Formation law and prediction of weld morphology for high-frequency oscillating laser-arc hybrid welding of aluminum alloy

High-frequency oscillating laser-arc hybrid welding has been shown to control the microstructure and mechanical properties of the weld in aluminum alloy through the stirring effect. However, there is limited research on weld morphology control, thus hindering its industrial application. In this study, the effects of laser beam oscillating frequency (f) and amplitude (A) on the formation characteristics of laser-arc hybrid welding of AA6082 aluminum alloy were systematically investigated, particularly focusing on the influence of surface spatters, the width of the laser-affected zone beneath the weld, and the ratio of penetration depth. The formation mechanism of weld morphology was discussed based on the energy distribution characteristics of the oscillating laser beam and the transition of the laser welding mode. Subsequently, the optimization range of the oscillating parameters was determined based on the number of weld formation defects and the laser deep penetration welding mode, specifically within the range of 300 Hz ≤ f ≤ 500 Hz and 0.4 mm ≤ A ≤ 1.0 mm. Finally, by normalizing the oscillating parameters with the oscillating line velocity, a linear quantitative relationship between the characteristic values of the weld within the optimized parameter range was established with an accuracy of 89.8%, providing data support for the prediction and control of the morphological characteristics of high-frequency oscillating laser-arc hybrid welding.