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One of the most important challenges industry has always been facing is the wear phenomenon. Wear is the cause of huge deteriorations in parts and results in a drop in performance and lifetime of different machines. Therefore, finding solutions to reduce friction coefficient and wear is of special importance. The present research aims at numerical and experimental investigation of friction coefficient and wear in the presence of nano-lubricants. In the numerical section, to tackle different scales of contact components, two sub-models are developed. In the first one, contact of asperities is modeled and the properties of contact surfaces are taken into account. Second sub-model simulates nano-particles in the contact region. Furthermore, a series of experiments are conducted under different loads, speeds, and different values for Zinc Oxide nano-particle weight percent using a pin-on-disk test rig. Results show that predicted friction coefficient and wear volume in theory are reasonably in agreement with experimental results. It was found that adding nanoparticle to the lubricant can be beneficial in terms of friction reduction.

Friction is a critical factor in metal forming processes, influencing material flow, surface quality, tool life, and overall production efficiency. This comprehensive review explores the experimental methods employed to evaluate friction behavior in metal forming, including pin-on-disk tests, ring compression tests, stretch forming tests, and tribometers. The integration of advanced measurement technologies such as infrared thermography, digital image correlation, and high-speed imaging has significantly improved the accuracy of friction assessments. Furthermore, the review highlights the key parameters affecting friction, including lubrication conditions, material pairings, surface roughness, and process temperature. Surface engineering strategies, such as coatings and texturing, are also discussed as effective approaches to control friction. The insights provided aim to support researchers and practitioners in selecting suitable evaluation techniques and in developing optimized surface treatments for enhanced metal forming performance.

This paper carries out the pin-on-disc wear test on the wear characteristics of the slipper-rail material under different loads and different speeds, and the research results show that: with the increase of load, the wear extent increases, but the relationship between speed and wear extent is not single; through linear regression analysis method to fit the pin-on-disc test wear extent, we get the wear coefficient k = a + b(pv) + c(pv) 2 of the slipper material when mating with the U71Mn steel, where a = 2.604 x 10 −5 , b = 1.115 x 10 −10 , c = 4.944 x 10 −16 . Then, from the wear loss effect of the slipper, the formula for calculating the wear extent of the slipper was derived, and the wear thickness of the slipper was calculated when the sled was accelerated to 1700m/s in a project.

This research work is carried out to study the mechanical and wear behaviour of inorganic particle filled polymers. Epoxy matrix filled with varying ratios of Solid glass microspheres (SGM) were fabricated using mechanical stirring process. The weight percentage of SGM were varied from 0 - 30, with a step size of 5wt%. Effect of weight percentage of SGM particles on bending strength, compression strength and compression modulus of the composites was evaluated. The Wear resistance of the composites against En-32 steel disk, was evaluated in terms of mass loss for various ratios of SGM using pin-on-disk test rig. Besides these, density of the composites was also evaluated. Mechanical and wear properties of the composites were improved by adding suitable percentage of the filler. Moreover density increased with the increase in percentage of SGM particles in the composites.

In this study, pure and hexagonal boron nitride (hBN)-doped zinc oxide (ZnO) nanoparticles with different doping ratios (1, 5 and 10 wt%) were synthesized and their structural morphological properties were investigated. ZnO-hBN nanocomposite particles were used as reinforcement material in AZ91 magnesium alloy. AZ91 powder reinforced with ZnO-hBN nanocomposite particles was combined by powder metallurgy. Hardness of AZ91 matrix composites was measured at 5 different points on each sample and averaged. The specimens were subjected to wear tests in a pin-on-disk test apparatus. As a result of the tests, the hardness value of pure AZ91 alloy was found to be 62 HB, while the hardness value of AZ91-ZnO-10 hBN sample was found to be up to 85 HB. In the wear tests, it was observed that ZnO-hBN additives resulted in low weight losses in wear losses and also decreased the friction coefficient of the hBN additive in the friction coefficient graphs. A hybrid GA (genetic algorithm)-SVR (support vector regression) model was proposed for the prediction of wear quantities of composites. The purpose of using a hybrid system combining SVR and GA is to improve the wear prediction by optimizing the hyperparameters of t and GA. The results are observed using four different kernel functions in the SVR algorithm, and then, a hybrid GA-SVR structure is proposed and compared. With the proposed method, 98.80% prediction success of the wear quantities of the composite is achieved by the hybridized GA.

A vehicle start–stop system automatically shuts down and restarts the internal combustion engine to reduce the time the engine spends idling, thereby reducing fuel consumption and emissions. For the start–stop system to work, the engine must be at a certain temperature and conditions. If the engine is too hot, the system may not activate. This study explores the tribological characteristics of the start–stop system by applying principles of Continuum Damage Mechanics (CDM) to predict both the lifespan and wear volume subsequent to the start–stop cycles. A series of pin-on-disk tests were conducted to evaluate the efficacy of the modeling and predictions. The results from these tests were compared to the CDM predictions, demonstrating satisfactory accuracy. Additionally, a Finite Element Method (FEM) analysis was employed to model temperature variations during the start–stop cycles. Findings indicate that an increase in consecutive start–stop cycles impedes the system’s ability to sufficiently cool, thereby increasing wear. Conversely, extending the duration of the stop phase reduces wear and enhances the system’s lifespan.

The mechanical properties of TiAlN deposited on the steel are explained in this study. Thin films are deposited by RF magnetron sputtering on the steel substrates to improve the wear resistance and hardness of the samples. Due to their improved microstructure and nanograins, the nanofilms have improved the mechanical properties of the steel substrate surface. The thin film deposited has improved the wear resistance by 80% and has improved the hardness by 95%. The deposited thin films are tested for hardness by nanoindentation and wear test by the pin-on-disk test. SEM has tested films for their microstructure and adhesion by nanoscratch test.

This study deals with the development of Nylon-6 fused deposition modeling (FDM) filaments for additive manufacturing, which couples high mechanical performances with eco-sustainability. These filaments were extruded from recycled Nylon-6 granulates through a dedicated twin-screw extrusion line, which processes either pure Nylon-6 grains, or mixtures of such a material with minor fractions of acrylonitrile butadiene styrene (ABS) and titanium dioxide (TiO2). The rheological and thermal properties of the investigated filaments are analyzed, including melt flow index, melting temperature, and decomposition temperature, which are of the utmost importance when avoiding the overheating and decomposition of the material. Such a study is conducted in both pre-extrusion and post-extrusion conditions. The tensile strength, the wear resistance, and the printability of the examined recycled Nylon-6 filaments are also studied by comparing the properties of such filaments with those exhibited by different nylon-based filaments for FDM that are available in the market. The given results show that the recycling of Nylon-6 through the “caprolactam” regeneration route enables the newly formed material to retain high physical and mechanical properties, such as tensile strength at yield in the interval 55.79–86.91 MPa. Referring to the basic composition of the filaments examined in the present study, this remarkably high-yield strength is accompanied by a Young modulus of 1.64 GPa, and wear resistance of 92 µm, under a 15 min/1 kg load pin-on-disk test carried at the sliding speed of 250 rpm.

We investigated the tribological properties of CrAlN and TiN coatings produced by electron beam plasma-assisted physical vapor deposition by nano- and micro-scale wear tests. For comparison, we also conducted nano-indentation, nano-scanning wear tests, and pin-on-disk tribotests on uncoated M2 steel. The results indicate that, after nano-scale sliding tests against diamond indenter and pin-on-disk tests against ceramic alumina counterface pins, the CrAlN coating presents superior abrasive wear resistance compared to the TiN-coated and uncoated M2 steel samples. Against aluminum counterface, aluminum is more prone to attach on the CrAlN coating surface compared to TiN coating, but no apparent adhesive wear was observed, which has occurred on the TiN coating.

Diamond-like carbon coatings may decrease implant wear, therefore, they are helping to reduce aseptic loosening and increase service life of total knee arthroplasties (TKAs). This two-part study addresses the development of such coatings for ultrahigh molecular weight polyethylene (UHMWPE) tibial inlays as well as cobalt-chromium-molybdenum (CoCr) and titanium (Ti64) alloy femoral components. While the deposition of a pure (a-C:H) and tungsten-doped hydrogen-containing amorphous carbon coating (a-C:H:W) as well as the detailed characterization of mechanical and adhesion properties were the subject of Part I, the tribological behavior is studied in Part II. Pin-on-disk tests are performed under artificial synovial fluid lubrication. Numerical elastohydrodynamic lubrication modeling is used to show the representability of contact conditions for TKAs and to assess the influence of coatings on lubrication conditions. The wear behavior is characterized by means of light and laser scanning microscopy, Raman spectroscopy, scanning electron microscopy and particle analyses. Although the coating leads to an increase in friction due to the considerably higher roughness, especially the UHMWPE wear is significantly reduced up to a factor of 49% (CoCr) and 77% (Ti64). Thereby, the coating shows continuous wear and no sudden failure or spallation of larger wear particles. This demonstrated the great potential of amorphous carbon coatings for knee replacements.