AZ91D压铸镁合金的三维微观组织模拟

3D MICROSTRUCTURE SIMULATION OF AZ91D DIE CASTING MAGNESIUM ALLOY

针对工程上应用广泛的AZ91D压铸镁合金,建立了其凝固过程中微观组织演化的数学物理模型．采用改进的三维微观元胞自动机(CA)模型,耦合三维溶质场计算,结合压铸镁合金进行了微观组织模拟．模拟结果再现了在多晶粒同时生长的情况下,初生晶间的溶质扩散、溶质富集直至共晶转变的全部演化过程．应用此模型模拟了实际AZ91D压铸件不同部位的微观组织,模拟结果与金相观察结果符合较好．

A set of mathematical and physical models has been proposed to describe the microstructure evolution in solidification process of the AZ91D die casting magnesium alloy, which is a modified 3D micro-scale cellular automaton （CA） model coupled with 3D model of solute concentration field. For multi-grains growth simultaneously, this model successfully revealed the whole evolution process of solute diffusion among the primary grains, solute enrichment and the eutectic transformation. The improved model was applied to simulate the microstructures of different parts of the actual AZ91D die casting, and the simulation results are in good agreement with the experimental ones.