In situ synthesis and mechanical properties of bulk Ti_3SiC_2/TiC composites by SHS/PHIP

摘要

Ti_3SiC_2/TiC composites were synthesized by self-propagating high temperature combustion synthesis with pseudo-hot isostatic pressing procedure (SHS/PHIP) from titanium, silicon, silicon carbide and carbon black powders. The phase and crystal structures were investigated by X-ray diffraction (XRD), and scanning electron microscope (SEM). The results show that the volume fraction of Ti_3SiC_2 varies with the increasing amount of silicon carbide in the raw material, peaking at 85.4%. The flexural strength increases from 411 ± 17.9 MPa to 547 ± 17.9 MPa with the increasing amount of silicon carbide. However, there is no significant change in compressive strength and fracture toughness. The Vickers hardness of composites varies as a function of applied loads and increases with the increase of relative density. The fracture and damage mechanisms were also discussed.