6061铝合金表面激光熔覆温度场的仿真模拟

Simulation of laser cladding temperature field on surface of 6061Al alloy

利用连续波Nd:YAG固体激光在6061铝合金表面激光熔覆SiC陶瓷粉末,采用ANSYS有限元软件对6061铝合金激光熔覆过程中热量传递及温度场分布进行模拟,在分析过程中采用三维单元,并考虑了材料热物性的非线性及对流和辐射的边界条件,建立了有限元模型,得出了熔覆过程中试样表面的温度分布模拟图.结果表明,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,熔池内最高温度与激光扫描速度、光斑半径均成反比,与激光功率成正比.模拟结果为陶瓷-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.

With 2 kW continuous wave Nd：YAG laser, SiC ceramic powder was laser cladded on the surface of 6061 aluminum alloy. The heat transfer and temperature field during laser cladding of 6061 aluminum alloy was simulated using ANSYS software. The 3-D solid elements were used in FEM model, and temperature dependent material properties as well as the boundary conditions of convection and radiation were considered. The temperature distribution on the surface of the laser cladding 6061 alloy was attained. The results show that the isotherms of temperature field are ellipse and dense at the head of the moving heat source. The temperature gradient is high at the head of the moving heat source, while the isotherms are sparse and the temperature gradient is low at the end of the moving heat source. The highest temperature in the field is inversely proportional to the sweep speed and facular radius, and directly proportional to the laser power. The simulated result provides the theoretical reliance for the optimization of the laser cladding parameters on metal matrix composites.