Wear Behavior Of Aluminum Research Articles

Dry Sliding-Friction and Wear Behavior of Hot-Extruded Al6061/Si3N4/Cf Hybrid Metal Matrix Composite

The effects of reinforcement addition and hot extrusion on the microstructures, micro hardness, friction, and wear behavior of aluminum (Al) hybrid composite were investigated. Al6061 dispersed with electroless nickel-coated Si3N4 (6 wt.%) and copper-coated carbon fiber (Cf) (1 wt.%) hybrid composites was developed through stir casting followed by hot extrusion. Optical micro-structural studies confirmed that the size of reinforcements decreased, and their orientations were in the extrusion direction. The decrease in the grain size (29%) of hybrid composites was larger than that in the grain size of matrix alloys under hot-extruded conditions. The synthesized hot-extruded Al6061 hybrid composite exhibited a lower coefficient of friction (51%) and high wear resistance (39%) compared with the hot-extruded Al6061 base alloy.

Effect of MoS2 on the Wear Behavior of Aluminium (AlMg0.5Si) Composite

Aluminium alloy with silicon as alloying element finds more comprehensive applications and this induces the development of aluminium composite with the matrix AA6063 (AlMg0.5Si) alloy. The applications of aluminium composites are majorly in the automotive, defence and aerospace industries, where the parts subject to relative motion. Wear and friction are significant issues, and the effective method to overcome is the replacement of newer materials with self-lubrication properties. An attempt is made to develop one such self-lubricating composite material with aluminium matrix is made with the addition of solid lubricant molybdenum disulfide. The present study focus on the investigation of wear performance of the developed self-lubricating composite through the dry sliding wear analysis. The addition of solid lubricant enhanced the wear resistance even at the initial stage of the run and resulted in a steady state of wear from 200 m sliding distance. Also, the wear mechanisms which influence the wear performance were detected through the microstructural examination, and it was discussed.

Studies on Wear Behaviour of Aluminium 6061Alloy Reinforced with B4C & Mica Particulates Hybrid Metal Matrix Composite

Hybrid Metal matrix composites are commonly used in Aerospace, Automobile industries because of its light weight, High tensile strength, high resistance to wear and improved specific strength. This is mainly due to improved mechanical and tribological properties like strength, stiffness, abrasion, impact resistance and wears resistance. In the present scenario, a lot of research activities were on automobile. This paper direct the researchers and engineer towards suitable selection of materials by its properties in the relevant area and various techniques involved in fabrication of metal matrix composites, predominantly on the liquid state metal processing method. In this work Al6061, Boron carbide, mica and hybrid Aluminium metal matrix composites are fabricated using Stir casting Techniques with varying mass fraction of mica 3%, 4%, 5% incorporated into the alloy, Sustaining the mass fraction of boron carbide as 10% for all proportions. Mica and B4C ceramic particles were incorporated into Al 6061 alloy by stir-casting method. In Stir casting method of composite materials synthesis, a dispersed phase (ceramic particles, short fibers) is mixed with a molten metal matrix by means of mechanical stirring. The samples were studied using scanning electron microscope (SEM) one of the most useful instrument for future research to know its microstructure. This study emphasize on the dry siding wear behaviour of aluminium reinforced with 3%,4%,5% mica and constant quantity of 10% boron carbide hybrid composite using a pin on disc. Wear performance of the hybrid composites were evaluated over a different load ranges and at different sliding velocities.

Optimization of hybrid aluminum composites wear using Taguchi method and artificial neural network

PurposeThis research aims to describe the influence of weight per cent of graphite (Gr), applied load and sliding speed on the wear behavior of aluminum (Al) alloy A356 reinforced with silicon carbide (SiC) (10 Wt.%) and Gr (1 Wt.% and 5 Wt.%) particles. The objective is to analyze the effect of the aforementioned parameters on a specific wear rate.Design/methodology/approachThese hybrid composites are obtained by means of the compo-casting process. Tribological analyses were conducted on block-on-disc tribometer at three different loads (10, 20 and 30 N) and three different sliding speeds (0.25, 0.5 and 1 m/s), at the sliding distance of 900 m, in dry sliding wear conditions. Optimization of the tribological behavior was conducted via the Taguchi method, and ANOVA was used for the analysis of the specific wear rate. Confirmation tests are used to foresee and check the experimental results. Examined samples were analyzed via a scanning electron microscope (SEM). Regression models for predicting specific wear rate were developed with Taguchi and ANN (artificial neural network) methods.FindingsThe biggest impact on value of specific wear rate has the load (43.006%), while the impact of Wt.% Gr (31.514%) was less. After comparison of the results, i.e. regression models, for predicting the specific wear rate, it was observed that ANN was more efficient than the Taguchi method. The specific wear rate of Al alloy A356 with SiC (10 Wt.%) and Gr (1 Wt.% and 5 Wt.%) decreases with a decrease in the load and weight per cent of Gr-reinforcing material, as well as with a decrease in sliding speed.Originality/valueThe results obtained in this paper using the Taguchi method and the ANN method are useful for improving and further investigating the wear behavior of the SiC- and Gr-reinforced Al alloy A356.

Effect of ZrO2 on microstructure and wear properties of Al2O3/Al–Si composites

This study has investigated the dry sliding wear behaviour of aluminium (Al)–silicon (Si) alloy matrix hybrid composites reinforced with nanosized alumina (Al2O3) and zirconia (ZrO2) in cast and heat-treated conditions. Dry sliding wear tests were performed on a pin-on-disc apparatus under a normal load of 10 N. Optical microscopy, X-ray diffraction and scanning electron microscopy examination were used to investigate the microstructures and tribological properties of the composites and the base alloy. For comparison of the wear behaviours of the samples, the wear constant (K) was measured based on the wear rate data. The lowest wear constant was observed in the heat-treated composite containing 2 wt.% zirconia, which shows a decrease of around 65% in comparison to the non-reinforced base alloy. It has been suggested that the wear process is controlled by nucleation and propagation of cracks; however, in the case of heat-treated composites, the fragmentation of layers decreases due to the spherical nature of silicon particles.

Densification and tribological profile of niobium oxide

The origin of the intrinsic wear resistance of NbC-based materials is investigated through an assessment of the tribological performance of fully dense, crack-free spark plasma sintered Nb2O5 (here as a reduced polymorph: monoclinic Nb12O29 or NbO2.416). The most likely wear mechanism on NbC is the tribo-oxidation to Nb2O5. The unlubricated (dry) friction and wear behavior of alumina (99.7%) mated against rotating disks of crack-free niobium(V)oxide (Nb2O5) under unidirectional sliding (0.03–10m/s; 22°C and 400°C) and oscillation (f=20Hz, dx=200mm, 2/50/98% rel. humidity, n=105/106 cycles) will be presented. The microstructure and mechanical properties of the crack-free Nb2O5 are assessed. The tribological data obtained are benchmarked with different NbC grades, ceramics, cermets and thermally sprayed coatings.

Abrasive Wear Performance of Aluminium Modified Epoxy-Glass Fiber Composites

For a long time, Aluminum filled epoxies molds have been used in rapid tooling process. These molds are very economical when applied in manufacturing of low volume of plastic parts. To improve the thermal conductivity of the material, the metallic filler material is added to it and the glass fiber improves the wear resistance of the material. These two important parameters establish the life of composites. The present work reports on abrasive wear behavior of Aluminum modified epoxy and glass fiber composite with 5 wt.% and 10 wt.% of aluminum particles. Through pin on disc wear testing machine, we studied the wear behaviors of composites, and all these samples were fabricated by using hand layup process. Epoxy resin was used as matrix material which was reinforced with Glass fiber and Aluminum as filler. The composite with 5 wt.% and 10 wt.% of Al was cast with dimensions 100 × 100 × 6 mm. The specimens were machined to a size of 6 × 6 × 4 mm for abrasive testing. Abrasive tests were carried out for different grit paper sizes, i.e., 150, 320, 600 at different sliding distance, i.e., 20, 40, 60 m at different loads of 5, 10 and 15 N and at constant speed. The weight loss due to wear was calculated along with coefficient of friction. Hardness was found using Rockwell hardness machine. The SEM morphology of the worn out surface wear was analyzed to understand the wear mechanism. Results showed that the addition of Aluminum particles was beneficial for low abrasive conditions.

A Study on Dry Sliding Wear Behaviour of Hybrid Metal Matrix Composites at Room Temperature

An attempt has been made to study the dry sliding wear behaviour of Aluminium based hybrid composites in room temperature.Al 2219 is used as base material with B4C and MoS2 as reinforcements. The hybrid composite were prepared by conventional stir casting technique. The dry sliding wear test were carried out for various parameters like sliding distance, applied load and sliding speed. The Optical Microscope and SEM results showed the presence of B4C and MoS2, which are fairly uniform and randomly dispersed on matrix material.XRD analysis, shown the presence of B4C and MoS2 phases in the prepared composites.The incorporation of reinforcement particles B4C and MoS2 reduces the specific wear rate of composites. The addition of MoS2 as a secondary reinforcement has significant effect on reducing specific wear rate of prepared composites. By using SEM worn surface of hybrid composites were studied.

Mechanical and tribological behavior of alumina and alumina‐CNT reinforced hybrid unsaturated polyester composites

Micro‐ and nano‐scale wear behavior of alumina vis‐á‐vis alumina‐carbon nanotube‐reinforced hybrid composites has been studied. In comparison to the pristine alumina, the alumina‐carbon nanotube hybrid reinforcement resulted in reduced scratch depth and lower frictional coefficient. Addition of carbon nanotube has effectively modified the pristine alumina into a superior wear resistant filler. POLYM. COMPOS., 37:1577–1586, 2016. © 2014 Society of Plastics Engineers

Production and characterization of Al-xNi in situ composites using hot pressing

In this study, a new metal matrix composite of aluminium was designed with the addition of nickel alloy particles. To produce in situ intermetallic formation, aluminium-nickel powder mixtures with different ratios ranging from 5 to 40 wt% Ni were consolidated at 550?C for 15 minutes under 40 MPa pressure. The interlayer phase formed during sintering was determined using X-ray diffraction and energy dispersive X-ray spectroscopy. The effect of nickel and Al-Ni intermetallics on the mechanical properties of the material was studied. The results demonstrated that the addition of nickel enhanced the hardness and wear behaviour of aluminium by forming a strong bonding interface between the aluminium and nickel particles.

Dry Sliding Wear Behaviour of Aluminium/Be<sub>3</sub>Al<sub>2</sub>(SiO<sub>3</sub>)<sub>6</sub> Composite Using Taguchi Method

The present study deals with investigation relating to the influence of wear parameters like sliding speed, applied load and sliding distance on the dry sliding wear of aluminium metal matrix composites. The design of experiment approach was employed to acquire data in controlled way using Taguchi method. A Pin-on-disc apparatus was used to conduct the dry sliding wear test. An orthogonal array, signal-to-noise ratio and analysis of variance were employed to investigate the wear behavior of aluminium and it’s composite. The mathematical model was obtained to determine the wear rate of the aluminium and it’s composite. The confirmation tests were conducted to verify the experimental results. The incorporation of Be3Al2(SiO3)6 as reinforcement material in aluminium matrix material improves the tribological characteristics.

Cryogenic effects during casting on the wear behavior of aluminum-alloy/glass MMCs

This paper studies the wear behaviour of aluminum alloy/glass composites cast using cryogenically cooled copper chills. The size of the glass particles range from 50 to 100 μm and the content by weight ranges from 3% to 12% in steps of 3%. The superior mechanical properties of the castings, particularly their ultimate tensile strength (UTS), hardness and wear resistance, are discussed in relation to their microstructure. Results of the investigation indicate that, strength, hardness and wear resistance of the composite developed are highly dependent on the chilling rate and also the dispersoid content of the composite. The wear mechanisms are also studied using scanning electron microscopy.

Wear behaviour of aluminium matrix TiB2 composite prepared by in situ processing

The wear behaviour and microstructure of aluminium and Al-12Si alloy (A413) matrix composites containing 1 and 5 vol.-%TiB2 particles have been investigated. The composites were prepared by an in situ reactive slag technique. The wear surfaces and wear products were studied after reciprocating and rolling - sliding tests. Wear resistance increased with increasing particle content, and the Al-12Si composites were more wear resistant than those with Al matrixes. The wear mechanisms are briefly discussed.

Wet erosion behaviour of low SiC alumina-SiC nanocomposites

We have investigated the erosive wear behaviour of alumina and Al2O3-SiC “nanocomposites” with SiC content between 1 and 5%. Nanocomposites (grain sizes between 3.15 and 7.16 μm) and alumina (grain size 4.43 μm) were eroded with SiC particles using a custom-built erosive slurry wear tester. The erosion resistance of the nanocomposites increased slightly with decreasing grain size. Nanocomposites of all grain sizes showed better wear resistance than the alumina. Erosion resistance increases with SiC content, though this effect is not strong for SiC contents greater than 2%. These results are compared with related results from the literature.

Correlation between the characteristics of the mechanically mixed layer and wear behaviour of aluminium, Al-7075 alloy and Al-MMCs

The sliding friction and wear behaviour of aluminium (Al), aluminium alloy 7075 (Al-7075) and SiC particulate reinforced aluminium matrix composites (Al-SiC) have been investigated under dry sliding wear conditions. The wear tests were carried out at a sliding speed of 1 m/s and at normal load ranging up to 220 N. The overall objective of the study is to improve our current understanding with regard to the influence of mechanically mixed layers (MML), which form on the surface of the wearing material during the course of the wear test, on the friction and wear behaviour. The aluminium alloy 7075 was used in both solution treated and aged conditions. The aluminium based metal matrix composites studied contained 10 and 40 vol.% of SiC particles as the reinforcing phase. A detailed characterisation of the MML was carried out using SEM, EPMA and microhardness testing in order to understand the influence of test material and load on the composition, hardness and thickness of the MML formed and in turn the influence of the MML on the friction and wear behaviour. On the basis of the above characterisation, it is demonstrated that the observed friction and wear behaviour of Al, Al-7075 alloy and Al-SiC can be best understood in terms of the formation and fracture rate of the MML rather than the bulk properties of the material.

Influence of Apparent Pressure on Wear Behavior of Self‐Mated Alumina

Dry sliding wear experiments were conducted on self‐mated polycrystalline alumina using a ball‐on‐disk configuration. Instantaneous nominal pressures and corresponding wear rates were calculated from the measured contact diameter during sliding. Nominal pressure decreased with sliding and the wear rate decreased with decreasing pressure. These results show a good correlation between the nominal pressure and the wear rate, implying the importance of nominal pressure on the wear behavior of alumina. Although such a correlation is not new for metals, it is for ceramics.

Scratching of alumina in various environments

The purpose of this work was to study the frictional and wear behavior of alumina under scratching in various environments. The scratch tests were performed at loads from 0.5 to 50 N and a sliding velocity of V=0.4 mm s −1 during 100 cycles in water, paraffin oil and in laboratory air (humidity ∼ 50%). Diamond standard spherical indenter was used as the contrabody. The acoustic emission, friction coefficient, wear losses and failure development in the scratch tracks were evaluated. It was found that the friction coefficient increased during some cycles and then a steady friction state with approximately constant value of the friction coefficient was reached in all environments. The maximal friction coefficient, ( f=0.2), was in contact with paraffin oil, while the minimal value of f=0.09 was obtained in the wear test with water. The opposite effect was obtained in the determination of the wear rate. The width of the wear track was maximal and minimal in contact with water and paraffin oil, respectively. The trapping and agglomeration of wear particles was observed in the wear track under contact with air and water. Intergranular and transgranular fractures were found to be the dominant damage mechanisms in contact with paraffin oil. Close relation between signals of acoustic emission and friction and wear properties was exhibited under different environmental conditions. The bond between the trapped wear particles and the substrate was analyzed. It is supposed that the trapping of the wear particles is caused by triboelectrification of alumina. This effect was maximal in dry friction. Almost no trapping was observed in contact with paraffin oil.

Erosive wear behaviour of aluminium based composites

Al-MMCs reinforced with short fibres or particles of ceramics such as alumina, titanium diboride and silicon carbide result in composites of high specific strength and stiffness, suitable for advanced engineering applications such as in the aerospace and automotive industries. This paper studies the erosion wear behaviour of Al-based composites reinforced with alumina-fibre and in-situ TiB2 particles using a water/SiC particles slurry jet. From the results of our experiment, the erosion resistance of reinforced Al-MMCs depends on that of the Al-alloy and the reinforcing ceramics, as well as on the bonding strength between the matrix and ceramic fibres or particles. Some design strategies to enhance the erosion resistance of Al-MMCs reinforced with short fibres and particles have been discussed.

Effect of Grain Size and Test Configuration on the Wear Behavior of Alumina

The effects of grain size on the tribological behavior of alumina were investigated. Alumina specimens with three different grain sizes, namely 4, 8, and 14 m, were used as pins and disks in a flat‐pin wear test in which the apparent contact area was maintained constant during the test. In contradiction with previously published reports obtained with the regular round pin, our work has found that in this case the alumina wear decreases with increasing grain size. The evidence presented here suggests that the effect of grain size on alumina wear behavior is strongly influenced by the test configuration. Small grains and large grains exhibit two different wear mechanisms: brittle fracture such as grain pull‐out and microchipping as well as abrasive wear are the dominant mechanisms in the small grain size alumina, whereas plastic deformation plays a significant role in the wear behavior of coarser‐grained alumina.

Wear behaviour of alumina and sialon in line contact lubricated with diamond slurry

Investigation into the wear behaviour of alumina and sialon was carried out in the line contact configuration lubricated with diamond slurry. The experiments were conducted using different counterface materials, contact loads and size of the diamond abrasive particles in the slurry. The results indicate that the material removal rate depends significantly on the action of the diamond particles and counterface material. Both contact conditions facilitate easy ingress of diamond particles into the interface and the ability of the counterface material to entrap diamond particles contributes to a high rate of material removal.