Growth of TiC octahedron obtained by self-propagating reaction

A large amount of titanium carbide (TiC) octahedra were synthesized in situ by self-propagating high-temperature synthesis using Al, Ti, C elemental powders as source materials. The phase constituents and microstructure morphologies of as-product were characterized by X-ray powder diffraction, field emission scanning electron microscopy and transmission electron microscopy. Due to the strong faceting tendency of the growing TiC crystal, the TiC grain grew as an octahedral morphology. If V[1 0 0]/V[1 1 1]=1.5, the TiC grain will grow as a perfect octahedral morphology. While if V[1 0 0]/V[1 1 1]>1.5, the TiC grain will grow as an imperfect octahedral morphology. According to the experimental results, the detailed microstructure and growth mechanism of TiC octahedron have been observed and analyzed. The models have been proposed to understand the formation and growth mode of TiC octahedron.