由于铝合金对激光的高反射和自身的高导热性, 铝合金汽车动力电池外壳的密封焊接存在较大的困难。采用Nd∶YAG脉冲激光器对1 mm厚的3003 H14铝壳进行激光密封焊接。为改进动力电池铝合金外壳封装工艺, 满足成品电池壳的密封焊要求以及所能承受的压力要求, 详细研究了Nd∶YAG激光器脉冲波形对铝合金焊接效果的影响。通过理论分析和实验验证, 预热保温的脉冲波形是获得优质密封焊接效果的良好选择, 其焊接样品拉伸断裂机制为脆性韧性综合型断裂, 在平均输出功率200 W、频率10 Hz、焊接速度3 mm/s等工艺参数下能获得成形良好、无缺陷的焊缝。

Due to the high reflection of lasers and high thermal conductivity, there exits many difficulties on the seal welding of aluminium power battery shells. The laser seal welding of 3003 H14 aluminium shell of 1 mm was carried out by a Nd∶YAG pulse laser. For improving the aluminum power battery shell encapsulation process which can satisfy the demands of battery shell sealing welding and withstand the pressure requirements, the influence of the laser pulse waveform to the effect of aluminium welding was studied. Through theoretical analysis and experimental verification, preheat pulse waveform can obtain high-quality seal welding effect. The fracture mechanism of the welding samples is a combination of brittle and ductile. The well- formed and non-defective welds can be obtained under the parameters of 200 W output power, 10 Hz frequency and 3 mm/s welding velocity.