FORMATION MECHANISM OF TIC BY MECHANICAL ALLOYING

Titanium carbide (TiC) has been synthesized by mechanically alloying the elemental powder mixture of titanium and graphite at composition of Ti 1-xCx (x=0.35, 0.43, 0.50). Under the employed milling condition, the formation of TiC has been found to undergo an abrupt, exothermic reaction. The final product is TiC for x=0.43 and 0.50, and TiC+Ti (small amount) for x=0.35. It is suggested that this reaction appears to be a self-sustained high-temperature synthesis process. The initial milling stage seems to be an incubation duration for the reaction, and the mechanical impacts to be the ignition of the following abrupt reaction. It is believed that this type of reaction is an important mechanism for mechanical alloying of the highly exothermic alloy systems. © 1994 American Institute of Physics.