A New Ternary Al-Ti-N Alloy Prepared by Reaction Sintering (II)

Formation of L1₂-Al₃Ti Phase

Abstract

Nickel was added to improve the ductility of a new reaction sintered Al-Ti-N alloy which consists of A1₃Ti and A1N phases. The added Ni transformed the crystal structure of Al₃Ti from DO₂₂ to a high symmetry L1₂, and as a result, improved the ductility of the alloy.
The DV-X α molecular orbital calculation suggested that Ti atoms were able to locate at the 2nd neighbor sites of Ti atoms by substitution of Ni atoms for a part of Al atoms, namely, the 1st neighbor sites of Ti atoms. This atomic configuration is the mechanism for the stabilization of the L1₂ crystal structure of AI₃Ti by the addition of Ni.