Improvement In Wear Properties Research Articles

Fabrication of Al6061/Ti3AlC2 MAX phase surface composite by friction stir processing and investigation of wear properties

Aluminium 6061 has a widespread applications in the automotive and aerospace sectors. However, because of its poor tribological properties, its life is limited. In this investigation, a surface composite of Ti3AlC2 and Al 6061 alloy was prepared using friction stir processing and its effects have been studied. The examination of microstructure of the fabricated samples were studied using optical microscopy and scanning electron microscopy. The microstructural analysis revealed reduction in grain size within both the base metal FSPed and aluminium- Ti3AlC2 composites. The area mapping showed uniform dispersion of Ti3AlC2 particles within the friction stir processed zone. The microstructure refinement lead to increase in the microhardness. The average microhardness of the base metal was 65 HV0.2 and that of base metal FSPed and Al- Ti3AlC2 were 85 HV0.2 and 135 HV0.2. The grain refinement and uniform distribution of particles were found responsible for the improvement in wear properties. It was observed that the wear resistance improvement of more than 100% in comparison to the parent metal. The predominant wear mechanism, as demonstrated by scanning electron microscopy micrographs, was abrasive wear with varying degrees and features.

Tensile and wear properties of as-cast and extruded AZ91-xCNT and AZ91-1B4C-1SiC-xCNT composites

Tensile and wear properties of as-cast and extruded AZ91-xCNTs and AZ91-1%B4C-1%SiC-xCNT (x:0.25,0.5,1wt.%) composites were studied. Compared to as-cast AZ91 matrix alloy, hot extruded AZ91-0.25%CNT showed a significant enhancement in UTS (385 MPa) and elongation (16%), with no substantial improvement in wear properties however, the AZ91-xCNT composites containing micron-sized 1%B4C and 1%SiC particles met the lower tensile properties. Interesting wear behaviour was obtained after adding 1wt.%B4C and 1wt.%SiC to AZ91-xCNT where improvement in wear results was considerable. Development in wear properties of the AZ91-1%B4C-1%SiC-xCNT composites can be attributed to the enhanced hardness and reduced coefficient of friction. Wear analyses of two composites exhibited various wear mechanisms, but the abrasion mechanism dominated after CNT addition and hot extrusion at 20 N load.

Comparison of wear behaviour of LM13 Al−Si alloy based composites reinforced with synthetic (B4C) and natural (ilmenite) ceramic particles

Dry sliding wear behaviour of stir-cast aluminium matrix composites (AMCs) containing LM13 alloy as matrix and ceramic particles as reinforcement was investigated. Two different ceramic particle reinforcements were used separately: synthetic ceramic particles (B4C), and natural ceramic particles (ilmenite). Optical micrographs showed uniform dispersion of reinforced particles in the matrix material. Reinforced particles refined the grain size of eutectic silicon and changed its morphology to globular type. B4C reinforced composites (BRCs) showed maximum improvement in hardness of AMCs. Ilmenite reinforced composites (IRCs) showed maximum reduction in coefficient of friction values due to strong matrix−reinforcement interfacial bonding caused by the formation of interfacial compounds. Dry sliding wear behaviour of composites was significantly improved as compared to base alloy. The low density and high hardness of B4C particles resulted in high dislocation density around filler particles in BRCs. On the other hand, the low thermal conductivity of ilmenite particles resulted in early oxidation and formation of a tribo-layer on surface of IRCs. So, both types of reinforcements led to the improvement in wear properties of AMCs, though the mechanisms involved were very different. Thus, the low-cost ilmenite particles can be used as alternative fillers to the high-cost B4C particles for processing of wear resistant composites.

Analysing the Microstructures and Pin-on-Disc Wear Properties of 1010 Steel-Based and B<sub>4</sub>C-Added Materials Produced through Powder Metallurgy

The present study makes use of two distinct production methods. The first method involves producing 1010 steel-based materials containing SiC, MgO, H3BO3, and B4C (wt%10 - wt%30) with varying weights through powder metallurgy. This step was followed by hot pressing. In the second group, after all the chemicals were stirred, 20 ml of epoxy and epoxy hardener were added to the mixture. Then, the mixture was set aside to harden. XRD and SEM-EDS analyses were conducted on the mixture to observe the morphological impacts. Furthermore, friction coefficient values of the materials were also identified following wear tests under varying weights. The XRD analyses revealed the phase structures of Fe3C, SiC, MgO, H3BO3, B4C, and Fe2O3. As for the SEM-EDS analyses, they concluded the surface appearance of S60 and S55B20, the hot-pressed materials, dependent on liquid phase sintering. SEM of epoxy- based S60E20 and S55B20E20 revealed white spherical structures and a flat matrix structure with shallow surface holes. In the pin-on-disc wear experiment, the friction coefficient value was reduced with the addition of SiC, MgO, and H3BO3 (S60) to 1010 steel (S100). By adding various amounts of B4C, the friction coefficient was reduced even further, resulting in the improvement of wear properties.

Optimization of Cryogenic Process for Enhancing the Wear Resistance of Novel HNMS Steel for Cryogenic Bearings of Launch Vehicle

Bearings are highly engineered components that have to tolerate vibratory stresses, bending moments, and high rotational speeds in cryogenic applications. AISI 440C is most widely used for antifriction bearings due to its good strength and high hardness but is prone to carbide banding and failure during service. High-nitrogen martensitic stainless steel (HNMS) was recently developed by partially substituting carbon with nitrogen. This article explores the possible improvement in wear properties by cryotreating HNMS steel. The hardening temperature was varied from 1050 to 1100 °C, cryosoaking period from 0 to 12 h at −196 °C, and tempering temperature from 100 to 300 °C for 1 h. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) analysis revealed the presence of carbides and carbonitrides. The phase fraction and size of the precipitates was found to be influenced by the cryosoaking period. The carbide density variation with the cryosoaking period followed a sigmoidal curve. Eight hours of cryogenic treatment at −196 °C was observed to be the optimal cryosoaking period for HNMS steel. Maximum hardness (671 HV) and minimum wear rate (0.00714 mm3/m) and adhesive wear were observed for the optimum heat treatment condition. Compared to conventional hardening-tempering (HT) treatment, the optimized hardening-cryogenic-tempering (HCT) treatment cycle resulted in a 38% increase in hardness and a 31% decrease in the wear rate. The improved properties can be attributed to the presence of fine and uniform distribution of precipitates in the matrix and transformation of retained austenite to martensite.

Surface Treatment of S355JR Carbon Steel Surfaces with ZrB2 Nanocrystals by CO2 Laser

To improve mechanical properties of S2355JR carbon steel, pre-synthesized ZrB2 nanocrystals were used to coat the metal surface by laser cladding using 2000 W CO2 laser. ZrB2 nanocrystals were synthesized by mechanochemical process. The effect of laser power on the coating layers was examined for optimizing the most effective coating conditions. Microstructural studies were carried out using optical microscope, scanning electron microscope and X-ray diffraction to analyze phase structures of the coated layers. Mechanical characteristics of the laser coated layers were evaluated by studying microhardness, wear and scratch resistance properties. Maximum hardness of the coated layers was observed while cladding with 75 and 125 W laser powers, when other processing parameters and conditions were kept at optimum levels. EDS analysis of these laser cladded layers indicated the formation of complex boro-nitrides, nitrides and carbides of Zr and Fe that contributed to vast increase in hardness of the laser-clad coating on S2355JR steel. Depending upon the laser powers used, the thickness of the coated layers was found to be in the range of 15–37 µm. The wear and micro-scratch tests results revealed significant improvement in wear properties.

Evaluation of mechanical and wear performance of glass/carbon fiber reinforced polymer hybrid composite

Fiber reinforced polymer composites are used in various applications due to their improved mechanical properties and lighter weight. However, these materials have inadequate wear resistance in different abrasive wear environment such as gears, bearings and rollers. Thus, the evaluation and improvement of wear properties of polymer matrix composites is necessary for structural and abrasive wear environment. In this article, the three body abrasive wear properties of glass/carbon reinforced hybrid composites are investigated with different operating conditions. The Box-Behnken Design of Experiment was used to conduct the experiments. A polynomial mathematical model has been developed through Response Surface Methodology (RSM). The model predicted optimum conditions for minimum specific wear rate of the hybrid composite ([G3C2]s) is applied load of 33N and sliding distance of 1221m. Furthermore, a confirmation test has been performed experimentally and found a good agreement between them.

Improvement in tribological behavior of commercial pure titanium (CP-Ti) by surface mechanical attrition treatment (SMAT)

Abstract In the present work, commercial pure titanium (CP-Ti) samples were subjected to surface mechanical attrition treatment (SMAT) under different durations in order to improve surface properties and produce an ultrafine grain layer. Cross section and surface of SMATed samples were analyzed through optical microscopy (OM) and scanning electron microscopy (SEM) methods. The finest grain size on surface, measured with X-ray diffraction (XRD) test, was 12.2 nm. While the initial grain size was measured to be averagely 70 μm. Hardness of SMATed samples increased by 2.8 times. Increase in hardness was due to plastic deformation and work-hardening. SMAT led to improvement of wear properties in CP-Ti so that its friction coefficient decreased by 66%. On the other hand, wear rate of CP-Ti samples decreased by about 60%. According to the established relationships between hardness and wear rate, increase in surface hardness and creation of a deformed layer led to reduction of wear rate. Surface roughness continuously increased with SMAT. Surface roughness after SMAT was increased by almost 6 times. Increase in surface roughness was due to impact of balls on samples surfaces leading to formation of valleys and peaks.

The effect of GNPs on wear and corrosion behaviors of pure magnesium

This study aims to investigate the role of graphene on wear and corrosion behaviors of pure magnesium. Magnesium/Graphene Nanoparticle (GNP) composites were fabricated via semi powder metallurgy method with a different content of graphene (0.1, 0.25 and 0.5 wt%). The effect of graphene in pure magnesium was examined by hardness, wear and corrosion tests. Microstructural and phase analysis were carried out by Scanning Electron Microscope (SEM) and X-ray Diffraction (XRD) analysis. Experimental results revealed that, hardness values increased with the addition of graphene. There was a same trend in wear behaviors with increase of graphene rate. The best wear performance was belonging to the 0.50 wt% graphene/mg composite under load of 10N. So improvement of wear properties was achieved using graphene as reinforcement. According to the microstructural evolution, the uniform distribution was achieved for all samples but partially agglomeration could be seen in Mg-0.50 wt% graphene. Compared to the pure magnesium, corrosion performance was affected negatively in graphene reinforced composites.

Wear behavior of FDM parts fabricated by composite material feed stock filament

Purpose In this study the friction and wear behavior of fused deposition modeling (FDM) parts fabricated with composite material and acrylonitrile butadiene styrene (ABS) material feedstock filament were realized and compared under dry sliding conditions. Design/methodology/approach The tests were performed by applying the load of 5, 10, 15 and 20 N with sliding velocity of 0.63 m/s for the duration of 5 and 10 min at room temperature. Findings The results highlight various wear mechanisms such as adhesion, abrasion and fatigue during the investigation. It was observed that the wear volume, friction force, friction co-efficient and temperature were sensitive to the applied load and time duration. The composite material showed a remarkable improvement in wear properties as compared to the ABS material. Research limitations/implications The investigations reported in the present research work is based on comparative analysis (of composite material and ABS material feedstock filament). The results may be different in practical applications because of different operating conditions. Practical implications The parts fabricated with proposed composite material feedstock filament are highly wear resistant than basic ABS filament. This may lead to the development of better wear resistance components for numerous field applications. Originality/value The potential of this research work is to fabricate FDM parts with composite material feedstock filament to cater need of wear resistant industrial components.

Influence of Combined Addition of Boron and Strontium on High-Temperature Wear Behavior of A356 Alloy

In the present study, the effect of the combined addition of boron (B) and strontium (Sr) on the high-temperature dry sliding wear behavior of A356 alloy has been investigated using a pin-on-disc wear testing machine attached with a furnace. During wear studies, the effect of alloy composition, normal pressure, sliding speed, and sliding distance on A356 alloy at four temperatures, namely, room temperature and 100, 200, and 300°C, have been investigated. Further, the cast alloys and worn surfaces of A356 alloy with and without B and Sr were characterized by scanning electron microscopy (SEM)/energy-dispersive spectroscopy (EDS) microanalysis. Results indicate that the combined addition of B and Sr to A356 alloy has led to improvements in wear properties. This is due to a change in microstructure, improvement in mechanical properties, and the formation of an oxide layer between the mating surfaces during the sliding wear process.

English

Study involves the comparison between wear properties of commercially pure Mg, Mg-4Zn, Mg-4Zn- 3MnO2 and Mg-4Zn-3MnCl2 by addition of Zn and Mn (by changing their sources). The wear behaviour of all systems investigated under applied loads of 5, 10, 15, 20, 25 and 30 N at the room temperature. The wear tests carried out by pin-on-disk type wear testing machine at sliding speed of 0.25 m/s for a total sliding distance of around 452 meter. The result shows that the wear property of pure magnesium improved by addition of 4.0% zinc but by addition of manganese in improvement of wear properties is not noticeable. At lower load condition (5N & 10N) the highest wear resistance obtained in Mg-4Zn-3MnCl2 system. At higher load (20N, 25N & 30N) wear resistance remain almost equal in all systems (Mg-4Zn, Mg-4Zn-3MnO2 & Mg-4Zn-3MnCl2).

Improvement in Wear Properties of a Hypereutectic Aluminium Silicon Alloy with Manganese

Improvement in wear properties of rare earth Cerium base hypereutectic Aluminium-Silicon alloy with Manganese modification has been reported in this paper. Wear studies were carried out on cast samples of hypereutectic Aluminium-Silicon alloy (Al-Si) with rare earth Cerium oxide (CeO2) and Manganese (Mn) modification. Final wear properties of rare earth Cerium oxide and Manganese modified hypereutectic Aluminium Silicon alloy were compared with the values of author's previous work on rare earth Cerium oxide modified hypereutectic Aluminium Silicon alloy and hypereutectic Aluminium Silicon base alloy. Rare earth Cerium oxide and Manganese modification in hypereutectic Aluminium Silicon base alloy reduced the wear rates as compared to rare earth Cerium oxide modified hypereutectic Aluminium Silicon alloy and hypereutectic Aluminium Silicon base alloy. A comparison of wear rates at same velocity, load and sliding distance was made between above three different conditions and it was observed that rare earth Cerium oxide and Manganese modified alloy performed with least wear rates. Wear rates for rare earth Cerium oxide and Manganese modified hypereutectic Aluminium Silicon alloy was 6.36 times lesser than wear rate of hypereutectic Aluminium Silicon base alloy and was 2.97 times lesser than rare earth Cerium oxide modified hypereutectic Aluminium Silicon alloy. Wear rates were also calculated for rare earth Cerium oxide and Manganese modified hypereutectic Aluminium Silicon alloy at various velocities ranging from 0.2 m/s to 1.0 m/s at an equal interval of 0.2 m/s. It was noticed that minimum wear occurred at 1.0 m/s velocity and maximum at 0.2 m/s velocity. Further, scanning electron micrographs (SEM) of worn surfaces and wear debris of rare earth Cerium oxide and Manganese modified hypereutectic Aluminium Silicon alloy were compared at low velocity (0.2 m/s) and high velocity (1.0m/s) conditions at constant load (30 N) and sliding distance (500 m). It was observed that worn surface and wear debris of rare earth Cerium oxide and Manganese modified hypereutectic Aluminium Silicon alloy, showed mild oxidative wear irrespective of lower velocity.

Dry sliding wear of aluminium-high silicon hypereutectic alloys

One of the main limitations on using aluminium-high silicon (with silicon contents greater than about 20wt%) alloys is the formation of coarse, brittle silicon particles under conventional solidification conditions. However, an increase in silicon content generally gives an improvement in wear properties so there is a drive to produce the high silicon alloys with relatively fine microstructures. Rapid solidification processing (RS) is very effective in limiting the coarsening of primary silicon due to the high cooling rate. Here flakes of material produced by chopping melt-spun ribbon have been degassed, consolidated, hot isostatically pressed and then extruded. The resulting material has been subjected to dry sliding reciprocating multi-pass wear testing at room temperature against a steel ball bearing at 10N and 100N load. The alloys compared can essentially be characterised as ‘low in silicon (around 21wt%), high in intermetallic-forming elements (Fe, Cu, Ni)’ and ‘high in Si (around 30wt% Si), low in intermetallic forming elements’. The wear results show that extruded bar with composition Al 21Si 3.9Cu 1.2Mg 2.4Fe 1.4Ni 0.4Zr has higher hardness, and hence wear resistance, than extruded bar with composition Al 29.8Si 1.3Cu 1.4Mg 0.3Fe 0.3Ni 0.3Zr, despite the higher Si content. It is thought that, at the higher Si content, there may be silicon particle pull-out which may subsequently lead to a three-body abrasive wear mechanism. In addition, for the lower Si alloy, the higher amounts of intermetallic-forming elements are thought to be contributing to the wear resistance.

Effect of Carbon Nanotube Addition on the Wear Behavior of Basalt/Epoxy Woven Composites

The effect of acid-treated carbon nanotube (CNT) addition on the wear and dynamic mechanical thermal properties of basalt/epoxy woven composites was investigated in this study. Basalt/CNT/epoxy composites were fabricated by impregnating woven basalt fibers into epoxy resin mixed with 1 wt% CNTs which were acid-treated. Wear and DMA (dynamic mechanical analyzer) tests were performed on basalt/epoxy composites and basalt/CNT/epoxy composites. The results showed that the addition of the acid-treated CNTs improved the wear properties of basalt/epoxy woven composites. Specifically, the friction coefficient of the basalt/epoxy composite was stabilized in the range of 0.5-0.6 while it fell in the range of 0.3-0.4 for basalt/CNT/epoxy composites. The wear volume loss of the basalt/CNT/epoxy composites was approximately 68% lower than that of the basalt/epoxy composites. The results also showed that the glass transition temperature of basalt/CNT/epoxy composites was higher than that of basalt/epoxy composites. The improvement of wear properties of basalt/epoxy composites by the addition of acid-treated CNTs was caused by the homogeneous load transfer between basalt fibers and epoxy matrix due to the reinforcement of CNTs.

Investigation of the effect of Al-8B master alloy and strain-induced melt activation process on dry sliding wear behavior of an Al–Zn–Mg–Cu alloy

This study was undertaken to investigate the influence of Al–8B master alloy and modified strain-induced melt activation process on the structural characteristics and dry sliding wear behavior of Al–12Zn–3Mg–2.5Cu aluminum alloy. The optimum amount of B containing master alloy for proper grain refining was selected as 3.75wt.%. The alloy was produced by modified strain-induced melt activation (SIMA) process. Reheating condition to obtain a fine globular microstructure was optimized. The optimum temperature and time in strain-induced melt activation process are 590°C and 10min, respectively. T6 heat treatment was applied for all specimens before wear testing. Significant improvements in wear properties were obtained with the addition of grain refiner combined with T6 heat treatment. Dry sliding wear performance of the alloy was examined in normal atmospheric conditions. The experimental results showed that the T6 heat treatment considerably improved the resistance of Al–12Zn–3Mg–2.5Cu aluminum alloy to the dry sliding wear. The results showed that dry sliding wear performance of globular microstructure specimens was a lower value than that of B-refined specimens without strain-induced melt activation process.

Minimizing tribolayer damage by strength–ductility matching in dual-scale structured Al–Sn alloys: A mechanism for improving wear performance

A mechanism for significant improvement of wear properties has been investigated. This operates by inducing a dual-scale structure consisting of coarse-grains (CG) and ultrafine-grains (UFG) in Al–12wt%Sn alloys, in comparison with uniform UFG or CG structured alloys. It has been found that a dynamic steady tribolayer consisting of fine crystalline oxides plays a dominant role in improving the wear properties of both the UFG and dual-scale alloys. For the CG alloys, poor wear properties, caused by delamination wear of the tribolayer, could not be maintained on the worn surface. The tribolayer is formed on the worn surface by compacting and tribo-sintering of fine loose particles produced by sliding wear. However, the damage of the dynamic steady tribolayer is governed by the matching between ductility and strength of the matrix. The low ductility of the UFG alloy substrate causes the tribolayer to suffer crack damage rather easily, which limits any further improvement of its wear resistance. In contrast, for the CG alloys, the tribolayer is broken up and extruded into the matrix as a result of its low strength and a stable tribolayer could not be formed. The dual-scale structured alloy has excellent ductility–strength matching, and therefore a dynamic stable tribolayer can easily be maintained on the worn surface, leading to excellent wear performance.

Tribological behavior of a novel alumina/nano-zirconia/niobium biocomposite against ultra high molecular weight polyethylene

The present work has studied the dry sliding behavior of Al2O3–nZrO2–Nb micro–nanobiocomposites against ultrahigh molecular weight polyethylene (UHMWPE) in air. The tests were carried out with a reciprocating wear tester with an applied load of 30N, a sliding speed of 0.06m/s and sliding distance up to 10km. Under the adopted testing conditions, the ceramic–metal composite against UHMWPE shows one and a half order of magnitude lower wear rate than the monolithic alumina; and friction coefficient as low as half of that for pure alumina–UHMWPE system. This behavior is related with: (a) the improvement in mechanical properties (toughness and strength) that will lead to the corresponding improvement in wear properties, and (b) the formation of a self-lubricating layer that will provide sufficient lubrication in order to considerably reduce the friction, as compared to monolithic alumina against UHMWPE combination.

Effect of Cobalt Content on Wear and Corrosion Behaviors of Electrodeposited Ni–Co/WC Nano-Composite Coatings

Metal-ceramic composite coatings are widely used in automotive and aerospace industries as well as micro-electronic systems. Electrodeposition is an economic method for application of these coatings. In this research, nickel-cobalt coatings reinforced by nano WC particles were applied on carbon steel substrate by pulse electrodeposition from modified Watts bath containing different amounts of cobalt sulphate as an additive. Saccharin and sodium dodecyl sulphate (SDS) were also added to electroplating bath as grain refiner and surfactant, respectively. The effect of cobalt content on wear and corrosion behavior of the coatings was investigated. Wear and corrosion properties were assessed by pin-on-disk and potentiodynamic polarization methods, respectively. Phase analysis was performed by X-ray diffraction (XRD) using CuK(alpha) radiation and the worn surfaces were studied by means of Scanning Electron Microscopy (SEM). The results showed that the addition of cobalt improved the wear resistance of the coatings. In the presence of 18 g/L cobalt in electrodeposition bath, the wear rate of the coating decreased to 0.002 mg/m and the coefficient of friction reduced to 0.695 while they were 0.004 mg/m and 0.77 in the absence of cobalt, respectively. This improvement in wear properties can be attributed to the formation of hcp phase in metallic matrix. Meanwhile, the corrosion resistance of the coatings slightly reduced because cobalt is more active metal with respect to nickel.

708 グラファイト粒子の複合化によるCU基メタルボンド砥石の摩耗特性改善

708 グラファイト粒子の複合化によるCU基メタルボンド砥石の摩耗特性改善