Phase analysis and wear behavior of in-situ spark plasma sintered Ti3SiC2

In-situ synthesis of dense near-single phase Ti3SiC2 ceramics from 3Ti/SiC/C/0.15Al starting powder using spark plasma sintering (SPS) at 1250 degrees C is reported. Systematic analysis of the phase development over a range of sintering temperatures (1050-1450 degrees C) suggested that solid state reactions between intermediate TiC and Ti5Si3 phases lead to the formations of Ti3SiC2. The effect of starting powder composition on phase development after SPS at 1150 degrees C 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 Ti3SiC2 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 Ti3SiC2 decomposition, exhibited higher microhardness and better wear resistance compared to near single phase Ti3SiC2. (C) 2013 Elsevier Ltd and Techna Group S.r.l. All rights reserved.