Phase field simulation on grain growth with particles located on grain boundaries

The grain size is a key characteristic to strongly affect the mechanical properties and performance, and the presence of additional phases plays an important role in affecting the microstructure evolution. In this work, a phase field model was adopted for immobile second-phase particles distributed at grain boundaries and analysed its pinning effect on polycrystalline grain growth. According to the size and distribution characteristics of second-phase particles in extruded AZ80 magnesium alloy, the effects of the particle morphology, particle size and volume fraction on the grain growth were investigated. The results showed that small-sized rod high-dispersion particles exhibit a stronger pinning effect on grain boundary migration. In addition, the generalised Zener relation of Rlim = 2.49rsp/fsp−0.322 was obtained for the particles located at grain boundaries.