Abstract A three-dimensional transient heat and mass transfer model for laser-powder coupling is created based on the lumped parameter method. A super-Gaussian beam model that is closer to the fiber laser beam profile for welding is employed instead of a frequently-used Gaussian beam. A beam characteristic parameter identification method is proposed to identify the beam characteristic parameters such as the focal spot radius and Rayleigh length. The spatial distribution of the beam power density is reconstructed. The super-Gaussian beam model has a better goodness-of-fit index than the Gaussian beam model. Finite difference method is used to solve the heat and mass transfer model developed. Some powder particles, under the action of three types of laser beams, have evaporated before falling into the laser-induced pool. The average heating rate for the super-Gaussian beam and non-ideal Gaussian beam is lower than that of the ideal Gaussian beam. Although the heated powder distribution zone and the melted powder distribution zone on the workpiece surface for the super-Gaussian beam are larger, the maximum powder mass loss by evaporation is the smallest. The effect of the identified super-Gaussian beam and non-ideal Gaussian beam on the heat and mass transfer zone and evaporation-induced mass loss is not significantly different, except for the ideal GB.

中文翻译：

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光束轮廓对填充粉末激光焊接传热传质的影响

摘要 基于集总参数法建立了激光-粉末耦合的三维瞬态传热传质模型。采用更接近用于焊接的光纤激光光束轮廓的超高斯光束模型代替常用的高斯光束。提出了一种光束特征参数识别方法来识别光束的焦斑半径、瑞利长度等光束特征参数。光束功率密度的空间分布被重建。超高斯光束模型比高斯光束模型具有更好的拟合优度指数。采用有限差分法求解所开发的传热传质模型。一些粉末颗粒在三种激光束的作用下，在落入激光诱导池之前已经蒸发。超高斯光束和非理想高斯光束的平均加热速率低于理想高斯光束。虽然超高斯光束在工件表面的受热粉末分布区和熔化粉末分布区较大，但蒸发造成的最大粉末质量损失最小。除理想GB外，识别出的超高斯光束和非理想高斯光束对传热传质区和蒸发引起的质量损失的影响没有显着差异。