Wear Behavior Research Articles

On the Mechanical Properties of Copper Oxide (CuO)-Decorated Graphene Oxide/Epoxy Nanocomposites

ABSTRACT The primary aim of this study was to determine the influence of CuO-decorated graphene oxide nanoplatelets (CuO@GONPs) loading (0.05, 0.1, 0.3, 0.5, and 0.7 wt.%) on the flexural and wear properties of epoxy-matrix nanocomposites. It is worth noting that the Copper (II) chloride (CuCl2) was used as a nano-CuO generator on the surface of the GONPs in the presence of NaOH. Various analyses such as X-ray diffraction (XRD), Atomic-force microscopy (AFM), Raman spectra, and energy dispersive X-ray (EDX) confirmed the successful synthesizing of the CuO@GONPs hybrid. The results of the flexural tests revealed that the highest obtained flexural strength and flexural modulus belonged to the specimens containing 0.3 wt.% and 0.5 wt.% CuO@GONPs, with 51.8% and 21.3% enhancements respectively, as compared to the neat epoxy. The wear test results showed that adding 0.5 wt.% CuO@GONPs into the epoxy matrix was caused to decrease the wear rate and friction coefficient by 87.4% and 29.6%, respectively. Additionally, the CuO@GONPs/epoxy nanocomposite denoted better flexural and wear behaviors than the pristine GONPs/epoxy one. Overall, the controlled introduction of the CuO@GONPs hybrid into the epoxy matrix was found to be an effective strategy for enhancing its flexural and wear properties.

The influence of graphene oxide on the microstructure and properties of ultrafine-grained copper processed by high-pressure torsion

New metal matrix nanocomposites with enhanced thermal stability were produced in a three step process consisting of mechanical milling, spark plasma sintering and High-Pressure Torsion (HPT). The nanocomposites consisted of a copper matrix and the addition of 1 wt% Graphene Oxide (GO) as a reinforcement. A nanocrystalline microstructure, enhanced hardness and improved thermal stability were achieved. The grain size of the nanocomposites was ∼55 nm which is almost four time smaller than for Cu HPT at 210 nm. Hardnes and ultimate tensile strength of the nanocomposites reach 250 Hv and 700 MPa, respectively, which was more than three times higher than for the initial material. The most important result is that the nanocomposites remained ultrafine-grained up to 500 ⁰C whereas the Cu HPT fully recrystalized after annealing at 300 ⁰C The report also includes an investigation of the electrical conductivity of the copper-based composite which was slightly better than for copper after HPT together with the wear behaviour of this material. This is one of the first reports on copper reinforced with graphene oxide composites produced by HPT and it gives information on its thermal stability, electrical conductivity and wear behaviour together with the microstructural characteristics and mechanical properties.

Wear and Friction Behavior on Extrusion-Based 3D Printed Short Carbon Fiber Reinforced PETG Composites with Annealing and Laser Treated Effects

Wear and Friction Behavior on Extrusion-Based 3D Printed Short Carbon Fiber Reinforced PETG Composites with Annealing and Laser Treated Effects

Tribological behavior of TiN, AlTiN, and AlTiCrN coatings in atmospheric and vacuum environments

In this study, the tribological characteristics of TiN, AlTiN, and AlTiCrN coatings sliding against a SUS420J1 stainless steel pin were investigated in atmospheric and vacuum environments. The coatings were deposited on SUS440C substrates using the arc-physical vapor deposition technique. The friction and wear behavior of the coatings were evaluated based on the systematic analyses of the friction coefficient data as well as the physical and chemical state of the wear track. The results revealed that the friction coefficients of the SUS440C specimen and AlTiCrN coatings increased, whereas those of the TiN and AlTiN coatings decreased when the environment was changed from atmospheric to vacuum. It was confirmed that the formation of an oxide layer and adsorption of oxides on the surface were dominant factors that influenced the tribological behavior in the atmospheric environment. On the other hand, the compatibility, oxidation inhibition, and droplets of the surface mainly affected the frictional characteristics in the vacuum environment. The results of this work are expected to aid in the selection of proper coating materials for tribological systems operating in a vacuum.

Comparative study on tribological behaviors of interproximal tooth enamel against zirconia under fretting and sliding conditions

Interproximal contact loss (ICL) between zirconia crown and adjacent natural teeth is a common complication that could lead food impaction and compromise the periodontal/peri-implant tissue health and patient’s satisfaction. Both fretting and sliding wear mode can be found in the frictional pair between zirconia crown and interproximal enamel during mastication. In this study, fretting and sliding wear behavior of interproximal enamel against zirconia in artificial silva was investigated. The wear damage of the interproximal enamel in a sliding movement was higher than in a fretting movement. In fretting mode, the running condition fretting map (RCFM) composed of partial slip regime (PSR), gross slip regime (GSR), and mixed fretting regime (MFR) was constructed depending on different normal loads and displacement amplitudes. Intact surface was observed in the PSR. Plastic deformation at contact center and microcracks at contact margin were detected in the MSR. Severe wear damage occurred in the GSR, predominated by microfracture, brittle deformation. Macroparticles generation, fatigue delamination and abrasive wear prevailed in sliding mode. In contrast, enamel debris could be transferred on zirconia surface while the material loss of the antagonist zirconia was negligible in both fretting and sliding test.

Wear behavior of functionally graded cemented carbides with CoNiFeCr multi-principal-element alloy binder

The good combination of mechanical and wear properties for cemented carbides is crucial. In this work, the wear behavior of functionally graded cemented carbide (FGCC) and non-graded cemented carbide (CC), with CoNiFeCr multi-principal-element alloy (MPEA) binder, has been investigated by performing sliding wear tests and composition characterization. The results showed that compared with CC, FGCC had higher hardness, stronger fracture toughness, better wear performance, and similar TRS. FGCCs exhibited lower wear rates (3.44 × 10−7–6.95 × 10−6 mm3/(N m)) and coefficients of friction (COFs) (0.27–0.39) than CCs from RT to 600 °C due to mitigation of multiple risks caused by binder removal, fragmentation and pull-out of WC grains, high-temperature oxidation and softening. In the low-temperature wear stage, the MPEA binder underwent dynamic recrystallization (DRX) and twinning deformation before removing from the surface. The binder removal caused dislocation pile-ups and stacking faults (SFs) to form under high stress, resulting in fragmentation and pull-out of WC grains. The low-temperature wear was dominated by abrasive wear and adhesive wear, with a low wear rate and a high and unstable COF. In the high-temperature wear stage, initial pitting oxidation of WC grains generated many subgrain boundaries, reducing heat transfer and exacerbating oxidation, resulting in an oxide layer enriched with WO3, MxOy, and MWO4. High-temperature wear was dominated by oxidation wear and high-temperature softening, with a high wear rate and a low and smooth COF. The results from the present study do not only provide theoretical guidance for an understanding of the antiwear mechanism of WC-CoNiFeCr, but also a new approach for the preparation of cemented carbides with high wear resistance.

Wear behaviour of Al-MWCNT composites by varying MWCNTs concentration

The present study illustrates the mechanical and wear behaviour of Al-MWCNT composites by varying MWCNTs concentration (0 %,0.25 %, 0.50 % & 1 %) by weight in composites. These composites were synthesized through sintering in the muffle furnace after mechanical alloying which involved flattening and welding particles to form flake-shaped lamellar particles. The presence of MWCNT lamellas restricted grain growth, creating a 2D aluminium layer between the MWCNTs during sintering. Increasing the MWCNT content in aluminum refined the interlayer thickness of the composites. The compressive strength of Al is increased exponentially with the addition of CNTs. By adding CNTs to aluminium, the maximum strength was reached at 460 MPa in 1% samples, and the compression strength of the aluminium increased by 84 % as well. The sintered composites exhibited higher hardness and its value increased significantly when CNTs were added to the Al composite. The wear resistance of aluminium is substantially increased when CNTs are added, and the maximum wear resistance is achieved when CNTs are added at 0.5 wt%. The addition of CNTs reduced wear resistance, which could be attributed to the decrease in interface adhesion and agglomeration effects of CNTs.

Microstructural and wear properties of iron slag reinforced aluminum alloy (LM30) based composite prepared through a stir casting method

Aluminum alloys are widely used in various industries due to their as low density, high strength-to-weight ratio, and good corrosion resistance. However, their wear resistance is often inadequate for certain applications. Utilization of industrial waste materials, such as iron slag, as reinforcement in aluminum alloy matrix composites offers a sustainable approach to material development and waste management. The utilization of industrial waste materials for aluminum alloy matrix composite fabrication offers a waste utilization to material development. The loading of this reinforcement varied from 0 to 15 wt.% and different particle size range (220-140, 140-70, and 70-0 µm). A microscopic analysis indicated that the iron slag particles are spread uniformly inside the metallic matrix. There is also a reduction in the size of primary silicon, as well as morphological changes (acicular to globular shape). The wear behavior was calculated using a pin-on-disk wear set up in accordance with ASTM G99 standard. The composites were employed to dry sliding wear test under various operating conditions such as applied pressure (0.2–1.4 MPa), and sliding distance (0–3000 m). The 15F composite outperformed all other composite samples in terms of wear rate under all working conditions. When compared to the base alloy, it demonstrated a remarkable 67% drop in steady state wear rate. The enhancements in wear performance for the 15F composite were attributed to the effects of Fe slag reinforcement. The inclusion of iron slag particles induced strong interfacial bonding between matrix and reinforcement particles improving the durability of the mechanical mixed layer developed during relative motion. Importantly, the wear rate parameters of the 15F composite were similar to those of the brake drum material used in commercial applications. This emphasizes the composite suitability for usage in a variety of automobile components.

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.

Preparation and Characterization of Al-ZrB2 Composites by Planetary Milling and Equal Channel Angular Pressing: Effect of ZrB2 Amount and Milling Time on Wear Behavior and Compressive Strength

Preparation and Characterization of Al-ZrB2 Composites by Planetary Milling and Equal Channel Angular Pressing: Effect of ZrB2 Amount and Milling Time on Wear Behavior and Compressive Strength

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.

Investigations into rubbing wear behavior of honeycomb land against labyrinth fin with periodic-cell model

The periodic-cell model was proposed to simulate the successive contacts between the labyrinth fin and multiple honeycomb cells. With the experimental data, the finite-element-analysis (FEA) method with the periodic-cell model was validated. The effects of incursion parameters (i.e. incursion depth, incursion rate and sliding velocity) on the contact force, frictional temperature, material loss, and worn geometry of the honeycomb seal during the incursion process were studied. With the predicted worn geometry, the sealing performance degradation in the honeycomb seal was analyzed. The results showed that the proposed periodic-cell model has an excellent accuracy in predicting the wear behavior of honeycomb seal in rubbing events. The contact force between the honeycomb liner and labyrinth fin is pronounced especially at low sliding velocity and high incursion rate conditions, which increases the possibility of wear damage in the rotor part. At low sliding velocity and low incursion rate conditions, the frictional heat transferring to rotor part is increased, which increases the thermal stress near the contact region of the rotor part. As the clearance gap of honeycomb seal increases from 0.6 mm to 0.9 mm in the rubbing event, the leakage rate is increased by about 12%, and the carry-over effects downstream of the worn cells are increased.

Wear behavior and microstructure evolution of lamellar γ-TiAl alloy at room and elevated temperatures

The wear behavior of lamellar Ti-46Al-2Nb-2Cr was investigated by reciprocating sliding at room and service temperatures. The wear scar and subsurface microstructure were studied via scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The coefficient of friction (COF) increased with the temperature. However, the wear volume loss first decreased and then increased, due to the formation of a relatively complete tribo-layer at 750 ℃. Abrasive wear, oxidative wear and adhesive wear were activated at elevated temperatures. Reciprocating sliding introduced gradient nano-grained structures covered with tribo-layers. Compared to room temperature, the oxidative tribo-layer and nano-grained layer formed at 750 ℃ were thicker. And the nano-grains were finer. Nano-grains at room temperature and 750 ℃ were related to defects and enhanced dynamic recrystallization, respectively.

Effect of CrAlTiN Coating on Fretting Wear Behavior of Inconel 690 Alloy in Dry and Seawater Conditions

Effect of CrAlTiN Coating on Fretting Wear Behavior of Inconel 690 Alloy in Dry and Seawater Conditions

Analysis of abrasive impact wear of the Mn8/SS400 bimetal composite using a newly designed wear testing rig

In this study, the abrasive impact wear behaviour of a bimetal composite made of medium manganese steels (MMSs) and low carbon steels (LCSs), i.e., the Mn8/SS400 bimetal composite, was investigated using a newly designed wear-testing rig. The need for a new rig arose from the difficulty in replicating real-world wear conditions. Our rig allows for precise control and measurement of wear, simulating harsh environments more accurately than other wear-testing rigs. The bimetal composite Mn8/SS400 demonstrated superior wear resistance, showing an improvement of up to 2.8 times compared to benchmark steels, attributed to its enhanced work hardening sensitivity. Scanning electron microscopy (SEM), X-ray diffractometer (XRD), and electron backscatter diffraction (EBSD) analyses were employed to elucidate the wear mechanisms. After 300 h of abrasive impact wear, the subsurface microhardness of Mn8 reached 601.31 HV, significantly higher than that of the matrix hardness of 292.24 HV, indicating a substantial work hardening effect. The wear mechanism of the Mn8/SS400 bimetal composite was found to be a synergistic effect of grain refinement strengthening, dislocation strengthening, and twin strengthening. Initially, twin strengthening was the dominant mechanism up to 200 h of wear testing. However, after 300 h, contributions from all three mechanisms became increasingly significant, enhancing the overall wear resistance of the composite.

Wear and Corrosion Behavior of Connectors in High-Temperature Environment

Wear and Corrosion Behavior of Connectors in High-Temperature Environment

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.

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.

Research on microstructure, mechanical property and wear mechanism of AlCoCrFeNi/WC composite coating fabricated by HVOF

In this study, HVOF spraying technology was utilized to prepare AlCoCrFeNi/WC composite coatings with varying WC content on 40CrMnMoA steel substrate. The microstructure, elemental distribution, phase structure and chemical valence states of wear scratches of the composite coatings were analyzed using the SEM, EDS, XRD and XPS. Microhardness was measured using single-point digital microhardness tester, while nanohardness and elastic modulus were determined using a nano-indenter. The bonding strength of the composite coatings was evaluated using a tensile tester. Friction and wear tests were conducted to assess the wear behavior of the composite coatings. The results indicated that the microstructure, microhardness, nanohardness and elastic modulus of AlCoCrFeNi HEA coating increased with the addition of WC, attributed to the hard phase effects of WC. However, the bonding strength first decreased and then increased. Compared to the W 0 coating, the wear rates of the other composite coatings decreased by 30.5 %, 46.1 %, 65.3 %, and 82.1 %, respectively, which demonstrating that the effect strengthening of WC. After the friction and wear tests, the wear mechanism of the W 0 and W 1 coatings represents adhesive wear, abrasive wear and severe oxidation wear. In contrast, the W 2 and W 3 coatings exhibited slight adhesive wear, slight abrasive wear and slight oxidation wear, while the W 4 coating showed the slightest abrasive wear, the slightest adhesive wear and the slightest oxidation wear.

Effects of silicon content and test conditions on the dry wear behaviour of Zn–30Al–3Cu–(0–5)Si Alloys

ABSTRACT Dry sliding wear performance of Zn-30Al-3Cu-(0-5)Si alloys was studied using a block-on-disc type test apparatus. Their microstructure consisted of β dendrites, α, η, and ϵ (CuZn4) phases, and silicon particles. Hardness and tensile strength of the alloys increased with silicon content but above 1% Si the trend reversed for the tensile strength. Total percent elongation, impact energy, compressive strength, and quality index of the alloys decreased with silicon content. However, the friction coefficient and wear volume showed different changes with silicon content, sliding distance, contact pressure, and sliding velocity. Worn surface examinations indicated that the wear of these alloys occurs by both abrasion and adhesion. Non-linear regression analysis showed that the friction coefficient and wear volume of the alloys can be calculated in terms of silicon content and either sliding distance or contact pressure and sliding velocity using the empirical equations developed in this work. Zn-30Al-3Cu-0.5Si alloy exhibited the highest quality index and wear resistance among the alloys tested. It was concluded that the hardness and tensile strength of the alloys containing hard and brittle phases have opposite effects on their dry wear behaviour. The wear volume of such alloys decreases with increasing hardness but increases with tensile strength.