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Effects of ECAP on the mechanical properties of Mg-Al2O3 nanocomposites
Abstract
The purpose of this paper is the study of the effect of equal channel angular pressing (ECAP) on the mechanical properties of the Mg-Al2O3 nanocomposites. Magnesium and its alloys have excellent physical and mechanical properties for a number of applications. In particular its high strength: weight ratio makes it an ideal metal for automotive and aerospace applications, where weight reduction is of significant concern. Design/methodology/approach: Severe plastic deformation is a useful methodology to refine the grain size to the submicron or even nanometer size Findings: In the present work the influence of number of passes of ECAP by grain size, evolution of microstructure, mechanical properties and fracture of magnesium composites with different volume fraction of Al2O3 particles has been investigated by means of optical microscopy, tensile tests and scanning electron microscopy. Research limitations/implications: It has been found, that the grain size decreases with increasing number of passes. The mechanical properties of magnesium alloys are significantly influenced by the testing temperature leading to a decrease in the strength, by reinforcement and/or grain reinforcement leading to an increase in the strength. Originality/value: From previous studies, it was found that the MMCs using different size particles and different ECAP passes can improved the mechanical properties. But the research of Mg MMCs reinforcement with different wt.% nanoscale Al2O3 particles is not adequate.
... Such limitations can be overcome with the incorporation of proper, harder, and stiffer ceramic particles such as SiC [4], Al 2 O 3 [7], CNT [8], etc., to fabricate a reinforced Mg metal matrix composite (MMC). The addition of single reinforcement particles can improve the specific strength, specific stiffness, creep, wear, and corrosion properties and provide enhanced wettability [4,9]. ...
Magnesium is a low-density metal which is used in extensive structural applications such as load-bearing components in the automobile industry. To improve the strength and ductility of the magnesium alloys, method of production of metal matrix composites have been developed. In this study, AZ61 magnesium alloy was reinforced with hybrid particles (2 wt% Al2O3 and 1 wt% SiC) fabricated by the stir casting method. Then, the casted samples were homogenized at 410 °C for 24 h, aged at 200 °C for 10 h followed by severe plastic deformation (SPD) processing using equal channel angular pressing (ECAP). The obtained microstructure observation showed that the hybrid reinforcement particles were uniformly distributed in the metal matrix. After the ECAP process, the grain size was significantly reduced from 148.79±79 μm to 12.2±8 μm due to the dynamic recrystallization (DRX) mechanism during the plastic deformation. The mechanical properties of hardness, yield strength (YS), ultimate tensile strength (UTS), and elongation are effectively improved after each ECAP pass; the maximum values achieved were 61.2±4.6 HV, 110.3 MPa, 250.1 MPa, and 19.3%, respectively on the ECAP-2P AZ61/Al2O3/SiC hybrid composite. The enhancement of the mechanical properties of the AZ61 hybrid composites was mainly attributed to the Hall-Petch strengthening mechanism.
... Usually, light-weight materials reinforced using ceramic particles, such as SiC, Al 2 O 3 , TiB 2 , carbon nanotubes (CNT), and others, are used to produce MMCs [8][9][10][11][12][13]. Among these particles, SiC is the most applicable reinforcement for aluminum and magnesium alloys due to its high strength and hardness, low cost, and good compatibility with the metallic matrix. ...
Magnesium alloys are attractive for the production of lightweight parts in modern automobile and aerospace industries due to their advanced properties. Their mechanical properties are usually enhanced by the incorporation with reinforcement particles. In the current study, reinforced AZ31 magnesium alloy was fabricated through the addition of bulk Al and the incorporation of SiC nanoparticles using a stir casting process to obtain AZ31-SiC nanocomposites. Scanning electron microscope (SEM) investigations revealed the formation of Mg17Al12 lamellar intermetallic structures and SiC clusters in the nanocomposites. Energy dispersive spectroscopy (EDS) detected the uniform distribution of SiC nanoparticles in the AZ31-SiC nanocomposites. Enhancements in hardness and yield strength (YS) were detected in the fabricated nanocomposites. This behavior was referred to a joint strengthening mechanisms which showed matrix-reinforcement coefficient of thermal expansion (CTE) and elastic modulus mismatches, Orowan strengthening, and load transfer mechanism. The mechanical properties and wear resistance were gradually increased with an increase in SiC content in the nanocomposite. The maximum values were obtained from nanocomposites containing 1 wt% of SiC (AZ31-1SiC). AZ31-1SiC nanocomposite YS and hardness were improved by 27% and 30%, respectively, compared to AZ31 alloy. This nanocomposite also exhibited the highest wear resistance; its wear mass loss and depth of the worn surface decreased by 26% and 15%, respectively, compared to AZ31 alloy.
This study addressed the development and investigation of an AZ61 hybrid composite (HBC) fabricated by the stir casting method followed by equal channel angular pressing (ECAP). The HBC was reinforced using both Al2O3 and SiC nanoparticles. The microstructural examination showed that the introduced reinforcements broke down the round-like formed precipitates into needle-like shapes that enhanced the ductility. Furthermore, the grain size of the HBCs is highly reduced while increasing the number of ECAP passes due to dynamic recrystallization (DRX). The obtained mechanical properties showed that the optimal yield strength (YS), ultimate tensile strength (UTS), and elongation were observed in the AZ61+2%Al2O3+1%SiC hybrid composite after two passes of ECAP. The HallPetch strengthening mechanism was primarily responsible for the improved mechanical properties of AZ61 HBC, jointly with the mutual contribution of several mechanisms, including the coefficient of thermal expansion, Orowan looping, and load transfer mechanisms.
Michael J. Zehetbauer’s name appears incorrectly in the original electronic version of this article. It has been corrected here.
The method of 'in-situ tensile test in SEM' is suitable for investigations of fracture mechanisms because it enables to observe and document deformation processes directly, thank to which the initiation and development of plastic deformation and fracture can be reliably described. The deformation and fracture mechanisms of Cu-Al2O3 nanomaterials with 5 vol. % of Al2O3 phase has been analyzed using technique of the 'in-situ tensile testing in SEM'. It has been shown that the deformation process causes break-up of large Al2O3 particles and decohesion of smaller ones. The final fracture path is influenced also by boundaries of nanograins, through which the principal crack propagates towards the sample exterior surface. Based on the experimental observations a model of damage and/or fracture mechanisms has been proposed.
In this work, the microstructures and tensile properties of a commercial magnesium alloy “AZ61” processed by a combination of hot extrusion and thermomechanical processing (TMP) were investigated. The TMP was consisting of two or three hot rolling steps with large reductions per pass, thus allowing significant grain refinement. The microstructural evolution has been studied by means of optical and scanning electron microscopes, as well as X-ray diffraction analysis. The as-cast material is extruded in the form of a cylinder with initial diameter of 250 mm to a final diameter of 110 mm (80% reduction in cross-sectional area). Then hot rolling regimes were performed at 300 °C with different percentage of strain per pass. Tensile and hardness tests were performed in the samples (as-cast, extruded, and rolled) at room temperature in order to evaluate the mechanical properties of the material. The results of experiments demonstrated that fine grain size might be achieved in magnesium alloy AZ61 by using a two-step processing route involving an initial extrusion step followed by thermomechanical processing with large reduction in thickness per pass. This two-step process, designed to achieve average grain sizes of ∼10–20 μm.
Basic mechanical and wear properties of a commercial copper based composite Glidcop were studied. A Glidcop AL-60 grade (with 1.1 wt.% Al2O3) was used as the initial material. It was further treated by the Equal Channel Angular Pressing (ECAP) process in order to induce massive plastic deformation and to achieve very fine grained microstructure. Both, as-received and ECAP-ed materials were then characterized and the results compared. Hardness and elasticity modulus of the experimental materials were measured by instrumented indentation. Tribological properties were studied by pin-on-disk technique in dry sliding against a steel ball at a various temperatures from room temperature up to 600 °C. For all systems the coefficient of friction and specific wear rates were evaluated. Worn surfaces were studied by scanning electron microscopy and level of oxidation was measured using EDX spectrometry. It was found that above 200 °C the coefficient of friction decreased by about 50 %. The wear resistance with increasing temperature increased due to formation of harder oxide rich surface layer. Damage mechanisms were identified and their relationship with structural characteristics was inferred.
Plasma spraying is one of the methods used for combating wear. The processing of materials using plasma spraying leads to inhomogenities, such as unmelted particles, oxide particles, oxide inclusions and porosity and the structure markedly different from that of cast, wrought or even powder metallurgy materials. Despite of its wide spread industrial use, little is known about the basic friction behavior and mechanism by which such coatings wear. In this work, the abrasive wear resistance of plasma sprayed Al2O 3 and ZrO25CaO coatings has been investigated through pin-on-disc test according to ASTM G99. From the investigation it was found that the wear rate is mainly affected by load applied, splats, porosity and microhardness of coatings. The coefficient of friction was found to be more significantly effected by load than other test parameters. This study showed that pin on disk is a well controlled test and can be used to understand certain basic relationships between the sliding friction and wear behavior of plasma sprayed coatings. It also includes the characterization of coating systems.
Tribological properties by two copper based composites (Micro-Cu-Al 2O 3 with grains size 1-2 μm and Nano-Cu-Al 2O 3 with grains size 100-200 nm) were studied by pin-on-disk technique against a steel ball at a range from room temperature up to 873 K. For both systems the coefficient of friction decreased between 473 K and 673 K by about 25 %. At lower temperatures the nano-Cu was about three times more wear resistant than the micro-Cu but the wear rate of both systems decreased down to zero at 673 K due to formation of hard oxide layers.
The basic aim of the present investigation is to study the role of particle size for high-temperature application of ZrSiO4-reinforced aluminum-based LM13 alloy composite as a bearing material. Composites containing 15 wt pct ZrSiO4 particles of two different size ranges (20 to 32 and 106 to 125 μm) in different proportion were prepared by the stir casting route. The microhardness measured at different areas indicates good interfacial bonding. Transition in the wear mode for all composites occurs after temperature 423 K (150 °C). The overall wear properties of DPS-2 composite containing 12 pct fine and 3 pct coarse particles are better at all temperatures for both low and high loads.
The nature and distribution of hard ceramic particles in composite materials influences the properties to greater extent. In the present work, the role of hard ceramic reinforced particles on the tribological behaviour of aluminum metal matrix composites consisting of single (SRP) and dual reinforced particles (DRP) is studied at different temperatures. Zircon sand and silicon carbide particles of size 20–32 μm were used as reinforcement in commercial grade LM13 piston alloy. Composites of dual reinforced particles in aluminum matrix (DRP-AMCs) were developed by mixing 15 wt% reinforced particles by two step stir casting technique. The wear behaviour of DRP-AMCs and SRP-AMCs (single reinforced particles aluminum matrix composite) was investigated using a pin-on-disc method at high temperatures under dry sliding condition. The microstructural examination of developed composites shows globular and finely distributed eutectic silicon in the vicinity of the reinforced particles. Metallographic investigation revealed that the wear zone of the SRP composite consisted of a hardened layer, which is responsible for high wear loss observed in the SRP composite. The results further indicate a transition in the wear mode that occurs after 150 °C for all composites. Study reveals that the dual reinforcement of particles enhances the wear resistance as compared to single reinforced particles if mixed in a definite ratio. A combination of 3% zircon sand and 12% silicon carbide particle reinforced composite exhibits better wear resistance as compared to other combinations at all the temperatures for low and high loads both.
The main aim of this paper was to determine the amount of Al2O3 reinforcement that results into best combination of strength. Magnesium nano composites containing 3.5, 7.0 and 14 volume percentage of Al2O3 were synthesized through powder metallurgy route. Resistance of furnace sintering technique (heating rate: 49°C/min).Micro structural characterization revealed reasonably uniform distribution of Al2O3 particulates in the matrix and the presence of nanopores. Thermo mechanical analysis revealed significant reduction in CTE of magnesium as a result of presence of alumina nano particulates. Mechanical characterization studies revealed that hardness, work of flexural strength of pure Mg increased when 3.5, 7.0 and 14 vol. % of nano alumina reinforcements are added into Mg matrix. Where as 14 vol.% is revealed that decrease the strength of hardness. The studies revealed that the best combination of mechanical properties is realized from the compositecontaining 7 volume percentage of alumina.
Dispersion hardened Cu-Al//2O//3-materials were produced by intensive grinding of Cu-Al-CuO-powder mixtures with successive hot extruding, and their mechanical properties and microstructures were investigated. The connection found experimentally between the yield strength and the amount of dispersoid is approximated most closely by the Fisher-Hart-Pry equation. The effect of the grain size of the dispersoids, their distribution, and the subgrain size on the deformation behavior is discussed.
This research chose nano-scaled Al2O3 granular materials as the reinforcement particle and used the modified disintegrated melt deposition (DMD) technique to integrate the particle Al2O3 p with AZ91D as the magnesium metal matrix composites (Mg MMCs). Subsequently, the melt soup was formed with rapid stirring, and the different heat treatment processes were used to improve the mechanical properties of the composites. With increase of the weight percentage of the particles added into AZ91D, the hardness was increased. But the hardness of the composite added with the particle is declined moderately under the process of air cooling and water cooling. With room temperature cooling condition, the ultimate tensile strength (UTS) of present Al2O3 p/AZ91D MMCs is 189.55 MPa. With the water cooling condition, UTS of present MMCs increases to 191.86 MPa. However, with the air cooling condition, UTS of present MMCs increases up to 271.86 MPa. After T6 heat treatment, the hardness of 1wt.% Al2O3 p added MMCs is improved to 78.94 HV due to the aging effect and its UTS is 254.63 MPa under the condition of the 32hr aging treatment.
Structure and Properties of Solids. Solid Surface Characterization. Contact Between Solid Surfaces. Adhesion. Friction. Interface Temperature of Sliding Surfaces. Wear. Fluid Film Lubrication. Boundary Lubrication and Lubricants. Micro/Nanotribology. Friction and Wear Screening Test Methods. Bulk Materials, Coatings, and Surface Treatments for Tribology. Tribological Components and Applications. Problems. Appendix. Index.
A review starting from material science trough production technology to testing properties of the Cu‐Al2O3 system, based on several years of research and development in materials research, is presented. Microstructural design, microstructure evaluation by different methods, first the importance of correct secondary phase particle spatial distribution evaluation, influence of microstructure on properties, and modifications of production technology, are described. Evaluations are compared to microstructural parameters of a real material: volume fraction, distribution calculations, as well as interparticle distance. Strength and plastic properties at room and higher temperatures are presented and the failure mechanism described. A simplified model of the failure mechanism is proposed. Influence of dispersed Al2O3 particles on recrystallisation is characterised, too.
Results of investigation of the tribological contact characteristics of R18 tool steel in interface with AZ91D magnesium alloy
hardened with SiC disperse powder filler and by severe plastic deformation (SPD)—specifically, equal-channel angular pressing
(ECAP)—are presented. It is established that introduction of the SiC powder filler into the magnesium alloy increases the
friction coefficient and reduces the wear rate. The size and volume of the powder filler particles, the normal load, and the
relative sliding velocity influence these tribological characteristics. SPD of the original material leads to reduction of
the molecular component of the friction coefficient.
抄録
In order to improve the mechanical properties of magnesium alloys, silicon-carbide dispersion-strengthened magnesium (SiCp/ Mg), in which SiC particles (SiCp) were milled with pure Mg by an attritor ball mill and used as reinforcement, was produced by hot pressing. Silicon-carbide dispersion strengthening by the mechanical alloying (MA) method in magnesium was investigated. The experimental results are summarized as follows. By raising the milling force of the ball mill in which the pAl2O3/ Mg MA powder of the previous report was made, the density of SiCp/ Mg was made higher than that of the pAl2O3/ Mg of the previous report. The SiCp/ Mg was about 2/3 times as light as the practical aluminum alloys. The hardness of the SiCp/ Mg was about 1.5 times as high as that of the pAl2O3/ Mg and exceeded that of AZ91D, which excels at the mechanical properties in the practical Mg alloys. The highest value was 95HV. The bending strength of the SiCp/ Mg was better than that of the pAl2O3/ Mg. From the analytical results of XRD and SEM-EDAX on the SiCp/ Mg, it is thought that SiCp is almost uniformly finely dispersed in Mg and that the Mg grain becomes superfine.
Temperature can have a considerable effect on the extent of wear damage to metallic components. During reciprocating sliding, under conditions where frictional heating has little impact on surface temperatures, there is generally a transition from severe wear to mild wear after a time of sliding that decreases with increase in ambient temperature. This is due to the generation and retention of oxide and partially-oxidized metal debris particles on the contacting load-bearing surfaces; these are compacted and agglomerated by the sliding action, giving protective layers on such surfaces. At low temperatures, from 20 to 200°C, the layers generally consist of loosely-compacted particles; at higher temperatures, there is an increase in the rates of generation and retention of particles while compaction, sintering and oxidation of the particles in the layers are facilitated, leading to development of hard, very protective oxide ‘glaze’ surfaces. This paper reviews some of the main findings of extensive research programmes into the development of such wear-protective layers, including a model that accounts closely for the observed effects of temperature on wear rates during like-on-like sliding.
Three processing routes of equal channel angular extrusion (ECAE) were used to process Mg alloy. Tensile strengths, grain sizes and textures of these processed billets were measured to investigate the effect of processing route on the mechanical properties, and the strengthening mechanism. Route A is the only route that can increase the strength by ECAE. A multiple-temperature ECAE procedure has been developed to produce high-strength Mg alloy, which is a combined result of submicron grain structure and texture strengthening.
From the practical necessity to obtain the friction and wear characteristics of materials used in machinery, various types of wear-testing machines have been developed and used. To obtain useful data for practical application, it is desirable that the investigation is carried out by a full-scale wear-testing apparatus having approximately similar contact conditions. Generally speaking, the obtained wear characteristics are different for every wear-testing apparatus used. When the type of wear-testing machine is not suitable, one cannot obtain the required wear characteristics. There are various parameters in wear-testing machines, such as configuration of contact surface and form of the relative motion between the test specimens. Thus, in this report, the effect of relative motion between contacting pair and friction process on obtained test results is investigated, for the combination of a copper pin specimen and a flat steel specimen. The microscopic structure of the pin specimen may be varied due to the friction and wear process. An optical microscope is used for the observations. The pin specimen is made from pure copper, which can be deformed easily.
The indentation load-displacement behavior of six materials tested with a Berkovich indenter has been carefully documented to establish an improved method for determining hardness and elastic modulus from indentation load-displacement data. The materials included fused silica, soda–lime glass, and single crystals of aluminum, tungsten, quartz, and sapphire. It is shown that the load–displacement curves during unloading in these materials are not linear, even in the initial stages, thereby suggesting that the flat punch approximation used so often in the analysis of unloading data is not entirely adequate. An analysis technique is presented that accounts for the curvature in the unloading data and provides a physically justifiable procedure for determining the depth which should be used in conjunction with the indenter shape function to establish the contact area at peak load. The hardnesses and elastic moduli of the six materials are computed using the analysis procedure and compared with values determined by independent means to assess the accuracy of the method. The results show that with good technique, moduli can be measured to within 5%.
The microstructural, physical and mechanical properties of pure magnesium reinforced with different volume fractions of 0.6μm silicon carbide (SiC) particulates were investigated. It was found that pure magnesium were synthesized using the disintegrated melt deposition technique (DMD). It was observed that the methodology including DMD coupled with hot extrusion could be utilized to synthesize elemental and sub-micron size silicon carbide reinforced reinforced magnesium with minimal porosity. The results reveal that superior coefficient of thermal expansion (CTE), hardness, elastic moduli and 0.2% yield strength could be obtained using much lower amount of SiC particulates in sub-micron-length scale.
Sliding wear can be influenced significantly by heat, either frictional or externally applied, since it can facilitate oxidation of the contacting metal or alloy surfaces. This can result in a decrease in wear rate, usually associated with a change from metallic debris to oxide debris. The present paper reviews some of the models developed to account for the generation of oxide during sliding and the effects of such oxides on the rates of wear. Emphasis is placed on high-speed unidirectional sliding, where frictional heat can lead to surface temperatures that are sufficiently high to result in relatively thick oxides on the contacting surfaces, and low-speed reciprocating sliding, where frictional heat is low but externally applied heat can lead to oxidation of the surfaces. Under the former conditions, wear is caused by spallation of oxide from the contacting asperities; this occurs when the oxide attains a critical thickness, leading to mild-oxidational wear. At very high speeds, surface temperatures may be high enough for the oxide to melt, leading to severe-oxidational wear. Under low speed, reciprocating sliding conditions, oxide and oxidized metal debris can be retained and compacted onto the contacting surfaces, giving wear protection. Here, increased temperature facilitates the generation of oxide debris and assists in compaction of the debris to give the wear-protective layers. At low temperatures, such layers consist mainly of loosely-compacted particles; at higher temperatures, typically >250°C, smooth `glaze' surfaces develop on top of solidly compacted particle layers, giving even more effective protection against wear damage.
A new process called “mechanical alloying” has been developed which produces homogeneous composite particles with an intimately
dispersed, uniform internal structure. Materials formed by hot consolidation of this powder achieve the long-sought combination
of dispersion strengthening and age-hardening in a high temperature alloy. While the process is amenable to making a variety
of alloys, its first use has been to combine yttrium oxide and gamma prime hardening hr at 1400°F and 15,000 psi for 100 hr
at 1900°F together with excellent sulfidation and cyclic oxidation resistance. From a fundamental standpoint, results show
that the age-hardening dominates the low-temperature strength, dispersion strengthening dominates at high temperature, and
the two are augmentative in the intermediate temperature range 1300° to 1500°F.
Pure magnesium-30 Vol.% SiC particle composite are fabricated by melt stir technique without the use of a flux or protective inert gas atmosphere. After hot extrusion with an extrusion ratio of 13, Mg-30 vol.% SiCP composites have been evaluated for their tensile properties at room and elevated temperatures (up to 400°C). Composites in the as-cast conditions do not show any change in dendrite arm spacing/cell size compared to unreinforced pure magnesium. However, in the extruded conditions average grain size of the composites is 20 μm compared to 50 μm in the pure magnesium. Microstructure shows no evidence of reaction product at particle/matrix interface. At room temperature, stiffness and UTS of the extruded composites are 40 and 30% higher compared to unreinforced pure magnesium, signifying significant strengthening due to the presence of the SiC particles. Further, up to temperatures of 400°C, composites exhibit higher UTS compared to pure magnesium. Mg composites show a wear rate lower by two orders of magnitude compared to pure Mg, when tested against steel disc using pin-on disc machine.
Surface texture of a harder mating surface has a great influence on frictional behavior during sliding against softer materials. In the present investigation, experiments were conducted using a Pin-on-Plate inclined sliding tester to study the effect of the surface texture of hard surfaces on the coefficient of friction and transfer layer formation. 080 M40 (EN8) steel plates were ground to attain surfaces of different texture with different roughness. Pure magnesium pins were then slid at a sliding speed of 2 mm/s against the prepared steel plates. Scanning electron micrographs of the contact surfaces of pins and plates were used to reveal the morphology of transfer layer. It was observed that the coefficient of friction, formation of transfer layer, and the presence of stick–slip motion depend primarily on the surface texture of hard surfaces, but independent of surface roughness of hard surfaces. The effect of surface texture on coefficient of friction was attributed to the variation of plowing component of friction for different surfaces.
The peculiarities of a submicron-grained structure formation in a series of aluminium- and magnesium-based alloys by means of a special strain-heat treatment are examined in this paper. The unusual mechanical properties of alloys displayed in this state at room temperature as well as at enhanced temperatures are found. The nature of the plastic deformation of these materials is discussed.
The production methods and properties of metal matrix composite materials reinforced with dispersion particles, platelets, non-continuous (short) and continuous (long) fibres are discussed in this paper. The most widely applied methods for the production of composite materials and composite parts are based on casting techniques such as the squeeze casting of porous ceramic preforms with liquid metal alloys and powder metallurgy methods. On account of the excellent physical, mechanical and development properties of composite materials, they are applied widely in aircraft technology and electronic engineering, and recently in passenger-car technology also.
Fatigue lifetime under stress control of ultrafine-grained Cu of 99.9% purity prepared by equal channel angular pressing is shown to exceed that of conventionally grained cold worked counterparts by a factor of 1.7 in the low-, high- and very-high-cycle region. The electron back scattering diffraction technique did not reveal changes of bulk microstructure due to cyclic loading. Minor changes of dislocation microstructure were detected by transmission electron microscopy. Qualitative change from moderate cyclic hardening to cyclic softening was observed with increasing stress amplitude.Comparison of S–N data with those available in literature shows substantially higher lifetime of the material studied in this work in the high- and very-high-cycle region. This effect is attributed to the high stability of the grain structure and lower purity of the examined ultrafine-grained copper.
The work presents the results of the investigation of the influence of a submicrocrystalline structure, texture, and phase composition conditioned by different types of deformation–heat treatment (rolling, torsion strain on Bridgman anvils, lateral extrusion, and subsequent annealing) of copper, CuAlFe bronze and CuZnPb brass on wear resistance at dry sliding under the following conditions: sliding velocity 0.78 m s−1, pressure 0.2 to 10 MPa, and sliding distance 0.5 to 10 km. The results indicate an essential effect of some structural parameters (grain size, phase composition, texture) on wear resistance of this materials. Scanning electron microscopy observations were used to confirm the well-known mechanisms of `mild' wear of copper and bronze with submicrocrystalline structure and delamination of brass with microcrystalline structure under given conditions.
Wear Analysis for Engineers
- R G Bayer
Bayer, R.G. (2002) Wear Analysis for Engineers, HNB Publishing, New York.
Verfestigung von aluminium mit metallischen dispersoiden (strengthening of aluminum with metallic dispersoids
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- F Feher
Jangg, G., Kutner, F., Korb, G. and Feher F. (1975) 'Verfestigung von aluminium mit metallischen
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