【摘要】 采用3kW的CO2激光器焊接4mm厚的AZ31B变形镁合金板材,研究了气体保护方式和焊接工艺参数对焊缝表面成形的影响。试验结果表明,保护气流的方向和气流量对焊缝表面成形存在显著影响,当气流方向与焊接方向相反并与水平方向呈30°角、气流量为2000L/h时,焊缝的表面成形最为均匀平整。通过调整激光功率和焊接速度等工艺参数来改变焊接热输入,可以获得"未熔透"、"仅熔池透"、"适度熔透"和"过度熔透"等不同熔透状态和表面成形特点的焊缝,其中"适度熔透"状态的焊缝正、背面成形最均匀;在相同的焊接热输入条件下,强参数规范条件下获得的焊缝表面成形效果最佳。更多还原

【Abstract】 Sheets of wrought magnesium alloy AZ31B were welded with CO2 laser,and the influences of gas shielding condition and welding parameters on weld surface appearance were investigated.The results show that the direction and flow rate of shielding gas could seriously influence the weld surface appearance,and the smoothest surface appearance is obtained when the shielding gas is at 30 degree to the horizontal with a flow rate of 2 000 L/h.With heat input varied,welds of "partial penetration","weld pool penetration","moderate penetration" and "excessive penetration" are obtained,among which the moderate penetrated weld possesses the smoothest surface appearance.And with the same heat input,the parameters in combination of high laser power and welding velocity can ensure the smoothest weld surface appearance.更多还原