Influence of graphite content on the dry sliding and oil impregnated sliding wear behavior of Al 2024–graphite composites produced by in situ powder metallurgy method (original) (raw)
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An Investigation on Wear Behavior of Graphite Reinforced Aluminum Metal Matrix Composites
2018
The present work investigates the 6061Al alloy – Graphite composite with graphite particle dispersions upto 9% to identify its potential to act as a self lubricating material at an optimum level of graphite. The required specimens are prepared using stir casting method with graphite proportions ranging from 3 to 9% by weight. Experiments were carried out to evaluate the tribological behavior of the composite material with varying graphite content in terms of coefficient of friction and wear rate. Under dry sliding conditions, effects of the sliding distance and sliding speed have also been studied. Under dry sliding conditions, minimum coefficient of friction and wear rate has been observed for 9% graphite content. Consequently 6061Al-graphite showed its capability to act adequately as a self lubricating material. Keywords—Aluminium-graphite MMC, Wear behavior, 6061Al-Graphite particulates, Coefficient of Friction
A study on wear behaviour of Al/6101/graphite composites
Journal of Asian Ceramic Societies, 2017
The current research work scrutinizes aluminium alloy 6101-graphite composites for their mechanical and tribological behaviour in dry sliding environments. The orthodox liquid casting technique had been used for the manufacturing of composite materials and imperilled to T6 heat treatment. The content of reinforcement particles was taken as 0, 4, 8, 12 and 16 wt.% of graphite to ascertain it is prospective as self-lubricating reinforcement in sliding wear environments. Hardness, tensile strength and flexural strength of cast Al6101 metal matrix and manufactured composites were evaluated. Hardness, tensile strength and flexural strength decreases with increasing volume fraction of graphite reinforcement as compared to cast Al6101 metal matrix. Wear tests were performed on pin on disc apparatus to assess the tribological behaviour of composites and to determine the optimum volume fraction of graphite for its minimum wear rate. Wear rate reduces with increase in graphite volume fraction and minimum wear rate was attained at 4 wt.% graphite. The wear was found to decrease with increase in sliding distance. The average coefficient of friction also reduces with graphite addition and its minimum value was found to be at 4 wt.% graphite. The worn surfaces of wear specimens were studied through scanning electron microscopy. The occurrence of 4 wt.% of graphite reinforcement in the composites can reveal loftier wear possessions as compared to cast Al6101 metal matrix.
Dry wear of al-graphite particle composites
Wear, 1981
Under lubricated conditions, ~-~phite particle composite is a good antiseizure bearing and antifriction material possessing properties which inhibit excessive temperature rise in bearings. The present study characterizes the dry wear properties of the composite. The dry wear characteristics of the Al-(2.7% -5.7% graphite particle) (50 -200 pm) composite were found to deteriorate with the addition of graphite, load and sliding distance. Roth rnicro~~~u~ and microhardness studies of the worn subsurfaces and analysis of wear debris show that the reductions in strength and ductility of the composite due to graphite addition are the most likely causes of deterioration in the wear properties of the composite.
Wear Characteristics of Al 6061 reinforced with graphite under different loads and speeds
This work investigates Al 6061 alloy with graphite particle impregnated metal matrix composites under dry sliding conditions. The conventional casting techniques were used for preparing the composite material. Experiments were conducted under dry sliding conditions for determining the wear behavior of Al 6061 alloy-Graphite composite material with varying wt % graphite content under different sliding speeds and at different loads. Sliding distance of 250m was commonly used for the wear test. A pin on disc machine was used for conducting the wear test. The test was conducted under atmospheric conditions. Wear rate decreases with increased sliding speed and increases with increasing load. Worn surfaces of the composites were examined through scanning electron microscope. The wear loss of the composite material with 5Wt % graphite was found to be minimum with respect to sliding speeds and loads.
Effect of Graphite Content on Tribological behaviour of Aluminium alloy - Graphite Composite
Euro Journals
An attempt has been made to study the influence of operating parameters such as applied load, sliding speed, percentage of reinforcement content and sliding distance on the dry sliding wear of 6061 aluminium with SiC and B4C particulate reinforced composite. The particulate reinforced 6061 aluminium alloy with a constant weight percentage of B4C particulate and varying range of SiC particulate is produced by stir casting technique. In order to achieve good binding between the matrix and particulates, 1% of magnesium alloy is added. Under dry condition the hybrid composite performances were investigated by pinon-disc with varying load conditions. The uniform distribution of particulates reinforced in the matrix was examined with the help of Optical-Microscope. The wear surfaces of the specimen at room temperature were examined before and after the wear test by using Scanning Electron Microscope (SEM). The hardness of the specimen at room temperature was also measured before the wear test by Rockwell hardness test machine. As the volume fraction of SiC and B4C reinforcement increases, the magnitude of hardness also increases. This investigation overviews that 6061 hybrid composite with high hardness can replace the conventional material used in automobile components for better performance and longer life.
Application of factorial techniques to study the wear of Al hybrid composites with graphite addition
The wear and sliding friction response of a hybrid aluminium metal matrix composite reinforced with hard ceramic (5 wt.% of SiC) and soft solid lubricant (0, 5, and 10 wt.% of graphite) fabricated by powder metallurgy was investigated. The influence of the percentages of reinforcement, load, sliding speed and sliding distance on both the wear and friction coefficient were studied using the pin-on-disk method with tests based on the design of experiments. Analysis of variance (ANOVA) was used to investigate the influence of the parameters on both the wear rate and the coefficient of friction. The hardness of the composites decreases as the % of graphite (Gr) increases. The wear and friction coefficient were mainly influenced by both the sliding distance and the load applied. The morphology of the worn out surfaces and the wear debris was analysed to understand the wear mechanisms. The wear resistance of the hybrid composite containing 5 wt.% SiC and 5 wt.% graphite is superior to that of the graphite free composites and the other hybrid composites. This study reveals that the addition of both hard reinforcement like SiC and soft reinforcement like graphite improves the wear resistance of aluminium composites significantly.
Journal of Nanomaterials, 2022
The dry sliding wear performance of eutectic Al-7075-CNT-Gr composites was estimated using a pin-on-disc wear test. According to the results, the wear and friction coefficients dropped gradually as the weight % of graphite elements improved. The composite’s wear resistance increased significantly as the sliding speed increased from 1 m/s to 2 m/s at 49 N while the load remained constant. 7075-7.5 wt percent Gr amalgamated, on the other hand, had a more significant coefficient of friction as the sliding speed increased from 1 m/s to 2 m/s at 49 N. After the test, the researchers looked at how the worn-out surfaces of the specimens originated. The mechanically mixed layer of oxides and iron was used as an effective tribolayer to increase the wear resistance at more incredible sliding speeds in the wear test.
Aluminum-graphite (Al/Gr) composites were fabricated by a proposed technique called "ex-situ and in-situ powder metallurgy" to avoid an interfacial reaction between the graphite and the aluminum. In the present study, a cooled compact pressing of material powders followed by hot extrusion techniques were used. Varies weight percentages of graphite flakes were mixed with Al powder using a mechanical mixing stirrer. The effects of graphite content and SiC formation on microstructures and wear properties of composites were investigated. The SiC particles are formed by in-situ reaction at temperatures above 252 0 C. SiC particles have greatly improved the wear and tensile properties of fabricated composites. The results also showed the SiC particles were refined (< 1µm) and uniformly distributed in the matrices as a result of hot extrusions and little pores were found in the composites. This significantly improves mechanical and wear properties.
ry sliding wear investigation of Al 6082 / Gr metal atrix composites by response surface ethodology
2016
The effect of graphite particles on the dry sliding wear behaviour of Al6082 alloy composites produced by conventional stir casting method has been investigated. The percentage of reinforcement was varied from 0% to 12% in a step of 3. The result showed that with the addition of graphite particles microand macro-hardness reduced by 11.11% and 10.44%, respectively. The tribological behaviour of composites was investigated by pin on disc apparatus. Percentage reinforcement, load, sliding speed and sliding distance were taken as the process variable. Response surface methodology has been used to plan and analyze the experiment. Results showed that sliding distance is the most influential factor and load is the factor which affects the wear least. © 2015 Brazilian Metallurgical, Materials and Mining Association. Published by Elsevier luminium matrix composites AMCs) luminium (Al) Editora Ltda. All rights reserved.