【摘要】 为阐明活性剂对铝合金激光焊熔池作用机理，建立了三维瞬态移动热源作用下的激光焊接熔池数学模型，研究表面张力梯度及激光吸收率对温度场以及流场的影响规律，揭示活性剂作用下激光焊熔深的增强机制。结果表明，在无活性剂时模拟得到的焊缝形貌与实际试验结果吻合。在低功率铝合金活性激光焊接中，活性剂的加入虽然可以改变表面张力梯度，但表面张力梯度的改变对熔深增加效果不明显。分析认为，活性剂的加入使铝合金对激光吸收率的提高才是熔深增加的主要原因。更多还原

【Abstract】 In order to clarify the action mechanism of active flux on the molten pool during laser welding of aluminum alloys, a mathematical model of the molten pool with a three-dimensional transient moving heat source was established. The influence of surface tension gradient and laser absorptivity on the temperature field and flow field was studied, so as to reveal the enhancement mechanism of penetration depth under the action of active flux. The results showed that the simulated weld morphology was consistent with the actual test results without active flux. In low-power active laser welding of aluminum alloys, although the addition of active flux changed the surface tension gradient, the change of surface tension gradient had no obvious effect on the increase of penetration depth. The analysis showed that the main reason for the increase of penetration depth was the increase of laser absorption rate with the addition of active flux.更多还原