Wear Characteristics Research Articles

Analysis of co-relation on LPBF process parameter on wear characteristics of Cu-Cr-Zr alloy

Copper alloy bearings, gears, and fasteners have a significant impact on industrial sectors. However, due to the defect formation and void generation during the manufacturing of copper alloy parts using (Laser Powder Bed Fusion) LPBF technique, the wear resistance of the copper alloy was significantly affected. Hence, the prime novelty of the current research is enhancing wear resistance by analyzing the interaction of combined LPBF parameters. In order to decrease cavity forms and reduce the wear rate of the printed Cu alloy components, the important LPBF process parameters such as Scan Velocity (SV) of 550, 750, and 950 mm s−1, Laser Power (LP) of 460, 540, and 620 W, and Re-melting Range (RR) of 5, 25, and 45% were selected and studied. The results of the experimental investigation were supported by the use of Grey Relation Analysis (GRA). A comparative study was conducted with five distinct parameter combinations to investigate the relative influence of each parameter on the relative density, wear rate and elastic modulus. The research findings verify that the application of optimal SV of 750 mm s−1 and RR of 45% with maximum LP of 460 W resulted in the maximum relative density of 99.91%, minimal wear rate of 0.52 × 10−5 mm3/Nm, and maximum elastic modulus of 140.22 GPa.

The crack initiation mechanism of steel disc when paired with Fe-PM pad for high-speed train braking

In this study, the Fe-based powder metallurgy (Fe-PM) brake pad was paired with a cast steel brake disc to conduct braking tests on a full-scale flywheel braking dynamometer. We systematically analyzed the morphologies of the worn surfaces and the disc temperatures during braking, uncovering the friction and wear characteristics of the friction pair. As well as highlighted the changes in contact status between the friction pair throughout the braking process, which further affected the pad wear rate and thermal fatigue damage to the brake disc. The wear rate of the pad was 0.16 cm3/MJ during the braking tests at an initial brake speed (IBS) of 250 km/h. However, it rapidly increased to 0.66 cm3/MJ as the IBS rose to 380 km/h, indicating a severe decline in wear resistance as the speed increased. The curves of the instantaneous coefficient of friction (COF) displayed significant fluctuations throughout the single braking process and got more pronounced with the increase in the IBS, similar phenomena also occurred on the measured temperature during each braking test. These were caused by the constant changing of the contact status arose by dynamic equilibrium of the formation, spalling, and regeneration for the third body layer (TBL) on the contact surfaces. Additionally, the changing of the contact status also resulted in an uneven distribution of temperature on the disc surface, which in turn generated a temperature gradient and thermal stress. Concurrently, as the braking continued, high frequency alternating thermal stress (HFATS) on the disc surface was induced by the continuously changing contact status, which was confirmed by finite element method (FEM) simulation. As a result, the brake disc would undergo thermal fatigue after fewer braking cycles, and thermal cracks would appear on the disc surface.

Evaluation of dry sliding wear characteristics of hybrid a356 composite

As advancements in lightweight and synthetic materials have evolved, our ability to tailor materials to meet societal demands has expanded. Aluminium alloys, known for their high strength-to-weight ratio and cost-effectiveness, are extensively utilized in engineering applications, including structural casting and automotive components. This study employed the stir casting method to investigate the impact of silicon carbide (SiC) and graphite (Gr) on a hybrid A356 composite, aiming to enhance its tribological applicability. SiC and Gr particles were processed using a vibratory ball milling machine for two hours, followed by composite fabrication with varying particle sizes. Microstructural investigation using optical microscopy revealed maximum hardness values of 127 BHN and 125 BHN for A356 composites reinforced with 12.50% SiC, 15.50% Gr, and 11.43% SiC, 15.86% Gr, respectively. Wear rate analysis demonstrated that reinforced A356 composites exhibited higher wear resistance compared to unreinforced alloys. Notably, the sample reinforced with 11.43% SiC and 15.86% Gr displayed exceptional wear resistance. Photo micrographs of A356-SiC-Gr samples at different sliding distances, velocities, and loads revealed minimal plastic deformation during wear testing, resulting in abrasive and cohesive wear. Overall, this study underscores the effectiveness of graphite (Gr) and silicon carbide (SiC) as reinforcement materials for enhancing the tribological properties of A356 composites.

Correction: Effect of hBN Content on the Friction and Wear Characteristics of Al2O3-B2O3-CaO-hBN Ceramic Composites under Dry Sliding Condition

Correction: Effect of hBN Content on the Friction and Wear Characteristics of Al2O3-B2O3-CaO-hBN Ceramic Composites under Dry Sliding Condition

A Review on Mechanical and Wear Characteristics of Magnesium Metal Matrix Composites with Machine Learning Modelling

A Review on Mechanical and Wear Characteristics of Magnesium Metal Matrix Composites with Machine Learning Modelling

Optimization and statistical analysis on mechanical, thermal, wear and water-absorption characteristics of fragrant screwpine fiber-reinforced polymer biocomposites

Optimization and statistical analysis on mechanical, thermal, wear and water-absorption characteristics of fragrant screwpine fiber-reinforced polymer biocomposites

Enhancement of ceramic tool behaviour with textured grooves during machining of Inconel® 718

Inconel® 718, known for its excellent mechanical properties in extreme conditions, presents machining challenges due to its low machinability. The chip formation process, influenced by its high ductility and low thermal conductivity, leads to material adhesion and high cutting forces. Ceramic tools have been proposed to mitigate these inconveniences. Textured cutting tools have emerged as a promising solution, aiming to optimise tool-chip contact and, with it, the tribological conditions and the cutting forces. This study investigates the influence of textured grooves on ceramic tools when turning Inconel® 718. Two groove inclinations, 0° and − 25° relative to the cutting edge, were tested. Texturing was performed using a laser station. Experimental results showed improved tool wear characteristics with textured tools, indicating favourable chip extraction and reduced material adhesion. Cutting forces were notably lower with textured tools compared to the reference tool, attributed to reduced notch wear and altered chip flow. Chip morphology analysis revealed differences in chip shape and thermal stability between the reference and textured tools. In conclusion, textured tools, particularly those with − 25° inclined grooves, demonstrated enhanced performance in machining Inconel® 718.

Mechanical, Corrosion and Wear Characteristics of Cu-Based Composites Reinforced with Zirconium Diboride Consolidated by SPS

This study aimed to investigate the physical, mechanical, corrosion, and tribological properties of Cu-based composites with varying zirconium diboride content. The composites were successfully consolidated using spark plasma sintering (SPS) at temperatures of 850 °C and 950 °C and a pressure of 35 MPa. The effect of the ZrB2 content and the sintering temperature on the properties of the Cu-based composites was investigated. Scanning electron microscopy (SEM), electron backscatter diffraction (EBSD), and X-ray diffraction were used to analyse microstructure evolution in copper matrix composites. Microhardness tests were used to evaluate mechanical properties. Wear behaviour was evaluated using a ball-on-disc method. Corrosion properties were estimated on electrochemical tests, such as potentiodynamic polarisation. The results demonstrated an enhancement in the density and porosity of the composites as the sintering temperature increased. A uniform dispersion of ZrB2 was observed in the copper matrix for all composites. With an increase in the content of the ZrB2 reinforcement phase, there was an increase in microhardness and an improvement in the wear resistance of the sintered composites. A reduction in densification and corrosion resistance of Cu-based composites was observed with increasing ZrB2 content.

Aircraft propeller erosion wear and aerodynamic characteristics

Aircraft propeller erosion wear and aerodynamic characteristics

Influence of Heat Treatment on Fretting Wear Behavior of Laser Powder Bed Fusion Inconel 718 Alloy

Abstract This research paper focuses on the fretting wear characteristics of self-mated laser powder bed fusion (L-PBF)-produced Inconel 718 alloy, with the primary aim of characterizing its distinct wear-rate in relation to fretting cycles. This study investigates both the as-built and heat-treated Inconel 718 Superalloy. Experiments were conducted under aggressive contact conditions, involving a flat-on-flat contact pressure of 100 MPa (1645 N) and a temperature of 650 °C sustained over a million cycles. From the preliminary observation, the microstructure reveals that the heat-treated L-PBF alloy has denser and harder precipitates than its as-built counterpart. This indicates that heat-treated alloy is much harder (470 HV0.3) than the as-built Inconel 718 (275 HV0.3). The heat treatment process resulted in the precipitation of beneficial strengthening phases like γ′ and γ″, along with maintaining stable carbides (NbC). Notably, the heat-treated material displays an approximately two-fold lower wear-rate (0.103 μm/cycle at the end of 1000 k cycles) compared to the as-built material (0.238 μm/cycle), attributed primarily to its high strength characteristics. Additionally, the heat-treated material demonstrates a reduced steady-state friction coefficient (0.34) in contrast to the as-built material (0.37), owing to its inherent capability to form a uniform and stable lubricious glaze oxide layer. Both as-built and heat-treated systems show dominant adhesive wear mechanisms along with localized abrasion resulting from the combination of oxidation and cyclic wear processes.

Research on alloy composition-process-wear properties of medium manganese steel based on machine learning

To reveal the complex relationship between the wear properties of medium manganese steel and related parameters, the effects of silicon elements and heat treatment temperature on the wear properties of medium manganese steel under different impact energies were discussed. The microstructure, hardness, impact toughness, and wear resistance were analyzed by various tests. Based on machine learning, a comprehensive framework linking the alloy composition, heat treatment, and wear characteristics of Fe-Mn-Al-C medium manganese steel was developed. After experimental analysis and verification, silicon-containing steel shows the best wear resistance under high impact load at 700 °C heat treatment temperature. In addition, the IPSO-SVM model effectively predicted the impact wear performance, reaching an R2 value of 0.97 during testing.

Mechanical and Optimization of Wear Characteristics of Aluminium Alloy Reinforced with Exfoliated Vermiculite Composite

Mechanical and Optimization of Wear Characteristics of Aluminium Alloy Reinforced with Exfoliated Vermiculite Composite

Wear Characteristics of Textured Floating Oil Seal Surfaces: A Simulation and Experimental Study

This study aimed to analyze the effects of surface texture on the wear amount of floating oil seals and how these effects are related to the texture parameters. To achieve this, a finite element model was constructed to simulate the frictional behavior of seal discs under both textured and non-textured conditions. The study focused on a specific set of texture parameters. The texture depth was held constant, while the area density and diameter of the textures were varied. Three different area densities were considered: 10%, 20%, and 30%. Similarly, three different texture diameters were included in the study: 100, 200, and 300 μm. For each combination of area density and diameter, three different texture depths were evaluated: 50, 100, and 150 μm. The results show that compared with the non-texture, the wear loss of the texture is significantly reduced, and the wear loss is reduced by 56.8%. As the texture depth increases, the corresponding increase in wear remains relatively small. In contrast, increasing the texture diameter and area density leads to a more significant increase in wear, indicating that these two parameters have a more significant effect on the wear behavior of the seal. Under the condition of dry friction, the average friction coefficient analysis shows that the texture area density is 30%, the texture diameter is 200 μm, and the minimum value is about 0.602. Under the lubrication condition, the lowest average friction coefficient is about 0.147, the texture area density is 20%, and the texture diameter is 300 μm.

Cutting performance and wear mechanism of submicron and ultrafine Ti(C, N)-based cermets

The complex thermal-mechanical coupling among Ti(C, N)-based cermet tool, workpiece and chip affects immensely the tool life, machining quality and costs during high-speed cutting, which makes the investigation on wear mechanisms of tools quite important. In this work, submicron and ultrafine Ti(C, N)-based cermet tools were prepared by vacuum sintering technology, and the cutting performance of the tools was evaluated by continuous dry cutting. The aim of this work is to unravel the wear mechanisms of submicron and ultrafine Ti(C, N)-based cermet tools based on the cutting performance and wear characteristics of both the cutting tools and chips generated during high-speed cutting. The Vickers hardness, flexural strength and tool lifespan of ultrafine Ti(C, N)-based cermets are significantly superior to those of submicron Ti(C, N)-based cermets because of grain refinement strengthening and the improved distribution of metal phases. Tool wear depends to a large extent upon the contact states and heat transfer ability at different locations of the tool edge, which are characterized by simultaneous action and mutual transition from abrasive, adhesion, surface fatigue and oxidative wear. Overall, ultrafine Ti(C, N)-based cermet tools with excellent comprehensive properties exhibit a distinctly reduced tool wear at different wear regions.

Wear behaviour analysis of thermo-mechanically processed AA7075 and AA7075/SiC/Graphite composite

The current work focuses on investigating the tribological performance of AA7075 alloy and AA7075 hybrid composite with SiC and graphite reinforcements of 2 and 0.5 wt percentages, respectively. The alloy and hybrid composite are fabricated through stir casting and thermo-mechanically processed through hot rolling routes. Dry sliding wear characterization has been carried out using a pin-on-disc wear testing setup for alloy and composite under various processing conditions using experiments designed according to Taguchi's L9 orthogonal array. The technique for order preference by similarity to ideal solution (TOPSIS) method has been adopted to achieve a single multi-response index (MRI) considering the minimization of multiple objective functions for specific wear rate (SWR) and coefficient of friction (COF). The analysis of variance (ANOVA) results of the MRI indicated that sample processing condition and load were the most significant parameters. The wear mechanism at different experimental conditions was studied using Scanning electron microscope (SEM) micrographs, energy dispersive spectroscopy analysis and 3D surface profile of wear track. The AA7075 composites are found to be comparatively good in all experimental conditions compared to the base alloy due to load-bearing SiC particles and solid lubricant graphite as reinforcing elements. The mechanically mixed layer (MML) formation in hybrid composites helped achieve good tribological properties. The AA7075 alloy and hybrid composites cross rolled at 350 °C yielded better results than other samples. The wear mechanism was abrasive and adhesive at low temperature and low load conditions in both alloy and hybrid composites. Whereas, at higher temperatures and high loads oxidative wear mechanism with delamination was prevalent. The transition of SWR from mild to severe value occurs at 250 °C in all experimental cases. The specific wear rate was improved by 85.64 % between worst and best conditions, i.e., annealed alloy and cross rolled composite.

Sliding wear characteristics of epoxy composites reinforced with steel wire and flax fiber mats: An experimental and analytical study

Sliding wear characteristics of epoxy composites reinforced with steel wire and flax fiber mats: An experimental and analytical study

Tribological properties of diamond-like carbon films lubricated with water-emulsified engine oil

In this work, the tribological properties of two diamond-like carbon (DLC) films were investigated at different temperatures using water-engine oil emulsions as lubricants, considering emerging fuel systems such as hydrogen and ammonia. The results revealed that the friction coefficient of a-C film raised with the increasing water content at 80 °C. The friction coefficient of a-C:H film initially raised and then decreased with varying water fractions at different temperatures. Elevated temperature exacerbated the wear of both DLC films at high water contents. The most significant wear was observed for a-C film at 80 °C and a-C:H film at 50 °C. The a-C:H film exhibited more sensitive wear characteristics to water content than the a-C film. Surface analysis indicated that water-engine oil emulsions prevented the formation of phosphate tribo-film on steel friction pair for two DLC films but promoted the tribo-oxidation of steel pair sliding contact with a-C film, especially at higher temperatures. Distinct reactivities of two DLC films towards water molecules could affect the adsorption of lubricants on DLC surfaces, leading to their different friction and wear behavior. It suggests that the water-caused emulsification of lubricating oil will be a pivotal consideration in tribological applications of DLC films in future internal combustion engines.

Influence of Arc Length Correction on Friction and Wear Characteristics of Wire-Arc Additive Manufactured AA 5356 Alloy

Influence of Arc Length Correction on Friction and Wear Characteristics of Wire-Arc Additive Manufactured AA 5356 Alloy

Impact of Aging Time on the Morphological, Mechanical, and Tribological Behavior of Al-6.6Si-0.2Mg-0.2La Hypoeutectic Alloy

Abstract The present work aimed to examine the influence of Lanthanum (La) on the morphological, mechanical, and tribological characteristics of Al-6.6Si-0.2Mg alloy. The alloy specimens were exposed to an aging process at 180°C for 8h and 12h. The morphological transformation due to La addition was analysed with an emphasis on altering primary and eutectic silicon morphology, grain refinement, and intermetallic phase distribution. The experimental investigations were carried out using scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) whereas the hardness and wear characteristics were analyzed by performing Vickers microhardness and pin-on-disc tests. The obtained results demonstrated that lanthanum inclusion causes significant microstructure refinement, resulting in enhancing the microhardness by up to 60 %, proliferating the tensile characteristics by 70%, and aiding in improving the tribological characteristics of the Al-Si-Mg alloy. The results provide a clearer understanding of the alloy modification process and offer valuable insights for enhancing the performance of Al-Si-Mg aluminium alloys in automotive and aerospace applications.

Simplified Wear Model for Power Cylinder under Engine Operating Conditions

A simple numerical approach is developed to predict the wear and friction of piston ring pack and cylinder liner during the break-in period and under transient speed conditions. In the model, a solution of mixed lubrications using the load-shearing concept is presented based on the selected elastic-plastic equations of asperity contacts in conjunction with well-established elastohydrodynamic equations. The model takes shear-thinning, thermal effects in elastohydrodynamic lubrication (EHL) and lubricant starvation effects into account. Modified Archard’s wear coefficient to describe the piston ring against cylinder liner wear is introduced. The approach is valid for the calculations of the asperity pressure at low values of the ratio of oil film thickness to combined roughness of the interacting surfaces, that is, less than 0.5. Applications are discussed, including association of piston side thrust force on wear and friction characteristics of piston ring/cylinder bore, gas blowby through the ring pack on the cylinder liner wear, a strong coating dependence for the piston ring wear, and wear distribution across the stroke under engine operating conditions. A good agreement between the experimental and analytical data indicates that the proposed model can be used to predict the wear and friction of the piston ring pack sliding against cylinder liner.