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Highlights Unique hybrid thermoplastic composites based on polyoxymethylene copolymer (POM C), 10 wt.% glass fiber (GF) and graphite (Grt) filler at 1, 3, and 5 wt.% were developed using injection molding technique. According to the Taguchi L16 orthogonal array, present experiments were carried out with the aim of determining the coefficient of friction (COF) and specific wear rate (SWR) under a range of loads (namely, 5, 10, 20, and 30 N), sliding speeds (namely, 200, 400, 600, and 800 rpm), and run times (namely, 15, 30, 45, and 60 min) with varying wt.% of Grt (namely, 1, 3, and 5 wt.%) throughout the experiment. Analysis of variance (ANOVA) was used to evaluate the most significant factors that affect the output functions (viz., COF and SWR). The findings demonstrated that POM C/10GF composites' tribo‐mechanical, structural, and thermal properties were considerably improved upon by including Grt. Various microscopical methods were also employed to study the wear mechanisms of the composites and the surface morphology of the worn samples. The POM C/10GF with a 3 wt.% of Grt exhibited superior tribological properties owing to its enhanced interfacial bonding characteristics, resulting to increased wear resistance. Injection molded POM C/10GF hybrid composites with 1, 3, and 5 wt.% graphite (Grt) Structural, thermal, chemical, tribo‐mechanical and microstructural studies Design of experiment with variable loads, times, speeds, and Grt compositions COF and specific wear resistance as response Optimization of hybrid composite composition using Taguchi L16 orthogonal array [ABSTRACT FROM AUTHOR]

This research focuses on the development of carbide-free nanostructured bainitic steel through the process of austempering at 250°C. The selected steels are also patented at 550°C, to get fine pearlitic structure. In austempered steels, microscopic analyses encompassing optical, scanning, transmission electron microscopy and X-ray diffraction revealed the presence of nanoscale bainite, filmy and blocky austenite. In contrast, lamellar pearlite was observed in the patented steels. With increase in the austempering duration, the extent of bainite improved, while the volume percentage of blocky retained austenite (RA) decreased. The tribological performance of high-carbon bainitic steels is compared with patented one of same composition against a tungsten-carbide counter disc. The specific wear rate as well as coefficient of friction decreases with rise in load from 10 to 50 N. The hardening volume of B15VA-1 sample is greater than that of B15VA-2 and P15VA, and it is mainly due to the transformation of blocky RA to strain-induced martensite. The bainitic pins with higher hardness exhibited superior tribological response than the pearlitic ones. SEM analysis of worn surfaces confirmed that at lower load (10 N), abrasive wear occurs, but at higher load (50 N), wear mechanism changes to adhesive along with abrasive in bainitic steel and oxidative wear along with adhesive and abrasive wear in pearlitic steel. [ABSTRACT FROM AUTHOR]

The MAX phase ceramics namely Ti2AlCx, Cr2AlCx, and (TiCr)2AlCx were examined under dry sliding conditions against stainless steel ball at room temperature and 5 N applied normal load using a Ball-on-disk tribometer. At 5 N, 100 m sliding distance and 20 cm/s sliding velocity, Cr2AlCx, and (TiCr)2AlCx ceramic samples exhibited low specific wear rate (3.2 × 10-7 cm3/Nm and 4.2 × 10-7 cm3/Nm), while the coefficients of friction were 0.31 and 0.10, respectively. At 5 N, 100 m and increasing velocity from 5 cm/s to 20 cm/s, Ti2AlCx sample the coefficients of friction decreases from 0.25 to 0.14. The specific wear rate of Ti2AlCx sample was 6.7 × 10-7 cm3/N m at 5 N, 100 m and 5 m/s, and decreases with increasing velocity (3.3 × 10-7 cm3/N m at 20 m/s). The correlations between observed tribological properties and tribo-film characteristics were discussed.

In various applications like bearings, gear pairs, and brake pads, understanding how polymer composites interact with harder counterparts during sliding motions is crucial. A challenge arises from the heat generated during sliding friction, which has the potential to raise the contact temperature. This temperature increase, if it exceeds the material's glass transition temperature, can compromise the thermal stability of the composites, leading to rapid material wear. In the present investigation, dry sliding wear test was performed on 25 wt. % of short carbon fiber (SCF) reinforced polyethersulfone (PES) composites filled with 2.5 and 5.0 wt. % of potassium titanate whisker (PTW) using pin-on-disc tribometer. Wear test was planned and executed according to the experiment design formulations obtained by central composite design method. Contact temperature at the interface between composite pin and steel disc was monitored with an infrared thermal camera. Wear resistance was found to increase with the addition of fibers and fillers. PTW filled composites exhibited minimum wear with maximum coefficient of friction. Morphology studies were carried out on worn surfaces of the composites using scanning electron microscope to identify and describe the mechanism of wear involved. This investigation sheds light on the intricate behavior of polymer composites during sliding interactions.

In this study, the dry sliding wear behaviour of plasma sprayed composite Ni-Cr coatings with nano Al2O3 particle concentrations of 0, 5, 10, 15, 20, and 100 wt.% on Al6061 substrate material was analysed. The coatings were characterised by scanning electron microscopy. The results showed higher porosity and coating thickness values for 100% and 20% nano Al2O3 particle coatings. The microhardness was found to increase with an increase in nano Al2O3 particle concentration in the Ni-Cr coating matrix. The porosity values were found to decrease with an increase in coating thickness. It is found that the specific wear rate of the Ni-Cr/15% Al2O3 particle coating is reduced by 54.02% compared to the Al2O3 particle coating. [ABSTRACT FROM AUTHOR]

Do two different and independent methods of estimating the wear rate of a test sample yield the same numerical result? Numerical values of specific wear rates estimated on the basis of alternative methods using a set of dry sliding rotary-pin-on-disk experiments are presented. Wear rates of brass and aluminium alloy pins were estimated using gravimetric and wear scar area methods. Gravimetric and linear displacement methods were used to assess wear rates of ABS plastic and machinable wax pins. Scepticism about the estimated nominal values of wear rates is reduced when alternative assessment methods result in comparable numerical values, or values having the same order of magnitude. This is particularly useful when ranking competing materials for wear rates, when the differences in these rates are small. Uncertainties in individual test sample wear rates, and dispersion in the nominal values of wear rates are also computed to support the aforementioned observations. [ABSTRACT FROM AUTHOR]

Purpose: This study explores how titanium oxide (TiO2) filler influences the specific wear rate (SWR) in flax fiber-reinforced epoxy composites (FFRCs) through a Taguchi approach. It aims to boost abrasive wear resistance by incorporating TiO2 filler, promoting sustainable and eco-friendly materials. Design/methodology/approach: This study fabricates epoxy/flax composites with TiO2 particles (0–8 wt%) using hand layup. Composites were tested for wear following American Society for Testing and Materials (ASTM) G99-05. Statistical analysis used Taguchi design of experiments (DOE), with ANOVA identifying key factors affecting SWR in abrasive sliding conditions. Findings: The study illuminates how integrating TiO2 filler particles into epoxy/flax composites enhances abrasive wear properties. Statistical analysis of SWR highlights abrasive grit size (grit) as the most influential factor, followed by normal load, wt% of TiO2 and sliding distance. Grit size has the highest effect at 43.78%, and wt% TiO2 filler contributes 15.61% to SWR according to ANOVA. Notably, the Taguchi predictive model closely aligns with experimental results, validating its reliability. Originality/value: This paper integrates TiO2 filler and flax fibers to form a novel hybrid composite with enhanced tribological properties in epoxy composites. The use of Taguchi DOE and ANOVA offers valuable insights for optimizing control variables, particularly in natural fiber-reinforced composites (NFRCs). [ABSTRACT FROM AUTHOR]

Casing wear is a persistent issue in oil and gas drilling facilities that call for innovative more wear-resistant materials to mitigate casing failures. The present work examines the tribological performance of a novel composite lining comprised of Kevlar honeycomb in a matrix of epoxy reinforced with Zirconia particles against hardband drillpipe tooljoint (DP-TJ). Three side loads (1000, 1200, and 1400 N) and three DP-TJ speeds (0.43, 0.76, and 1.02 m/s) were considered under dry sliding conditions. The results showed that the specific wear rate (K) increased with speed at all side loads. However, K value was found to reach a maximum, reaching 20.3*10−8 MPa−1 at 1200 N before dropping to about 8.5*10−8 MPa−1 when the load is increased to 1400 N. This decline in specific wear rate at the load of 1400 N was attributed to the growth of a double transfer layer through the alignment of zirconia particles in the lining. The scanning electron microscope (SEM) images of worn surfaces revealed that higher K values are associated with more adhesion, delamination, and fiber breakage. Energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD) analysis of the worn surface and the debris collected after the wear test reveals minimal wear of DP-TJ. The epoxy/Kevlar-honeycomb composite lining demonstrated appreciable wear resistance even under dry sliding conditions.

The present work emphasizes the effect of graphene nanoplatelets (G) filler loading on mechanical and abrasive wear behavior of carbon fibre reinforced epoxy (C/E) composites. Graphene nanoplatelets were mixed with epoxy framework using a temperature-controlled magnetic stirrer and then ultrasonically treated. The parameters considered for the abrasive wear study are the applied load in N (5, 10 and 15), abrading distance in m (75, 150, and 225) and weight percentage of reinforcement (0, 1, and 1.5). The incorporation of 1 wt. % G into C/E composites increases hardness by 14 % and interlaminar laminar strength by 19 % when compared to C/E composites. According to the Taguchi design of tests, a filler loading of 1 wt. % G, an abrading distance of 225 m, and an applied load of 15 N are ideal. Analysis of variance (ANOVA) was done to establish the dominant parameter, and the filler loading with abrading distance was shown to be significant. With 36.4 %, the filler loading had the biggest influence on the composite specific wear rate. The combination of filler loading with 1 wt. %, load of 15 N, and abrading distance of 225 m yields the lowest specific wear rate. The involved wear mechanisms during the abrasive wear process have also been explained with scanning electron micrographs.

The present research article describes a study on the wear resistance of high manganese Hadfield steel produced through a clean metallurgical process during dry sliding wear conditions; solidified ingots are subjected to heat treatments, such as annealing, ice water quenching, and age hardening for 2 h at 550 °C, 600 °C, 650 °C, and 700 °C. Samples are prepared as per the standards for mechanical and tribological tests. The peak hardness of 292.87 HV is observed for alloy 4 aged at 600 °C. The ultimate tensile strength of 434.18 MPa is observed for alloy 3 aged at 600 °C. The minimum specific wear rate of 1.5649E-05 mm3/N-m is witnessed for the as-cast sample of alloy 4 at 50 N load and 1.885 m/s speed. Wear tracks are analyzed through SEM, and microstructures are retrieved from OM, SEM, and TEM. The XRD patterns revealed the developed steel is austenitic in nature. Furthermore, to validate the wear rate, a total of 8 machine learning models/ensembles are developed and trained as it is obvious to associate tribological and material features with ML models. With an efficiency of 94%, Decision Tree Regressor outperformed all other constructed models using R2 values as the performance assessment criterion. [ABSTRACT FROM AUTHOR]

In various applications like bearings, gear pairs, and brake pads, understanding how polymer composites interact with harder counterparts during sliding motions is crucial. A challenge arises from the heat generated during sliding friction, which has the potential to raise the contact temperature. This temperature increase, if it exceeds the material's glass transition temperature, can compromise the thermal stability of the composites, leading to rapid material wear. In the present investigation, dry sliding wear test was performed on 25 wt. % of short carbon fiber (SCF) reinforced polyethersulfone (PES) composites filled with 2.5 and 5.0 wt. % of potassium titanate whisker (PTW) using pin-ondisc tribometer. Wear test was planned and executed according to the experiment design formulations obtained by central composite design method. Contact temperature at the interface between composite pin and steel disc was monitored with an infrared thermal camera. Wear resistance was found to increase with the addition of fibers and fillers. PTW filled composites exhibited minimum wear with maximum coefficient of friction. Morphology studies were carried out on worn surfaces of the composites using scanning electron microscope to identify and describe the mechanism of wear involved. This investigation sheds light on the intricate behavior of polymer composites during sliding interactions. [ABSTRACT FROM AUTHOR]

The selection of tribopairs, including mating materials, plays a crucial role in controlling material loss under rubbing conditions. In a fast breeder nuclear reactor, almost all moving components have been provided with a hardfaced coating at the mating surfaces for their longer life. Though, in most cases, the hardfaced surfaces come into contact with the components having the same coating; in some instances, they are allowed to rub against other materials. In the present investigations, an effort was made to study the wear behaviour of a Ni-based hardfaced coating made on 316LN stainless steel under similar and dissimilar mating conditions. Prior to wear tests, a defect-free hardface coating of Ni-based hardfacing alloy was made on 316LN stainless steel using plasma transferred arc welding process and subsequently characterized for its microstructure and hardness. Wear tests under dry sliding conditions were carried out at ambient temperature. The specific wear rate for dissimilar mating conditions was found to be one order of magnitude higher than the same rate obtained from similar mating conditions. Moreover, adhesive wear was the dominant wear mechanism in both mating conditions. It is clear from the study that similar material combinations should be given preference in the design of tribopairs instead of dissimilar material combinations to avoid significantly higher material losses for materials with lower hardness. The reported results will provide insight for carefully designing the tribopairs for critical applications. [ABSTRACT FROM AUTHOR]

The present work emphasizes the effect of graphene nanoplatelets (G) filler loading on mechanical and abrasive wear behavior of carbon fibre reinforced epoxy (C/E) composites. Graphene nanoplatelets were mixed with epoxy framework using a temperature-controlled magnetic stirrer and then ultrasonically treated. The parameters considered for the abrasive wear study are the applied load in N (5, 10 and 15), abrading distance in m (75, 150, and 225) and weight percentage of reinforcement (0, 1, and 1.5). The incorporation of 1 wt. % G into C/E composites increases hardness by 14 % and interlaminar laminar strength by 19 % when compared to C/E composites. According to the Taguchi design of tests, a filler loading of 1 wt. % G, an abrading distance of 225 m, and an applied load of 15 N are ideal. Analysis of variance (ANOVA) was done to establish the dominant parameter, and the filler loading with abrading distance was shown to be significant. With 36.4 %, the filler loading had the biggest influence on the composite specific wear rate. The combination of filler loading with 1 wt. %, load of 15 N, and abrading distance of 225 m yields the lowest specific wear rate. The involved wear mechanisms during the abrasive wear process have also been explained with scanning electron micrographs. [ABSTRACT FROM AUTHOR]

The tribological behavior of titanium dioxide (TiO2) filled with jute fiber reinforced interpenetrating polymer networks (IPNs) were studied by using a pin-on-disc wear test rig at dry slide conditions. During the study, 70 wt.% of epoxy and 30 wt.% of polyurethane have been chosen as the base matrix material. As well, various proportionate of titanium dioxide such as 0%, 3% and 5% have been utilized to fabricate the particulate reinforced IPN laminate. To do the wear analysis such as materials type (A), sliding speed (B) and applied loads (C) were kept as the influencing parameters whereas coefficient of friction (COF) and specific wear rate (SWR) have been seen as the outcome of the entire study. Taguchi technique was chosen to plan the entire experiments. Similarly, an orthogonal array and analysis of variance (ANOVA) was employed to examine the impact of process parameters on wear of the IPN laminate. Out of all, results show that, addition of particulate materials into the composite predominately increased the specific wear resistance of the IPN laminate significantly.

This work aims to explore the impact of side loads, drill-pipe tool-joint (DP-TJ) speed (rpm), and mud type on the austenitic stainless steel SM2535-110 casing wear characteristics. Actual field drill pipe tool joints, casings, and drilling muds are used in this study. The results of the study show that under both types of lubrication, the wear volume increased with radial load and DP-TJ speed. SM2535-110 casing specimens tested under oil-based mud (OBM) lubrication had higher casing wear volumes than those obtained under water-based mud (WBM) lubrication. This unexpected behavior is mainly due to the increase in the surface hardness of the casing specimens tested under WBM. The results also show that the specific wear rate or wear factor (K) (which is defined as the volume loss per unit load per unit distance sliding) values of specimens tested under WBM are in general two to four times higher than those obtained under OBM. While K values under WBM increase with both the side load and rpm, those under OBM show a sharp decrease with rpm. This behavior under OBM is due to this lubricant's higher viscosity and the change of lubrication regime from thin film to thick film lubrication at higher rpm. Scanning electron microscopy (SEM) and the digital microscopic imaging (DMI) of SM235-110 casing specimens show that an aggressive combination of adhesive, abrasive, and plastic deformation was observed under WBM, while the dominant wear mechanism under OBM is abrasive wear. [ABSTRACT FROM AUTHOR]

Growing environment concern has forced us for the development of environmentally acceptable lubricants. In this study, tribological properties of sesame oil and castor oil containing imidazolium-based ionic liquid 1-ethyl 3methylimidazolium dicyanamide ([EMIM][DCN]) (IL1), phosphonium-based ionic liquid Trihexyltetradecylphosphonium bis(2,4,4-trimethylpentyl) phosphinate ([P66614][BTMPP]) (IL2) and titanium oxide (TiO2) nanoparticles (NPs) as hybrid additives have been investigated using four-ball tester with ASTM D4172B. Three different concentrations of IL1, IL2 and TiO2 NPs were selected for the formulation of vegetable oil–based ionanolubricants. It was found that castor oil with the addition of 0.03 ∅ of TiO2 NPs and 1.3 vol.% of IL1 shows the lowest specific wear rate amongst all investigated lubricant samples. It is evident from field emission scanning electron microscopy analysis of worn-out surfaces of steel balls that a combination of ball bearing effect and tribofilm formation is responsible for the improved tribological characteristics. [ABSTRACT FROM AUTHOR]

This research paper investigated the hardness and tribological performance of novel Grewia optiva/Basalt fiber reinforced hybrid polymer composites. Two different configuration of hybrid composite that is, woven and chopped fiber reinforced composite are considered for the study. The chopped fiber configuration of the composite is further divided into two types based on fiber length and wt%. The fiber lengths studied are 6 and 12 mm while the wt% studied are 0, 6, and 12 wt%. Woven fiber reinforced composite is divided into five configurations based on wt% of G. optiva fiber with 0, 3, 6, 9, and 12 wt%. In all configurations, maximum fiber content of 12 wt% is maintained. B6/GO6 composite exhibits minimum specific wear rate and maximum hardness among all the compositions. Wear experimental results are analyzed by Taguchi optimization technique and based on the five levels and four control factors (sliding velocity, fiber loading, sliding distance, and normal load) L25 partial orthogonal array was suggested for the woven fiber reinforced composites. Fiber content is the main control parameter for hardness testing and L9 orthogonal array was suggested according to four control factors and three levels. [ABSTRACT FROM AUTHOR]

Abstract To enhance the friction performance of resin‐based friction materials, five types of specimens with different polymer ether ketone (PEEK) contents were fabricated and their physiomechanical behaviours were tested and, their tribological properties were investigated using a JF150F‐II constant‐speed tester. It was found that the addition of PEEK had a positive influence on the properties of the friction materials, and sample FM‐3 (the shorthand of ‘Friction Materials‐3’, containing 2 wt% PEEK) exhibited improved friction performance with a fade ratio and recovery ratio of 8.6% and 101.1% respectively. Among all samples, FM‐4 (the shorthand of ‘Friction Materials‐4’, containing 3 wt% PEEK) had the lowest specific wear rate with a value of 0.622 × 10−7 cm3 (N·m)−1 at 350°C. The PEEK can fill the microcracks in the composite at a high temperature and can also cover the hard abrasive particles to prevent them from directly damaging the composite. The findings from this study afford a foundation for studies to further improve the properties of resin‐based friction materials.

When creating polymer-based composites, plain weave fabrics and micron-sized fillers offer bidirectional strength and reduced voids/inhomogeneity. In the present work, It was investigated how glass fabric reinforced epoxy composite (G-E) performed during three-body abrasive wear with and without ceramic fillers (SiO2, Al2O3, graphite, and fly ash cenospheres). In experiments, loads of 20 N and 40 N were applied at various abrading distances of 500 m, 1000 m, 1500 m, and 2000 m. According to the results of sand abrasive wear test, the specific wear rates of G-E based composites are sensitive to fibre and filler/matrix adhesion. Under all tribo-test settings, the SWR for all particulate G-E composites decreases in the following order: G-E > Gr/G-E > SiO2/G-E > Al2O3/G-E > fly ash cenosphere/G-E. Furthermore, the specific wear rate of the fly ash cenosphere filled G-E composites were found to be lower than the G-E and other filler materials filled G-E composites. There was 38.7% reduction in the specific wear rate at 40 N, 2000 m in fly ash cenosphere filled G-E composite. As per the evidence of scanning electron microscope images of worn-out surfaces, mechanisms such as ploughing, fibre breakage, fibre pull-out, fibre thinning, and a network of microcracks caused the wear in composites.

The environment is a very important topic today as well as in the future. One source of air pollution that has the potential to harm health is the wear particles released by vehicle braking systems. If these wear particles come from hazardous materials, they could destroy human health and the environment. Based on these conditions, exploring more environmentally friendly materials to substitute hazardous materials as friction materials is necessary. In this study, brake linings were prepared from bamboo fiber and eggshell (ES) particles with various pre-treatment conditions. The composition of the material frictions consisted of phenolic resin, bamboo fiber, bamboo particles, ES particles, zinc, alumina, and graphite in the following: 35% phenolic resin, 10% graphite, 10% bamboo fiber, 10% alumina powder, 5% zinc powder, and 30% bamboo particles and ESs. This study focused on observing the mechanical and tribological behavior of friction materials when using ES particles as fillers. There are three stages to manufacturing friction material: a cold press, a hot press, and heat treatment. The optimization of the characteristics of ESs as organic brake linings was carried out using the Taguchi method and analyzed using data envelopment analysis-based ranking (DEAR). An interesting finding from this study was that when ES particles were calcined at 900°C for 120 min, the ES particle size was 200 mesh, and the ES volume fraction at 25% resulted in the most optimal brake lining performance. Calcination at 900°C for 120 min completely changed the CaCO3 phase to CaO. This study also shows that calcined ES particles have the potential to be developed as friction materials for environmentally friendly two-wheeled vehicles in the future. The produced brake linings exhibited hardness, a coefficient of friction, and specific wear rates of 92.82 HR, 0.32, and 4.43 × 10−6 mm3·N−1·m−1, respectively.

In this work, the dry sliding wear characteristics of Ti6Al4V (Ti64) – EN31 (steel) tribo-pair at incremental sliding velocity (SV, 0.838–1.466 ms-1) and load (L, 50–100 N) conditions are elucidated. As evident, specific wear rate (SWR) and coefficient of friction (CoF) increases and decreases, respectively with load and SV. The wear response of Ti64 undergoes a transition from composite type (oxidative and metallic) to delamination. The evolved oxides, viz. TiO and Ti8O15 were majorly in the form of free particulates. At low SV (0.838–1.047 ms-1) and low load (50–70 N), the movable particulates can activate a separation effect limiting the damage due to wear. During severe sliding (SV = 1.257–1.466 ms-1 and L = 70–100 N), the combined influence of frictional heating instigated thermal softening, and the formation/retainment of hard-coarse particulates at the interaction zone causes perforation into the substratum, assisting in spalling. [ABSTRACT FROM AUTHOR]

The current work involves the development of polymer matrix composites (PMC) filled with rubber crumb (RC) for tribological applications. The novelty of the proposed composite lies in harnessing of waste rubber crumb into useful filler material in polymer matrix composites for tribological applications owing to compliant nature of rubber. The proposed composites with different filler weight percentage have been developed and subjected to three body abrasion at different control factors (filler weight percentage, load and time). For the abrasion investigation, three body abrasive test rig was used, and Taguchi's orthogonal arrays were used in the design of trials. The Taguchi technique was used to find the best parameter settings for minimizing specific wear rate. The effect of input factors (filler weight percentage, load and time) on abrasion resistance of proposed composites was evaluated, and statistically analysed using ANOVA. The effect of addition of RC on mechanism of abrasion was also studied. RC greatly improves the abrasion resistance of the suggested composites, according to the findings. The abrasion mechanisms involved are also studied. The results reveal that the composite with 20 wt% filler, subjected to three body wear at 30N load for 10min results in minimal specific wear of 0.31 x 10-22m³/Nm which is approximately 15.5 times higher than the combination (A2B1C2) that exhibits least resistance to wear/higher specific wear rate. [ABSTRACT FROM AUTHOR]

The present paper reports the study on manganese-silicon steel cast through a clean liquid metallurgical route; in order to assess the tribological behaviour of the steel, the solidified ingots were subjected to heat treatments, such as annealing, ice water quenching, followed by ageing the quenched steel at 550 °C, 600 °C, 650 °C and 700 °C for two hours. For evaluation of hardness, tensile strength and sliding wear properties; the desired samples were prepared as per usual standards. The best combination of the ultimate tensile strength (476.83 MPa), microhardness (252.23 HV), and mean specific wear rate of 2.269E-05 mm3/N-m is achieved for alloy 1 after ageing at 650 °C. Fractography of broken tensile samples and microstructural characterization of worn-out surfaces are carried out by scanning electron microscopy (SEM); these have aided in the determination of the dominant wear mechanism and mode of fracture during tensile loading. The mixed-mode fracture is predominantly observed in most of the fractured surfaces, and the dominant wear mechanism is found to be adhesive wear. Moreover, X-ray diffraction (XRD) analysis has shown the presence of phases like austenite, α' martensite, ɛ martensite, along with AlNi3, Ni2Al3, and M2C precipitates. [ABSTRACT FROM AUTHOR]

The prerequisites for a brake disc material include a lower specific wear rate, a high coefficient of friction against brake pad material, lighter weight, and a higher heat dissipation rate. The present research studied the dry sliding wear behavior of as-cast Si-Mo-Cr ductile cast iron (DCI). A series of pin-on-disc wear tests are conducted using Taguchi L16 array for the optimum combination of load, sliding velocity, and temperature on a rotary tribometer setup at controlled temperatures ranging from 30°C to 240°C. The analysis of variance, first-order regression analysis, and confirmation tests are done to validate the results obtained for the material's wear properties. SEM and EdX analysis of wear surfaces is also done. It founds that the sliding velocity has a more significant influence on the specific wear rate. In contrast, the applied load is the key influencing parameter for a higher value of the coefficient of friction.

In the present investigation, acrylic acid treated short rattan fibre reinforced epoxy (RF/Epoxy) composite was fabricated by taking various weight percentages (i.e. 5, 10, 15, 20, 25 wt%) of fibres using hand layup technique. Different mechanical properties such as tensile, flexural, and impact strength were investigated. By regression analysis it was found that 18 wt% of acrylic acid treated rattan fibre reinforcement (optimum fiber loading) gave 21.17%, 32.74% and 40.10% increase in above properties in comparison to untreated one. The tribological performances such as specific wear rate, friction coefficient and weight loss were analysed in terms of speed, load and sliding distance under multipass two body abrasion condition. It was observed that tribological performance was also better at optimum fibre loading similar to mechanical properties. The microstructure of worn-out surface of the composite was studied with the help of scanning electron microscope (SEM) and was found that with increasing sliding velocity, the surface deterioration and matrix breakage become predominant reducing the composite’s wear resistance.

The natural fiber composites are emerging as replacement materials in wide engineering fields. In this work, banana, sisal, and banana-sisal fibers of three different fiber lengths namely 3 mm, 5 mm, and 7 mm are used as reinforcements in the epoxy matrix. The composite samples are prepared by using the injection molding technique. Frictional and wear characteristics of the composites are evaluated under dry operating conditions with the parameters like applied load (15–35 N), sliding speed (300–500 rpm) for a duration of 15 mins. Water absorption characteristics are studied at an interval of 6 days for a duration of 120 days. The results indicate that the incorporation of fibers at different lengths influences frictional force, coefficient of friction and specific wear rate of the composites to an extent. Frictional force and specific wear rate are greater at higher loads. Banana-sisal hybrid fiber composites are showing amplified coefficient of friction and specific wear rate than other composites. Composites made of Sisal fibers (12.4%) are showing more resistance to water absorption than banana (21.5%) and banana-Sisal (15.4%) fibers. SEM images explores the wear characteristics of testing surface with presence of micro cutting, fiber breakage, voids, and debris.

Al-Cu alloy samples with 5%-20% (mass fraction) Cu were prepared by die-casting process. The hardness of the samples was measured on a Brinell hardness tester. The wear experiments with three kinds of load (1-5 N) were carried out with a ball-disk reciprocating wear tester. The wear mechanism of the samples with different Cu contents was analyzed by SEM and EDS. The results show that as the Cu content increases from 5% to 20%, the volume fraction of θ phase in Al-Cu alloy increases from 2.00% to 25.80%, and the size of θ phase increases gradually; the hardness increases from 59HB to 170HB. The coefficient of friction changes within the range of 0.4-0.85; with the increase of Cu content, the specific wear rate of Al-Cu alloy samples decreases sharply at first and then tends to be gentle. When Cu content is more than 15%, the specific wear rate of alloy samples does not change much, and the lowest specific wear rate is about 4.1×10-4 mm3·N-1·m-1. The specific wear rate of samples with lower Cu content changes significantly with the load, and the specific wear rate difference decreases with the increase of Cu content. The main wear mechanisms of Al-Cu alloys are adhesive wear and abrasive wear. For samples with low Cu content, adhesive wear is dominant; while for samples with high Cu content, abrasive wear is dominant. With the increase of load, the adhesive wear degree of the samples with low Cu content increases, and the abrasive wear degree of the samples with high Cu content increases.

As multi-walled carbon nanotubes (MWCNTs) filled polymer composites reinforced with natural fibers are ruling gradually increased applications, a considerable volume of investigation has focused on enhancing their wear and mechanical characteristics. This paper presents the wear behavior of the hybrid composites reinforced with banana-glass fiber. The epoxy resin diffused with MWCNT by ultrasonicator is considered as a matrix face for natural fiber-reinforced composites. The wear performances of the composites filled with MWCNT are measured using a pin-on-disc wear tester. Taguchi’s method in experimental design is considered with the control parameters such as sliding speed, load, temperature and wt.% of MWCNT. The worn surface is studied through the scanning electron microscopy (SEM) and atomic force microscope (AFM).

This research aims to assess the mechanical characteristics of high-performance copper composites made utilizing powder metallurgy. The composites were produced by adding reinforcement elements (Al2O3-Cr3C2) at different rates (3-6–9 wt.%) into copper-graphite (Cu-5Gr) via hot pressing technique. The microstructure, hardness, three-point bending and wear performance were analysed. The results determined that hybrid reinforced composites exhibited higher density, hardness and bending strength compared to Cu-Gr composites. The highest hardness of 73.02 HB was found in the CG-4 (copper graphit-4) sample. The maximum bending stress of 151.06 MPa occurred in sample CG-2. In addition, it was observed that the wear resistance increased significantly with the addition of the hybrid reinforcements. The lowest specific wear rate of 7.961 × 10−7 mm3/N.m occurred in sample CG-6. As a result, 15.92%, 58.16% and 83.21% improvements were achieved in hardness, bending strength and wear performance, respectively. The current work indicates that certain mechanical properties of copper can be improved via the powder metallurgy process and the addition of reinforcements which could expand the applications and use of this metal in different industries. [ABSTRACT FROM AUTHOR]

The tribological behavior of titanium dioxide (TiO2) filled with jute fiber reinforced interpenetrating polymer networks (IPNs) were studied by using a pin-on-disc wear test rig at dry slide conditions. During the study, 70 wt.% of epoxy and 30 wt.% of polyurethane have been chosen as the base matrix material. As well, various proportionate of titanium dioxide such as 0%, 3% and 5% have been utilized to fabricate the particulate reinforced IPN laminate. To do the wear analysis such as materials type (A), sliding speed (B) and applied loads (C) were kept as the influencing parameters whereas coefficient of friction (COF) and specific wear rate (SWR) have been seen as the outcome of the entire study. Taguchi technique was chosen to plan the entire experiments. Similarly, an orthogonal array and analysis of variance (ANOVA) was employed to examine the impact of process parameters on wear of the IPN laminate. Out of all, results show that, addition of particulate materials into the composite predominately increased the specific wear resistance of the IPN laminate significantly. [ABSTRACT FROM AUTHOR]

Featured Application: This article deals with a method for directly determining the volume loss during a pin-on-disc test. The results can provide a reliable basis for an in-depth study of the performance of prosthetic joints, including a tribo-pair consisting of a Ti6Al4V pin produced by EBM and a UHMWPE sheet. Debris formation is a crucial aspect that determines the lifespan of prosthetic joints. The wearing contact between ultra-high molecular weight polyethylene (UHMWPE) and a Ti alloy surface has been studied in the literature. However, when measuring mass loss, potential errors can arise due to the very small values involved (on the order of some units of 0.1 mg in experiments lasting several hours) and be caused by the absorption of humidity in the specimen, in addition to the lack of accuracy typical of weight scales. These errors can hardly be avoided, but accurate cleaning and drying processes can minimize them. With these premises, the present work aims to determine, by pin-on-disc test, the wear effect in the UHMWPE rotating sheet and Ti6Al4V pin produced by Electron Beam Melting (EBM) under dry and lubricated conditions. The morphology of the worn surface was documented by optical microscopy, and the volume loss of both the rotating specimens and the pin was accurately calculated through the detection of the wear track observed by optical microscopy. In particular, the present work proposes a method for directly determining the volume loss of the polymer to compare it with that obtained with the weight measurement. For both procedures, the uncertainty in evaluating the specific wear rate was analyzed, demonstrating that volume measurement allows for avoiding any possible error associated with weighing the polymeric specimens. [ABSTRACT FROM AUTHOR]

To enhance the friction performance of resin‐based friction materials, five types of specimens with different polymer ether ketone (PEEK) contents were fabricated and their physiomechanical behaviours were tested and, their tribological properties were investigated using a JF150F‐II constant‐speed tester. It was found that the addition of PEEK had a positive influence on the properties of the friction materials, and sample FM‐3 (the shorthand of 'Friction Materials‐3', containing 2 wt% PEEK) exhibited improved friction performance with a fade ratio and recovery ratio of 8.6% and 101.1% respectively. Among all samples, FM‐4 (the shorthand of 'Friction Materials‐4', containing 3 wt% PEEK) had the lowest specific wear rate with a value of 0.622 × 10−7 cm3 (N·m)−1 at 350°C. The PEEK can fill the microcracks in the composite at a high temperature and can also cover the hard abrasive particles to prevent them from directly damaging the composite. The findings from this study afford a foundation for studies to further improve the properties of resin‐based friction materials. [ABSTRACT FROM AUTHOR]

The effect of tungsten, aluminum, and cobalt on the mechanical properties of iron-based composites prepared by powder technology was studied. Five samples with different contents of tungsten, aluminum, and cobalt were established. The five samples have the following chemical compositions: (I) full iron sample, (II) 5wt.% tungsten, (III) 5wt.% tungsten-4wt.% cobalt-1wt.% aluminum, (IV) 5wt.% tungsten-2.5wt.% cobalt-2.5wt.% aluminum, and (V) 5wt.% tungsten-1wt.% cobalt-4wt.% aluminum. The mixed composite powders were prepared by mechanical milling, in which 10:1 ball to powder ratio with 350 rpm for 20 h was cold compacted by a diaxial press under 80 bars, then sintered at temperatures ranging from 1050 °C to 1250 °C in an argon furnace. The samples were characterized mechanically and physically using XRD, SEM, a density measuring device, a hardness measuring device, a compression test device, and a tribological device for wear and friction tests. XRD results refer to the formation of different intermetallic compounds such as Fe7W6, Al5Co2, Fe2W2Co and Co7W6 with the main peaks of Fe. The good combination of tribological and mechanical properties was recorded for sample number five, which contained 5% W, 4% Al, 1% Co and Fe base, where it obtained the highest wear resistance, largest hardness, acceptable compressive strength, and lowest friction coefficient due to the good combination of hard and anti-friction intermetallic action compared with the other samples. This sample is a good candidate for applications which require high wear resistance and a moderate friction coefficient accompanied with high toughness, like bearing materials for both static and dynamic loading with superior mechanical and tribological properties. [ABSTRACT FROM AUTHOR]

When creating polymer-based composites, plain weave fabrics and micron-sized fillers offer bidirectional strength and reduced voids/inhomogeneity. In the present work, It was investigated how glass fabric reinforced epoxy composite (G-E) performed during threebody abrasive wear with and without ceramic fillers (SiO2, Al2O3, graphite, and fly ash cenospheres). In experiments, loads of 20 N and 40 N were applied at various abrading distances of 500 m, 1000 m, 1500 m, and 2000 m. According to the results of sand abrasive wear test, the specific wear rates of G-E based composites are sensitive to fibre and filler/matrix adhesion. Under all tribo-test settings, the SWR for all particulate G-E composites decreases in the following order: G-E > Gr/G-E > SiO2/G-E > Al2O3/G-E > fly ash cenosphere/G-E. Furthermore, the specific wear rate of the fly ash cenosphere filled G-E composites were found to be lower than the G-E and other filler materials filled G-E composites. There was 38.7% reduction in the specific wear rate at 40 N, 2000 m in fly ash cenosphere filled G-E composite. As per the evidence of scanning electron microscope images of worn-out surfaces, mechanisms such as ploughing, fibre breakage, fibre pull-out, fibre thinning, and a network of microcracks caused the wear in composites. [ABSTRACT FROM AUTHOR]

Ni-Cr-B-Si hardface coating plays an important role in the mating components of nuclear power plants. Obtaining a crack-free coating with low dilution and optimum hardness is essential for reactor applications. In general, it is difficult to achieve this through conventional high heat input processes. In this work, Ni-Cr-B-Si hardface coating was successfully developed on 316LN stainless steel substrate by Cold Metal Transfer (CMT) welding process using metal-cored filler wire. Moreover, for comparative analysis, Ni-Cr-B-Si hardface coating was deposited using Plasma Transferred Arc (PTA) process. The obtained coatings were characterised for their microstructure, hardness, and wear behaviour. Results revealed higher hardness and lower specific wear rate of hardface coating made by the CMT process compared to the coating made by the PTA process. The superior behaviour of the CMT coating obtained may be due to its low dilution compared to the coating made using the PTA process. Confocal microscopy on the worn pins revealed abrasive and adhesive wear as a dominant mechanism in the CMT and PTA coatings, respectively. This study concluded that CMT could be used as an alternate potential process for depositing a crack-free hardface coating with superior wear behaviour. [ABSTRACT FROM AUTHOR]

In the modern day, natural fiber-reinforced composites are becoming one of the most appealing materials for research. Vachellia farnesiana fibers were chosen for this study and extracted manually using a retting process. Chemically, the resulting fiber was treated with sodium hydroxide (NaOH) solutions and then crushed and reinforced in epoxy matrix. The hand layup procedure was used to create a composite containing 0, 3, 6 and 9% NaOH-treated Vachellia farnesiana (NVF). Two-body abrasive wear characteristics were studied for the manufactured NVF composites. Material, load (N) and sliding distance (m) were used as input factors, while coefficient of friction (COF) and specific wear rate (SWR) were analyzed as output features. ANOVA was used for evaluating the input characteristics over the output characteristics which revealed that applied load (42.70%) was the dominant factor for SWR and for COF material was the dominant factor (59.89%). The wear mechanisms were studied using worn surface morphology which revealed that the addition of fillers resulted in increased wear resistance. Finally, using the additive ratio assessment approach, the result was optimized. From the output of ARAS method, it was found that the 9 wt.% material, 20N load and 100 m sliding distance have better wear resistance. [ABSTRACT FROM AUTHOR]

The natural fiber composites are emerging as replacement materials in wide engineering fields. In this work, banana, sisal, and banana-sisal fibers of three different fiber lengths namely 3 mm, 5 mm, and 7 mm are used as reinforcements in the epoxy matrix. The composite samples are prepared by using the injection molding technique. Frictional and wear characteristics of the composites are evaluated under dry operating conditions with the parameters like applied load (15–35 N), sliding speed (300–500 rpm) for a duration of 15 mins. Water absorption characteristics are studied at an interval of 6 days for a duration of 120 days. The results indicate that the incorporation of fibers at different lengths influences frictional force, coefficient of friction and specific wear rate of the composites to an extent. Frictional force and specific wear rate are greater at higher loads. Banana-sisal hybrid fiber composites are showing amplified coefficient of friction and specific wear rate than other composites. Composites made of Sisal fibers (12.4%) are showing more resistance to water absorption than banana (21.5%) and banana-Sisal (15.4%) fibers. SEM images explores the wear characteristics of testing surface with presence of micro cutting, fiber breakage, voids, and debris. [ABSTRACT FROM AUTHOR]

This article aims at exploring the dry sliding wear performances on the aluminum (AA7075) metal matrix composites reinforced with molybdenum disulfide, which is a solid lubricant using response surface methodology (RSM). Specific Wear Rate (SWR) for the AA7075 pure alloy, AA7075+2wt% molybdenum disulfide, and AA7075+4wt% molybdenum disulfide were measured according to ASTM G99 standards in pin-on-disc apparatus. Design of experiments was selected with changed parameters like the varying percentage of molybdenum disulfide (%), applied load (N), and sliding velocity (m/s) based on Central Composite Design in response surface methodology, considering them as continuous factors. Experiments for the specific wear rate of pure alloy and the composites were conducted. The volume loss was measured using the pin-on-disc apparatus from which the specific wear rate value was calculated. The obtained results are analyzed, and a mathematical model was formulated using the response surface methodology. The optimum level parameters for the specific wear rate have been identified, and the results of the experiment specify that the sliding velocity and molybdenum disulfide percentage have a substantial role in controlling the wear behavior of composites when compared with the other parameter. The optimum condition for the specific wear rate was identified and experimented with for studying the result. [ABSTRACT FROM AUTHOR]

This work studies the friction and the sliding wear behaviour of surface treated SAE 4140 steel. The performance of ion nitriding and PVD TiN coatings applied by means of industrial processes as single or duplex treatments was evaluated. Although the deposited TiN coatings (0.7 µm thick) resulted thinner than most of the typically employed for sliding situations, the present work shows that they can provide very good protection. The use of ion nitriding as a pretreatment proved to be beneficial when combined with such a thin coating. However, in the pin on disc sliding tests the coated discs developed the highest friction coefficients and boosted the damage in the steel pins. [ABSTRACT FROM AUTHOR]

Bronze metal matrix composites (MMCs) are futuristic materials that may find applications in automobile, aviation, and marine industries, specifically for propellers in submarines, bearings, and bushings for defence purposes. The present investigation studied the effect of Si3N4 (5, 10, 15 wt%) ceramic particles on the physical, metallurgical, and tribological behaviour of Cu-10Sn/Si3N4 MMCs. Cast rods of three composites and a base alloy were fabricated using the liquid metallurgy route. The microstructural characterisation for the cast samples was conducted using FESEM (Field Emission Scanning Electron Microscope), EDS (Energy Dispersive Spectroscopy), XRD (X-ray diffraction), and TEM (Transmission Electron Microscope), which revealed that the Cu-10Sn alloy reinforced with 5 wt% of Si3N4 had homogeneous distribution and perfect bonding of the Si3N4 with the bronze MMC. The dry sliding wear test was performed by varying parameters such as the applied load (10, 20, 30 N) and sliding velocity (1, 2, 3 m/s). The specific wear rate (SWR) increased against an increased load. However, the SWR and coefficient of friction decreased and then increased against an increasing sliding velocity due to tribolayer formation. The primary wear mechanism observed at low and high loads was severe delamination. In contrast, the wear mechanism was adhesion wear at high and low velocities. Amongst the researched samples, Cu-10Sn/5 wt% Si3N4 composites revealed the least SWR at a load of 10 N and sliding velocity of 2 m/s and hence can be recommended for manufacturing bearings and bushings in the automobile and defence industry. [ABSTRACT FROM AUTHOR]

The introduction of external surface features on mating contact surfaces is an effective method to reduce friction and wear between the contact surfaces. The tribological properties of the contact surfaces can be improved by controlling the geometrical parameters (shape, size, depth) of the surface texture effectively. In the present study, the tribological properties of Al6061-T6 cylindrical workpieces with various micro-dimple-texture geometries and an AISI 52100 steel stationery block are tested experimentally, in a rotating cylinder-on-pin configuration of the friction test. The dual-frequency surface texturing method is employed to create micro-dimple textures using a polycrystalline diamond tool. The effect of a hierarchical micro-dimple texture is then investigated under boundary lubrication conditions. Hierarchical micro-dimples, with an increase in length, show a lower friction coefficient under high load and sliding speed conditions. Secondary hierarchical nano-structures help in improving the tribological characteristics by generating an additional hydrodynamic lift effect. [ABSTRACT FROM AUTHOR]