Fabrication of highly dense Ti3SiC2 ceramics by pressureless sintering of mechanically alloyed elemental powders

Pressureless sintering of Ti3SiC2 ceramics has been investigated by using mechanically alloyed elemental Ti, Si and C powder mixture as the starting materials. It has been found that mechanical alloying enhanced both the formation of Ti3SiC2 phase and the densification during sintering process. Highly dense Ti3SiC2 ceramics with a relative density up to 99% and a phase purity of ∼80% Ti3SiC2 (TiCx as the secondary phase) were obtained by sintering the mechanically alloyed powders at relatively low temperatures near 1773 K in an argon atmosphere of 0.1 MPa. The physical properties of the present pressureless-sintered Ti3SiC2-based ceramics are comparable to those of nearly single phase Ti3SiC2 ceramics fabricated by the reactive hot-isostatic pressing (HIP) that had been used so far.