TRANSIENT THERMAL-ANALYSIS OF SOLIDIFICATION IN A CENTRIFUGAL CASTINGFOR COMPOSITE-MATERIALS CONTAINING PARTICLE SEGREGATION

One-dimensional heat-transfer analysis during centrifugal casting of a luminum alloy and copper base metal matrix composites containing Al2O3 , SiCp, and graphite particles has been studied. The model of the part icle segregation is calculated by varying the volume fraction during c entrifugal casting, and a finite difference technique has been adopted . The results indicate that the thickness of the region in which dispe rsed particles are segregated due to the centrifugal force is strongly influenced by the speed of rotation of the mold, the solidification t ime, and the density difference between the base alloy and the reinfor cement. In the case where the base alloy density is larger than that o f the particles, the thickness of the particle-rich region near the in ner periphery decreases with an increase in speed, thereby increasing the volume fraction of dispersion. The solidification time of the cast ing is also dependent upon the speed of rotation of the mold, and it d ecreases with an increase in speed. This study also indicates that the presence of particles increases the solidification time of the castin g.