Effect of SiC whisker on densification and mechanical properties of hot-pressed TiC-based composites

Abstract

The impact of adding 40 vol% SiC whiskers on the sinterability, flexural strength, and hardness of TiC ceramics was studied. The hot-pressing route was employed to fabricate the TiC–SiC composite, as well as the monolithic TiC ceramic. The microstructural studies and X-ray diffractometry revealed the precipitation of carbon within the TiC matrix owing to the formation of non-stoichiometric TiCx during the hot-pressing. The addition of SiC whiskers noticeably improved the sinterability of TiC, attaining a fully dense composite sample. The nucleation and growth of new SiC grains were identified as the dominant factors in enhancing the relative density of the TiC-40 vol% SiC composite. Moreover, the SiC additive had an effective impact on both flexural strength and hardness of TiC, standing at 543 MPa and 2280 HV0.5 kg, respectively.