基于热导机制的光纤激光焦点高频旋转点焊工艺

Fiber Laser High-Frequency Focus Rotation Spot Welding Process Based on Thermal Conductivity

利用焦点高频旋转方法进行了光纤激光点焊工艺研究,并与传统激光点焊工艺进行了对比分析。结果表明,在热导焊接模式下,利用激光焦点高频重复扫描的熔池热积累效应,通过调节激光旋转工艺参数,可以有效调控焊点形貌。随着热量的不断累积,焊点形貌由双"V"形转变为"W"形,直至"U"形。与传统激光点焊工艺相比,焦点高频旋转点焊的焊点宽深比大,且基本无气孔缺陷。同时,该方法可以有效调控焊点显微组织及显微硬度。

The fiber laser spot welding process is studied with the high-frequency laser focus rotation method and compared with the traditional laser spot welding processes. The results show that, under the thermal conduction welding mode, the spot weld morphology can be effectively controlled by using the heat accumulation effect from the laser focus high-frequency repetitive scanning and the adjustment of the laser rotation process parameters. With the further heat accumulation, the spot weld morphology changes from the double ＂V＂ shape to the ＂W＂ shape and until to the ＂U＂ shape. Compared with those for the traditional laser spot welding process, the width-depth ratio of the spot welds is relatively larger for the high-frequency focus rotation spot welding process and substantially free of porosity defects. Simultaneously, the microstructure and microhardness of spot welds can be effectively regulated by the proposed method.