利用500W脉冲Nd:YAG固体激光对2mm厚的AZ31B变形镁合金的焊接工艺进行了研究。结果发现,平均功率和脉冲宽度相同时,熔深熔宽随着脉冲频率的增大而减小;平均功率和脉冲频率相同时,峰值功率和脉冲宽度是影响焊缝几何尺寸的主要参数;脉冲频率和脉冲宽度相同时,熔深熔宽随着平均功率、峰值功率和单脉冲能量的增大而增加;在相同的平均功率、峰值功率和占空比下,脉冲宽度是影响焊缝几何尺寸的主要参数,峰值功率较高时,大的脉冲频率导致大量飞溅的产生,增加了熔池的不稳定性;脉冲激光焊接镁合金时应遵循较大脉宽、低频率、中等峰值功率的原则。

2mm thin AZ31B wrought magnesium alloy plate was studied using a pulse Nd:YAG solid-state laser. The results show penetration deepth and penetration width decrease with pulse frequency under the same average power and pulse width. Peak power and pulse width are the primary parameter which affect the pool geometry size under the same average power and pulse frequency. Keeping pulse width and pulse frequency constant,penetration deepth and penetration width increase with average power,peak power and pulse energy. Keeping average power,peak power and duty cycle constant,pulse width is the primary parameter which affects the weld geometry size. However,bigger pulse frequency causes a lot of spatters and increases instability of the pool when peak power is higher. Wider pulse width,low pulse frequency and medium peak power should be used when pulse laser welds magnesium Alloy.