were used to analyze the worn surface of brushes, and a thermocouple was used to measure the bulk temperature of the brush. The results show that wear rate of brush made without MoS2 in 10% relative humidity(RH) is two times larger than that in 50% RH, whereas the wear rates change little for the brushes made with MoS2. The wear of brushes has much to do with the surface film. In low humidity, the surface film can not be formed for the former brush while a sulfur layer can be formed for the latter brushes,which can reduce sparks, frictional heat and wear rate, and play a role like the water film in high humidity.

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

    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

  8. Uni and multidirectional wear resistance of different crosslinking degrees in UHMWPE for artificial joints

    J.M. Llamas; E. Espinar; Stroosnijder, R.; Hoffmann, M.; González-Mora, V. A.; M. Fernández-Fairén; F. J. Gil

    2011-01-01

    The aim of this work was to study the effect of UHMWPE crosslinking on wear performance. Differently treated UHMWPEs were studied by means of unidirectional and multidirectional wear tests. Unidirectional tests simulate total knee replacement and multidirectional tests simulate total hip replacement movements. The samples tested were observed by optical and scanning electron microscopy in order to determine wear mechanisms that explain the dif-ferent results obtained in the uni- and multidire...

  9. Wear Assessment of Fe-TiC/ZrC Hardfacing Produced from Oxides

    S. Corujeira-Gallo

    2015-03-01

    Full Text Available The direct conversion of oxides into carbides during plasma transferred arc welding is a promising processing route to produce wear resistant overlays at low cost. In the present study, Fe-TiC and Fe-ZrC composite overlays were produced by carbothermic reduction of TiO2 and ZrO2 during plasma transferred arc deposition. The overlays were characterised by optical microscopy, electron microscopy and X-ray diffraction. The microstructure consisted of small TiC and ZrC evenly dispersed in a pearlitic matrix. The Vickers microhardness was measured and low-stress abrasion tests were conducted. The results showed increased hardness and promising wear resistance under low-stress abrasion conditions.

  10. Surface modifications to enhance the wear resistance and the osseo-integration properties of biomedical Ti-alloy

    Kami, Pavani

    The current study focuses on improving the wear resistance of femoral head component and enhancing the osseo-integration properties of femoral stem component of a hip implant made of a new generation low modulus alloy, Ti-35Nb-7Zr-5Ta or TNZT. Different techniques that were adopted to improve the wear resistance of low-modulus TNZT alloy included; (a) fabrication of graded TNZT-xB (x= 0, 1, 2 wt%) samples using LENS, (b) oxidation, and (c) LASER nitriding of TNZT. TNZT-1B and TNZT-O samples have shown improved wear resistance when tested against UHMWPE ball in SBF medium. A new class of bio-ceramic coatings based on calcium phosphate (CaP), was applied on the TNZT sample surface and was further laser processed with the objective of enhancing their osseointegration properties. With optimized LASER parameters, TNZT-CaP samples have shown improved corrosion resistance, surface wettability and cellular response when compared to the base TNZT sample.

  11. 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

    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

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

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

    2016-01-01

    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...

  13. Nanopowder processing of ultrafine Si3N4 with improved wear resistance

    Alex C. Lee

    2015-03-01

    Full Text Available The processing, microstructure, and material properties of monolithic Si3N4 were investigated by using two amorphous Si3N4 nanopowders doped with (1 6 wt% Y2O3 and (2 6 wt% Y2O3 + 8 wt% Al2O3. The orthorhombic Si2N2O-based phase was found in the two as-sintered bulks. Carbothermal reduction treatment (CRT was thus applied at 1400 °C for 10 h with 3 wt% and 6 wt% carbon black added to the precursor powders of the Si–Y–O–N and Si–Y–Al–O–N systems, respectively, resulting in an increased nitrogen-to-oxygen (N:O ratio and elimination of Si2N2O within the sintered bulks. The possible mechanisms of nucleation and grain growth of Si3N4 are discussed during CRT and the sintering process. The best wear resistance was achieved in ultrafine Si3N4 doped with Y2O3, which has good hardness, indentation toughness and a protective tribo-film.

  14. Improved wear resistance of Al-15Si alloy with a high current pulsed electron beam treatment

    Hao, Y.; Gao, B.; Tu, G. F.; Li, S. W.; Dong, C.; Zhang, Z. G.

    2011-07-01

    A hypereutectic Al-15Si alloy (Si 15 wt.%, Al balance) was irradiated by high current pulsed electron beam (HCPEB). The HCPEB treatment causes ultra-rapid heating, melting and cooling at the top surface layer. As a result, the special "halo" microstructure centering on the primary Si phase is formed on the surface due to interdiffusion of Al and Si elements. The composition of the "halo" microstructure is distributed continuously from the center to the edge of the "halo". Compared to an untreated matrix, the remelted layer underneath the surface presents single contrast because of the compositional homogeneity after HCPEB treatment. The thickness of the remelted layer increases slightly from 4.4 μm (5 pulses) to 5.6 μm (25 pulses). HCPEB treatment broadens and shifts the diffraction peaks of Al and Si. The lattice parameters of Al decreases due to the formation of a supersaturated solid solution of Al in the melted layer. Through analysis of Raman spectra and transmission electron microscopy (TEM), the amorphous Si (a-Si) and nanocrystalline Si are formed in the near-surface region under multiple bombardments of HCPEB. The relative wear resistance of a 15-pulse sample is effectively improved by a factor of 9, which can be attributed to the formation of metastable structures.

  15. A Comparative Study on the Formation Mechanism of Wear Scars during the Partial and Full Scale Fretting Wear Tests of Spacer Grids

    Lee, Young Ho; Shin, Chang Hwan; Oh, Dong Seok; Kang, Heung Seok [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2012-05-15

    Fretting wear studies for evaluating the contact damages of nuclear fuel rods have been focused on the contact shape, rod motion, contact condition, environment, etc.. However, fretting wear mechanism was dramatically changed with slight variation of test variables such as test environments and contact shapes. For example, in an unlubricated condition, effects of wear debris and/or its layer on the fretting wear mechanism showed that the formation of a well-developed layer on the contact surfaces has a beneficial effect for decreasing a friction coefficient. Otherwise, a severe wear was happened due to a third body abrasion. In addition, in water lubrication condition, some of wear debris was remained on worn surface of fuel rod specimens at both sliding and impacting loading conditions. So, it is apparent that a wear rate of fuel rod specimen was easily accelerated by the third-body abrasion. This is because the restrained agglomeration behavior between generated wear particles results in rapid removal of wear debris and its layer. In case of contact shape effects, previous studies show that wear debris are easily trapped between contact surfaces and its debris layer was well developed in a localized area especially in a concave spring rather than a convex spring shape. Consequently, localized wear was happened at both ends of a concave spring and center region of a convex spring. So, it is useful for determining the fretting wear resistance of spacer gird spring and dimple by using part unit in the various lubricated conditions. It is well known that the fretting wear phenomenon of nuclear fuel rod is originated from a flow-induced vibration (FIV) due to the rapid primary coolant. This means that both rod vibration and debris removal behavior were affected by flow fields around the contact regions between fuel rod and spring/dimple. However, all most of the fretting tests were performed by simulating rod vibrating motions such as axial vibration, conservative rod

  16. Use of dentifrices to prevent erosive tooth wear: harmful or helpful?

    Ana Carolina Magalhães

    2014-01-01

    Full Text Available Dental erosion is the loss of dental hard tissues caused by non-bacterial acids. Due to acid contact, the tooth surface becomes softened and more prone to abrasion from toothbrushing. Dentifrices containing different active agents may be helpful in allowing rehardening or in increasing surface resistance to further acidic or mechanical impacts. However, dentifrices are applied together with brushing and, depending on how and when toothbrushing is performed, as well as the type of dentifrice and toothbrush used, may increase wear. This review focuses on the potential harmful and helpful effects associated with the use of dentifrices with regard to erosive wear. While active ingredients like fluorides or agents with special anti-erosive properties were shown to offer some degree of protection against erosion and combined erosion/abrasion, the abrasive effects of dentifrices may increase the surface loss of eroded teeth. However, most evidence to date comes from in vitro and in situ studies, so clinical trials are necessary for a better understanding of the complex interaction of active ingredients and abrasives and their effects on erosive tooth wear.

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

    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)

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

    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.

  19. Patients presenting with miliaria while wearing flame resistant clothing in high ambient temperatures: a case series

    Garcia Anisa M

    2011-09-01

    Full Text Available Abstract Introduction Clothing can be a cause of occupational dermatitis. Frequent causes of clothing-related dermatological problems can be the fabric itself and/or chemical additives used in the laundering process, friction from certain fabrics excessively rubbing the skin, or heat retention from perspiration-soaked clothing in hot working environments. To the best of our knowledge, these are the first reported cases of miliaria rubra associated with prolonged use of flame resistant clothing in the medical literature. Case presentation We report 18 cases (14 men and 4 women, with an age range of 19 to 37 years of moderate to severe skin irritation associated with wearing flame resistant clothing in hot arid environments (temperature range: 39 to 50°C, 5% to 25% relative humidity. We describe the medical history in detail of a 23-year-old Caucasian woman and a 31-year-old African-American man. A summary of the other 16 patients is also provided. Conclusions These cases illustrate the potential serious nature of miliaria with superimposed Staphylococcus infections. All 18 patients fully recovered with topical skin treatment and modifications to their dress ensemble. Clothing, in particular blend fabrics, must be thoroughly laundered to adequately remove detergent residue. While in hot environments, individuals with sensitive skin should take the necessary precautions such as regular changing of clothing and good personal hygiene to ensure that their skin remains as dry and clean as possible. It is also important that they report to their health care provider as soon as skin irritation or rash appears to initiate any necessary medical procedures. Miliaria rubra can take a week or longer to clear, so removal of exposure to certain fabric types may be necessary.

  20. Wear resistance of Cu-18 vol.% Nb (P/M) composites

    Friction and wear behavior of copper matrix composites reinforced by unidirectional Nb fibers were explored using both pin-on-ring and pin on disk set-ups. Composite specimens were manufactured from a Cu-18 vol.% Nb powder mixture. Through various mechanical processes and heat treatments, this powder mixture was converted to a 'ribbon-shaped Nb' fiber reinforced copper composite with final average fiber thickness of about 10 nm and aspect ratio of about 30. The friction and wear properties of this composite were evaluated against gray cast iron with the hardness of 92 HRB. The effects of normal load, sliding speed and fiber orientation on the friction and wear of this composite were investigated. Steady state wear was observed upon formation of a thin film on the wear surface for all the specimens. This film formed due to the material transfer from the disk to the composite surface due to low ductility of the copper matrix. The wear rate was proportional to the sliding distance and normal load for all specimens, while specimens with fibers normal to the sliding surface showed the lowest wear rate. Moreover, the wear rate appeared to be an exponential function of the sliding speed. This was related to temperature rise at the interface of sliding surfaces and recovery of Cu matrix and possible breakage of the Nb fibers. Metalographic examination of Cu-Nb micro-fiber reinforced composite showed that when exposed to temperature greater than 600 deg. C, fibers start to break and spherodized. This phenomenon significantly reduces the strength of Cu-Nb composite and increases its wear rate. Some insight into the mechanisms of wear was obtained using optical and scanning electron microscopy and energy dispersive spectrometry analysis of the surface

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

    Dong Y; Formosa D.; Fernandez J.; Li X; Fuentes G.; Zoltan K.; Dong H.

    2015-01-01

    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 tr...

  2. Wear resistance of Al2O3 and Cr2O3 coatings deposited by water-stabilized plasma spraying

    Nohava, Jiří; Chráska, Pavel

    Bari : Department of Chemistry, University of Bari, 2003 - (d'Agostino, R.; Favia, P.; Fracassi, F.; Palumbo, F.), s. - [International Symposium on Plasma Chemistry/16th./. Taormina (IT), 22.06.2003-27.06.2003] R&D Projects: GA ČR GA106/01/0094 Institutional research plan: CEZ:AV0Z2043910 Keywords : plasma spraying, wear resistance, ceramics coatings Subject RIV: BL - Plasma and Gas Discharge Physics

  3. Extremely high wear resistance and ultra-low friction behaviour of oxygen-plasma-treated nanocrystalline diamond films

    The diamond nanowire (DNW) film was deposited by N2-enriched microwave plasma-enhanced chemical vapour deposition (MPECVD) process. As-deposited DNW film was treated in O2 plasma which resulted in chemical and microstructural modification. Sheath of the DNW film is chemically constituted by amorphous carbon (a-C)- and graphite (sp2C=C)-like bonding. However, nanowires transformed into ultra-small spherical grains after the O2-plasma treatments. In this condition, a-C and sp2C=C bonding significantly reduced due to plasma etching caused by oxygen atoms. After the O2-plasma treatment, formation of functional groups such as C=O, C–O–C, O–H, O–CH3 and H2O was observed on the surface and inside the wear track as evident from the micro FTIR analysis. H2O is hydrogen bonded to oxygen-containing groups such as –OH and –H. The O2-plasma-exposed DNW film exhibits surface charging and causes formation of dangling bonds and electron trapping centres. This results in significant decrease in contact angle, hence superhydrophilic behaviour. The friction coefficient of O2-plasma-treated film showed super low value ∼0.002 with high wear resistance 2 × 10−12 mm3 N−1 m−1. In the reciprocating ball-on-disc tribology test, only ∼80 nm wear loss was observed after the 1 km of sliding distance at 10 N loads. Such an advance in tribological properties is explained by passivation of covalent carbon bonding and transformation of sliding surfaces by weak van der Waals and hydrogen bondings. High surface energy and the consequent superhydrophilic behaviour of film is attributed to the formation of the above-mentioned functional groups on the surface. This protects against deformation of the wear track leading to extremely high wear resistance. (paper)

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

    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

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

    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. Development of a Wear Map for the Sliding and Rotational Wear behavior of Shafts

    Al-mahasne M. Mohammad

    2006-01-01

    Full Text Available This study was an attempt to study the wear calculation method for rotating shaft in the friction couple type shaft-cuff in conditions of oiling in high dusty environment. The size and quantity of abrasive particles that go into the clearance between friction surfaces, definition of the pressure including the load in conjugate that is given by the cuff spring as the radial force, and the effected contact area including the micro hardness of the shaft surface (taking into account the influence of the finishing treatment as a diamond pressing have been calculated by utilization of above mentioned method. Furthermore, the volume wear has been calculated by the energy of friction including both the factor of energy transition to heat and the latent melting heat of shaft material. In this study the experimental scheme for wear testing of steel shaft in the friction couple type “shaft-cuff” and the theoretical and experimental results have been given, Fig. 4. It has proved that this method permits to choose the effective materials for parts making and the use of effective finishing treatment. Morethan, it permits to choose optimum properties of the parts surface layer. This may be attained on the stage of designing- to prognosis shaft and couple friction conjugates wear. Therefore, this method provides a maximum wear resistance and the ability to calculate parts life before damage.

  7. Improving corrosion and wear resistance of FV520B steel by high current pulsed electron beam surface treatment

    Highlights: • HCPEB surface treatment was conducted on FV520B steel. • Surface layer ∼10 μm was refined with elements homogenization. • Remelted layer exhibited 〈2 0 0〉 preferential orientation. • Corrosion potential increased and corrosion rate decreased one order of magnitude. • Wear resistance increased by 3 times. - Abstract: High current pulsed electron beam (HCPEB) surface treatment was conducted on FV520B steel with accelerating voltage 27 kV, pulse duration 2.5 μs, energy density 5 J/cm2 and 1–25 pulses. The surface microstructure and element distribution were examined by using scanning electron microscope (SEM), electron probe micro-analysis (EPMA) and X-ray diffraction (XRD) methods. After HCPEB treatments, the surface microstructure became refined and uniform with an average grain size less than 2 μm and a preferential solidification orientation in 〈2 0 0〉 direction. The thickness of surface remelted layer was ∼4 μm. The initial precipitated particles in surface layer of depth ∼10 μm were dissolved into the base matrix and gave a homogenous element distribution. The HCPEB modified surface exhibited an effective improvement in corrosion and wear resistance. The corrosion potential shifted towards positive and the corrosion rate decreased nearly one order of magnitude, while the wear resistance after 25 pulses of HCPEB treatment increased by 3 times as compared with the initial FV520B steel

  8. Two-silane chemical vapor deposition treatment of polymer (nylon) and oxide surfaces that yields hydrophobic (and superhydrophobic), abrasion-resistant thin films

    This article describes a two-silane, chemical vapor deposition (CVD) approach to creating hydrophobic (or even superhydrophobic), abrasion-resistant coatings on silicon oxide and polymer (nylon) substrates. This multistep approach employs only reagents delivered in the gas phase, as follows: (i) plasma cleaning/oxidation of the substrate, (ii) CVD of 3-isocyanatopropyltriethoxysilane, which is used as an adhesion promoter for the substrate, (iii) hydrolysis with water vapor, and (iv) CVD of (tridecafluoro-1,1,2,2-tetrahydrooctyl)trichlorosilane (the ''Rf-Cl silane''). Surfaces are characterized by wetting, spectroscopic ellipsometry, x-ray photoelectron spectroscopy (XPS), and time-of-flight secondary ion mass spectrometry (ToF-SIMS). This work has the following unique features. First, the authors explore an all gas phase deposition of a new silane coating that is scientifically interesting and technologically useful. Second, the authors show that the presence of an adhesion promoter in the process leads to thinner films that are more robust in abrasion testing. Third, results obtained using plasma/deposition equipment that is relatively inexpensive and/or available in most laboratories are compared to those obtained with a much more sophisticated, commercially available plasma/CVD system (the YES-1224P). The entire deposition process can be completed in only ∼1 h using the industrial equipment (the 1224P). It is of significance that the polymer surfaces modified using the 1224P are superhydrophobic. Fourth, the thickness of the Rf-Cl silane layer deposited by CVD correlates well with the thickness of the underlying spin coated nylon surface, suggesting that the nylon film acts as a reservoir of water for the hydrolysis and condensation of the Rf-Cl silane

  9. Study on torsional fretting wear behavior of a ball-on-socket contact configuration simulating an artificial cervical disk

    Wang, Song [State Key Laboratory of Tribology, Tsinghua University, Beijing 100084 (China); Department of Mechanical Engineering, Tsinghua University, Beijing 100084 (China); Wang, Fei [School of Material Science and Engineering, China University of Mining and Technology, Xuzhou 221116 (China); Liao, Zhenhua [Department of Mechanical Engineering, Tsinghua University, Beijing 100084 (China); Biomechanics and Biotechnology Lab, Research Institute of Tsinghua University in Shenzhen, Shenzhen 518057 (China); Wang, Qingliang [School of Material Science and Engineering, China University of Mining and Technology, Xuzhou 221116 (China); Liu, Yuhong [State Key Laboratory of Tribology, Tsinghua University, Beijing 100084 (China); Department of Mechanical Engineering, Tsinghua University, Beijing 100084 (China); Liu, Weiqiang, E-mail: weiqliu@hotmail.com [Biomechanics and Biotechnology Lab, Research Institute of Tsinghua University in Shenzhen, Shenzhen 518057 (China); State Key Laboratory of Tribology, Tsinghua University, Beijing 100084 (China)

    2015-10-01

    A ball-on-socket contact configuration was designed to simulate an artificial cervical disk in structure. UHMWPE (ultra high molecular weight polyethylene) hot pressed by powders and Ti6Al4V alloy were selected as the material combination of ball and socket. The socket surface was coated by a ~ 500 nm C-DLC (carbon ion implantation-diamond like carbon) mixed layer to improve its surface nano hardness and wear resistance. The torsional fretting wear behavior of the ball-on-socket model was tested at different angular displacements under 25% bovine serum lubrication with an axial force of 100 N to obtain more realistic results with that in vivo. The fretting running regimes and wear damage characteristics as well as wear mechanisms for both ball and socket were studied based on 2D (two dimension) optical microscope, SEM (scanning electron microscope) and 3D (three dimension) profiles. With the increase of angular displacement amplitude from 1° to 7°, three types of T-θ (Torsional torque-angular displacement amplitude) curves (i.e., linear, elliptical and parallelogram loops) corresponding to running regimes of PSR (partial slip regime), MR (mixed regime) and SR (slip regime) were observed and analyzed. Both the central region and the edge zone of the ball and socket were damaged. The worn surfaces were characterized by wear scratches and wear debris. In addition, more severe wear damage and more wear debris appeared on the central region of the socket at higher angular displacement amplitude. The dominant damage mechanism was a mix of surface scratch, adhesive wear and abrasive wear for the UHMWPE ball while that for the coated socket was abrasive wear by PE particles and some polishing and rolling process on the raised overgrown DLC grains. The frictional kinetic behavior, wear type, damage region and damage mechanism for the ball-on-socket model revealed significant differences with those of a ball-on-flat contact while showing better consistency with that of in

  10. Study on torsional fretting wear behavior of a ball-on-socket contact configuration simulating an artificial cervical disk

    A ball-on-socket contact configuration was designed to simulate an artificial cervical disk in structure. UHMWPE (ultra high molecular weight polyethylene) hot pressed by powders and Ti6Al4V alloy were selected as the material combination of ball and socket. The socket surface was coated by a ~ 500 nm C-DLC (carbon ion implantation-diamond like carbon) mixed layer to improve its surface nano hardness and wear resistance. The torsional fretting wear behavior of the ball-on-socket model was tested at different angular displacements under 25% bovine serum lubrication with an axial force of 100 N to obtain more realistic results with that in vivo. The fretting running regimes and wear damage characteristics as well as wear mechanisms for both ball and socket were studied based on 2D (two dimension) optical microscope, SEM (scanning electron microscope) and 3D (three dimension) profiles. With the increase of angular displacement amplitude from 1° to 7°, three types of T-θ (Torsional torque-angular displacement amplitude) curves (i.e., linear, elliptical and parallelogram loops) corresponding to running regimes of PSR (partial slip regime), MR (mixed regime) and SR (slip regime) were observed and analyzed. Both the central region and the edge zone of the ball and socket were damaged. The worn surfaces were characterized by wear scratches and wear debris. In addition, more severe wear damage and more wear debris appeared on the central region of the socket at higher angular displacement amplitude. The dominant damage mechanism was a mix of surface scratch, adhesive wear and abrasive wear for the UHMWPE ball while that for the coated socket was abrasive wear by PE particles and some polishing and rolling process on the raised overgrown DLC grains. The frictional kinetic behavior, wear type, damage region and damage mechanism for the ball-on-socket model revealed significant differences with those of a ball-on-flat contact while showing better consistency with that of in

  11. Microstructure and wear resistance of composite layers on a ductile iron with multicarbide by laser surface alloying

    Multicarbide reinforced metal matrix composite (MMC) layers on a ductile iron (QT600-3) were fabricated by laser surface alloying (LSA) using two types of laser: a 5 kW continuous wave (CW) CO2 laser and a 400 W pulsed Nd:YAG laser, respectively. The research indicated that LSA of the ductile iron with multicarbide reinforced MMC layers demonstrates sound alloying layers free of cracks and porosities. The microstructure, phase structure and wear properties of MMC layers were investigated by means of scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD), as well as dry sliding wear testing. The microstructure of the alloyed layer is composed of pre-eutectic austenite, ledeburite, spherical TiC, Cr7C3 and Cr23C6 with various morphologies. TiC particles are dispersed uniformly in the upper region of MMC layers. The average hardness of LSA layers by CO2 laser and pulsed Nd:YAG laser is 859 HV0.2 and 727 HV0.2, respectively. The dry sliding wear testing shows the wear resistance of ductile iron is significantly improved after LSA with multicarbide.

  12. Flux cored wire for hardfacing of wear resistant band on drill pipe%钻杆接头耐磨带堆焊药芯焊丝的研究

    刘希学; 贺定勇; 蒋建敏; 周正; 王智慧; 崔丽; 赵秋颖

    2013-01-01

    A kind of flux cored wire was developed to deposited the wear resistant band on drill pipe. The deposited alloys of Fe-B-Nb-Ni were prepared by CO2 gas shielded flux cored arc welding. The microstructures of the Fe-B-Nb-Ni alloys were investigated by optical microscopy, scanning electron microscopy,X-ray diffraction,etc. At the same times,its hardness and the wear resistance of the surfacing layer were tested. The results show that the Fe-B-Nb-Ni alloy exhibits, excellent wear resistance which is higher 37% than the imported flux-cored wire. The hardness value of the Fe-B-Nb-Ni alloy is up to HRC60. 5 ~ 62. 2. The microstructure of the Fe-B-Nb-Ni alloy consists of ferrite + martensite + Fe3C + NbC + eutectic structure Fe3 ( B,C) + Fe23 (B,C)6 + Fe2B. A large number of fine niobium carbides are randomly dispersed in the microstructure of the alloys. The martensite as wear skeleton shows well strength and wear resistance. The wear mechanism of Fe-B-Nb-Ni abrasive wear resistant layer was mainly plough and brittle peeling.%研制一种Fe-B-Nb-Ni系钻杆耐磨带堆焊药芯焊丝,采用CO2气体保护堆焊方法,制备Fe-B-Nb-Ni耐磨堆焊合金,利用OM,SEM,XRD等方法对堆焊合金的显微组织进行了观察分析,对堆焊层的硬度及耐磨性能进行了测试分析.结果表明,Fe-B-Nb-Ni堆焊合金耐磨性能比国外某进口药芯焊丝提高了约37%,其宏观硬度值达到HRC60.5~62.2.Fe-B-Nb-Ni堆焊合金的显微组织为马氏体+铁素体+少量渗碳体+颗粒状NbC+包晶Fe3(B,C)+共晶Fe23(B,C)6、Fe3(B,C)+少量共晶Fe2B相,其中NbC硬质颗粒弥散的分布于基体中,基体中的马氏体组织具有优异的强度和耐磨性,起到了很好的耐磨骨架的作用.Fe-B-Nb-Ni堆焊合金的磨损机理主要是犁沟式微切削和局部的硬质相剥落.

  13. Mechanical modelling of tooth wear.

    Karme, Aleksis; Rannikko, Janina; Kallonen, Aki; Clauss, Marcus; Fortelius, Mikael

    2016-07-01

    Different diets wear teeth in different ways and generate distinguishable wear and microwear patterns that have long been the basis of palaeodiet reconstructions. Little experimental research has been performed to study them together. Here, we show that an artificial mechanical masticator, a chewing machine, occluding real horse teeth in continuous simulated chewing (of 100 000 chewing cycles) is capable of replicating microscopic wear features and gross wear on teeth that resemble wear in specimens collected from nature. Simulating pure attrition (chewing without food) and four plant material diets of different abrasives content (at n = 5 tooth pairs per group), we detected differences in microscopic wear features by stereomicroscopy of the chewing surface in the number and quality of pits and scratches that were not always as expected. Using computed tomography scanning in one tooth per diet, absolute wear was quantified as the mean height change after the simulated chewing. Absolute wear increased with diet abrasiveness, originating from phytoliths and grit. In combination, our findings highlight that differences in actual dental tissue loss can occur at similar microwear patterns, cautioning against a direct transformation of microwear results into predictions about diet or tooth wear rate. PMID:27411727

  14. Effects of applying an external magnetic field during the deep cryogenic heat treatment on the corrosion resistance and wear behavior of 1.2080 tool steel

    Highlights: ► Deep cryogenic increases the carbide percentage and make a more homogenous distribution. ► Deep cryogenic improve the wear resistance and corrosion behavior of 1.2080 tool steel. ► Applying the magnetic field weaker the carbide distribution and decreases the carbides percentage. ► Magnetized samples showed weaker corrosion and wear behavior. -- Abstract: This work concerns with the effect of applying an external magnetic field on the corrosion behavior, wear resistance and microstructure of 1.2080 (D2) tool steel during the deep cryogenic heat treatment. These analyses were performed via scanning electron microscope (SEM), optical microscope (OM), transmission electron microscope (TEM) and X-ay diffraction (XRD) to study the microstructure, a pin-on-disk wear testing machine to study the wear behavior, and linear sweep voltammetry to study the corrosion behavior of the samples. It was shown that the deep cryogenic heat treatment eliminates retained austenite and makes a more uniform carbide distribution with higher percentage. It was also observed that the deep cryogenic heat treatment improves the wear behavior and corrosion resistance of 1.2080 tool steel. In comparison between the magnetized and non-magnetized samples, the carbide percentage decreases and the carbide distribution weakened in the magnetized samples; subsequently, the wear behavior and corrosion resistance attenuated compared in the magnetized samples.

  15. Efecto del conteo de nódulos en la resistencia al desgaste por abrasión de los hierros dúctiles austemperados. // Effect of nodules count in the waste by abrasion resistance for ductile austempering irons.

    C. J. Diez Cicero

    2004-05-01

    Full Text Available Entre los materiales metálicos de mayor demanda, la producción de hierro con grafito nodular, ocupa en la actualidad unode los lugares más importantes entre los hierros fundidos de alta resistencia, y con la introducción del tratamiento térmicode austemperado aplicado a estas fundiciones, se da lugar a una nueva familia de materiales, caracterizados por su altaresistencia mecánica y elevada tenacidad, que mantienen la economía y facilidad de producción de las fundicionesnodulares.Este trabajo, hace una valoración del comportamiento de hierros nodulares, con diferentes conteos de nódulos, a los que lesfue aplicado el tratamiento de austemperado y posteriormente se les sometió a ensayos de desgaste abrasivo.Con los resultados obtenidos se hace un análisis de la influencia del conteo de nódulos en dichas propiedades, así comotambién de la interrelación del conteo de nódulos con las variables de tratamiento térmico utilizadas en las muestrasensayadas.Palabras claves: Hierro nodular, conteo de nódulos, austemperado.____________________________________________________________________________Abstract.Between the metallic materials of greater demand, the iron production with nódular graphite occupies at the present time,one of the most important places between fused irons of high resistance, and with the introduction of the austempering heattreatment, applied to these meltings, brings a new family of materials, characterized by its high mechanical resistance andelevated tenacity, that maintain the economy and facility of production of the nodular smeltings.This work makes a valuation of the nodular irons behaviors, with different counts from nodules, to which the austemperingtreatment was applied, and later they were put under tests of abrasive wearing.Of the obtained results, takes control of the influence the nodules count in these properties, as well as, of the interrelation ofthe nodules count, with the used variables of heat

  16. Ti(C,N and (Ti,AlN hard wear resistant coatings

    K. Gołombek

    2010-04-01

    Full Text Available Purpose: Investigation the influence of kind of PVD coatings structure (homogenous or gradient on properties of deposited tool materials: cemented carbides and cermets.Design/methodology/approach: Analysis of the structure, analysis of the mechanical and functional properties: surface roughness, microhardness tests, scratch tests, cutting tests. The Ti(C,N gradient coating was investigated by XPS method with multifunctional PHI 5700/660 spectrometer. The characteristic of surface region coating were determined from XPS depth profile. X-ray qualitative phase analysis and the grazing incidence X-ray diffraction method (GIXRD was employed to collect the detailed information about phase composition of investigated material’s surface layer. Microstructural of investigations substrates and coatings by transmission electron miocroscopy (TEM were done.Findings: Results of the investigation the influence of PVD coatings structure (homogenous or gradient and kind on properties of coated tool materials: cemented carbides and cermets are given in the paper. Coatings are characterized by dense, compact structure, there have been identified no pores, fractures and discontinuities. The coatings were deposited uniformly onto the investigated substrate materials and show a characteristic columnar, fine-graded structure. The results of roughness, microhardness and cutting tests confirm the advantages of the PVD coatings. The coatings deposited onto the investigated substrates are characterised by good adhesion and causes increasing of wear resistance. The grazing incidence X-ray diffraction method (GIXRD in the investigated coatings were used to describe the structure and gradient character of the coatings.Practical implications: Deposition of hard, thin, gradient coatings on materials surface by PVD method features one of the most intensely developed directions of improvement of the working properties of materials.Originality/value: New techniques of gradient

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

    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.

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

    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.

  19. Effect of tetrahedral amorphous carbon coating on the resistivity and wear of single-walled carbon nanotube network

    Iyer, Ajai; Kaskela, Antti; Novikov, Serguei; Etula, Jarkko; Liu, Xuwen; Kauppinen, Esko I.; Koskinen, Jari

    2016-05-01

    Single walled carbon nanotube networks (SWCNTNs) were coated by tetrahedral amorphous carbon (ta-C) to improve the mechanical wear properties of the composite film. The ta-C deposition was performed by using pulsed filtered cathodic vacuum arc method resulting in the generation of C+ ions in the energy range of 40-60 eV which coalesce to form a ta-C film. The primary disadvantage of this process is a significant increase in the electrical resistance of the SWCNTN post coating. The increase in the SWCNTN resistance is attributed primarily to the intrinsic stress of the ta-C coating which affects the inter-bundle junction resistance between the SWCNTN bundles. E-beam evaporated carbon was deposited on the SWCNTNs prior to the ta-C deposition in order to protect the SWCNTN from the intrinsic stress of the ta-C film. The causes of changes in electrical resistance and the effect of evaporated carbon thickness on the changes in electrical resistance and mechanical wear properties have been studied.

  20. Wear resistance behavior between gaseous carburising followed by salt bat nitriding and gaseous nitrocarburising of microalloyed steels

    Full text.The effect of salt bath nitriding and nitrocarburising on the microstructure, and the microhardness and the wear resistance of microalloyed steels was investigated. The wear tests were carried out on the specimens nitrocarburised in the ambient atmosphere and the results are compared with those of the nitrided specimens. Nitrocarburising and nitriding process have been carried out respectively at 1203 degreK for 5h in CH4/ NH3 atmosphere and 853 degreK for 7h. The heat treatment applied after the nitrocarburising process and which consists to an quenching and tempering induces in the near surface, one composed structure of martensite and the very fine precipitation of nitrides and carbonitrides. However, this structural state improves the microhardness profile and the wear resistance. It was found that the weight loss of nitrocarburised samples is more less pronounced than that the nitrided samples. The microstructures of the nitrided and nitrocarburised cases and worn surface topographies were observed by optical microscope and scanning electron microscope (SEM. The phases structures formed since the near surface to the substrat were determined by x-ray diffraction (XRD) using Cu Kα radiation