The Effect of Ti Addition on Phase Equilibria among Ni (A1), Ni₃Al (L1₂) and Ni₃V (D0₂₂) Phases

Abstract

The effect of Ti addition on phase equilibria among Ni (A1), Ni₃Al (L1₂) and Ni₃V (D0₂₂) phases at 950°C was investigated by means of TEM/EDS analysis on heat-treated alloys. The three-phase coexisting region of A1+L1₂+D0₂₂ was found to exist around the composition of Ni–4Al–19V (at.%) in the Ni–Al–V ternary system. By addition of Ti into the ternary system the three-phase coexisting region was shifted to the Ni rich side. Ti partitioned most into the L1₂ phase and least into the A1 phase. These results suggest that the addition of Ti stabilizes the L1₂ phase against D0₂₂ and A1 phases.