The Phase Evolution of the TiC Cermet Fabricated by Spark Plasma Sintering

Abstract

The TiC cermet widly used for high hardness working dies and tool materials was fabricated by carbo-thermic reduction of thtania-precusor or self-propergating high temperature synthesis(SHS) reaction. In this paper, the titanium hydride, carbon and iron alloy(D'AE) powders which were mixed for uniform microstructure by spex mill was sintered directly in the spark plasma sintering(SPS) furnace. The nano TiC powders which were fabricated by mechanical alloying using TiH 2 powders mixed with carbon powder were sintered also in the SPS furnace. The effects of mechanical alloying time and sintering procedure on the phase changes of sintered microstructure were evaluated with X-ray diffraction, electron microscopy, EDS, and hardness tester. As-milled powders for 5 hours were successfully synthesized to the TiC phase of 300nm mean particle size. The microstructure of spark plasma sinterd TiC/Fe cermet using TiC powders fabricated by 5 hours milling shows lower density in compare with the spark plasma sintered cermet using mixed powders. The nano size TiC particles were formed homogeneously during spark plasma sintering by the selfpropergating synthesis reaction.