Microstructure and mechanical properties of vacuum hot-pressing SiC/Ti–Cu–Ni–Sn bulk metallic glass composites

Abstract

In the present study, Ti 50Cu 28Ni 15Sn 7 (at.%) metallic glass and its composite powders reinforced with 4–12 vol.% of added SiC were successfully prepared by mechanical alloying. In the ball-milled composites, an amorphous matrix with a homogeneous dispersion of SiC particles was developed. The metallic glass composite powders were found to exhibit a large supercooled liquid region before crystallization. The presence of SiC particles did not change the glass-formation ability of the amorphous Ti 50Cu 28Ni 15Sn 7 powders. Consolidation of the as-milled Ti 50Cu 28Ni 15Sn 7 composite powders was performed at a temperature slightly higher than the glass-transition temperature under a pressure of ∼1.2 GPa; using this method, the bulk metallic glass composite discs were prepared successfully. However, partial crystallization of the amorphous matrix during the hot-pressing process was noticed. The fracture strength of consolidated composite compacts was increased with SiC additions. The pre-existing particle boundaries may serve as the crack initiation sites which resulted in the brittle failure of the Ti 50Cu 28Ni 15Sn 7 BMG composites.