Phase Field Simulation on the Effect of Interatomic Potentials at L1 2 Interface in Ni 75 Al 16 Cr 9 Alloy

Abstract

Microscopic phase-field model with varying interatomic potentials was used to simulate the ordered domain interfaces formed between L1 2 phases in Ni-Al-Cr alloy. The behavior of interfaces migration and atoms segregation at the interfaces were investigated using the atomic evolution picture and occupation probability. The results show that there are stable domain interfaces and transition interface formed between L1 2 phases. The crystallization speed and the interfaces migration speed are related to the interatomic potentials. The crystallization speed gets faster when the interatomic potentials given 10% bigger than literature data, however, the crystallization speed gets slower and the final morphology of phases are very different while the interatomic potentials smaller. The elements of alloy have different preferences of segregation or depletion varying interatomic potentials at different interfaces (stable interfaces and migratory interfaces). In one case, at the interface of two Ni atoms between the planes (100) vs (100), the interface migration speed gets faster when the interatomic potentials bigger, and Al and Ni are depleted faster but Cr is segregated faster when the interatomic potentials given bigger values, conversely when the interatomic potentials given smaller values.