6061铝合金表面激光熔覆温度场的模拟与验证

Simulation and experimental investigations of laser cladding temperature field on 6061 Al alloy

根据激光熔覆的特点,建立了移动激光高斯热源作用下三维激光熔覆温度场的计算模型,利用有限元软件ANSYS对温度场分布进行了动态模拟。结果表明,激光熔覆温度场模拟等温线呈椭圆形,在移动热源的前方等温线密集,温度梯度较大,热源后方的等温线稀疏,温度梯度较小。采用高功率连续波Nd:YAG激光在6061铝合金表面激光熔覆SiC陶瓷粉末,形成SiCp/Al金属基复合材料改性层,熔覆层除含有Al,SiC之外,还含有少量的Al4C3,Al4SiC4相,通过熔覆层组织形貌观察及相结构分析验证了模拟结果的准确性和可靠性,为陶瓷—金属基复合材料激光熔覆工艺参数的优化提供了理论依据。

According to the characters of laser cladding, a computational model was established for analysis of 3D laser cladding temperature field caused by moving gauss distribution heat source and laser cladding temperature field of 6061 Al alloy was simulated dynamically by finite element method with software ANSYS. The results show that the isotherms of temperature field simulation look like ellipse and are dense at the head of the moving heat source. And the temperature gradient is high at the head of the moving heat source. But at the end of the moving heat source the isotherms are sparse and the temperature gradient is low. With continuous wave Nd:YAG laser, SiC ceramic powder was cladded on the 6061 Al alloy surface and the SiC reinforced metal matrix composites (MMC) modified layer was abtained. Al, SiC and Al4C3, and a little Al4SiC4 were included in this layer. It was shown that the simulation results of temperature field are in accordance with the experimental results. It offers the reliance for the optimization of the laser parameters on metal matrix composites.