Particle Pushing during the Solidification of Metal Matrix Composites

AbstractThe migration behaviour of ceramic particles during the liquid phase processing of metal matrix composites has been explored with the aid of centrifugal casting. Body forces were applied to the ceramic to act in opposition to pushing forces generated at the liquid-solid interface. The magnitude of the body force and solidification rates were varied, to observe the effect on the particle distribution. Of particular interest was the transition from sedimentation-dominated to particle-pushing-dominated redistribution. It is deduced that, for 13 μm diameter alumina particles in CP Al, the critical (maximum) pushing velocity, in the absence of body forces, is in the approximate range of 1–5mm/s−1.