Synthesis of NiAl–TiC nanocomposite by mechanical alloying elemental powders

A NiAl–TiC nanocomposite has been synthesized by mechanical alloying from Ni, Al, Ti, and C powders. During milling, an abrupt reaction occurred, resulting in simultaneous formation of NiAl and TiC phases. It is suggested that two separate exothermic explosive reactions, i.e. Ni+Al→NiAl and Ti+C→TiC, were involved. However, the reactions were incomplete with the existence of a small amount of elemental powders. Prolonged milling led to a gradual formation of NiAl and TiC as well as grain refinement. The final grain size for TiC was 3.5 times as large as that for NiAl. The formation mechanism of the NiAl–TiC nanocomposite during mechanical alloying was also discussed.