刘立君　张金婷　刘大宇　崔元彪　贾志欣　李继强

摘要：针对修复模具表面失效的问题，采用数值模拟技术对激光熔覆Ni/SiC过程进行参数优化。建立了以不同激光电流、扫描速度及离焦量作为优化工艺参数的有限元分析模型，进行激光熔覆仿真分析，通过改变工艺参数的大小对温度场和应力场进行研究。结果表明：温度和残余应力都随激光电流的增大而升高，且它们都随着扫描速度和离焦量的增大而减小。其中，激光电流、离焦量对温度场的影响比扫描速度明显;离焦量对应力场的影响比激光电流和扫描速度明显。经应力场实验验证，最终实验结果与应力场模拟结果的横向残余应力最高处相差76MPa，纵向残余应力最高处相差86MPa。实验结果与应力场模拟结果仅存在细微误差，且误差在合理范围内，证明了模拟结果的正确性。对激光熔覆工艺参数进行优化，优化后的工艺参数为：激光电流120A，扫描速度为60mm/min，离焦量为50mm。

关键词：激光熔覆Ni/SiC;工艺参数优化;有限元模拟;温度场;应力场

DOI：10.15938/j.jhust.2022.04.011

中图分类号： TG456.7

文献标志码： A

文章编号： 1007-2683（2022）04-0081-11

ANSYS Numerical Simulation of Laser Cladding

Ni/SiC Process Parameter Optimization

LIU Li-jun ZHANG Jin-ting LIU Da-yu CUI Yuan-biao JIA Zhi-xin LI Ji-qiang

（1.School of Materials Science and Engineering， Harbin University of Science and Technology， Harbin 150080， China;

2.School of Mechanical Engineering， Harbin Institute of Technology， Harbin 150081， China;

3.Ningbo Institute of Technology， Zhejiang University， Ningbo 315100， China）

Abstract：To overcome the issue of repairing mold surface failure， the parameters of the laser cladding Ni/SiC process is optimized using numerical simulation. The different laser currents， scanning speeds and defocusing are adjusted to optimize simulation result of laser cladding. Meanwhile， the influence of the temperature field and stress field also is studied by changing the size of the process parameters. The simulation results show that temperature and residual stress both increase with the increase of laser current and decrease with the increase of scanning speed and defocusing amount. Among them， the influence of laser current and defocusing amount is more obvious than that of scanning speed on temperature field. The influence of defocus on the stress field is more obvious than that of laser current and scanning speed. Experimental verification shows that the maximum horizontal welding residual stress difference is 76MPa and the maximum longitudinal welding residual stress difference is 86MPa. The experimental error within a reasonable range proves the correctness of the simulation results. Finally， the optimized laser cladding process parameters is obtained： laser current is 120A， scanning speed is 60mm/min， and defocus is 50mm.

Keywords：laser cladding Ni/SiC; process parameter optimization; finite element simulation; temperature field; stress field

0引言

激光熔覆技术是指在高能激光束的作用下，使合金粉末熔凝在基体表面，使其与基体达到良好冶金结合的表面强化技术[1-5]。在不改变基体性质的前提下，激光熔覆技术可以在廉价金属基体表面，制备含稀有金属的涂层，改善其表面性能，不仅可以节约稀有金属材料，而且还可以降低加工成本。该技术经济效益较高，在工业生产中具有重要的研究價值[6-10]。……