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Particulate-reinforced aluminium matrix composites (PRAMCs) have gained significant attention for their high strength, good ductility, and excellent thermal conductivity, making them suitable for a wide range of modern engineering applications. In this study, micro-sized titanium carbide (TiC) particles were incorporated into an aluminium matrix through liquid-state stir casting, with TiC added at 0%, 3%, 6%, and 9% by weight. The investigation examined the combined influence of TiC content and sliding speed (0.75, 1.5, 2.25, and 3 m/s) on the wear behaviour of the composites when tested against an EN31 steel disc. All wear tests were performed under a constant load of 30 N over a sliding distance of 2000 m. The results show that increasing TiC content leads to a higher wear rate, whereas the coefficient of friction decreases correspondingly. Conversely, increasing sliding speed reduces the wear rate but results in a higher coefficient of friction. These findings demonstrate the coupled effects of TiC reinforcement and sliding velocity on the tribological performance of aluminium matrix composites and provide valuable insights for tailoring their behaviour in industrial applications.

Over the last few decades, particle-reinforced Zn based metal matrix composites have begun to supplant monolithic Zn matrix. High strength to weight ratio, near-isotropic characteristics and cost are the key factors. The current research effort on \"Investigation on sliding wear behaviour of Zn alloy reinforced with nano B4C composite\" was done to analyze the mechanical, wear activities of a unique composite Zn-Sn alloyed with nano B4C based on the literature. The effect of nano-sized B4C particulates on Zn85-Tin 15alloy is investigated. Nano B4C particulates are employed as reinforcement. Instep of B4C 0%, 2%, 4%, 6% and 8% by weight, composites are manufactured utilizing a two-step approach method. On a pin-on-disc type wear testing machine, wear tests were performed on all specimens under various operational settings such as typical loads of 10N, 20N, 30N and 40N and sliding speeds of 1.4, 1.8, 2.3 and 2.8 m/s at 2000m sliding distance and 90mm track diameter. Each specimen was subjected to 16 wear tests, resulting in a total of 80 wear tests. As the usual load increases, the volumetric wear rate increases, the volumetric wear rate reduces as the sliding speed increases. Corresponding worn out surface, wear debris and EDS are reveled. The surface roughness and surface hardness values increase as the sliding speed increases.

Owing to their high producibility and resistance to corrosion, austenitic chromium–nickel steels are widely used in the chemical, petroleum, and food industries. However, their significant disadvantage lies in their poor structural performance, which cannot be improved by heat treatment. This significantly limits the usability of these steels in parts of machines that operate under friction loads. Hardening can be achieved by decreasing the size of grains and applying deformation-induced martensitic transformation. Nanostructuring burnishing (NSB) may be one of the technologies suited for producing parts of tribological assemblies with enhanced operating characteristics. Nanostructuring burnishing using a sliding indenter is being developed as a method of industrial surface nanocrystallization through severe plastic deformation used in the mechanical machining of various types of parts. This article investigates the possibility of enhancing the mechanical and tribological properties of nanocrystallized surfaces of austenitic steels, which are formed through nanostructuring burnishing using a tool with a natural diamond spherical indenter and a change in sliding speed from 40 to 280 m/min with one, three, and five passes. Increasing the tool sliding speed makes surface nanostructuring machining of big parts highly effective. This paper aims to establish the influence exerted by the sliding speed and number of indenter passes on the formation of a nanocrystalline structure, as well as on the modification of microhardness and residual stresses, texture, and tribological properties of the surface layer in the nanostructuring burnishing of AISI 304 steel. Transmission microscopy and microdurometry, 3D-profilometry, and tribological tests of surfaces nanocrystallized with the “ball-on-disk” scheme with dry and lubricated friction established the optimal values of speed and number of passes for a spherical indenter in nanostructuring burnishing.

Wear rate of WC/Co-based cermet materials under severe tribological conditions is a critical thermomechanical property that can limit the practical application of various tools and industrial machinery. In this paper, three machine learning (ML) algorithms including Random Forest, Gradient Boosting Regressor, and XGBoost are employed to predict the wear rate of WC/Co-based cermets elaborated through powder metallurgy, utilizing dry friction under severe pin-on-disk conditions at elevated temperatures. The study analyzes 116 experimental tribological data points to assess the impact of sliding speed, additive content, hardness, friction coefficient, density, and temperature on estimating the wear of various cermet samples, all tested under a constant normal load of 20 N. The performance assessment shows that ML-based models could effectively predict the wear rate, with the Random Forest algorithm outperforming the others, achieving a coefficient of determination ( R 2 ) of 0.8438. Additionally, a comparative analysis is conducted to assess the performance of the ML-based models relative to one another. The models successfully predicted the wear rate of WC/Co-based cermets across various grades, tribological parameters, and physical and mechanical properties, achieving satisfactory accuracy.

Purpose With the rapid development of the pipeline transportation and exploitation of mineral resources, it is urgent requirement for the high-performance polymer matrix composites with low friction and wear to meet the needs of solid material transportation. This paper aims to prepare high-performance ultrahigh molecular weight polyethylene (UHMWPE) matrix composites and investigate the effect of service condition on frictional behavior for composite. Design/methodology/approach In this study, UHMWPE matrix composites with different content of MoS2 were prepared and the tribological performance of the GCr15/composites friction pair in various sliding speeds (0.025–0.125 m/s) under dry friction conditions were studied by ball-on-disk tribology experiments. Findings Results show that the frictional behavior was shown to be sensitive to MoS2 concentration and sliding velocity. As the MoS2 content is 2 Wt.%, composites presented the best overall tribological performance. Besides, the friction coefficient fluctuates around 0.21 from 0.025 to 0.125 m/s sliding speed, while the wear rate increases gradually. Scanning electron microscopy images, energy-dispersive spectroscopy and Raman Spectrum analysis present that the main wear mechanisms were abrasive and fatigue wear. Originality/value The knowledge obtained herein will facilitate the design of UHMWPE matrix composites with promising self-lubrication performances which used in slag transport engineering field.

Cermets have been widely used in industry to combat wear and erosion because of their elevated strength and hardness and good wear resistance. This study investigated the tribological properties of WC-6Ni (YN6X), WC-6Co (YG6X), and WC-TiC-Co–Ni (TiCN) cermets during sliding over silicon carbide (SiC) in prepared seawater. Tribological experiments of 440C and GCr15 steel coupled with SiC were conducted for comparison. The influence of sliding speed was examined by multiple sequential increases in speed from 0.1 to 0.4 m s −1 . The results showed that the tribological properties of the tribopairs were enhanced with growing sliding speed and were influenced by complex factors including material hardness, wear radius, the lubricating medium environment, and the tribochemical reaction. YN6X performed particularly well due to its high hardness and presence of Ni which effectively reduced the corrosion effect of seawater. However, YG6X showed better wear resistance relative to YN6X in tap water due to its higher hardness. In particular, through an investigation of the wear process of the tribopairs in seawater, this study proposed the coefficient of friction model for cermet/SiC. The results indicated that a combination of YN6X/SiC has excellent potential for application to seawater hydraulic components. Graphical Abstract

Microscratch responses of four different thermoplastics including polytetrafluoroethylene, polyethylene, polyvinyl chloride, and polyetheretherketone were investigated under constant normal load by Berkovich indenter with the focus on quantifying effects of sliding speed and normal load on scratch variables such as penetration depth, elastic recovery rate, contact scratch hardness, residual scratch hardness, lateral hardness, width of residual groove, and scratch friction coefficient. The results show that penetration depth is more sensitive to sliding speed than lateral force, and power law functions are applicable to describe dependences of scratch variables on sliding speed and normal load. Correlations between scratch variables and mechanical properties such as yield strength and Meyer hardness are also discussed, and contact scratch hardness is linearly correlated with yield strength, Meyer hardness, and elastic recovery rate.

There are many typical symmetric large plastic deformation problems in aluminum alloy stamping. Warm stamping technology can improve the formability of materials and obtain parts with high-dimensional accuracy. Friction behavior in the stamping process is significant for the forming quality. An accurate friction coefficient is helpful in improving the prediction accuracy of forming defects. It is hard to obtain a unified and precise friction model through simple experiments due to the complicated contact conditions. To explore the effect of friction behavior on the forming quality, warm friction experiments of the AA6061 aluminum alloy and P20 steel with different process parameters were carried out using a high-temperature friction tester CFT-I (Equipment Type), including temperatures, the interface load, and sliding speeds. The variation curves of the friction coefficient with various parameters were obtained and analyzed. The results show that the friction coefficient increases with temperature and decreases with the sliding speed and load. Then, the influences of process parameters on the surface morphology of the samples after friction were observed by an optical microscope; adhesive wear occurred when the temperature increased, and the surface scratch increased and deepened with the increase in the load. Finally, the friction coefficient models of the speed and load were established by analyzing the data with Original software. Compared with the experimental and the finite element analysis results of the symmetrical part, the errors of the velocity friction model in thickness and springback angle are less than 4% and 5%, respectively. The mistakes of the load friction model are less than 6% and 7%, respectively. The accuracy of the two friction models is higher than that of the constant friction coefficient. Therefore, those coefficient models can effectively improve the simulation accuracy of finite element software.

During the voltage regulation of on-load tap changers (OLTCs), the movement of the contacts can easily cause arcing, which may lead to erosion or malfunction. To reduce the energy and probability of arcing, we focus on designing an optimal range for the sliding speed and contact pressure of the contacts to minimize arc energy. Initially, our research introduces a novel OLTC arc testing platform to simulate the motion of static and dynamic contacts, exploring the relationship between different sliding speeds, contact pressures, and factors like arc voltage waveform, arcing rate, arc resistance, and arc energy. Subsequently, by employing multiple nonlinear regression methods, we establish functional relationships between sliding speed and arc energy, as well as contact pressure and arc energy, evaluating the fit using correlation coefficients. Finally, through analyzing their nonlinear behaviors, we determine the ideal sliding speed and contact pressure. The results indicate that when the OLTC contacts slide at an optimal speed between 89 and 103 mm/s and optimal contact pressure between 1.5 and 1.7 N, the arc energy can be minimized, thereby enhancing the performance and lifespan of the on-load tap changer. This study offers feasible insights for the design and operation of OLTCs, aiding in the improvement of power system regulation.

Purpose. Reducing the downtime of transport equipment due to technical malfunction of the chain transmission by disclosing the uncertainty in the friction change of the plate roller open-chain through the estimation of the chain friction coefficient at idle speed. Methodology. To achieve the goal, the following tasks were set: to carry out a research on the change in the plate roller chain friction at idle speed; to develop a method for evaluating friction in the roller plate chain at idle speed. Research on the state of the roller plate chain in laboratory conditions is carried out on the bench by measuring the motor torque during the rotation of the chain. Data processing of the random process of changing the state of the plate roller open-chain predetermines the use of methods of mathematical statistics and correlation analysis. Findings. The research carried out to control the state of the plate roller chain made it possible to disclose the static dependence of the change in friction per day and the correlation dependence of the change in friction in the chain for all days of the experiment. To estimate the change in the state of the conveyor chains, a method was developed for determining the friction coefficient of the plate roller chain through the torque of the motor rotating the open-chain. During the experiment, the increase in the coefficient of friction was more than 20 percent. Originality. The relation of the change in the parameter of the torque of the motor rotating the chain at idle speed during the experiment due to the change in the friction of the chain or the sliding speed in the joints of the chain was disclosed. Practical value. It consists in using the developed method for estimation of the friction in the open-chain at idle speed for planning the timing of scheduled maintenance of transport equipment. An increase in the magnitude of the motor torque that rotates the open-chain at idle speed is associated with a decrease in the sliding speed of the chain joints, an increase in the friction coefficient, which is a criterion for estimation the state of the drive chain. The results of changing the friction coefficient of the developed method showed similarity with the results of the correlation method for estimation of the state of the roller plate chain.