Microstructure and mechanical properties of in-situ B4C reinforced TC4 composites prepared by laser melting deposition

Abstract

In order to satisfy the increasingly harsh service environments of modern aircrafts, the novel in-situ reinforced xB4C/TC4 (x = 0–1.5 wt%) composites were prepared by laser melting deposition (LMD) and their microstructure, mechanical properties were investigated. The dual reinforcement phases of TiC and TiB were formed after B4C addition. A more favorable microstructure of refined α-Ti grains and uniformly-distributed reinforcement phases was obtained after adding 0.5 wt% B4C. The 0.5B4C/TC4 composite exhibited a moderate anti-abrasion ability owing to its beneficial microstructure and relatively high microhardness. Furthermore, it possessed the highest strength due to the effects of grain strengthening and dispersion strengthening induced by the (TiC + TiB) phases. This work provides theoretical basis and technical guidance for the development of high-performance Ti matrix composites.