Effects of technical factors on MgAl 2O 4–TiN composites produced by aluminothermic reduction and nitridation

Abstract

MgAl 2O 4/TiN composites were formed by aluminothermic reaction between Al, TiO 2, and MgO powders in nitrogen gas. The effects of addition of graphite, α-Al 2O 3 into mixtures 8Al–6TiO 2–4MgO, and shaping pressure on the synthesized composites was investigated by X-ray diffraction. The results showed that: addition of graphite can lead to formation and lattice parameters change of Ti(C, N). When α-Al 2O 3 powder was added into mixtures 8Al–6TiO 2–4MgO, theoretic spinel transformed into alumina-rich spinel and lattice parameters of the spinel became low. Inadequate N 2 gas caused by higher shaping pressure can give rise to the formation of intermediate product Al 3Ti alloy in the synthesis of the composites.