CO_2激光焊接工艺对AZ31B变形镁合金焊缝表面成形的影响  

Influence of CO_2 laser welding process on weld surface formation of wrought magnesium alloy AZ31B

作　　者：谭稳达[1] 单际国[1] 雷祥[1] 张婧[2] 陈武柱[2] 

机构地区：[1]清华大学机械工程系,北京市100084 [2]先进成形制造教育部重点实验室,北京市100084

出　　处：《焊接》2007年第11期27-32,共6页Welding & Joining

基　　金：高等学校博士学科点专项科研基金资助项目(20060003070)

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。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.

关 键 词：AZ31B变形镁合金 CO2激光焊接 焊缝表面成形 气体保护方式 

分 类 号：TG457.19[金属学及工艺—焊接]