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采用MIG填丝焊实现镁-铝异种金属的焊接,通过金相显微镜、扫描电镜、万能试验机和显微硬度计等手段对焊接接头进行结构和性能表征。结果表明,镁-铝MIG焊接线能量较低时,其焊接接头熔宽较小,焊透性较差;线能量较大时,出现焊穿现象,氧化严重。随着焊接线能量增加,镁-铝MIG焊接头气孔数量和尺寸增加,接头拉伸强度先增加后减小,焊接线能量为45 k J/m时,拉伸强度达到最大值70.32 MPa。镁-铝异种金属MIG焊接头镁侧界面区显微硬度值最高,达到230 HV。
The welding of magnesium - aluminum dissimilar metals was carried out by using MIG wire welding. The structure and properties of the welded joints were characterized by metallographic microscope, scanning electron microscopy, universal testing machine and microhardness tester. The results show that when the energy of magnesium-aluminum MIG welding line is lower, the weld joint width is smaller and the penetration is poor. When the energy of the wire is larger, the welding phenomenon occurs and the oxidation is serious. With the increase of welding wire energy, the number and size of pores in magnesium-aluminum MIG welding joint increased, the tensile strength of joint increased firstly and then decreased, and the tensile strength reached 70.32 MPa when welding energy was 45 kJ / m. Magnesium - aluminum dissimilar metal MIG welded joints magnesium side of the interface area of the highest microhardness, up to 230 HV.