Wear Rate Values Research Articles

Influence of the alloying elements on the tribological performance of DLC coatings in different sliding conditions

Reduction of friction and wear at the sliding surfaces are the main concern in several applications. From an extensive list of low friction hard coatings, DLC type is one of the most studied and develop for achieving low wear and friction. The addition of an alloying element is extensively used, since it can change significantly the coatings performance. Therefore, in this research the tribological behaviour of DLC coatings alloyed with different elements was evaluated, since no works comparing the tribological properties of DLC films with approximately the same alloying elements concentration are reported in the literature. The coatings were deposited by physical vapor deposition and alloyed with: tungsten (W), silver (Ag), silicon (Si), silicon and oxygen (SiO), with concentrations of metallic elements between 10 and 15 at. % and a pure DLC coating was also deposited for comparison purposes. The coatings hardness varied between 23 GPa for the pure DLC and 11 GPa for the alloyed with Si and O. The tribological behaviour of the coatings was evaluated by pin-on-disk against 10 mm 100Cr6 steel balls, at room temperature (RT) and 100 °C. The best wear resistance was achieved with the pure DLC and DLC-W for RT tests. At RT the lowest friction was obtained with the DLCSi and DLCSiO coatings. Despite of the low COF values, those coatings displayed the highest specific wear rate values among all the films. This is attributed to the presence of hard SiC particles stick at the ball counterpart which promotes severe abrasion of the coatings surface. The increase of the temperature to 100 °C increases significantly the friction coefficient for the DLC and DLC-W coatings, whilst, for DLC-Ag, DLC-Si and DLC-SiO coatings a slight decrease is noticed. At this temperature DLCAg coating is the more performing due to the formation of a tick tribolayer rich in Ag adhered at the counterpart surface. With this work it was concluded that friction and wear are not directly related, and the third bodies formed on the sliding surfaces have major influence on the tribological performance of the system.

Influence of various tool shoulder design on hybrid surface composite of AA7075-T651/SiC/graphene through friction stir processing

ABSTRACT In the recent work, tool shoulder designs such as flat shoulder (TFS), kurl shoulder (TKS), scroll shoulder (TSS), and knurling (TKNS) were creatively designed to improve the surface properties. The AA7075/SiC/Graphene hybrid surface composites were fabricated through friction stir processing using different shoulder designs. The influence of shoulder designs on microstructure, mechanical, tribological, and corrosion properties were examined. The material characterizations such as macrostructure, microstructure, particle dispersion, and elemental analysis were studied through optical microscopy and field emission scanning electron microscopy with energy-dispersive X-ray spectroscopy. The current study found that the dispersion of SiC and graphene particles inside the matrix fabricated by the TSS tool design was more uniform due to the tool shoulder feature, leading to improved material flow during stirring. The sample fabricated using the TSS tool displayed higher grain refinement, the smallest grain size, which was 3.5 μm. The TSS design effectively eliminated the cluster formation and obtained a defect-free composite resulting in greater hardness (197 HV), lower wear resistance (0.0038 mm3/m) and higher corrosion resistance (– 0.650 mV) compared to other tool designs. However, the lowest values of hardness, wear rate, and corrosion resistance were obtained by TFS design.

Tribological Behavior of TiO2 PEEK Composite and Stainless Steel for Pediatric Crowns

Dental decay still presents a major health problem among children. Its treatment usually requires the use of stainless steel crowns. This study compares the wear behavior of 316 L stainless steel and polyetheretherketone (PEEK) composite under identical test conditions. The wear tests were conducted in a reciprocating ball-on-plate tribometer (Plint TE67/R) using alumina balls as a counterface and artificial saliva as a lubricant at 37 °C to faithfully mimic oral conditions. The coefficient of friction (COF) and specific wear rate (k) values were determined and SEM/EDS examinations were performed to identify the predominant wear mechanisms. Results showed that PEEK exhibited a significantly lower coefficient of friction (COF = 0.094 ± 0.004) and thus lower wear volume (ΔV = 0.0078 ± 0.0125 mm3) and higher wear resistance, with an average value of specific wear rate of k = 9.07 × 10-6 mm3N-1m-1 when compared to stainless steel (COF = 0.32 ± 0.03, ΔV = 0.0125 ± 0.0029 mm3, k = 1.45 × 10-5 mm3N-1m-1). PEEK was revealed to be a potential material for use in pediatric crowns due to its high wear resistance while overcoming the disadvantages associated with steel at both an aesthetic and biological level.

Improvement of Ti-6Al-4 V alloy in terms of mechanical and tribological properties by oxidation and nitriding

In this study, we aimed to compare the mechanical properties and tribological properties of specimens after different thermal treatments. We treated specimens in oxidation and nitriding with argon in the chamber with 900 °C and 950 °C respectively. The results of the microhardness showed that the oxidized specimens were observed the highest value of 788VHN (0.05). We found that comparing to oxidized specimens (CoF=0.6 ± 0.09), the nitrided specimens showed lower coefficient of friction (CoF=0.52±0.06). There was around two times improvement of microhardness comparing to untreated specimens. And oxidized specimens (1.61±0.29 μm3/Nmm) showed five times lower value of wear rate than nitrided specimens (4.12±0.79 μm3/Nmm), and around ten times lower value of wear rate than nitrided with mechanic pump (9.54±0.68 μm3/Nmm). We concluded that oxidation could help to achieve the enhancement of hardness and wear properties, but with thinner layer on the surface. Nitriding with diffusion pump increased the efficiency of Ar+ and N+ diffusion than only with mechanic pump.

Pengaruh Penambahan Nano-Aditif Ke Dalam Fluida Polyolester Terhadap Gesekan Dan Keausan Material AISI52100 Vs Cast Iron

Synthetic lubricants have environment problems because they are difficult to decompose and be-come pollutant materials when disposed into the environment. Therefore, there is an increasing demand for biodegradable lubricants. One of the methods to achieve biodegradability of a lubricant is by using eco-friendly base material and nanoparticles from organic materials as additives, such as nanofibers, cellulose and graphene nanoplatelets. In previous studies, it has been confirmed that applying bacterial cellulose at various volume percentages into polyester (POE) oil has reduced friction and wear of the material up 49%. Other studies also mentioned that the addition of several layers of graphene as an additive to Polyalphaolefin (PAO) oil have decreased the value of the fric-tion coefficient from 0.15 to 0.08. In this study, due to their desirable properties, the bacterial cellu-lose (BC) and graphene nanopartcles were used as additives in polyester (POE) oil. Four types of lubricant specimens with different additive content were prepared for the study. The friction tests were carried out using a reciprocating pin on disk type tribometer at temperatures of 65°±3°C and 27°C. The results indicated improvements in the tribological properties; 60% friction reduction at temperature of 65°±3°C and 66.7% at a temperature of 27°C, with the presence of both BC and graphene in POE compared to those without the additives. In addition, the wear analysis from the results of micro-surface observation of the specimen indicates the reduction of the specific wear rate values as the effect of additives. It is found that the specific wear rate decreased from 6.09×10-6 mm3/N.m to 4.82×10-7 mm3/N.m at 65°±3°C and from 1.57×10-6 mm3/N.m to 2.38×10-7 mm3/N.m at 27°C with the presence of both BC and graphene in POE compared to those without the addi-tives.

A tribological behavior assessment of steel contacting interface lubricated by engine oil introducing layered structural nanomaterials functionalized by oleic acid

Traditional lubricating oil in the lubrication process leads to oil film rupture and lubrication failure due to thermal instability under high temperatures. Tribological characteristics of synthetic oil (5W-40) can be potentially improved by the application of layered nanoparticles (h-BN and MoS2 NPs). The tribological properties of base oil, MoS2, and h-BN nanolubricants (NLs) were comprehensively investigated under varying loads, rotating speeds, and temperatures using a four-ball tribometer. Moreover, this study confirmed that the COF and wear rate values of wear scar lubricated by h-BN NL and MoS2 NL decreased by approximately 21.5% and 13%, 91.6% and 90.9%, respectively, compared with base oil, showing the brilliant tribological performance following the introduction of NL. The results showed the wear interface lubricated by NL with oleic acid (OA) functionalization contributed to the appearance of tribo-film along with chemical absorption film due to the complicated oxidizing reaction. Eventually, the synergistic role between OA and nanomaterials responsible for the increasing tribological properties is elaborately elucidated.

Effect of cryogenic treatment on wear behavior of Sleipner cold work tool steel

Cryogenic treatment, also known as subzero heat treatment, is a cooling process that complements conventional heat treatment to improve the properties of metals. Unlike coatings, it is a one-time, inexpensive, permanent operation that affects the entire part. This method is mainly applied to tool steels used in mold making. In this study, the changes caused by the effects of shallow and deep cryogenic treatment on Sleipner cold work tool steel were investigated in terms of microhardness, microstructure, coefficient of friction (COF), and wear rate (WR). For this purpose, the test specimens were subjected to the cryogenic treatments performed at two different temperatures (−80 ºC for the shallow cryogenic treatment (SCT) and − 180 ºC for the deep cryogenic treatment (DCT)) and various retention times (12 h, 24 h for SCT and 12 h, 24 h, 36 h for DCT). Dry sliding wear tests were carried out under different loads (10 N and 20 N) and varying test durations (60, 120, and 240 min) at a constant sliding speed of 0.075 m/s. According to the microhardness results, it was determined that the cryogenic treatment increased the hardness by 6.53 %. According to the microstructure investigations, a more homogeneous structure was observed with the cryogenic treatment, and secondary carbide precipitations were detected. It was observed that the conventional heat-treated (CHT) sample gave the highest COF value with an average coefficient of friction of 0.63. The lowest COF value of 0.58 was observed in the DCT-12 sample. After the wear tests, the lowest wear rate value for both load values was obtained from the DCT-36 specimen.

Impact of aging temperature on the metallurgical and dry sliding wear behaviour of LM25 / Al2O3 metal matrix composite for potential automotive application

The current study exhibits the influence of aging temperatures on the metallurgical, hardness, and dry-sliding wear behaviour of LM25 (Al-6.6Si-0.2Mg) alloy reinforced with Al2O3 particles. The LM25 alloy reinforced with 10 wt% of alumina particles was fabricated using the liquid metallurgy route followed by solutionizing and aging. The baseline LM25 alloy and its composite were solutionized at 538 °C for 8 h and were aged at 155, 165, and 175 °C for 12 h. Optical, FESEM, EDS, and X-ray diffraction analysis were done on the fabricated alloy and its composite in all conditions. The microstructure revealed the formation of the Mg2Si phase in the baseline alloy and the MgAl2O4 spinel generated at the composite interface of the aluminium matrix. The heat-treated alloy and composites were tested for their hardness on the Vickers microhardness tester. It was concluded that the aging temperature of 155 °C displayed significant enhancement in hardness values for tested samples. The heat-treated alloy and composite samples displayed an increment of 96% and 55% in hardness values relative to LM25. The wear rate and friction coefficient for the fabricated samples were analyzed using the pin-on-disc tribometer under dry sliding conditions. The hardness value increased from the as-cast state to samples aged at 155 °C and then decreased at 165 and 175 °C. Based on the wear study, a 14% and 25% decrease in the wear rate values for heat-treated alloy and composites were noted when sliding velocity was increased from 1 m/s to 3 m/s. However, the coefficient of friction (COF) decreased by 23% and 13% for the specimens in the same conditions. Furthermore, a similar trend was displayed by age-hardened LM25 alloy and the composite when subjected to varying load (5, 10, 15 N) condition. Lastly, the worn-out surface mechanisms were examined using FESEM analysis. Amongst the investigated samples, LM25/10 wt% Al2O3 composite aged at 155 °C revealed the least wear rate when subjected to an external load of 5 N and sliding velocity of 2 m/s. Therefore, it can be suggested to manufacture components in the automotive industry.

In-Situ Al-Mg Alloy Base Composite Reinforced by Oxides and Intermetallic Compounds Resulted from Decomposition of ZrW2O8 during Multipass Friction Stir Processing.

In the presented work, the effect of friction stir processing admixing the zirconium tungstate ZrW2O8 powder on the microstructure, mechanical and tribological properties of the AA5056 Al-Mg alloy stir zone has been studied. The FSP resulted in obtaining dense composite stir zones where α-ZrW2O8 underwent the following changes: (i) high-temperature transformation into metastable β'-ZrW2O8 and (ii) decomposition into WO3 and ZrO2 oxides followed by the formation of intermetallic compounds WAl12 and ZrAl3. These precipitates served as reinforcing phases to improve mechanical and tribological characteristics of the obtained fine-grained composites. The reduced values of wear rate and friction coefficient are due to the combined action the Hall-Petch mechanism and reinforcement by the decomposition products, including Al2O3, ZrO2, β'-ZrW2O8 and intermetallic compounds such as WAl12 and ZrAl3. Potential applications of the above-discussed composites maybe related to their improved tribological characteristics, for example in aerospace and vehicle-building industries.

Thermodynamic foundations of the rational cutting modes choice under conditions of machining

Durability and tribological tests of standard grades of high-speed steels and experimental single-carbide hard alloys with modified cobalt binder, created on the basis of the standard VK8 grade, under conditions of friction and turning of structural steels 45 and 12Х18Н10Т were carried out. The experiments were carried out for various cutting speeds and friction in order to determine the dependence of the optimal modes from the point of view of reducing the wear rate for cutting materials with different structural and thermodynamic characteristics. It has been experimentally established that high-speed steels with high values of thermal entropy have greater wear resistance in comparison with low-entropy grades, and cutting (sliding) speeds corresponding to minimal wear rates are higher for them. For experimental hard alloys grades characterized by greater thermal entropy values of the binder lower wear rates at optimal cutting speeds compared to the base alloy were also recorded; the values of the optimal cutting speeds for these materials are also higher. Thus, high-entropy cutting materials allow machining at higher speeds, while reducing the wear intensity.

Wear and corrosion behavior of selected up-quenched and step-quenched CuZnSn shape memory alloys

The effect of thermal treatment on the wear and corrosion behavior of three categories of Cu-Zn-Sn-Fe SMAs designated A, B, and C is studied. Wear properties were investigated using a tribometer whilst corrosion in 0.3 M H2SO4and 3.5%NaCl media was studied using the potentiodynamic polarization method. The microstructure of the alloys mainly consists of FCC Cu-rich phase and Cu5Zn8phase. The up-quenched A alloys show the highest hardness and lowest wear rate values of 72.1 HRB and 0.143 mm3/N/m respectively. Average COF was higher for the samples subjected to direct-quenching (0.35–0.12) than the up-quenched (0.16–0.12) and step-quenched (0.2–0.08) samples. Wear occurred by mixed mode mechanisms of abrasion and adhesion evident by grooves and wear particles on the surface. In 0.3 M H2SO4medium, step-quenched alloys had corrosion rates in the range of 0.1022 to 1.1705 mm/yr, which is lower than the range of 0.1466 to 0.2855 mm/yr, and 0.1730 to 0.6027 mm/yr obtained for direct quenched and up-quenched samples respectively. In 3.5% NaCl solution, step-quenched alloys had the lowest corrosion rates 0.0251 mm/yr relative to samples subjected to up-quenching and direct quenching treatment. Generally, step-quenching treatment effectively improved the corrosion resistance of alloys in both media.

“Optimization and Characterization of Ni-B Coating of Using RSM Method”

Abstract: It is unique properties, the electroless method is used as an effective and important technique to create uniform coatings. Among the coatings that can be made by electroless process is Ni-B coating due to its excellent properties such as good corrosion resistance, high wear resistance, high hardness, favorable oxidation resistance. In this article, after introducing nickel-boron electroless coatings and examining the microstructure and wear rate, recent developments in strategies to improvement in corrosion resistance, tribological properties, and the use of nickel-boron electroless coatings as electrocatalysts. In this study operating parameters are optimized by using RSM method. operating parameters considered for the Reinforcement, temperature and frequency. This paper summarized, the parametric influence of Reinforcement, temperature and frequency on wear rate of Ni-B with ZrSi coating. Response surface methodology (RSM) is used for modelling and optimization. ANOVA has been carried out to identify importance of the operating parameters on the performance characteristics considered. Further the verification experiment has been carried out to confirm the performance of optimum parameters. The results from this study will be useful for selecting appropriate set of process parameters to Ni-B coating has been selected. The analysis of variance (ANOVA) has been used to determine effect of each parameter on wear rate so Finally, the confirmation test has been carried out to compare the predicted value of wear rate with the experimental value.

Machinability of B4C-reinforced Al2014 metal matrix composites in electric discharge machining

This study was conducted to clarify the effect of various variables such as the type of electric discharge machining, discharge current and reinforcement content of B4C-reinforced Al alloy metal matrix composite on workpiece removal rate, electrode wear rate and material removed per discharge pulse, which are not extensively explored in the literature. B4C-reinforced Al2014 matrix composite samples containing 5 and 10 vol.-% B4C particles, produced by vacuum infiltration method, were machined with electric discharge machining and powder mixed electric discharge machining at various discharge current settings. In both types of machining processes, the workpiece removal rate and electrode wear rates decreased and increased, respectively, when the reinforcement contents of the composites increased. However, powder-mixed electric discharge machining enhanced the machining stability, and a comparatively higher workpiece removal rate was observed with a decreased electrode wear rate. On the other hand, by increasing the discharge current, which was also verified as the most effective machining parameter in variance analysis, both workpiece removal rate and electrode wear rate values increased in both machining techniques. The experimentally calculated volumetric workpiece material removed by a discharge pulse was compared to that of a model in the literature, and they were also found to be consistent with each other.

Ion releasing direct restorative materials: Key mechanical properties and wear.

To investigate the depth of cure (DoC), fracture toughness (KIC) and wear of ion releasing resin-based composite (RBC) restorative materials. Two ion releasing RBCs, Activa (ACT) and Cention-N (CN) were compared to a conventional RBC (Z350) and a resin-modified glass ionomer cement (Fuji-II-LC). The DoC was measured in a 10-mm deep semi-circular metal mold with a 2-mm internal radius (n=8). The molds were irradiated from one end for 20-s. The Knoop hardness (KH) was measured at 0.5-mm intervals from the surface after the specimens had been stored at 37°C for 24-h. To measure the KIC, single-edge-notched specimens (n=15/group) were prepared (25×5x2.5-mm) for a 3-point bending test and then stored for either 1 or 30-days in water at 37°C. Disk-shaped specimens (n=10) were subjected to 250,000-load cycles of 49-N using a chewing simulator against spherical steatite antagonists. DoC and wear data were analyzed by one-way ANOVA and Tukey post hoc tests (p≤0.05). KIC data were analyzed by two-way ANOVA and one-way ANOVA, and the Tukey post hoc test (p≤0.05). In addition, an independent t-test was used to determine if storage time had any effect (α=0.05) on the KIC of each material. Maximum hardness value was the highest for Z350 and the lowest for ACT. The depth at which 80% of the maximum KH, was the highest for CN (9.2mm) and the lowest for Z350 (2mm). All tested materials met the manufacturers' claims for DoC. After 1-day, the highest KIC values were recorded for ACT and the lowest for Fuji-II-LC. Water storage (30-days) significantly reduced the KIC value for all materials except Fuji-II-LC. The highest wear rate values were recorded for CN followed by ACT. All tested materials met their manufacturers' claims for DoC. Water storage for 30-days significantly reduced the fracture toughness for ACT and CN. Wear was significantly higher for ACT and CN.

Multi objective optimization of parameters in EDM of Mirrax steel

ABSTRACT Accompanying the technological development and the advancement in the industry, the demand for materials with superior properties such as high strength, hardness and toughness is increasing. This made it difficult or impossible to cut these materials by conventional methods. Electric discharge machining (EDM) is one of the most important unconventional machining methods that have the ability to cut electrically conductive materials regardless of their mechanical properties. In this study, the machinability of Mirrax plastic mold steel was investigated experimentally employing the electrical discharge machining technique, and its machinability was optimized using gray relational analysis. Experiments were carried out using the Taguchi L27 orthogonal setup, with the electrode type, discharge current, pulse on time, and pulse off time as inputs. The surface roughness was measured, the material removal rate and the electrode wear rate values were calculated. A multi-purpose optimization study was carried out for the outputs. The analysis of variance results defined that the discharge current was the most influential parameter among the machining parameters, whereas the pulse off time was ineffective in the processing of Mirrax plastic mold steel via EDM. The Taguchi based gray relational analysis determined that the GRG value had been improved by 32.24%.

Mechanical, Corrosion, and Wear Properties of TiZrTaNbSn Biomedical High-Entropy Alloys

The phase composition, microstructure, mechanical, corrosion, and wear behaviors of the Ti15Zr35Ta10Nb10Sn30 (Sn30) and Ti15Zr30Ta10Nb10Sn35 (Sn35) biomedical high-entropy alloys (BHEAs) were studied. We found that the Ti–Zr–Ta–Nb–Sn BHEAs showed hyper-eutectic and eutectic structures with body-centered cubic (BCC) and face-centered cubic (FCC) solid-solution phases. The Sn30 BHEA exhibited a high Vickers hardness of approximately 501.2 HV, a compressive strength approaching 684.5 MPa, and plastic strain of over 46.6%. Furthermore, the Vickers hardness and compressive strength of Sn35 BHEA are 488.7 HV and 999.2 MPa, respectively, with a large plastic strain of over 49.9%. Moreover, the Sn30 and Sn 35 BHEA friction coefficients are 0.152 and 0.264, respectively. Sn30 BHEA has the smallest and shallowest furrow-groove width, and its wear rate is 0.86 (km/mm3); at the same time, we observed the delamination phenomenon. Sn35 BHEA has a wear rate value of 0.78 (km/mm3), and it displays wear debris and the largest–deepest furrow groove. Sn30 BHEA has the highest impedance value, and its corrosion current density Icorr is 1.261 × 10−7 (A/cm2), which is lower than that of Sn35 BHEA (1.265 × 10−6 (A/cm2)) by 88%, and the passivation current density Ipass of Sn30 BHEA and Sn35 BHEA is 4.44 × 10−4 (A/cm2) and 3.71 × 10−3 (A/cm2), respectively. Therefore, Sn30 BHEA preferentially produces passive film and has a small corrosion tendency, and its corrosion resistance is considerably better than that of the Sn35 BHEA alloy.

Dynamic tasks in models of product operability

When developing models of critical mechanical engineering products, it is necessary to solve dynamic problems, taking into account changes in the dimension chains of links in the process of functioning of mechanisms. A method of calculating dynamic dimension chains as applied to solving direct and inverse problems is proposed. The solution of a direct problem is given under the condition that the stray field of the master link includes the errors of production and those related to the changes in the dimensions of the initial links under the action of operational loads. To obtain the value of the product part wear rate we propose using empirical dependences of the relation between the wear rate and formation of hydrogen in the process of interaction of materials.

Effect of temperature on the tribocorrosion and high-temperature tribological behaviour of strong amorphization AlCrNiTiV high entropy alloy film in a multifactor environment

Here, we fabricated an AlCrNiTiV high entropy alloy amorphous film (HEAAF) by co-filter cathode vacuum arc deposition (Co-FCVAD). The systematic experiments demonstrate that excellent mechanical properties and a stable dense microstructure are important contributing factors in a friction-corrosion coupling environment, in which the AlCrNiTiV HEAAF oxidized at 600 °C exhibits optimal tribocorrosion resistance with a minimum Δ open circuit potential (ΔOCP), friction coefficient (COF) and wear rate of 0.015, 0.01 and 2.36 × 10−6 mm−3 N−1•m−1, respectively. Through study of the oxidation behaviour, it is found that the diffusion barrier formed in situ by the Al2O3, NiCr2O4 and Cr2O3 composite inner oxide layer after oxidation at 800 °C can effectively impede the outward diffusion of metal ions and inward diffusion of O ions, but the film shows a deterioration in hardness and a loose microstructure, which are the main failure factors under a friction-corrosion coupling environment. Additionally, the AlCrNiTiV HEAAF shows excellent high-temperature tribological performance under a friction-temperature (600 °C) coupling environment with the lowest COF (0.22) and wear rate values (1.1 × 10−5 mm3 N−1•m−1). However, a brittle oxide film composed of rutile TiO2 on the worn track is found to be responsible for the weak high-temperature tribological performance under a friction-temperature (800 °C) coupling environment.

Effect of Temperature and Heating Resistant Time on Wear Properties of Molybdenum/Alumina Composites

The wear properties of metals are very important in manufacturing. This is evidenced in the many studies that analyze the wear properties of a metal. This study uses Metal Matrix Composites, where the manufacturing process uses metal as the matrix and ceramics as reinforcement with powder metallurgy manufacturing methods. Where the powder of the two composite materials is compacted and heated at a certain temperature to form a solid composite material. The purpose of this study is to ensure that the mechanical properties of the Mo/Al2O3 composite are greater than that of the constituent material. In this study, molybdenum powder was used as a matrix material and alumina as a reinforcing material. Mo has excellent mechanical properties, namely hardness and excellent wear resistance. Al2O3 has excellent wear resistance properties. Research variables include heating temperature of 900, 1000, 1100°C and holding time of heating process for 0.5, 1, 1.5 hours with compaction pressure of 125 MPa and weight fraction of Mo by 80% and Al2O3 by 10%. Based on the test results, the highest sinter density was found at a sintering temperature of 1100oC and a sintering holding time of 1.5 hours at 6.831g/cm3. The value of porosity and wear rate is getting lower, namely 28.8% and the wear rate is 0.0012 mm/minute.

Effect of dry sliding wear parameters on the specific wear rate of α-MnO2-epoxy nanocomposites

Wear parameter optimization is critical for the successful use of materials in load-bearing applications. This study examines the optimization of various wear parameters using the Taguchi technique for the determination of the specific wear rate of alpha-manganese dioxide (α-MnO2)-epoxy nanocomposites. Four factors viz. wt.% loading of α-MnO2, sliding distance, sliding velocity, and normal load, were selected as controllable factors and a suitable L16 orthogonal array was chosen for conducting experiments. An X-ray diffractometer and field emission scanning electron microscope were used to examine phase identification, surface morphology, and chemical composition. With the addition of α-MnO2 in the epoxy, the tensile stress is decreased, while the elastic modulus is increased. The Taguchi result shows that the wear test in optimal condition is carried out with a wt.% loading of α-MnO2 of 0.5%, a sliding distance of 500 m, a sliding velocity of 1.5 m/s, and an applied normal load of 5 N. Analysis of variance shows the wt.% loading of α-MnO2 has the most influential parameter on specific wear rate with a contribution of 87.94%. The analysis also shows that the general linear model accurately describes the effect of sliding wear parameters on specific wear rates. The Monte Carlo simulated model shows that the experimental signal-to-noise ratios are consistent with the simulated model values. The confirmation test result shows that the % error between the predicted and experimental values of the specific wear rate at the optimum level combination is 4.67%. The worm surfaces of different trial runs show that the material removal process is caused by crack propagation. High-resolution scanning electron microscopic images of fractured surfaces show the formation of a stable tribo-layer at 0.5 wt.% α-MnO2 loading resulted in a significant decrease in the specific wear rate of the sample.