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激光深熔焊以小孔效应为特征,小孔使得激光束流与被焊接材料之间的耦合效率大大提高。小孔内的逆轫致吸收使得激光能量逐步衰减。另一方面,小孔内等离子体向熔池传热,起到焊接内热源的作用。因此,利用建立组合体热源模型,选择旋转高斯热源和双椭球形体热源模拟激光能量的分布,结合SIMPLE算法,求解不可压缩流体的质量守恒、动量守恒和能量守恒方程,得到了大Péclet数下的小孔形态。模拟结果显示,控制容积法中的体热源传热方式不同于有限元法的表面热流密度分布方式。最后,将模拟结果和钛合金激光焊接的焊缝形状和尺寸进行了对比,说明所选择的体热源模型在激光深熔焊模拟中具有较好的适应性。
Laser deep penetration welding is characterized by a small hole effect that greatly increases the coupling efficiency between the laser beam and the material being welded. Inversely induced absorption within the aperture causes the laser energy to decay gradually. On the other hand, the plasma in the holes transfers heat to the weld pool and serves as a heat source within the weld. Therefore, by using the combination heat source model, choosing the rotating Gaussian heat source and the double ellipsoid heat source to simulate the distribution of laser energy and combining the SIMPLE algorithm to solve the mass conservation, momentum conservation and energy conservation equations of incompressible fluid, the large Péclet number The hole shape. The simulation results show that the heat transfer method of body heat source in control volume method is different from the surface heat flux density method of finite element method. Finally, the simulation results are compared with the shape and size of the weld of titanium alloy laser welding, which shows that the selected body heat source model has good adaptability in laser deep welding simulation.