INVESTIGATION OF TRIBOLOGICAL BEHAVIOR AND ITS RELATION WITH PROCESSING AND MICROSTRUCTURES OF AL6061 METAL MATRIX COMPOSITES

The present study deals with the investigation of wear behaviour of Al6061MMCs and its relation with Processing & microstructure. Al 6061 MMC composite containing different weight percentages of A l2O3 & keeping 2 weight % graphite constant have been fabricated using a Vortex method (stir casting method). A pin-on-disc wear testing tribometer was used to carry out the dry sliding wear tests on both Aluminum 6061 alloy composites and Aluminium 6061 monolithic alloy over a load range of 10-50N and sliding velocity of 1.88?5.65 m/s for various sliding distances of 1-3km. The SEM micrographs taken for the micro structure analysis of the reinforced composite specimens produced by casting show that the graphite and Al2O3 particulates are uniformly distributed in the matrix. The SEM of wear surfaces showed that the large grooved regions and cavities with Al2O3 particles were found on the worn surface of the composite. Also worn surface of the Al 6061composite is rougher than unreinforced Al6061 alloy, this indicates an abrasive wear mechanism results due to presence of Al2O3. Further, it was understood from the experimentation that the wear rate and coefficient of friction decreased linearly with increasing weight percentage of Al2O3. The wear rate increase as the sliding speed increases. The best results of minimum wear have been obtained at 8% weight fraction of Al2O3