Forced SHS Compaction of TiC-NiTi Composites

TiC-NiTi cermet composites were fabricated by forced SHS compaction from (Ti + C + Ni) mixtures with varying content of Ni + Ti from 28 to 90 wt %. The phase composition and microstructure were characterized by X-ray diffraction method, scanning electron microscopy, and energy dispersive spectroscopy. The microstructure of composites was shown to contain spherical TiC particles surrounded by the matrix including TiNi3, TiNi(B2), Ti2Ni, and Ti3Ni4 phases. As Ni + Ti content was increased, there was a change in the stoichiometry of TiC (from TiC1 to TiC0.43) and its particle size (from 6.5 to 0.2 mu m). It was found that the microhardness of TiC-NiTi composites dropped markedly from 23.5 to 6.4 GPa.