Effect of alloying time on fabrication of Ti 3 Si(Al)C 2 by spark plasma sintering

Abstract

3Ti–Si–2C–0·2Al mixture powders were used to fabricate high purity Ti₃SiC₂ ceramic through mechanical alloying (MA) and spark plasma sintering (SPS). The effect of ball milling time on the fabrication of Ti₃SiC₂ by SPS was also investigated. The results showed that the mixed powders were obviously refined after the MA of 5 h. After milling of 10 h, the mixed powders containing TiC, Ti₃SiC₂ were synthesised by a mechanically induced self-propagating reaction. After further milling to 20 h, the yield powders were refined. Ball milling time had a remarkable effect on SPS fabrication of Ti₃SiC₂. A shorter milling time of 5 h only helped to increase the Ti₃SiC₂ content in the sintered bulk. The samples subjected to the MA treatment of 20 h had a fine and dense organisation. Ball milling of 10 h was most beneficial for fabricating dense and high purity Ti₃SiC₂. Ti₃SiC₂ bulk with a purity of 96 wt-% was obtained by MA for 10 h and subsequent SPS at 850°C. When sintered at 1100°C, Ti₃SiC₂ bulk with a purity of 99·3 wt-% and a relative density of 98·9% was obtained.