THE DEVELOPMENT OF RAPIDLY SOLIDIFIED MICROSTRUCTURE IN SiC p/A356 COMPOSITES SUBJECTED TO LASER BEAM

The present investigation is aimed to understand the microstructure evolution of SiC p/Al Si composites, i.e. particle distribution and matrix microstructure in laser processing. Microstructures of SiC p/A356 composite and the monolithic alloy are comparatively studied through laser remelting process. It is observed that the particle remains its original distribution after re solidification, indicating rejection of particles by rapid solidification interface does not occur. The presence of particles does not lead to any change in the phase constitution and phase morphology in the matrix, but instead result in a considerable change in growth direction of primary phase. The underlying mechanism is rationalized based on the interplay between the particles and solidification interface.