The study is aimed to analyse the comparative behaviour of the high-temperature abrasive wear of H13 steel surfaces modified by laser melting and cladding with Stellite 6 and Stellite 6 + 30 wt% WC. ...3-body abrasive tests were conducted at room temperature, 450 °C, 550 °C, and 650 °C. The microstructural evolution, microhardness, wear surface morphology and mechanisms, and various phases formed during laser surface modifications were also studied. The laser remelting of H13 steel surface increased its room temperature microhardness to 750 ± 35 HV0.01, whereas laser cladding of Stellite 6 powder yielded hardness of around 600 ± 20 HV0.01 in the clad layer; and Stellite 6/WC composite clad layer had marginally higher hardness than the Stellite 6 clad layer in the matrix and much higher hardness of ~3000 HV0.01 at the sporadically distributed WC particle sites. Though the room temperature microhardness of laser remelted H13 surface is the highest, the volumetric wear loss in it was comparable to that of the Stellite 6 cladding. However, Stellite 6/WC composite layer recorded a relatively less volumetric loss as WC particles resisted the abrasive wear. With increasing temperature, the wear loss in laser remelt surfaces increased at a fast rate, while that in Stellite 6 and composite clad layers varied marginally with no definite trend. Overall, Stellite 6/WC composite cladding performed better than others in the current temperature range.
Abrasive wear of polyether ether ketone (PEEK) and aromatic thermosetting co-polyester (ATSP) based polymer composite coatings were examined with lunar regolith simulant environment by conducting ...pin-on-disk experiments under dry sliding conditions, contact pressure of 17.5 MPa, and sliding speed of 0.25 m/s. Three different tribo-interfaces, namely metal-on-metal, metal-on-polymer, and polymer-on-polymer were designed to evaluate the efficacy of each polymer coating on the friction and wear improvement, as well as the extent of sand-dust mitigation at the interface. The polymer-on-polymer system resulted in significant reduction in friction up to 70%. The wear mechanism was a mixed mode of two-body and three-body abrasion for metal-on-metal and metal-on-polymer tribopairs, while the polymer-on-polymer tribopair significantly mitigated the sand and dust accumulation at the interface with three-body abrasion as the dominant wear. Both polymer composites showed similar frictional behavior, while ATSP composite showed superior abrasive wear resistance, particularly under small size dust (<38 μm size) environment.
•Polymer coatings as an efficient method to reduce the COF and sand-dust mitigation.•ATSP coating showed higher resistance to abrasive wear compared with PEEK.•Continuous reduction of COF and wear by coating deposition on both pin and disk.•Metal-on-polymer sliding showed two-body abrasive wear as dominant wear mechanism.•Polymer-on-polymer sliding showed three-body abrasive wear as dominant mechanism.
The study examines the performance of ZA27 alloy reinforced with in-situ TiC under high-stress abrasive wear conditions. The ZA27 + 10 wt% TiC composite demonstrates superior wear resistance among ...all the materials tested. Response surface analysis revealed that increasing the applied load reduces the wear resistance of the specimens. Analysis of worn-out surfaces revealed mild grooves at low loads and deeper grooves at higher loads. The removal of material is mainly caused by ploughing and cutting actions from abrasive surfaces. Machine Learning models were employed to forecast wear rate, coefficient of friction, and temperature. The MLP model excelled, achieving an R² value of 0.88 during testing. Furthermore, feature importance analysis revealed that reinforcement wt% has the maximum influence in predicting the wear rate.
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The two body abrasive wear behavior of stir cast Al 6082–SiC–Gr (Al–SiC–Gr) hybrid composites was investigated and compared with its matrix alloy and SiC reinforced composites. The experiments were ...done on pin-on-disc equipment at test conditions of 5–15N load, 50–75m sliding distance and 200µm grit size. The wear results indicate that the hybrid composites yielded better wear resistance compared to matrix alloy and SiC reinforced composites. At higher load and sliding distance, wear improvement of Al–SiC–Gr composites was 16.4% and 27% in as cast and T6 heat treated condition respectively. The worn surface analysis of tested samples and grit papers was done by using scanning electron microscope (SEM).
Machine components operating in sandy environments will wear because of the abrasive interaction with sand particles. In this work, a method is derived to predict the amount of wear caused by such ...abrasive action, in order to improve the maintenance concept of the components. A finite element model is used to simulate various tips scratching a smooth surface. The model is verified by comparing the obtained results with a set of experiments performed earlier (M. Woldman, et al., 2013, Wear, 301(1-2), pp 76-81).
In polishing nickel-based superalloys, the surface quality and dimensional accuracy of the workpiece are closely related to the wear of the abrasive tools. Over the years, several researchers have ...studied the wear of grinding wheels or abrasive belts, including the effects of various machining methods, abrasive materials, and machining parameters on the wear of abrasive tools. However, there is not enough research on the wear mechanism of the abrasive cloth flap wheel (ACFW). In this paper, during polishing GH4169G with ACFW, the wear evolution mechanism of ACFW and its effect on the surface integrity of GH4169G were investigated. First, the variations in material removal and ACFW wear amounts during the polishing process were analysed, and the different wear stages were divided based on the polishing ratio. Second, the mic-morphology and surface element distribution of ACFW at different wear stages were investigated using SEM and, EDS, and the wear evolution mechanism of ACFW was analysed. Finally, the effects of ACFW wear on the surface morphology, surface oxidation and microstructure of GH4169G were investigated by SEM, EDS, XRD, and EBSD. The results showed that the primary wear forms of ACFW were stepped fracture, cleavage fracture, blunt, pull-out, and adhesion wear. During the initial wear stage, the proportion of each wear form was relatively balanced. In the medium wear stage, fracture wear was the main wear form. Blunt and adhesive wear were the primary forms of wear during the final wear stage. In addition, with ACFW wear, the surface roughness tend to decrease first and then increase, however, the refinement level of the grains, the intensity of plastic deformation and the intensity of the oxidation reaction gradually increased. This study provides effective guidance for developing more wear-resistant abrasive tools and optimising the grinding and polishing processes.
In this study, three polyurethanes (PUs) were synthesized, named PU-31, PU-35 and PU-41, whose tensile strength and modulus increased with the increasing hard segment content. The effect of different ...loads on wear behavior was investigated systematically. The results showed that the volume loss of PU-31, PU-35 and PU-41 were 1.84, 2.10 and 2.67 mm3 at 5 N load and 68.40, 53.67 and 42.34 mm3 at 120 N, respectively. It found that under low load, PU-31 with low modulus exhibited the best wear resistance. While under high load, PU-41 with high tensile strength was the best. This study revealed that the wear resistance was heavily dependent on the loads, which was crucial for improving the wear resistance of materials according to operation conditions.
•Under lower normal load, the modulus dominates the abrasive wear performance.•As the normal load increases, the tensile strength plays a key role in determining the wear performance.•Tensile strength and modulus are competing factors that affect the abrasive wear performance of polyurethanes.
Graphite filled polytetrafluoroethylene (PTFE) and polyimide (PI) composites were tested against tool steel under nominal contact pressure of 6.32 MPa and sliding speed of 1.91 m/s in clean ISO 46 ...lubricant, and also contaminated lubricant with 4200 ppm of silica sand. Pin-on-disk test results show higher friction and wear of the tribopair in the contaminated condition. Micromechanical properties of the bulk polymers were measured using nanoindentation technique, and softening of the material at elevated temperatures was measured. SEM analysis of the contacting surfaces before and after testing showed abrasive wear as the dominant wear mechanism, and microcutting was a less pronounced wear mechanism in the case of PI composite in contaminated test condition. EDS analysis showed that there was no film transfer from polymers to the countersurface, however it indicated higher oxidation on the wear track of the steel disk slid against PI. Particle embedding in the polymer was shown by EDS and is the reason for scratches seen on the steel disk wear tracks. Both polymers are found to be suitable materials from a tribological standpoint for bearing pad applications.
•Graphite-filled polyimide and PTFE composites performance under lubricated conditions.•Effect of silica contamination on the wear intensity of polymer composites.•Effect of graphite physical form on polymer composites tribological performance.
•Intermetallic composite was formed on the surface of Ti–6Al–4V by laser alloying.•The laser coatings consisted of hard titanium aluminides.•The hardness and abrasive wear resistance of composite ...coatings improved.•The material removal was dominated by abrasive and adhesive mechanisms.
Ti–6Al–4V alloy is lightweight, heat treatable and machinable with excellent strength characteristics. These properties favor its extensive applications in the automobile, aerospace and aeronautical industry. However, low hardenability, poor wear resistance and the tendency to gall and smear have reduced the use of Ti–6Al–4V. This study was designed to investigate the enhancement in the abrasive wear resistance of Ti–6Al–4V laser alloyed with three different premixed composition of Mo+Zr+Stellite 6 using a 4.4kW continuous wave (CW) Rofin Sinar Nd:YAG laser processing system. Microstructural evolution in the samples was studied by optical and scanning electron microscopes. The phase evolution was studied by X-ray diffractometer. There exists metallurgical reaction and bonding between the Ti–6Al–4V substrate and the laser coatings. Scanning electron micrographs and X-ray diffraction spectra of the coatings revealed the formation of various titanium aluminides among other complex phases. The β-phase of Ti was retained owning to the presence of Mo – a β-phase stabilizer, in the powder mixture. Three-body abrasive wear resistance test indicates that the wear of the coatings was dominated by adhesive mechanism which is characterized by fine scratches. A twenty-four fold improvement in wear resistance was obtained in the coatings when compared with the native alloy.
Observing the importance of intermetallic materials in mechanical and metallurgical applications, the present work investigates the micro-abrasive wear behaviour in a model–carbide reinforced iron ...aluminide system. Fe–30Al–6Cr (at.%) iron aluminide alloy with carbon additions “as cast” specimen was tested. Micrographs revealed a continuous network of eutectic chromium carbides at the interdendritic regions of the D03 ordered aluminide matrix. AISI 52100 bearing steel sphere of diameter 25.4 mm (1″) was used for wear tests as counter body. Micro-abrasive slurries were prepared with micro-abrasive particles of black silicon carbide – SiC or alumina – Al2O3, with distilled water or glycerin, in four possible combinations of materials ⇒ “Al2O3 + H2O distilled”, “Al2O3 + glycerin”, “SiC + H2O distilled” and “SiC + glycerin”. Further, keeping the normal force constant and together with different levels of micro-abrasive slurries compositions and sliding distances, a factorial experiment was designed. Result analysis showed that wear volume increased with an increase in micro-abrasive slurry concentration, independently of the type of micro-abrasive particle and liquid. However, the micro-abrasive slurries prepared with SiC and distilled water provided larger wear volumes than the volumes of wear reported under the micro-abrasive slurries formulated with Al2O3 and glycerin. The reason is attributed to the high hardness of SiC particles resulting in high abrasion, whereas the Al2O3 – glycerin slurry lubrication effect restricted high wear. Wear micrographs revealed a change in worn surface morphology from “grooving micro-abrasion” to “rolling micro-abrasion” due to an increase in sliding distance and micro-abrasive slurry concentration.
•Synergism between concentration, abrasive material and liquid influenced the Fe-30Al-6Cr (at.%) tribological behaviour.•There were transitions between abrasive wear modes as a function of the abrasive slurry composition and sliding distance.•Actuation map of abrasive wear modes was organised as a function of the abrasive slurry composition and sliding distance.•The abrasive slurry composition influenced the severity with which the Fe–30Al–6Cr (at.%) intermetallic alloy was worn.
In total, seventy-two (72) micro-abrasive wear tests by rotative ball were performed. Each experiment was carried out without interruption and the micro-abrasive slurry was continuously stirred and dripped between the test sphere and the specimen, during the experimental runs – additionally, the micro-abrasive slurry was not reused throughout the micro-abrasive wear tests, from one experiment to another.
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