激光熔覆过程温度场的数值模拟

The Numerical Simulation of Temperature Field in Laser Cladding

为描述预置粉Nd:YAG激光熔覆过程中温度场的变化规律,建立了三维预置粉激光熔覆物理模型,通过自行编程,利用三维表格施加高斯激光热流密度载荷,实现载荷的空间分布与时间移动,在ANSYS软件中模拟计算了预置粉Nd:YAG激光熔覆过程温度场。模拟结果表明光斑中心处温度最高,为2.8×10~3℃,并以光斑为中心逐层降低,等温线近似椭圆形,椭圆中心位于光斑后方。光斑点的升温变化率、降温变化率、热梯度分别为7×10~3℃/s、5×10~3℃/s、2×10~6W/(m^2·s)。这些结果数据为激光熔覆工艺参数的优化提供了理论依据。

For the purpose of depicting the rule of temperature field during Nd：YAG laser cladding with preset-powder,a threedimensional（3D） physical model of laser cladding with preset-powder has been made. The load of Gauss laser heat flux is imposed by 3D table and the load can be varied spatially and temporally. The temperature field of Nd：YAG laser cladding is simu lated and calculated by ANSYS software. The result shows that the highest temperature is about 2.8×10^3℃ at the spot and the temperature declines gradually along the radius with the center of the spot. The isothermal line is like a ellipse and the center is behind the spot. In the spot,the temperature build-up rate,the temperature rate of descent and the thermal gradient are 7×10^3℃/s, 5×10^3℃/s, 2 ×10^6℃ W/（m2·s）, respectively. These results provide theoretical guide for the parametric optimization of laser cladding.