Phase analysis and wear behavior of in-situ spark plasma sintered Ti_3SiC_2

摘要

In-situ synthesis of dense near-single phase Ti_3SiC_2 ceramics from 3Ti/SiC/C/0.15Al starting powder using spark plasma sintering (SPS) at 1250℃ is reported. Systematic analysis of the phase development over a range of sintering temperatures (1050-1450℃) suggested that solid state reactions between intermediate TiC and Ti_5Si_3 phases lead to the formations of Ti_3SiC_2. The effect of starting powder composition on phase development after SPS at 1150℃ was also investigated using three distinct compositions (3Ti/SiC/C, 2Ti/ SiC/TiC, and Ti/Si/2TiC). The results indicate that the starting powder compositions, with higher amounts of intermediate phase such as TiC, favor the formation of Ti_3SiC_2 at relatively lower sintering temperature. Detailed analysis of wear behavior indicated that samples with higher percentage of TiC, present either as an intermediate phase or a product of Ti_3SiC_2 decomposition, exhibited higher microhardness and better wear resistance compared to near single phase Ti_3SiC_2.