Papers by Keyword: Wear Behaviour

Abstract: The effects of laser machining process parameters namely, scan speed and frequency on wear performance of AISI H13 hot work tool steel were investigated in this study. The process parameters are combined with wear process factors and the responses of wear tests were evaluated. The results showed that both friction coefficient and wear rate are affected by process parameters. The average friction coefficient and wear rate increased with an increase in frequency at each set of scan speed. Lowest scan speed and highest frequency produced higher surface roughness and rough texture form.

Abstract: The sliding wear behavior of polyamide6/ultrahigh molecular weight polyethylene (PA6/UHMWPE, 90/10) blends loaded with 20 % carbon short fibers (CSF) as reinforcement and varying amounts of nanoclay filled nanocomposites were reported. Sliding wear loss, specific wear rate and coefficient of friction were investigated. 3 % nano clay filled composite exhibits better wear behaviour. Morphological study was evaluated for wear out surfaces of the composites using scanning electron microscopy.

Abstract: The paper presents the experimental results regarding the influence of the reinforcing elements on the wear behavior of Al-matrix composites discontinuously reinforced by SiC and Graphite. This antifriction composite material is processed by Reactive Mechanically Alloyed and then by Spark Plasma Sintering technology. In order to optimize the processing technology, especially the sintering parameters, the Spark Plasma Sintering process was applied because of its advantageous aspects: lower sintering temperatures, shorter sintering time and higher properties values of the sintered material vs. the corresponding ones obtained by the classical sintering route. The authors realized a comparative analysis on the wear behavior of the researched composite materials.

Abstract: The natural mulberry silk and high-count combed cotton were chosen as raw materials woven into a thin fabric, with classic colour designed as fashion vertical strips. In dying process, high-quality green dye formulations were used to ensure good quality of yarn; in sizing process, the modified starch based, supplemented by a new polypropylene slurry were combined as sizing, which had high concentration and low viscosity, uniform sizing and improved resistance to mill, reduced the regeneration hairiness; in finishing process, the formaldehyde-free anti-crease finishing agent was applied by wet short steaming process, the fabric had anti-crease property, smooth and non-formaldehyde residue. The material after finishing has firmly quality, smooth and fine, slippery and pleasant, safe and practical, has both the texture and luster of silk, also has the comfort of cotton fabric. Through the selection of raw material, production and finishing process, the eco-environmental was stand out, the colour generous and elegant, excellent performance, good market response. The product development process and wear behavior of this high-grade fabric were described in this article. With the textile low-carbon idea through and living standard’s enhancement, the demand of ecotype textile for consumer is getting more and more broad, for this reason, we have developed new product: the ecotype cotton-silk colur woven taffeta. The natural low tex combed cotton was selected as warp yarn and raw silk as weft, and the colour and style formula were careful designed, the high quality environmental protection dye and the formula in dyeing procedure was selected. In the sizing and after-treatment procedure made the key attract, highlight the green environmental protection performance, the fabric has silky quality and gloss, and has cotton comfort, the colour naturally lofty, has good performance, has good market echo. It satisfied the consumer to lining comfortableness, functionality, artistic request[1]. Presently this product’s development and the production process were shown as follow:

Abstract: Various different severe plastic deformation processes (SPD) have been developed to produce ultra-fine grained (UFG) materials during the last two decades. One very important material property that the UFG materials should have for structural materials application is good wear resistance. This review paper presents some recent work related to the wear resistance of materials processed by SPD, in particular for alloys processed by using equal-channel angular pressing (ECAP) and accumulative roll-bonding (ARB).

Abstract: The vacuum infiltration casting process was adopted to prepare cemented carbide (CC) particles reinforced high-Cr white cast iron (WCI) composite by using failed CC parts as reinforcement. The interfacial structures between the CC particle and iron matrix were analysed by optical microscope (OM) and X-ray diffraction (XRD); the wear behavior of the composite was studied by pin-on-disc wear tester. The results showed that: owing to partial dissolution of the CC particles and diffusion of elements such as W, C, Cr and Fe, compounds such as Fe3W3C and Co3W3C were formed, which ensured metallurgical bonding at the interface; the wear resistance property of the composite was much higher than that of the heat treated WCI, moreover, when the applied load increased from 0.4Kg to 2Kg, the wear resistance value of the composite was more than 3.5 times than that of the heat treated WCI. However, there was no significant difference in the wear loss between CC/WCI composite and WC/WCI composite.

Abstract: An MG-2000 high-speed and high-temperature friction-abrasion testing machine was used to evaluate the friction and wear behaviors of AISI1045 steel sucker rod sliding against J55 tubing string and J55 tubing strings coated with spray-welded wear-resistant coatings of various thicknesses in a ring-on-ring configuration and under the lubrication of oilfield wastewater as the lubricating medium. The worn surface morphologies of the sucker rod specimens coupled with the J55 tubing string and the J55 tubing string coated with the wear-resistant coating were observed with a scanning electron microscope. As the results, it was effective to increase the wear-resistance of the frictional pair with the addition of the wear-resistant coatings on the tubing string surface. The wear-resistant coating of a proper thickness also contributed to reducing the friction coefficient to some extent, which was helpful to reduce the friction force between the sucker rod and tubing string pair and increase the service lifetime of the pair. The decreased wear rates of the sucking rod specimens coupled with the tubing string specimens coated with the wear-resistant coating of a proper thickness were attributed to the action of the coating in decreasing adhesion wear. Moreover, the tubing string specimen recorded little difference in wear rate at normal temperature and 60°C. However, the sucker rod specimen registered as lightly larger wear rate at 60°C than at room temperature, which could be attributed to the enhanced adhesion wear and mild corrosive wear at elevated temperature. It was imperative to properly control the thickness of the wear-resistant coating on the tubing string surface so as to bring its friction-reducing and antiwear action into effect.

Abstract: The Ni-based alloy was used as raw materials to fabricate the surface infiltrated layer with 1-4mm thickness on cast steel substrate through vacuum infiltrated casting technology. The microstructure indicate that the infiltrated layer included surface melting and sintering layer, metallurgical fusion layer and diffusion layer. Wear property was investigated under different temperature conditions such as room temperature, 150°C, 300°C and 450°C. The results indicated that the abrasion volume of infiltrated layer was near to third of that of substrate, and it was nearly half of the substrate. This illuminated that the infiltrated had excellent wearable property. The adherence and fatigue abrasion was the main wear mechanism under low temperature. Oxidation abrasion and adherence dominated the wearing process under elevated temperature.

Abstract: A Cu55Zr40Al5 bulk metallic glass (BMG) was prepared by using copper-mold suction-casting and the structure and thermal stabilities of the amorphous alloy as well as the effect of isothermal annealing on its micro-hardness and friction property were studied. The results showed the glass transition temperature, onset temperature of exothermic reaction, and temperature interval of supercooled liquid region are 746.8 K, 793.5 K and 46.7 K, respectively. The BMG exhibits a micro-hardness value of 483.5 Hv and an average friction coefficient of 0.495. After isothermal annealing treatment, the micro-hardness has been enhanced and presents an upward trend with increasing the annealing temperatures. Meanwhile, the friction coefficients can be significantly decreased and the anti-wear property has been enhanced evidently.

Abstract: Ultra-high molecular-weight polyethylene (UHMWPE) has been used in total hip replacement for the last three decades. Despite the advancements in prosthesis design, the wear of UHMWPE remains a serious clinical problem; the release of wear debris may induce osteolysis and implant loosening. Understanding of wear behavior and wear debris morphology of the polyethylene is essential to improve the reliability of hip joint implants. The investigation in this paper carried out wear simulation tests of UHMWPE on Al2O3, 316L stainless steel, CoCrMo alloy and Ti6Al4V alloy, respectively. The lubrication of plasma solution and bovine serum solution was presented in wear tests. The effect of motion and loading on the wear behavior and wear debris morphology, and the influence of femoral head material and assembly style were studied in order to obtain a better understanding of the morphology of ultra-high molecular weight polyethylene wear particles. It is shown that the wear of UHMWPE acetabular cups against metal femoral heads was significantly higher than that against ceramic heads. The presence of protein in lubricant increases the wear of UHMWPE acetabular cups on Al2O3 heads. The wear rates of UHMWPE in multi-directional motion are approximately 2.5 times of those in uni-directional motion. The size distribution range of the UHMWPE debris particles for all head materials varies from submicron particles up to several hundreds micron. The size distribution range of wear debris particles is not directly related to wear resistance of UHMWPE, but significantly influenced by wear mechanisms. The UHMWPE debris particles produced in hip wear simulation tests are classified as round debris, flake-like debris and stick debris, which are closely related to the primary mechanisms of abrasive wear, adhesive wear and fatigue wear.