Structural heterogeneity and its effects on the properties of an in situ TiB2–TiC/Cu composite synthesised by hot pressing

Abstract

ABSTRACTIn situ TiB2 and TiC reinforced copper matrix composites with tailored heterogeneous structure were fabricated via high-energy ball milling of Cu, TiH2 and B4C powders followed by hot pressing. The microstructures of both ball-milled powders and hot-pressed composites were compared. Although the dislocation density of Cu matrix was changed after hot pressing, the mode of distribution of ceramic phases in the Cu matrix was noted to transmit from the ball-milled powders to hot-pressed composites in case of the TiH2 particles synthesised by the in situ reactions. The structural inheritance between the ball-milled powders and hot-pressed composites could be used to control microstructural features and thus to tune properties. The hot-pressed TiB2–TiC/Cu composites with tailored heterogeneous structure exhibited better performance than those of homogeneous counterparts.