Simulation of the coarsening behavior of Intermetallic precipitates in Ni₇₅Al_x V_25-x alloys

The coarsening behavior of L1₂ and DQ₂₂ in Ni₇₅Al_xV_25-x (x, at.%) alloys including coherent strain was investigated using the microscopic phase-field model. The simulation results indicate that the shape transition and spatial correlation of L1₂ and D0₂₂ are caused by the morphological-dependent anisotropic elastic interactions in the system. The coarsening process of the particles is by means of neighbor particles impingement and aggregation into larger ones. For the strain-induced interactions between the precipitates, the LSW theory is altered for the coarsening behavior of L1₂ and D0₂₂. In addition, the simulation reveals that the growth and coarsening of D0₂₂ present two obvious stages at lower Al concentration regions and proceed simultaneously at high Al concentration regions. The growth and coarsening processes of L1₂ at the same regions is reverse to those of D0₂₂.