激光金属熔覆成形过程中温度场演化的三维数值模拟  

Numerical Simulation of Temperature Field Evolution in the Process of Laser Metal Deposition

作　　者：张冬云[1] 吴瑞[1] 张晖峰 刘臻[1] 

机构地区：[1]北京工业大学激光工程研究院,北京100124

出　　处：《中国激光》2015年第5期104-115,共12页Chinese Journal of Lasers

基　　金：北京市自然科学基金重点研究专题(Z140002)

摘　　要：采用三维瞬态模型模拟了同轴送粉激光金属熔覆成形(LMD)技术制作直壁墙过程中温度场的演化,被加工的材料为定向凝固镍基高温合金Rene80。首先模拟了粉末在下落过程中与激光的相互作用,并分析了其对熔池温度场可能造成的影响,其次模拟了直壁墙成形过程中温度场的演化。模拟过程考虑了固液相变和液体流动对熔池温度场变化的影响,模拟过程所用的工艺参数为制作直壁墙实验中获得的最优参数。通过模拟获得的熔池温度场演化过程再现了成形过程中熔池形貌的变化及成形过程的不稳定性,模拟计算的温度场变化规律与实验测得结果相符。A comprehensive three-dinmensional transient model is developed for the evolution of the temperature field during the vertical wall manufacturing process using coaxial laser metal deposition （LMD）, the material manufactured is directional solidification （DS） superalloy Rene80. The interaction between laser and powder during the powder falling process is simulated, and its possible effect on the temperature field of molten pool is analyzed. After that, the evolution of temperature field during the vertical wall manufacturing process is studied. By numerical simulation, the change of phase （solid/liquid, and mushy zone） and the liquid flowing are considered and the parameters are from optimized vertical wall manufacturing experiments. The results reproduce the shape changing of the molten pool and the instability of laser metal deposition process. The changing rule of temperature field is in conformity with that of real vertical wall manufacturing experiment.

关 键 词：激光技术 激光金属熔覆成形 Rene80定向凝固镍基高温合金 温度场 三维数值模拟 

分 类 号：TG174.4[金属学及工艺—金属表面处理] TN249[金属学及工艺—金属学]