激光干预对镁合金焊缝成形性与力学性能的影响

Effect of Laser Intervention on Appearance and Mechanical Property of Weld on Magnesium Alloy

采用激光-氩弧复合焊技术焊接ZM5镁合金,研究激光-氩弧复合焊与钨极氩弧焊对镁合金焊缝成形性与力学性能的影响。成形性分析表明:在焊接速度为5、15 mm/s时,激光-氩弧复合焊能得到良好的焊缝,且无气孔缺陷;而钨极氩弧焊不适于高速焊接,且气孔缺陷明显。抗拉强度分析表明:激光-氩弧复合焊缝平均抗拉强度为246 MPa,屈服强度为94.53 MPa,断裂伸长率为2.48%,均大于钨极氩弧焊,且2种焊缝均呈韧性-脆性混合断裂。硬度测试分析表明:激光-氩弧复合焊缝区平均硬度为63 HV0.05,热影响区硬度值与母材区相当,约为55 HV0.05,均高于钨极氩弧焊的硬度。上述分析说明:激光的干预有利于提高镁合金焊缝成形性和力学性能,适用于焊接速度要求高、情况紧急时的焊接,这为装备镁合金零部件体积和结构损伤的修复与再制造提供了数据依据。

Laser-arc hybrid welding technology is used on welding ZM5 magnesium alloy to study and compare the differences of appearance and mechanical property of laser-arc hybrid welding and TIG weld-ing.The result of forming property shows that laser-arc hybrid welding can always achieve better beads when welding speed is 5 or 15 mm/s,however,TIG welding can not.Moreover,beads of TIG welding exist gas cavities,while beads of laser-arc hybrid welding have nothing.Furthermore,tensile strength of laser-arc hybrid welding is 246 MPa,yield strength is 94.53 MPa,and extension percentage is 2.48%, these datum are better than TIG welding.Hardness test shows that the average hardness of laser-arc hy-brid welding reaches 63 HV0.05 ,which is superior to TIG welding.Besides,these are proved that laser intervention increases appearance and mechanical property;it is applicable for high speed and emergency welding.And it provides the data support for repairing and remanufacturing of the surface and architec-ture damage on magnesium alloy of armored equipment.