Antisite Defects of the L12 Structure Determined by the Phase Field Microelasticity Model

Abstract

A phase field microelasticity simulation is performed to examine the antisite defect of L12-Ni3Al in Ni75 Al5.3 V19.7 ternary alloy. Combinimg strain energy with the phase field model leads to an atom configuration change as time proceeds. For the Ni sublattice, the antisite defect AlNi, the equilibrium occupancy probability (OP) of which declines, precedes NiNi and VNi in reaching equilibrium; subsequently, NiNi and VNi present a phenomenon of symmetrical rise and decline individually. Similarly, for the Al sublattice, the antisite defect NiAl, the OP of which eventually rises, takes fewer time steps than AlAi and VAl to attain equilibrium. Thereafter, AlAl rises while VAl declines symmetrically at the axes of the NiAlMAI curve. Furthermore, the OP for the Al sublattice is much more sensitive to strain energy than that for the Ni sublattice.