Phase field simulation of morphology evolution and coarsening of γ ′ intermetallic phase in Ni–Al alloy

Abstract

The morphology evolution and coarsening behaviour of γ′ (Ni₃Al) phase in Ni–Al alloys were investigated by using the Cahn–Hilliard and Ginzberg–Laudan phase field equations, and the composition, order parameter and average particles size evolution coupling with the internal elastic strain were studied. Cubic γ′ phase was presented firstly and then the rectangle particles were formed by means of coarsening; the mechanisms of γ′ phase coarsening are Ostwald ripening or coalescence of neighbouring particles. The average particle size of γ′ phase increases rapidly at the initial stage, and it slows down at the coarsening dominated stage. The average particle size follows a cubic law of ‘Lifshitz–Slyozov’ encounter modified theory in the coarsening regime.