多材料双通道激光熔覆过程的计算机仿真

摘要

在激光快速成型过程中研究激光熔覆载气式同轴送粉粉末颗粒的汇聚特性以及基体的温度场与应力场的分布情况.采用气体-粉末两相流理论以及双通道流对载气式同轴送粉喷嘴内的流场进行了数值模拟,应用FLUENT软件中的离散相模型计算了粉末颗粒的运动轨迹,并通过多物理场耦合程序MpCCI平台对熔覆过程进行了数值仿真.结果显示:粉末颗粒在距喷嘴距离15~20 mm之间具有最佳汇聚特性,在多物理场耦合作用下熔池的温度以及应力分布与实际情况相符合.%For studying convergence property of laser cladding carrier-gas type coaxial powder particle feeding and temperature & stress field distribution of matrix in the process of laser rapid prototyping,nu-merical simulation was carried out on flow field of gas-carrier coaxial feeding powder with gas-powder two-phase flow theory and two-channel flow,use discrete phase model in FLUENT to calculate movement lo-cus of powder particle,numerical simulation was carried out on cladding process through multi-physics coupling that is MpCCI.The result shows that powder particle has the best converge property which is 15-20 mm from nozzle.Under multi physics coupling,molten pool temperature and stress distribution diagram meet practical situation.