Pin-on Disc Research Articles

Wear studies on friction stir processed surface modified AZ61 magnesium alloy with nano titanium oxide

ABSTRACT Surface modification of magnesium alloy enables the improvement of wear characteristics for use in sliding applications and places where surface hardness improvement is essential without affecting the microstructure of the underneath material. In this study, a pin-on disc wear test was used to examine the dry sliding wear behaviour of AZ61 Mg alloy reinforced with nTiO2 by a recursive friction stir processing technique. The trio-behavior of the surface-modified Mg alloy was detailed by the response surface methodology-central composite design matrix with the use of design experiments, considering three levels of reinforcement (%), sliding speed, and axial load parameters. In order to achieve the desired results of minimal wear loss, lower friction coefficient (COF), and lower friction force between surfaces (FF), this present work employed design expert software to develop a generative mathematical model to optimize the process parameters. Wear mechanisms were investigated using images captured by scanning electron microscope.

Synergistic approach to wear rate forecasting in AZ31/5% Yttria stabilized zirconia reinforced composite through response surface methodology-genetic algorithm integration

In this work, the wear behavior of a novel AZ31 magnesium alloy reinforced with 5% yttria-stabilized zirconia (YSZ) composite was evaluated using a hybrid Response Surface Methodology (RSM) and Genetic Algorithm (GA) approach. The composite was fabricated using ultrasonic-assisted stir squeeze casting technique, ensuring homogeneous distribution of spherical YSZ particles, as validated by the scanning electron microscope integrated with energy dispersive spectroscope. Wear tests were carried out according to the ASTM standards using a pin-on-disc (POD) tribometer, with applied load (AL), sliding speed (SS), and sliding distance (SD) as the main parameters. An empirical wear rate regression model was developed using RSM/Box-behnken design, and Genetic Algorithm was deployed for parametric optimization, achieving a minimal wear rate of 0.0144 g/m under a load of 30 N, sliding speed of 260 rpm, and sliding distance of 400 m. Confirmation tests were performed to validate the GA predictions. The wear mechanisms were observed, showing reduced wear in GA-optimized samples due to optimized load distribution resulting minimized ploughing, grooving and delamination. This work highlights the efficacy of the hybridized RSM / GA for the wear performance in advanced magnesium alloy matrix composites.

Pin-on-disc tribological characterization of single ingredients used in a brake pad friction material

Researchers have long been studying the effects of the modification of friction material compositions on their tribological properties. Predictive models have also been developed, but they are of limited use in the design of new compositions. Therefore, this research aims to investigate the tribological behaviour of single ingredients in friction materials to develop a tribological dataset. This dataset could then be used as a foundation for a cellular automaton (CA) predictive model, intended to be a tool for designing friction materials. Tribological samples were almost entirely composed of four distinct friction material ingredients, and one sample composed of their mixture was successfully produced. Pin-on-disc (PoD) tribometer testing and scanning electron microscopy/energy-dispersive X-ray spectroscopy (SEM/EDXS) analysis were used for the tribological characterization. Each material showed distinct tribological properties and evolution of the contact surface features, and the synergistic effect of their mutual interaction was also demonstrated by their mixture.

Enhancing Tribological Characteristics of Titanium Grade-5 Alloy through HVOF Thermal-Sprayed WC-Co Nano Coatings by TOPSIS and Golden Jack Optimization Algorithm.

Thermal spray coatings have emerged as a pivotal technology in materials engineering, primarily for augmenting the characteristics related to wear and tribology of metallic substrates. This study aimes to delve into applying High-Velocity Oxygen Fuel (HVOF) thermalsprayed WC-Co nanocoatings on Titanium Grade-5 alloy (Ti64). The coating process, utilizing nano-sized WC-Co powder, undergoes systematic optimization of HVOF parameters, encompassing the flow rate of carrier gas, powder feed rate, and nozzle distance. Experimental assessments via Pin-on-Disc (PoD) tests encompass Loss of Wear (WL), Friction Coefficient (CoF), and Frictional Force (FF). Later, an exhaustive optimization of responses is conductede using the Technique for Order Preference by Similarity to the Ideal Solution (TOPSIS) method and the golden jack optimization algorithm (GJOA). Outcomes show a substantial increase in WL, CoF, and FF with a rise in the carrier gas and powder feed rate. However, with increasing spraying distance of powder, the WL, CoF, and FF tend to lower due to higher bonding, which leads to increased wear resistance. The ideal parametric settings achieved from TOPSIS and GJOA are 245 mm of spray distance, 30 gpm rate of powder feed, and 11 lpm of carrier gas flow rate. The powder feed rate contributes 88.99% to the control action, as seen from ANOVA. The confirmation experiment presents that the WL, CoF, and FF output responses are 42.33, 27.97, and 9.38% less than the mean of experimental data. These results highlight the HVOF process in spraying WC-Co nanocoatings to fortify the durability and performance of Ti64 alloy that can be patented for diverse engineering applications.

A comparative analysis of the tribological performance of coir, bamboo and wood filler reinforced polymer composites

Abstract Researchers and academics are increasingly favoring natural fibres for incorporation into polymer composites on account of their ecological compatibility and longevity. The aim of this comparative study is to identify the optimal natural filler by AHP-TOPSIS approach by analyzing the tribological performance of three distinct natural fillers: coir, bamboo, and wood reinforced polymer composite. These filler materials are pre-treated by alkali treatment to increase the interlinking properties between filler and polymer. The outcome of these treatments on the composites’ physical and mechanical properties are investigated. Using a Pin-on-disk (POD) machine under dry, wet, and heated sliding contact conditions, different natural fillers’ effects on polymer wear and friction are examined. The wear rate and coefficient of friction (COF) were quantified as a function of the sliding distance (0–2000 m) under various normal loads (5–40 N). It was observed from the different experimental results that coir filler reinforced composite shows best wear resistance property whereas wood filler reinforced composite shows the least wear resistance composite. Results revealed that lower filler support and low load show better wear resistant property compared to the higher filler support and high load condition. When seen through a microscope, the worn surfaces of the composite material exhibit micro and macro fissures, as well as debonding and plastic deformation. The coir filler-based composite was found to be the best alternative using the AHP-TOPSIS method, with a closeness coefficient of 0.770023.

Tribological behaviours of Si3N4-hBN composites /2507 stainless steel sliding pair in electroplating wastewater

In the wastewater treatment device, the core moving parts (such as the check valve in the pump body) are prone to failure due to wear and corrosion. There is an urgent need to develop high-performance self-lubricating materials suitable for moving components in electroplating wastewater. Therein, the tribological properties of Si3N4 (silicon nitride) based composites with the addition of hBN (hexagonal boron nitride) against 2507 duplex stainless steel in electroplating wastewater were investigated using a Pin-On-Disc (POD) tribometer. The results show that the addition of hBN to the ceramic matrix could effectively improve the tribological properties of Si3N4 materials. The friction coefficient and wear rate of Si3N4 are lowered to 0.14 when the hBN content reaches 30 wt%, which is attributed to the formation of a lubricating films (containing hBN, Si(OH)4 and Cu and its oxides) on the worn surfaces. A segmental test results indicate that the lubricating film undergoes processes such as formation, spalling, and regeneration during the friction process. Meanwhile, hBN and Si(OH)4, due to their inherent structural characteristics, can lubricate and protect the worn surfaces. The molecular dynamics simulation results indicate that Cu and its oxides are prone to slip under normal and transverse forces, and have a positive effect on reducing friction.

Exploring tribological properties in the design and manufacturing of metal matrix composites: an investigation into the AL6061-SiC-fly ASH alloy fabricated via stir casting process

This study investigates a novel methodology to intricately craft a HAMMC and thoroughly examine its multifaceted mechanical and tribological characteristics. By combining silicon carbide (SiC) and fly ash as reinforcements, a unique identity is bestowed upon this hybrid composite, enhancing its structural integrity and functional attributes. Stir casting is the chosen methodology for fabricating this composite, favored for its economic viability and suitability for large-scale manufacturing. In this research, the emphasis is on developing a cost-effective composite that not only meets stringent economic considerations but also exhibits improved material properties. Within the realm of hybrid metal matrix composites, the well-regarded Al6061 takes on the role of the matrix material, while the synergistic inclusion of fly ash and SiC serves as reinforcing constituents. Three specimens with compostion 90% Al6061 + 5% SiC +5% Fly ash, 90% Al6061 + 10% SiC +6% Fly ash and 90% Al6061 + 15% SiC +7% Fly ash were fabricated. To unravel the intricacies of the fabricated Al6061 metal matrix composite, comprehensive tests are employed. These tests, including the Pin-on Disc test, Scratch test, Rockwell Hardness test, and Charpy Impact test, collectively work to unveil the nuanced tribological and mechanical behaviors encapsulated within this innovative alloy. The results indicated significant improvement in wear resistance in specimen comprising 78% Al6061 + 15% SiC +7% Fly Ash and volumetric loss found to have 0.96 g. Superior hardness characteristics and enhanced abrasion resistance found in 78% Al6061 + 15% SiC +7% Fly Ash than other two specimens. The highest impact strength exhibited in 90% Al 6,061 + 5% SiC +5% Fly ash specimen.

Investigation of wettability and wear properties on 3D printed Polylactic acid/Molybdenum disulfide-Silicon carbide polymeric composite for sustainable biomedical applications

In the present work, investigations of the wettability, wear, and morphological study on 3D-printed polylactic acid (PLA)/molybdenum disulfide (MoS2)-silicon carbide (SiC) based composite have been performed. In the first stage, the PLA/MoS2-SiC composite was fabricated from the different types of filaments of 1.75 ± 0.10 mm size by taking MoS2-SiC as reinforcement at various extrusion temperatures (150°C–160°C) and screw rotational speed (3–7 r/min) of the extruder setup. The Taguchi L9 orthogonal array was used to design the experiments for 3D printing by varying the filament type, range of nozzle temperature (200°C–210°C), and infill density (40%–90%). The pin-on-disk (POD) setup was used for measuring specific wear rate (SWR) and showed the lowest value of 0.00141 g/N-m when composites were 3D printed by taking filaments manufactured at the parametric combination of 160°C extruder temperature and 7 r/min rotational speed, while 3D printed at 210°C nozzle temperature and 40% infill density. Contact angle (CA) values indicated that the reinforcement of MoS2 and SiC in PLA resulted in hydrophilic surface formation due to morphology and increased roughness (including mean roughness (Sa), mean root square of the Z data (Sq), and the highest peak (Sz)). The significantly increased surface free energy (SFE) of MoS2-SiC-reinforced PLA composite compared to pure PLA was reported which makes the prepared composite a promising candidate to be used for biocompatible implants with high wear resistance.

Optimization of tribological characteristics in cryo-treated plastic/graphene oxide modified CFRP via ANN-based predictive modeling for aerospace applications

Carbon fiber reinforced polymers (CFRP) were modified with polycarbonate (PC)/acrylic butadiene styrene (ABS), and silanized graphene oxide deposited (using electrophoretic deposition) carbon fibers. Using Pin-on-Disc (POD) experiment, the wear rate (WR) and coefficient of friction (COF) of modified CFRP samples were determined for room-temperature (RT) and cryo-treated (CT) conditions. For RT samples, the largest reduction in COF compared to NEAT samples was for SGO samples by 25.6%, while the largest reduction in WR was for PC/ABS samples at 42.1%. But for CT samples, the maximum reduction in COF was 32.6% by SGO, and PC/ABS achieved the maximum reduction in WR by 41%. Also, Analysis of Variance (ANOVA) found “sample composition” to be the most critical component for volume loss mean, whereas Taguchi analysis refined the parameters and achieved the desired outcome. To predict wear behaviour, the Levenberg-Marquardt algorithm, artificial neural network, and linear regression were used. Based on mean squared error (MSE) loss, the Matlab-based Neural Network method performed best, with 0.35% MSE for RT samples and 0.88% for CT samples. This work helps to understand and enhance CFRP materials for wear-resistant applications using optimization techniques.

Investigation of mechanical and tribological performance of wood dust reinforced epoxy composite under dry, wet and heated contact condition

Abstract Natural fibers have received a lot of attention from academia as well as industry in the context of sustainable materials. Since they are more environmentally friendly than traditional synthetic materials, their physico-mechanical and frictional properties such as porosity, moisture absorption, high strength, modulus, toughness, and wear resistivity make them appropriate for a variety of industrialized applications where issues involving a significant quantity of dumping must be taken into account. The paper introduces an attempt to use epoxy-based composites reinforced with wood dust for various applications. The composites are prepared with various wood filler stacks (0, 2.5, 5, 7.5, 10, and 12.5 wt%) embedded with epoxy resin and subjected to tensile and flexural testing. The highest ultimate tensile strength achieved at 7.5 wt% wood dust support is 22 MPa, whereas the highest flexural modulus is 0.48 GPa at 12.5 wt% composites. The composite’s wear properties is examined under dry, wet, and heated contact conditions using a pin-on-disk (POD) machine. In dry condition, coefficient of friction (COF) varies from 0.10 to 0.38 whereas, in wet condition, the value of COF decreased by 70–83 %. In heated state, the COF is increased by up to 15 % when varying the temperature from 40 °C to 80 °C. The composite exhibits better wear behavior in the lower filler support than in the higher filler support due to the sturdy connection between the matrix and filler. On the other hand, the wet state’s tribological performance is superior to the dry and heated states. During surface morphology analysis, it is found that various voids, crack formation, wear debris, and thin transfer layer formation take place on the composite.

Experimental tribological and mechanical behavior of aluminium alloy 6061 composites incorporated ceramic particulates using Taguchi analysis

Aluminium metal-matrix composites are broadly employed in industries like aerospace, marine, automobile-sector, and many others, generating a broad research interest. They are preferred for their high strength and low wear rate. This research work is mainly directed towards the fabrication of two types of metal-matrix composite materials using aluminium-alloy 6061(AA6061) as the matrix material and incorporating aluminium oxide (Al2O3), aluminium nitride (AlN), and silicon carbide (SiC) as a reinforcement material. AA6061 has been reinforced with Al2O3 and SiC particulates in AS series composites, while AA series composites, AA6061 has been reinforced with Al2O3 and AlN particulates. This hybrid metal composite was constructed using the stir-casting method. These hybrid composites have been investigated for their physical and mechanical characteristics, viz. density, hardness, impact strength, void content, flexural strength, and tensile strength following the ASTM standards. Tribological characteristics of these hybrid composites were performed by Pin-on-disc (POD) tribometer. Taguchi’s design of experimental technique was applied taking four factors viz. composition, sliding-velocity (SV), sliding-distance (SD), and load, and each having 4 levels. ANOVA was employed to find out meaningful parameters. SEM analysis of worn-surface was executed to find out the dominant wear mechanism. Experimental density was highest for AS42, and AA42 composites and void content were lowest for the same. Mechanical properties viz. density, hardness, impact strength, void content, flexural strength, and tensile strength were higher than the base alloy. From the response table of Taguchi analysis of AS and AA composite, the load factor significantly impacted the specific wear rate (SWR) to follow filler content (FC). It can be followed from the ANOVA table for AS composite that the load factor had a magnificent impact on the SWR. The SV and SD show no significant effect on SWR.

Investigation of tempered AISI 420 SS under dry slided conditions for sustainable applications

Martensitic stainless steel exhibits a lower corrosion resistance, higher hardness, wear resistance, and strength, but no ductility. As a result, tempering techniques have been used to stabilise the ductility. AISI 420 stainless were chosen and prepared in cylindrical shape for a dimension of 35 mm length, 10 mm diameter. The specimens were tempered to 245°C, 345°C, 445°C temperatures respectively and termed as T1, T2 and T3. The material which is not treated is kept on the other side for results comparison. Testing of hardness was taken up by Rockwell method. Wear tests were carried out for all the specimens using pin-on disc wear analyser. The changes in microstructure were distinguished with all the samples and were captured by electron microscopic techniques. The goal of the test is to determine, the best treated specimen suited for a particular application. It was noted that, phase change from martensite stage to residual austenite is determined.

Investigation of microstructural, mechanical and tribological properties of NiTi/nB4C metal matrix composites produced by spark plasma sintering

In this paper, it was aimed to improve the microstructure, mechanical and tribological properties of composite samples according to the alloy by adding 0.25%, 0.5% and 1% nano B4C to NiTi shape memory alloy. A 3D ball mixer device was used to prepare composite powders and the samples were produced by Spark Plasma Sintering technique. FE-SEM/EDS and XRD were used for microstructure and phase characterization, nanoindentation to determine mechanical properties, and pin-on disc wear device to determine wear properties. It was determined that with the increase in the reinforcement ratio added to the NiTi alloy, nB4C ceramic particles settled at the grain boundaries and the hardness value of the 1% nB4C (334 HV) sample with the highest hardness increased significantly by 30% unreinforced NiTi alloy (264 HV).

Wear assessment on AISI 410 steel by tempering process for constant load and speed sustainable applications

Stainless steels are readily available and inexpensively priced on the market. The reasonable corrosion resistance of AISI 410 martensitic stainless steel has made it a popular choice. Although it is not very ductile, AISI 410 martensitic stainless steel is very strong, robust, and resistant to wear. Due to their exceptional hardness and resistance to wear, martensitic stainless steels were favored for certain limited applications. Therefore tempering was chosen to improve the ductility by keeping stability in brittleness and hardness. The samples were underwent with tempering at 230°C, 430°C, 630°C and designated as T1, T2,T3 respectively. The samples were made cylindrical in shape with 12 mm diameter, length of 42 mm. A pin-on disc wear test instrument was used to assess the material's resistance to wear for all the samples. A sample that has not been treated is set aside for results comparison. All the samples were undergone with hardness measurement and Scanning electron microscope to examine the microstructure and the resulting data were compared.

Effect of e-waste nanofillers on the mechanical, thermal, and wear properties of epoxy-blend sisal woven fiber-reinforced composites

Abstract Lignocellulosic biomass extracted from plants that contain rich amounts of cellulose, hemicellulose, and lignin content can replace synthetic fibers in many engineering applications and is biodegradable. However, e-waste is rapidly evolving into one of the most serious environmental issues in the world owing to the presence of several toxic compounds that can contaminate the environment and pose a threat to human health. Printed circuit boards (PCBs) are one of the major components available in e-waste. In this research work, waste PCB (WPCB) powder is mixed in suitable proportions of 5%, 10%, 15%, and 20% with a lignocellulosic sisal woven fabric fiber mat, and blended with epoxy resin using the vacuum-assisted hand lay-up method. To determine the effect of particle size on the fabricated composites, mechanical, thermal, water absorption, surface roughness, and wear tests were conducted. It was found that the composition that contains 15% nanofiller composites gave better results in mechanical testing than the composition that contains 10% microfiller composites. Pin-on disc wear test and differential scanning calorimetric thermal test results show that 10% microfiller composites show better outcome results than 15% nanofiller composites. Testing values indicate that lignocellulosic sisal fiber composites with WPCB nano- and microfillers can be substituted for many engineering applications instead of being disposed of in landfills.

Wear Characteristics of AZ91D Magnesium Alloy under Dry Sliding Condition against Hardened Alloy EN31 Steel Disc

Magnesium alloys are very interesting materials used for engineering applications such as automotive, and aerospace industries. Wear is a degradation of material from surface of the workpiece when it is subjected to sliding motion. Also, coefficient of friction is important factor which affects the rate of wear and application of engineering materials. Wear and friction are important characteristics for making the mechanical components subjected to sliding motion. Hence study of wear and friction phenomenon of engineering materials like magnesium alloy is necessary. In this article tribological characteristics of magnesium alloy AZ91D against hardened alloy EN31 steel as counter disc has been studied. The pin-on-disc (POD) wear and friction test had been used for the analysis of failure of materials under sliding motion. The wear test was performed on 10N, 20N, 30N, and 40 N loads with sliding velocities of 0.42m/s, 0.52m/s, 0.63m/s and 0.73m/s. The effect of the sliding distance and the normal load on the wear rate, wear depth and the coefficient of friction has been investigated. The main wear mechanism was found to be plastic deformation and thermal softening.

Estimation of brake pad wear and remaining useful life from fused sensor system, statistical data processing, and passenger car longitudinal dynamics

The problem of estimating brake pad wear of cars has been considered, using friction work approximated from the product of longitudinal braking force and distance travelled during braking. The braking force is estimated from a longitudinal dynamics model with inputs from an inertial measurement sensing unit with Kalman filter based sensor fusion, and standard vehicle on-board diagnostics data. Wear coefficients are fitted with Bayesian linear regression on measurements from two series: (I) 16 measurements of previously worn pads over approx. 4,800 km with average wear of approx. -0.5 mm and (II) seven measurements of almost new pads over approx. 1,850 km and approx. -0.15 mm of wear. The approximated friction work appears to correlate well with the wear. The wear coefficients converge quickly after just 4-5 measurements. Coefficients ranging from −4.95⋅10−5mm3/J to −2.08⋅10−5mm3/J are obtained across the cases, when assuming a coefficient of friction μ=0.6 obtained through pin-on-disc (POD) tests. The wear coefficients are validated using POD tests, showing good agreements with the indirectly estimated wear coefficients from vehicle longitudinal dynamics. Data from series (II) is used for prediction of remaining useful life (RUL), where one additional measurement is carried out after 16,552 km. The RUL prediction requires knowledge of the relationship between usage feature and distance travelled. Different approaches are investigated for the predictions: wear based on only distance travelled, linear relationship between usage feature and distance, and three levels of braking severity based on the usage data. Four of the approaches underestimate the distance significantly at around 4,000 to 8,000 km against the actual distance of 16,552 km, while the low severity estimate is closest at 20,460 km, agreeing with expectations due to the driving being primarily on highways.

Study on the Tribological Characteristics of AA5010/Fly Ash/ Boron Carbide Metal Matrix Composites using Response Surface Methodology

In this study, a metal matrix composite (MMC) made from an AA 5010 base alloy with reinforcements of fly ash (FA) and Boron carbide (B4C) was tested for its wear and frictional behavior using a stir casting technique. Fly ash of 3, 6, 9, and 12 wt. % and 3, 6, 9, and 12 wt. % of B4C reinforcements were used to accomplish the goal. The mechanical characteristics acquired at 12 wt. % of FA and B4C were determined upon first through the use of mechanical experiments. The tribology characteristics of the composite were evaluated through a pin-on-disc (POD) device in dry circumstances after being manufactured using 12 wt. % FA and B4C reinforcements. The effects of distance (1200 m, 2400 m, and 3600 m), speed (2, 4, 6 m/s), and applied load (15, 25, and 35 N) on the wear parameters of dry sliding were studied. Experiments and determining the best wear parameters can be done reasonably and accurately using a response surface methodology (RSM). The RSM was also useful in determining the most influential factor, which turned out to be the rate of wear. Finally, it was determined that the load being applied is the single most important element in determining the rate of wear. It was that the performance indicator is less sensitive to changes in sliding velocity and sliding distance.

Wear Behaviour of Additive Manufactured Aluminium Alloy ER 5356

In the automotive industry, parts are mostly made from aluminium alloy due to its lightweight properties and high corrosion resistance. However, the drawback is that the aluminium alloy is easily worn due to wear and friction and will end up in the scrap yard. In order to salvage the aluminium component, the worn part can be repaired. Currently, wire arc additive manufacturing (WAAM) offers flexible remanufacturing of the worn part. However, the wear behaviour of the additively manufactured part needs to be studied first to improve the wear performance of the material. In this study, the gas metal arc welding (GMAW) or MIG-based WAAM machine was utilised to produce a 3D profile from the available aluminium alloy wire grade ER 5356. The wear test was carried out in accordance with ASTM G-99, using a pin-on disc in both dry and wet sliding conditions. It was found that on dry sliding, the specific wear rates are decreasing from 5.3632 x 10-11 mm3/Nm to 4.3496 x 10-11 mm3/Nm and 4.1513 x 10-11 mm3/Nm as the speed increases from 200 to 400 RPM at the constant 20 N load. Meanwhile, for wet sliding, it has been observed that the specific wear rate increases as similar speed values are used in dry sliding conditions, which are 6.8122 x 10-12 mm3/Nm, 1.1931 x 10-11 mm3/Nm and 3.7561 x 10-11 mm3/Nm with a similar constant 20 N load. Next, the coefficient of friction for dry sliding shows that as the speed decreases. In contrast, for wet sliding, it is observed that the coefficient of friction increases.

Triboinformatic Modeling of Wear in Total Knee Replacement Implants Using Machine Learning Algorithms

Pin-on-disk (PoD) tests, the most prevalent studies, are being carried out in order to evaluate tribological behaviour of different bearing materials. However, the comparison of results obtained from the PoD tests is very difficult. In this present study, several machine learning models were developed and trained and then these trained machine learning models were validated by quantifying forecasting error against the experimental data reported in literature. These machine learning based models can be utilized as alternative solution of PoD trials in order to minimize time consumption and experiment complexity.