Tianle Cheng¹, Youhai Wen², Jeffrey Hawk²; ¹U.S. Department of Energy, National Energy Technology Laboratory / LRST, ²U.S. Department of Energy, National Energy Technology Laboratory

In precipitation strengthened alloys the coherency state at the interface between precipitate particles and the matrix affects the morphology/stability of precipitates, kinetics of precipitate coarsening and the mechanical performance of the alloy. Khachaturyan’s phase-field microelasticity approach provides a close-form solution for arbitrary coherent precipitates. Nevertheless, for arbitrary incoherent and semicoherent particles research effort is insufficient. Here a variational approach is developed, within the phase field framework, to model precipitation with various coherency states in a multicomponent alloy. Simulation results with respect to the equilibrium morphology and stress state of ellipsoidal precipitates with various coherency states are compared with literature results. Coarsening of precipitate particles with various coherency states is studied and discussed under the context of classical Ostwald ripening theory.