Effect of reaction atmosphere on combustion synthesis of Ti2AlN

Combustion synthesis of Ti2AlN was carried out in air and pressurised N-2 respectively. The reaction atmosphere had an evident effect on the phase composition and microstructure of the products. By combustion synthesis in 2 MPa N-2, Ti2AlN was synthesised as the major product, but in the samples prepared in air, Ti2AlN was obtained only as a minor phase, and the predominant phases were Ti-Al intermetallics. The reaction mechanism has been studied, suggesting that TiN is a key intermediate in the formation of Ti2AlN. It is proposed that, in the combustion synthesis of Ti2AlN, the flux of N-2 plays an important role in determining both reaction kinetics and phase composition of the products.