A model of growth morphology for semi-solid metals Original Research Article

For the preparation of semi-solid slurry, the composition concentration field and temperature field of solidifying crystals were analysed under stirring condition. A shape determination model for grain growth was developed by using solidification velocity and flow speed of the liquid as variations of affecting the shape of crystals. The relationship of grain shape fraction fi with solidification velocity R and convection speed v was expressed as: fi=e−2Rv. The growth morphology of semi-solid metals was simulated with this model. Simulated results show that with the increase of convection speed or the decrease of solidification velocity, the grains changes from dendrite to spherical shape, and vice versa. The simulation results were in agreement with the experimental results.