焊接工艺对压铸镁合金CO_2激光焊缝气孔率的影响  

Effects of welding parameters on weld porosity during CO_2 laser welding of die-cast magnesium alloys

作　　者：张婧[1] 单际国[1,2] 温鹏[1,2] 任家烈[1] 

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

出　　处：《焊接学报》2011年第5期17-20,24,共5页Transactions of The China Welding Institution

基　　金：国家自然科学基金资助项目(50775124);高等学校博士学科点专向科研基金项目(20060003070)

摘　　要：研究了激光功率和焊接速度等焊接工艺参数对两种不同含气量的压铸镁合金激光焊气孔倾向(以气孔率为表征)的影响规律,并对气孔的防止措施进行了探索.结果表明,含气量较高的2 mm厚压铸镁合金激光焊气孔倾向大于含气量较低的5 mm厚压铸镁合金.两种厚度的压铸镁合金激光焊缝气孔率总体上均随着激光功率的升高及焊接速度的降低而升高.对于含气量较低的5 mm厚压铸镁合金,双面施焊及焊后重熔均可显著降低气孔率,气孔率分别降低到2.4%及2.5%,但对于含气量高的2 mm厚压铸镁合金,这些措施无法有效降低焊缝气孔率.The effects of welding parameters including laser power,welding speed,welding conditions on pore formation tendency(represented as porosity) during laser welding of die-cast magnesium alloys with two different gas contents were investigated,and the porosity prevention measures were also studied.It is shown that the pore formation tendency during laser welding of 2 mm thick die-cast magnesium alloys with higher gas content is greater than that of 5 mm thick die-cast magnesium alloys with lower gas content.As a whole,the porosity increases with the increase of laser power and the decrease of welding speed for both two thicknesses.For 5 mm thick die-cast magnesium alloys with lower gas content,low porosity weld bead can be obtained by both double sided welding and remelting after welding,and the porosity can reduce to 2.4% and 2.5%,respectively.However,for the 2 mm thick die-cast magnesium alloys,these porosity prevention measures are not effective.

关 键 词：气孔 气孔防止 激光焊接 焊接工艺 压铸镁合金 

分 类 号：TG115.28[金属学及工艺—物理冶金]