Phase-field simulation of phase coarsening at ultrahigh volume fractions

摘要

In this paper, the dynamics of phase coarsening at ultrahigh volume fractions (0.9≤ V_V 0.96) is first studied based on two-dimensional phase-field simulations by numerically solving the time-dependent Ginzburg-Landau and Cahn-Hilliard equations. It is shown that the cubic average radius of particles is approximately proportional to time that is in good agreement with one of experimental observations. The microstructural evolutions for different ultrahigh volume fractions are shown. The scaled particle size distribution as functions of the dispersoid volume fraction is presented. The interesting finding is that the particle size distribution derived from our simulations at ultrahigh volume fractions is close to Wagner's particle size distribution due to interface-controlled ripening rather than Hillert's grain size distribution in grain growth. The changes of shapes of particles are carefully studied with increase in volume fraction. It is found that some liquid-filled triple junctions are formed as a result of particle shape accommodation at ultrahigh volume fraction, V_V ≈ 0.96