Dry Wear Tests Research Articles

Development of Fe-Cr-C alloys with high Mn content for bone implant

The object of this study is to combine the properties of Mn and the advantages of Fe-Cr-C to improve biomaterial compatible characteristics. Three alloys of Fe-Cr-C with compositions of 12 wt. % Mn, 16 wt. % Mn, and 20 wt. % Mn, were investigated. Microstructural analysis was carried out using a scanning electron microscope (SEM), and a Vickers hardness test kit was used to evaluate the hardness. The pin-on-disc method was used for the dry slide wear test, and the corrosion test was carried out using the three-electrode cell polarization method. The hardness value of Fe-Cr-C alloy increased by 28.7 % with the increase of Mn content from 12 wt. % (231.8 VHN) to 20 wt. % (298.4 VHN). The tensile strength value increased by 30.3 % with an increase in Mn content from 12 wt. % (522.69 MPa) to 20 wt. % (680.89 MPa), while the strain value decreased by 30.9 %. However, impact toughness did somewhat decline, from 0.213 J/mm2 at 12 wt. % Mn to 0.169 J/mm2 at 20 wt. % Mn. The wear rate results for Fe-Cr-C 20 wt. % Mn 0.000156 mm3/kg. show a reduction of more than 15 wt. % when compared to Fe-Cr-C 12 wt. % Mn because of an increase in the hard-intermetallic area. Additionally, corrosion resistance improved significantly, with the corrosion rate decreasing from 0.005814 mm/yr at 12 wt. % Mn to 0.001780 mm/yr at 20 wt. % Mn, demonstrating that higher Mn content reduces material degradation in corrosive environments. Based on the experimental results, Fe-Cr-C 20 wt % Mn alloy has the highest mechanical and corrosion resistance of the three types of alloys. Fe-Cr-C with high Mn alloys are promising candidates for application as biomaterials for bone implants by optimizing the Mn content and corrosion resistance

Cuckoo search-artificial neural network aided the composition design in Al–Cr–Co–Fe–Ni high entropy alloys

In this work, we proposed a data-driven approach combining machine learning (ML), experiments and molecular dynamic (MD) simulation to accelerate the composition design and exploration of wear behavior in Al–Cr–Co–Fe–Ni based high entropy alloys. A Cuckoo Search-Artificial Neural Network (CS-ANN) model was proposed to deal with small sample data and showed fairly strong learning ability and generalization capabilities. Elemental analysis revealed that the microhardness can be enhanced by adding Al or reducing the proportion of Fe and Ni. Then the Al1.1CrCoFe0.9Ni0.9 HEAs were designed and prepared for experimental verification. The microstructure, phase composition, hardness, and wear resistance properties of the alloy were further investigated. Al1.1CrCoFe0.9Ni0.9 HEAs were composed of BCC+B2 phases, exhibited a microhardness of 580.6 HV. The wear rate was measured as 6.04×10−6 mm3/(Nm) by the reciprocating dry wear tests, the average COF was estimated as ∼0.5. The main wear mechanisms involved abrasive wear and oxidation wear. MD simulations are used to analyze the atomic evolution and deformation mechanism during the nano scratch process. The obtained information would help either facilitate developing novel HEAs or utilize the HEAs effectively to resist wear.

Study of tribological performance and corrosion resistance of aluminum alloy 6063 composites enhanced with a combination of silicon carbide and tungsten disulfide particles

This research explores the effects of wear on a 6063 aluminum alloy matrix combined with silicon carbide (SiC) and tungsten disulfide (WS2) particulates. Dry friction wear tests were conducted on three materials: pure 6063 aluminum alloy, a composite with 4 wt% SiC and 4 wt% WS2 reinforcement, and another composite with 6 wt% SiC and 4 wt% WS2 reinforcement. These materials were tested against AISI410 stainless steel discs under varying loads (10N, 20N, and 30N) and sliding rates (0.5, 1.0, and 1.5 ms−1) following a Taguchi L27 orthogonal experimental plan. Main effect graphs (S/N ratios) and ANOVA analysis were utilized to determine optimal parameter combinations, and confirmation tests were carried out to validate the Taguchi results. Scanning electron microscope (SEM) images of wear areas showed that incorporating SiC and WS2 significantly enhanced the wear resistance of the aluminum alloy. This indicates that incorporating SiC and WS2 reinforcement has the potential to enhance the wear resistance of aluminum alloys, making them suitable for applications such as piston rings in internal combustion engines, which is in line with the requirements of engine performance. Furthermore, potentiodynamic polarization studies evaluated the corrosion resistance of the Metal Matrix Composites AA6063 in 3.5% NaCl. Results indicated that the AA6063 + 6 wt% SiC + 4 wt% WS2 composite exhibited superior corrosion resistance compared to AA6063 alone.

Tribological Study of Fe–Cr Alloys for Mechanical Refinement in a Corn Stover Biomass Environment

The tribological behavior of three Fe–Cr alloys with Cr contents ranging from ~12 to 16 wt.% as well as low-alloy high-carbon 52100 steel were investigated using pin-on-disk wear testing. Wear tests were performed in both open atmospheric (dry) and biomass environments (wet). Delamination and abrasion were observed to be the dominant wear regimes following dry wear tests. For wet testing, adhesion and pitting corrosion were determined to be the primary wear mechanisms in the Fe–Cr alloys while adhesion and delamination/cracking were identified as the primary wear mechanisms in the 52100 steel. The 440C stainless steel and 52100 steel specimens exhibited the lowest wear volume following dry (7.58 ± 0.52 mm3 and 0.78 ± 0.05 mm3, respectively) and wet wear testing (0.11 ± 0.06 mm3 and 0.12 ± 0.09 mm3, respectively); however, these specimens exhibited the most significant corrosion damage. The 410 stainless steel specimen exhibited the best resistance to corrosion after wear testing in the deacetylated and disc-refined corn stover slurry and had measured wear volumes after dry and wet wear testing of 6.84 ± 0.88 mm3 and 0.33 ± 0.12 mm3, respectively. The worst wear resistance was observed by the 420 stainless steel specimen after both dry and wet wear testing.

Determination of the construction material for phononic band gap structures by tribological performance

This study investigates the tribological performances of commonly used stainless steel alloys (303, 304, 316L, and 420) to determine their suitability as construction materials for periodic structures designed for inertial amplification induced phononic band gap vibration isolators. Stainless steel alloys are extensively employed in engineering structures due to their ability to withstand large stresses and exhibit excellent cyclic loading properties. In this study, stainless steel specimens are examined by dry and lubricated wear test conditions. 420 stainless steel showed highest wear resistant properties for dry and lubricated conditions. Two grades of lubricants are compared in terms of viscosities, and it is revealed that higher viscosity blocked the flow of the lubricant so that semi-dry friction occurred. Low viscosity lubricant enabled less material removal due to friction.

Synergistic effects of heat-assisted ultrasonic rolling textures and self-lubricating coatings on the friction and wear properties of AISI 52100 steel

Wear is an important factor in limiting the service life of AISI 52100 steel components. In order to improve the tribological properties of AISI 52100 steel, we investigated the synergy between polyphenylene sulfide-silicon dioxide/polytetrafluoroethylene (PPS-SiO2/PTFE) self-lubricating coatings and surface textures fabricated by heat-assisted ultrasonic surface rolling process (USRP). The influences of different heat-assisted temperatures (20, 80, 140, and 200 ℃) on the surface characteristics of the textures such as morphology, hardness, and residual stress were investigated. The synergistic effects of self-lubricating coatings and textures at different heat-assisted temperatures were investigated by dry friction and wear tests. The results showed that the synergistic effect of the coating with the texture at 200 °C had a performance improvement than the individual effect, but the synergistic effects with textures at other heat-assisted temperatures had a negative influence. The heat-assisted temperature influenced the synergistic effect by affecting the texture shape and strengthening effect, and the influence of texture shape was stronger. The texture with an appropriate shape not only had a strengthening effect to increase the load-bearing capacity of the coating-substrate system, but also stored the coating material to improve the wear resistance.

Deposition of NiAl/Al3Ni2(CrB2) Coatings from Ni, Al and CrB2 Powders Using Mechanical Synthesis in Planetary Ball Mill.

Interest in composite thick coatings with an intermetallic matrix stimulates the development of new deposition techniques like the co-milling of pre-alloyed NiAl powder with platelet-shaped substrates. Obtained coatings were up to several micrometers thick as cold-welding of intermetallic particles was effective only at the start of this process, while later, chipping prevailed over added material. The present experiment covered the co-milling in the planetary ball mill of Ni and Al elemental powders (1:1 molar ratio) with AISI 304 steel platelets for 32 h at 300 rpm. Next, this process was repeated with an admixture of 15 wt.% of CrB2 powder. In both cases, their milling succeeded in producing up to a 200 μm coating after 4 h. The use of light, scanning and transmission electron microscopy (LM/SEM/TEM) helped to establish that the coatings had gradient microstructures with more refined crystallites of NiAl, Al3Ni2 and CrB2 closer to the surface. With the addition of a ceramic phase, the coatings presented higher hardness and lower friction during dry wear tests both at RT and at 500 °C.

Wear‐resistant layers containing graphene derivatives

AbstractThe effect of carbon filler wt% ratios on the microstructural and tribological properties of the ultra‐high molecular weight polyethylene (PE)/graphene nanoplatelets (GNP), PE/graphene oxide (GO), and PE/carbon nanotube (CNT) composites and PE/GNP‐GO hybrid composite layers was studied to determine the best tribological performance after the dry wear test. The layers had a semi‐crystalline structure like PE, but the shifts in the peaks showed the presence of interactions between the fillers and PE matrix, according to x‐ray diffraction (XRD) analysis. FTIR analysis results indicated that GO‐containing layers caused interactions and new bonds. The lowest values for the friction coefficient were found in layers containing GNP and GO, which had a lubricating effect. The friction coefficient decreased by 83.24% in the PE/0.7GO composite layer compared to PE. Wear resistance of the PE/3GNP and PE/1GO layers were the highest compared to PE and other layers. The PE/3GNP and PE/1GO layers improved the wear resistance of PE by 12% and 11%, respectively. Abrasive wear and fatigue wear tracks on the worn surface of the PE/3GNP and PE/1GO composite layer were significantly reduced compared to PE and other layers. This study suggests that layers that will provide the highest molecular interaction with PE and improve its wear resistance will be produced with GO and nano‐sized GNP.Highlights The interaction of graphene‐derived fillers with PE and its effect on friction and wear properties were investigated. GNP and GO are the best filler materials among the graphene derivatives for increasing wear resistance. High wear resistant of layers achieved at 3 wt% GNP loadings. Layers containing GO had the lowest friction coefficient values among the other layers.

Tribological behavior of SiC reinforced AZ91D composites manufactured by semisolid injection molding

Semisolid injection molding is a novel and ideal process for manufacturing particle reinforced magnesium composites. The main purpose of this article is to reveal the wear mechanism of SiC/AZ91D composite prepared by this method. AZ91D Mg alloy and its composites reinforced with 1 % and 2.5 % SiC particles were manufactured by the semisolid injection molding method and their microstructure and wear behavior were investigated. The composites are composed of a Mg matrix, consisting of unmelted AZ91D particles distributed in a resolidified Mg base, and uniformly-dispersed SiC particles. The dry wear tests showed that adding SiC reinforcement increases the friction coefficient, enhances the wear resistance at the low loads of 5 N and 10 N, but reduces the wear resistance at the high load of 20 N. The dominant wear mechanism is abrasive wear, accompanied by small contributions from adhesive and oxidative wear.

Replacing Toxic Hard Chrome Coatings: Exploring the Tribocorrosion Behaviour of Electroless Nickel-Boron Coatings

Electroless nickel-boron coatings present outstanding properties such as high hardness, excellent wear resistance and uniform coating, and thus they are considered to be alternative to toxic hard chrome coatings. However, they contain lead that is toxic and used as stabilizer in the plating bath. This study aims to investigate the tribocorrosion behaviour of lead-free electroless nickel-boron coatings. In the present research, several tests were carried out to investigate the behaviour of these coatings under both dry and tribocorrosion reciprocating sliding wear against alumina balls, at room temperature. The open circuit potential (OCP) method was used to determine the degradation mechanism of the coatings. The results of the tribocorrosion and dry wear tests showed that the performance of coatings was very different from each other. A steady state for the coefficient of friction (COF) is achieved during the tribocorrosion test, whereas the constant production of debris and their presence in the contact implied an increase in COF with distance during the dry wear test. The wear mechanisms of these coatings also presented variations in these tests. It was found that the wear area calculated from tribocorrosion is lower (56 µm2) than the one from dry sliding test (86 µm2).

Research on the mechanism of the two-dimensional ultrasonic surface burnishing process to enhance the wear resistance for aluminum alloy

The gradient nanostructure is machined on the aluminum (Al) alloy by the two-dimensional ultrasonic surface burnishing process (2D-USBP). The mechanism of why the gradient nanostructure enhances wear resistance is investigated. The mechanical properties and microstructure characterization for the gradient nanostructure are performed by operating a nanoindenter, transmission electron microscopy (TEM), and electron backscattered diffraction (EBSD). Dry wear tests are performed on the samples before and after machining to evaluate the wear resistance and mechanisms. The effect of the gradient nanostructure on the wear resistance is explored by developing the crystal plasticity (CP) finite element and molecular dynamics (MD) models. The characterization results show that the 2D-USBP sample prepared a gradient structure of ∼600 µm thick on the aluminum surface, increasing the surface hardness from 1.13 to 1.71 GPa and reducing the elastic modulus from 78.84 to 70.14 GPa. The optimization of the surface microstructure and the increase of the mechanical properties effectively enhance the wear resistance of the sample, with 41.20%, 39.07%, and 54.58% of the wear scar areas for the 2D-USBP treated samples to the original samples under 5, 10, and 15 N loads, respectively. The gradient nanostructure hinders the slip of dislocations inside the sample during the wear process and reduces the size and scope of plastic deformation; meanwhile, the resistance to deformation, adhesion, and crack initiation and propagation of the sample surface is improved, resulting in enhanced wear resistance.

Tribological behavior of Al matrix composites reinforced by hybrid Cu and SiC under SN500 + G lubricant

Al matrix composites reinforced with hybrid SiC and Cu reinforcement were prepared by powder metallurgy and sintering. The presence of Cu in the composite microstructure has caused the formation of a three-dimensional network of metallic reinforcing phase. Wear tests were performed (50 and 100 N, 1 mm/s, 1000 m) as dry wear and lubricated wear under SN500 base oil containing graphite particles. The friction results showed that the COF under lubricant compared to the dry wear test was decreased by ∼80 %. With increasing SiC/Cu content the wear rate was decreased up to 30 %. The SEM observation of the lubricated worn surfaces showed that adhesive wear was the dominant wear mechanism, which significantly decreased with the tribofilm formation.

Investigation on dry abrasion wear of natural and synthetic fiber reinforced polymer composites filled with stone waste

The fiber reinforced polymer composites filled with industrial stone waste was fabricated using vacuum assisted resin transfer molding (VARTM). The fabricated samples of composite plates were subjected to parametric studies of dry abrasion wear test. The control factors considered for parametric studies of were load, abrading velocity, percentage of stone waste and size of abrasive particles.The mean S/N ratios for dry abrasion wear were to be 4.71db, 6.48db and 7.98db for granite added jute, glass and carbon fiber reinforced polymer composites. ANOVA analysis helps to identified the order of most influencing input operating parameters on output response dry abrasion wear and order of most significance input operating parameters in decreasing order abrasion load > Wheel rotation > Filler content > Abrasive size for granite added jute, glass and carbon fiber reinforced polymer composites.

Influence of surface burnishing process with single strain path and reciprocating strain path on copper wear behavior

A single strain path (SSP) and reciprocating strain path (RSP) burnishing processes are implemented on copper surfaces using a multi-ball surface burnishing tool. Dry wear tests are performed on both machined samples to investigate the effect of different strain paths on the wear behavior. A backscattered scanning electron microscope and nanoindentation are operated to characterize the microstructure and mechanical properties between samples machined via different strain paths. Molecular dynamics models are developed to explore the mechanism that enhances wear resistance through the gradient grain structure in the surface layers machined by SSP and RSP. The wear test results show that the wear scar volumes of the SSP treated samples are about 70% of the original samples, while the RSP treated samples are about 60%, indicating that the RSP further enhances the wear resistance of copper. Compared to SSP machining, RSP machining activates the Bauschinger effect in the copper to produce the gradient structure with a larger thickness (500 μm–700 μm) and greater hardness (1.72 GPa–1.82 GPa). Consequently, RSP machining further improves the resistance to crack initiation and expansion, resistance to plastic deformation, total strain capacity, and elastic recovery in the wear process, which is why samples machined with RSP have better wear resistance.

Microstructure and wear behavior of arc-shaped 40CrNiMo steel after laser hardening

This study focuses on arc-shaped 40CrNiMo steel; the microstructure characteristics and formation mechanism of the hardened layer at different positions were investigated after laser hardening. Moreover, sliding friction experiments were conducted against GCr15 steel after the conventional heat treatment under dry friction conditions, and the wear characteristics of 40CrNiMo steel hardened after different laser process parameters was analyzed, the wear mechanism in different wear stages was studied. The results show that the martensite reliefs within different austenite grains have no effect on each other. The martensite relief within each individual austenite grain is closely related to the martensite growth in that grain. The laser hardening process parameters for obtaining the effective wear resistance performance of arc-shaped 40CrNiMo steel are as follows: the power was 2010 W, the spot size was 1 × 14 mm2 and the scanning speed was 800 mm/min. At the beginning of the friction wear tests, the wear type of arc-shaped 40CrNiMo steel is mainly abrasive wear. Abrasive wear causes spalling, and oxidation wear can easily occur at the peeling sites. As the dry friction wear tests continued, both oxidation wear and adhesive wear increased, and fatigue wear gradually occurred. The wear mechanism of the grinding plate with a similar hardness at different stages is similar to that of the circular-arc specimen.

Dry wear characteristics of TC21 titanium alloy at elevated temperatures

TC21 alloy is a new type of high damage tolerance titanium-based alloy, but its elevated-temperature wear characteristics such as wear mechanism and wear transition are still unknown. In present study, dry wear tests of TC21 alloy were carried out at experimental temperatures of 20 °C–300 °C under various applied loads. Volumetric wear rate was plotted against experimental temperature under each applied load to exhibit its variation trend and mild-severe wear transition. Scanning electron microscopy was used to examine worn surface morphologies. Confocal scanning laser microcopy and Vickers microhardness tester were utilized for characterizing the friction-affected microstructure and mechanical property in the subsurfaces. Four wear mechanisms, namely abrasion, adhesion, mild surface deformation and severe surface deformation, were observed. Severe surface deformation was found responsible for severe wear behavior, and it was aroused by the near-surface softening originating from dynamic recrystallization (DRX). The severe wear transition temperature was found to be decreased linearly with increasing applied load. By linearly fitting the relation between applied load and transition temperature, a critical surface temperature of 399.4 °C for severe wear transition is estimated, and it is further deduced to be the critical temperature for DRX realization of surface material during sliding.

Effect of High-Temperature-Assisted Ultrasonic Deep Rolling on Microstructure and Tribological Properties of Ni-WC Coatings

Cermet coatings are post-treated by a new surface microcrystallization technology, namely high-temperature-assisted ultrasonic deep rolling (HT + UDR). The process parameters of ultrasonic deep rolling significantly affect the microstructure and tribological properties of the Ni-WC coatings. In this paper, the samples were treated with different preloading depths (0.20 mm, 0.25 mm, and 0.30 mm), and the microstructure and properties of the coatings were characterized by SEM, EDS, X-ray stress analysis, and micro-Vickers hardness testing. An MMW-1A-type friction and wear tester was used for the dry friction and wear test at room temperature, respectively. Compared with the untreated sample, plastic rheology occurred on the surface of the coatings after HT + UDR, showing a phenomenon of “cutting peaks and filling valleys”. In the treated coatings, visible cracks were eliminated, and the inside of the coating was denser. The surface hard phase was increased as a “skeleton” and embedded with the soft phase, which played a role in strong and tough bonding. After HT + UDR + 0.25 mm treatment, the surface roughness increased by 68%, the microhardness of the surface layer reached a maximum of 726.3 HV0.1, and the residual tensile stress changed from 165.5 MPa to −337.9 MPa, which inhibited the germination and propagation of cracks. HT + UDR improved the wear resistance of the coating in many aspects. The coating after the 0.25 mm preloading depth treatment possessed the smallest friction coefficient and the lowest wear amount, which is 0.04 and 4.5 mg, respectively. The wear form was abrasive wear, and the comprehensive tribological performance is the best.

Dry sliding wear and microstructural behavior of stir-cast Al6061-based composite reinforced with cerium oxide and graphene nanoplatelets

The aluminum alloys possess high strength, ductility, castability, wear, and corrosion resistance. Due to such promising properties, aluminum alloy has wide applications in the aerospace and automotive industries. The present study, focused on the dry wear test of stir-cast hybrid aluminum metal matrix nano-composite (HAMNCs), fabricated using Al6061 (base alloy), graphene nanoplatelets (GNPs), and cerium oxide (CeO2). The reinforcements are added during stir casting in 1 to 3 weight percentages. The ASTM G99 standard was used to prepare the wear test specimens. The prepared test specimens were tested using pin-on-disc apparatus at four different loads (15 N, 30 N, 45 N, and 60 N). The worn-out surfaces are analyzed using the scanning electron microscope (SEM). It is found that the wear resistance of the hybrid nano-composite was enhanced with the addition of reinforcements. The lowest wear rate of 0.303 mm3/N-m was achieved with (3 wt% GNPs + 3 wt% CeO2) reinforcement in Al-6061 alloy. The coarser grain size and uniform dispersion were observed after examining the optical and SEM micrographs of the specimens, respectively. In future research work, the authors will expand this work by carrying out wear tests for the same pair at actual working settings and the same will be reported separately in subsequent research papers.

Dry wear behavior of Brass alloy before and after Nickel deposition treatment

Impact of electroplating affidavit of Nickel, treatment on mechanical properties, wear safety, and Vickers hardness of Brass alloy were studied. The examples were dealt with by utilizing electroplating testimony of Nickel on Brass surface specimens . The wear conduct of the samples were considered for all samples prior and then afterward treatment by Nickel statement and the dry wear tests were done by utilizing stick on-plate procedure. The samples were machined as a plate with width of 30 mm and. All samples were led by Scanning Electron Microscopy (SEM), Energy-Dispersive Spectrometry examination (EDS), optical microscopy, and Vickers hardness. The results demonstrated that the dry wear rate were diminished after Nickel affidavit and expanded Vickers hardness values by proportion of 2: 4 : 1. The results demonstrated that the estimations of wear rate for samples having electroplating affidavit of nickel are short of what specimens without deposition

Mo20Nb20Co20Cr20(Ti8Al8Si4) refractory high-entropy alloy coatings fabricated by electron beam cladding: Microstructure and wear resistance

The refractory high-entropy alloys (RHEAs) possess excellent mechanical properties and electron beam cladding (EBC) has the advantages of vacuum protection and higher energy utilization. In this study, the Mo20Nb20Co20Cr20(Ti8Al8Si4) RHEA coatings under different cladding currents (16, 17, 18,19 mA) are fabricated by EBC to improve the surface wear resistance of the Ti600 substrate. The microstructure and phase structure of RHEA coatings are investigated by OM, SEM, XRD, TEM. The mechanical properties of tcoatings and substrate are studied by microhardness, nanoindentation and dry wear test. The results show that the HEA coatings involve four main phases: BCC1(Mo,Nb,Al-rich-A2/B2), BCC2(Co,Cr,Ti-rich-B2), IMC1(Laves phase-CoTi) and IMC2((Ti,Nb,Zr)5Si3), respectively. With the cladding current increasing, the dilution rate of the substrate increases to cause the Ti content within coatings to rise. The size of BCC1(DR regions), IMC1 and IMC2 becomes larger and the microhardness, nanoindentation hardness, elastic modulus and room-temperature creep resistance decrease. The properties improvement of the coating is attributed to the solid solution, second phase and precipitation strengthening caused by the solid solution structures and intermetallic compounds. The maximum microhardness of the coatings at current 16 mA is 1150 HV0.2, more than 3 times that of the substrate and the friction coefficient of Ti600 is 2.16 times that of current 16 mA, which suggests that the Mo20Nb20Co20Cr20(Ti8Al8Si4) RHEAs can be used as an excellent wear-resistant coating with broad application prospect.