Vertical Centrifugal Casting of Aluminum Matrix Particle Reinforced Composites

Abstract

Centrifugal casting of composites gives rise to a certain distribution of reinforcement particles due to the natural liquid flow and solidification pattern. The particle rich regions are strongly influenced by rotational speed of the mold, particle size, relative density difference between particles and melt, initial pouring temperature, initial mold temperature, and by the nature of the particles added [1—3]. In the present work zirconia, silicon carbide, and ilmenite particles have been added to an aluminum—magnesium alloy and cast using a vertical centrifugal casting machine. The particle distribution and the resultant hardness variation have been analyzed. The particles are invariably associated with porosity. In the case of ilmenite particles, there is extensive reaction with the liquid metal. The combined effect of vol % of particles, porosity, and extent of reaction gives rise to a complex hardness variation. There is a substantial increase in hardness with particle addition. The particles tend to concentrate at the middle of the casting.