Coarsening kinetics of intermetallic precipitates in Ni₇₅ Al_xV_25-x alloys

The precipitation kinetics of growth and coarsening of γ'(Ni₃Al) and θ (Ni₃V) in Ni₇₅Al_xV_25-x alloys were investigated by microscopic phase-field simulation incorporated with elastic interactions. For the elastic interactions, γ' aligned along the (001) direction and θ aligned along the [100] direction, which resulted in plate shape. For the lower (x < 4, at.%) and higher (x > 6) content regions, the growth of first precipitates was dominant at the initial stage and then coarsening was dominant, but the growth and coarsening proceeded simultaneously for the second precipitates. The growth and coarsening of γ′ and θ were dominant, respectively, at the initial and late stages for middle content regions. In addition, dynamic scaling was analyzed in the two-phase systems. It was shown that the dynamic scaling regimes were attained simultaneously at late-stage coarsening for γ′ and θ, despite the different precipitation order.