摘要 :
Purpose - This paper aims to study the effect of Al-Ti-B grain refiners on the wear behaviour of hypoeutectic (Al-0.2, 2, 3, 4, 5 and 7Si alloys) Al-Si alloys against steel counterface using a Pin-On-Disc machine under dry sliding...
展开
Purpose - This paper aims to study the effect of Al-Ti-B grain refiners on the wear behaviour of hypoeutectic (Al-0.2, 2, 3, 4, 5 and 7Si alloys) Al-Si alloys against steel counterface using a Pin-On-Disc machine under dry sliding conditions. Design/methodology/approach - In the present study, Al-5Ti-1B and Al-1Ti-3B grain refiners were used for the refinement of a-Al dendrites in hypoeutectic Al-Si alloys. Various parameters such as alloy composition, normal pressure, sliding speed and sliding distance were studied on Al-Si alloys. Worn surfaces were characterized by SEM/EDX microanalysis. Findings - Wear resistance of hypoeutectic Al-Si alloys increases with the addition of Al-Ti-B refiners when compared with the absence of grain refiner. Research limitations/implications - The effects of normal pressure, sliding speed and sliding distance were studied by varying one parameter and keeping constant the other two parameters. Originality/value - This paper provides information on improvement in wear properties of Al-Si alloys by the addition of Al-Ti-B grain refiners. The effects of silicon and grain refiners containing Ti/B play a vital role and are responsible for the wear resistance of the alloys, which helps the industrialists in manufacturing Al-Si alloy components.
收起
摘要 :
The effects of abrasive particle size on wear resistance have been studied extensively. But, none of these studies is completely satisfactory for finding the relation between the abrasive particle size and wear rate. The abrasive ...
展开
The effects of abrasive particle size on wear resistance have been studied extensively. But, none of these studies is completely satisfactory for finding the relation between the abrasive particle size and wear rate. The abrasive wear resistance of non-heat-treated and heat-treated steels produced at broad range of different temperatures, have been determined by using a pin-abrasion machine having five abrasive papers ground on a small pin of the test materials. The mass loss of test material during abrasive wear was determined gravimetrically. The results for the non-heat-treated steels show that there is a parabolic relation between wear coefficient and abrasive particle size. This agrees with similar findings in the literature. There is a linear relationship between the abrasive wear resistance and hardness, depending on abrasive particle size. However, the relationships for the heat-treated steels show positive intercepts on the ordinate, depending on abrasive particle size. The relative wear resistance and hardness are related linearly for non-heat-treated steels, and this relationship does not depend on abrasive particle size. But, relative wear resistance for the heat-treated steels is dependent on abrasive particle size and the relationships for the heat-treated steels show positive intercepts on the ordinate.From the findings, the empirical mathematical wear resistance model as a function of abrasive particle size is derived. Additionally, the empirical equations of the relative wear resistance of these steels as a function of abrasive particle diameter are formulated.
收起
摘要 :
The Fe–30Mn–8Al–1.2 C–0.1Ti austenite lightweight steel exhibits excellent tensile properties and strain hardening rate. Herein, the friction and wear performance of the austenite lightweight steel was evaluated, and the load ...
展开
The Fe–30Mn–8Al–1.2 C–0.1Ti austenite lightweight steel exhibits excellent tensile properties and strain hardening rate. Herein, the friction and wear performance of the austenite lightweight steel was evaluated, and the load effects on the wear mechanism and microstructure were investigated. Results show that the specific wear rate decreases monotonically with increasing load. As the load increases, the wear mechanism transfers from oxidative wear, abrasive wear, adhesive wear to oxidative wear, abrasive wear, adhesive wear and fatigue wear. As the load increases, the plastic deformation of worn subsurface intensifies, and the dislocation density increases drastically. The excellent plasticity and strain hardening ability endow the lightweight steel with high hardness and elastic recovery energy under high loads, resulting in excellent wear resistance.
收起
摘要 :
Mar/scratch resistance characterization techniques are presented in this paper, in which a Nano-indenter and a scanning probe microscope (SPM) are used to measure the micro mar resistance (MMR), different responses of coatings to ...
展开
Mar/scratch resistance characterization techniques are presented in this paper, in which a Nano-indenter and a scanning probe microscope (SPM) are used to measure the micro mar resistance (MMR), different responses of coatings to the marring stress, and critical forces for rough trough, cracking, delamination, and chipping, quantitatively. It provides a full spectrum of the mar/scratch resistance behavior of the tested samples. To comprehensively evaluate a coating/material in a specified application, introduction of a quantitative index is very useful. The concept of the index and the procedure to calculate it are described in the paper, too. In addition, to meet the variety of coatings/materials properties and the requirements in their applications, some complementary test methods are discussed.
收起
摘要 :
The wear resistance of epitaxial layers of alpha- and beta-polymorphs of gallium oxide grown on sapphire substrates has been considered. This is one of the first studies of the tribological properties of a promising wideband semic...
展开
The wear resistance of epitaxial layers of alpha- and beta-polymorphs of gallium oxide grown on sapphire substrates has been considered. This is one of the first studies of the tribological properties of a promising wideband semiconductor crystal. As a result of tribotests conducted with the participation of a sapphire counterface in the process of dry friction in air, it has been shown that the layers of a metastable alpha-Ga2O3 are more resistant to abrasion than the layers of the thermostable beta-phase. At the same time, the obtained values of the wear coefficients allow us to attribute both polymorphs to wear-resistant materials and especially alpha-Ga2O3 with a corundum structure. In addition, alpha- and beta-Ga2O3 demonstrate extremely low values of friction coefficients: lower than those of sapphire.
收起
摘要 :
Purpose - The purpose of this study is to prepare WC-10Co-4Cr coatings using two processes of plasma spraying and high-velocity oxygen fuel (HVOF) spraying. The decarburization behaviors of the different processes are analyzed ind...
展开
Purpose - The purpose of this study is to prepare WC-10Co-4Cr coatings using two processes of plasma spraying and high-velocity oxygen fuel (HVOF) spraying. The decarburization behaviors of the different processes are analyzed individually. The microstructural characteristics of the as-sprayed coatings are presented and the wear mechanisms of the different WC-10Co-4Cr coatings are discussed in detail.
收起
摘要 :
Direct metal deposition process has been adopted for repair of oil pump gear shaft of an aero engine. The process is first optimized for the specific application of oil pump gear shaft material on a specimen and then the actual pa...
展开
Direct metal deposition process has been adopted for repair of oil pump gear shaft of an aero engine. The process is first optimized for the specific application of oil pump gear shaft material on a specimen and then the actual part was applied with deposition. The deposition on the gear shaft is validated through stringent quality checks and functionality check of the oil pump during bench test and engine test. The successful adoption of the deposition process is able to prevent failures which would otherwise cause catastrophic failure of the aero engine. Oil pumps are now withdrawn from service at a predetermined time prior to its scheduled inspection and overhaul for application of metal deposition.
收起
摘要 :
The wear resistance of alloys in corrosive medium always becomes worse, when the environmental variables, such as evolution of hydrogen from acidic media, certain content of chloride in acid solution and polluted sea water, etc., ...
展开
The wear resistance of alloys in corrosive medium always becomes worse, when the environmental variables, such as evolution of hydrogen from acidic media, certain content of chloride in acid solution and polluted sea water, etc., are sensitive torupture of alloys. An unusual high removal rate of alloys could not be explained only in terms of chemical aggression. An energy criterion of surface embrittlement of alloys has been investigated by means of single pendulum scratch test. Specific consumed energy (SCE) (energy loss per groove volume during an impact scratching) is suggested for evaluating environmental embrittlement. Hydrogen-induced embrittlement wear of HSLA steel and Ti alloy, Clˉ impelling embrittlement tear of stainless steel, surface embrittlemental wear of copper alloys in sea water polluted by S{sup}2- and NH{sub}3 and Ni-P electroless coating in alkaline solution have been described.
收起
摘要 :
Previously published expressions for the wear volume in the micro-scale abrasion test for curved specimen surfaces (K.L. Rutherford and I.M. Hutchings, Tribology Letters 2 (1996) 1-11) were based upon erroneous assumptions about t...
展开
Previously published expressions for the wear volume in the micro-scale abrasion test for curved specimen surfaces (K.L. Rutherford and I.M. Hutchings, Tribology Letters 2 (1996) 1-11) were based upon erroneous assumptions about the wear-scar geometry. Accurate volumes have now been computed, and the errors in the use of the original analytical equations are shown to be negligibly small (<0.5% error) for all practical cases.
收起
摘要 :
TiNi shape memory alloys are well known for their shape memory and superelastic effects, which are the result of reversible martensitic transformation. Materials exhibiting superelastic effect are characterized by high recoverable...
展开
TiNi shape memory alloys are well known for their shape memory and superelastic effects, which are the result of reversible martensitic transformation. Materials exhibiting superelastic effect are characterized by high recoverable strain during deformation due to stress induced martensitic transformation. It has been recently found that TiNi alloy has superior wear resistance compared to other conventional materials. Understanding the superelastic behavior of this material helps to increase its utilization in applications where high wear and denting are common as in gears and bearings. Unfortunately, limited work has been done to investigate the superelastic effect of TiNi under wear and indentation conditions. In this study the superelastic behavior of TiNi under sliding wear and indentation loading is investigated.
收起
原文获取