Simulation of grain growth and sintering process by combined phase-field/discrete-element method

A combination of the phase-field method (PFM) and the discrete-element method (DEM) is proposed to simulate simultaneously the movement of particles and the grain growth behavior in powder compacts during sintering. To take the mutual interaction into consideration, a precise way of coupling PFM and DEM is developed based on a sintering model. The sintering forces and the contact areas in linked particles are evaluated from the phase field variables, computed in PFM and introduced into the calculation of the rigid motion of particles in DEM. Before treating actual problems as the application, the sintering process of two particles is simulated first for fundamental verification, including the case with different particle sizes. It is confirmed that the changes in the neck size and the center-to-center distance between particles are reproduced well using the proposed method. Secondly, the simulation of microstructural evolution during sintering is implemented for some small clusters of particles. The internal spatial structure and the outer shape of the clusters vary with the shrinkage deformation as well as the grain boundary migration in sintering. The proposed method of simulating the microstructural evolution in sintering bodies may be effective in the computer-aided design of microscale components or thin films produced by powder processing.