Relationships among reinforcement volume fraction, microstructure and tensile properties of (TiBw + TiCp)/Ti composites after (α + β) forging

In this study, (TiBw + TiCp)/Ti composites reinforced with various volume fraction were prepared by in situ casting route and subsequent (α + β) forging. The relationships among reinforcement volume fraction, microstructure and tensile properties of the composites are investigated and discussed. The results indicate that the aspect ratios of the reinforcements are reduced and relatively uniform distribution of the reinforcements is obtained after (α + β) forging. Meanwhile, with the increase in volume fraction of reinforcement, the α phase is significantly refined due to dynamic recrystallization (DRX). The tensile testing results indicate that the yield strength and ultimate tensile strength of the composites exhibit a rising trend with the volume fraction of reinforcements while the elongations gradually reduce both at RT and elevated temperature. With the increasing of tensile temperature, the ultimate tensile strength of the composites obviously decreases while the elongation increases. The strengthening mechanism as well as the softening phenomena is discussed.