Phase field modeling of isothermal β → ω phase transformation in the Zr-Nb alloys

► Phase field model has been developed to simulate isothermal β → ω transformation. ► Four ellipsoid ω variants align along the four 〈1 1 1〉 directions are nicely simulated. ► The simulations predicted the microstructural evolution and soft impingement upon different conditions. ► The low growth rate of ω phase and stability of the ω + β microstructures are nicely explained by the model.