Production, testing and microstructural investigation on fly ash reinforced aluminium alloy matrix composite

In the present investigation Al 2024 + fly ash (5% and 7.5% wt.) composite is produced by motorised stir casting route and tested for hardness and ultimate tensile properties in Non-Heat Treated (NHT) condition. It is observed that these mechanical properties have improved with increase in quantity of fly ash at the cost of reduction in ductility. SEM images revealed the uniformity in distribution of fly ash in the matrix and precipitate phase were found to be along the grain boundaries. Elemental composition of precipitates is known by EDAX and Al2Cu is found to be major precipitate phase on the grain boundaries. The optical images are taken across the sections of 5% and 7.5% fly ash composite to do the fly ash quantification. The results of optical image fly ash quantification were agreeing with that of the actual fly ash quantity dispersed in the matrix during casting. SEM-EDAX is carried out on the fracture surface of tensile specimens of plain alloy and the 7.5% fly ash composite to analyse the fracture phenomenon.