Tensile failure behavior of SiC/Ti-6Al-4V composites manufactured by plasma spraying route

In this study, multi-ply SiC fiber reinforced Ti-6Al-4V composites have been manufactured by a novel plasma spraying technique and subsequent vacuum hot pressing. Two different sizes of Ti-6Al-4V feedstock powders were used for plasma spraying to form matrix. A considerable amount of oxygen from environment was incorporated into as-sprayed Ti matrix during plasma spraying, and consequently caused matrix embrittlement. The use of coarse-sized feedstock powder reduced oxygen incorporation, but tended to increase fiber spacing irregularity and fiber strength degradation. Longitudinal tensile strength and ductility of the SiC/Ti-6Al-4V composites in this study were mainly affected by Ti matrix properties. The embrittlement of Ti matrix occurred at oxygen contents higher than similar to 0.4 mass%, and consequently reduced the tensile strength and ductility of SiC/Ti-6Al-4V composites.