Elastic strain energy induced split during precipitation in alloys

•The solute concentration controled phase-field model is given.•The simulation for precipitating split is studied.•The split mechanism is the spinodal decomposition.•The necessary conditions of split are given.•The interaction energy among particles are studied.

The elastic strain energy induced split during the precipitation of the isostructural transformation in the modeled A–B alloys is simulated by the phase field method. The simulation implies that for the single precipitating particle in the modeded alloy, the particle with initial scale in the range from 80l to 320l (l = 12.18 Å) is to split during aging. For the modeled alloy, the γ′ particle is to split at about 5.0 × 103τ (τ = 4.45 s) after the split incubation period. At the end of split the total interfacial energy obtains a maxima and the total elastic energy holds a minima at about 2.4 × 104τ. The requirement of the four-blocks split may be given by the relationship between the elastic strain energy coefficient, the positive gradient energy coefficient and the solute concentration inhomogeneity. In multi-particles systems, the particles split into other appearances due to the additional interaction energy induced by the non-symmetrical arrangement of the particles, The increment of the interaction elastic energy has little effect on the interfacial energy during precipitation in multi-particles systems.