Microstructure, mechanical and thermal properties of titanium matrix composites with different reinforcements

Abstract

In this study, three titanium matrix composites (TMCs) reinforced with graphite, graphene, and boron carbide (B4C) were fabricated through powder metallurgical techniques. The morphologies of grains and secondary phases of these TMCs were observed through Optical Micrograph (OM) and Scanning Electron Microscopy (SEM). The results of the mechanical properties of the TMCs showed that B4C was the most effective in increasing the strength and hardness, while the strengthening effect was comparable between graphite and graphene. The plasticity of the graphene reinforced TMC decreased sharply because of the formation of strip-like agglomerations. The small sizes, large volume fraction, and uniform distribution of the secondary phases contributed to the enhancement of strength and hardness in boron carbide reinforced TMC. Although the thermal properties of the TMCs were lower than pure titanium in the temperature range of 25~300℃ , the thermal conductivities of the TMCs were all above 15.6W/m· K.