Derivation of phase field model for the second nearest interatomic potential of D022 structure and sedimentation process in N0.75AlxV0.25_x alloy

This paper obtains a new phase field method that can simultaneously calculate the interaction potential between the first and second neighbor atoms of the D022 structure Ni3V phase in the Ni0.75AlxV0.25_x alloy, and analyzes the interaction potential between the two neighbor atoms of the D022 structure with the change trend of tem-perature and concentration. The feasibility of using the phase field method to invert the interaction potential between two neighboring atoms of the D022 structure in the Ni0.75AlxV0.25_x alloy laws and the precipitation of D022 and the types of interfaces formed by D022 and L12 during the aging process to be used in the microscopic phase field equation is studied. The results show that with the increase/decrease of the temperature or the concentration of solute atoms, the first neighbor interaction potential between the first neighbor atoms of the D022 structure increases/decreases and the neighbor interaction potential between the second neighbor atoms of the D022 structure decreases/increases; Ni0.75AlxV0.25_x alloys form two ordered phase interfaces between L12 and D022 phases during high temperature precipitation; at the same temperature and the concentration, the calculated interatomic potential is similar to the interatomic potential obtained by other methods. The calculated interatomic potential is substituted into the phase field model, and the simulated alloy precipitation results are consistent with the experimental results.