'A METHOD FOR PROCESSING FUNCTIONALLY GRADED HYBRID METAL MATRIX COMPOSITES '

摘要

The present invention relates to the fabrication of functionally graded hybrid metal matrix composites by centrifugal casting, based on aluminum and its alloys as matrix material and silicon carbide, alumina, graphite and primary silicon as reinforcements, wherein both the hybrid particles, denser and lighter reinforcements with respect to matrix alloy are distributed at the inner periphery of the hollow cylindrical casting. In general, during centrifugal casting the lighter and denser reinforcements than the matrix alloy move towards the inner and the outer periphery of the casting respectively. On the other hand, in the present invention, both the denser and lighter reinforcements are distributed with a gradient near the inner periphery by controlling the material and solidification parameters such as melt viscosity, composite pouring temperature, mould temperature, heat extraction rate and mould spinning speed.