采用元胞自动机法和有限元法, 将宏观温度场与微观晶粒生长相耦合, 建立了激光熔注316L复合涂层晶粒生长模型, 研究了非均匀温度场条件下复合涂层的晶粒生长, 及增强相颗粒体积分数和颗粒尺寸对晶粒生长的影响。结果表明: 激光熔注复合涂层晶粒大小分布随熔池深度方向变化而变化, 熔池表面呈细小的等轴晶, 熔池底部晶粒粗大; 增强相颗粒体积分数含量越高, 晶粒生长越慢, 晶粒尺寸越小; 增强相颗粒尺寸越小,晶粒生长的越慢, 晶粒尺寸越小, 组织越均匀。

Based on cellular automata and finite element method, which coupling the macro temperature field with micro grain growth, a model of grain growth of laser melt injection 316L composite coating is established, the influence of grain growth with different volume fraction and size of reinforcement particles under the non-uniform temperature field was studied. The results show that the laser melt injection composite coating grain size distribution with pool depth direction changes, the surface of melt pool is fine equiaxed grain and the bottom of the pool is coarse grain, the volume fraction of the reinforcement particles is higher, the speed of the grain growth is slower, the grain size is smaller, the particles size is smaller, the grain grows is slower, the grain size is smaller and the microstructure is more uniform.