Tensile and Wear Behaviour of Al-4.5%Cu Alloy Reinforced Fly Ash/SiC by Stir and Squeeze Casting with Rolled Composites.

Abstract

Recycling of fly ash, the coal combustion waste product produced by thermal power plants, is an increasingly urgent problem associated with their storage and disposal, which may have negative effect on human and serious environmental issues. On the other hand, the high cost of aluminum Metal Matrix Composites (MMCs), reinforced with ceramic particles such as SiC and Al2O3 has limited their use in many engineering applications. In the present investigation, the Al-Cu matrix reinforced by fly ash and SiC particulate were fabricated using vortex stirring, followed by squeeze casting technique. The composites so produced were subjected to hot rolling for 30% reduction. The wear tests were carried out using a pin on disc technique. Microstructure of the composites was observed by scanning electron microscope (SEM). The results indicate that the hardness and tensile strength increases with increase in percentage of fly ash and SiC by stir, squeeze and rolled composites. But squeeze casting composites shows higher strength than stir casting. But rolled composites show higher mechanical properties than both stir and squeeze cast composites. The test results showed that rolled specimens fabricated by stir casting technique have greater wear resistance than those fabricated by squeeze casting technique. Microstructure shows better bonding between matrix particle interface and no fracture observed in rolled composites.