基于激光熔覆的镍基高温合金激光修复的数值模拟

Numerical Simulation on Laser Repairing of Nicked-Based Superalloy Based on Laser Cladding

选取激光修复中影响温度的关键因素,使用ANSYS参数化编程语言APDL对镍基高温合金GH4169激光修复过程进行数值模拟。分析了熔覆层和基体结合区温度场分布特性及凝固特性,通过研究激光功率、扫描速度、搭接率、送粉率对基体上熔池的形貌尺寸及熔池内熔体的凝固过程的影响,进行工艺优化,发现熔池深宽比为1:5时对应较好的工艺参数,搭接率为40%时获得良好的熔池内微观组织。并使用优化了的工艺参数对GH4169基体进行激光修复实验,金相分析熔池形貌、熔池内微观组织良好,为实际激光修复提供了一组可行的工艺参数。

Choosing the key temperature affected factors in Laser Repairing, we use APDL to simulate the Laser Repairing process of nicked-based superalloy and analyse the characteristic of the temperature field and solidification. We study the impact of the laser power, scanning speed, overlap rate, power feed rate on the molten pool shape and solidification .We found that when depth-to-width ratio of molten pool is 1：5 we got the preferred process parameters. When the overlap rate is 40% we got preferred bond zone microstructure.The porcess parameters has been optimized. Useing the optimized porcess parameters repaired the GH4169 substrate, the result shows that the porcess parameters is rational and obtained preferred molten pool shape and bond zone microstructure. It can be a viable set of process parameters as the actual laser repair.