Effect of high-rate heat transfer during casting on the strength, hardness and wear behaviour of aluminium—quartz particulate metal matrix composites

Abstract

This paper describes research on aluminium-based metal matrix composites (MMCs) reinforced with quartz particles cast in sand moulds using high-rate heat transfer techniques during solidification by means of metallic and non-metallic chills. The MMCs were fabricated by dispersing 3, 6 and 9 wt% of quartz particles ranging from 30 to 100μm in size in molten aluminium alloy above the liquidus temperature. The resulting composites, cast using chills, were tested for their strength, hardness and wear resistance. These properties of the MMCs were found to improve with the rate of heat transfer during casting. This rate of heat transfer is in turn dependent on the chill size and the chill material. After wear testing, the material surfaces were examined using scanning electron microscopy (SEM), and the wear mechanisms were analysed.