Stability of phase boundary between L12-Ni3Al phases: A phase field study

The evolution and stability of phase boundaries (PBs) between L12-Ni3Al phases in Ni75Al11V14 alloy aged at 1050k was studied using the microscopic equation phase-field method (MPFM). Four types of L1(2) PBs were found through atomic configuration, migration and occupation probability (OP). The evolution of metastable PBs and formation of stable PBs were tracked and explored, the effect of coherent elastic strain energy on the evolution and stability of PBs is also investigated by coupling the micro elastic theory with MPFM. In addition, the formation enthalpy, interface energy and electron distribution function of PBs are calculated by FP method, and the stability of PBs is further quantitatively predicted from the perspective of thermodynamic energy and gaining or losing electrons. FP calculation results are consistent with MPFM prediction, and the essence of the transition and stability of PBs is revealed based on the atomic migration dynamics, interface evolution morphology and thermodynamic energy. This is an effective method to further explore the formation and structure of PBs and design high stability PBs.

Automated summary

The evolution and stability of phase boundaries between L12-Ni3Al phases in Ni75Al11V14 alloy were studied using the microscopic equation phase-field method. Various types of phase boundaries were identified through atomic configuration, migration, and occupation probability. The impact of elastic strain energy and thermodynamic energy on the evolution and stability of phase boundaries was investigated. It was found that the calculations and predictions were consistent, and the essence of the transition and stability of phase boundaries was revealed. This research provides an effective method for studying the formation and design of high stability phase boundaries.