Microstructure and mechanical properties of Alborex + SiCp/AS52 hybrid metal matrix composites

AS52 based hybrid composites reinforced with aluminium borate whiskers and SiC particulates were fabricated by a squeeze casting method. In a hybrid preform, the volume fraction of the aluminium borate whisker was 15% and that of the SiC particulate was 5%. Microstructures of the specimens were observed using OM and SEM. In the hybrid composites, the Alborex whiskers were uniformly distributed in the matrix and a few agglomerations or clusters of SiC particulates were observed. Hardness and three point bending tests were carried out to measure the mechanical properties of the specimens. The mechanical properties of the hybrid composites were higher than those of whisker reinforced composites and the hybrid composite with finer size particulates showed higher strength than the one with coarse particulates.