基于镀锌钢板的铝镁异种金属CMT焊接试验研究
铝钢、镁钢的CMT搭接工艺试验结果表明：当焊接电流为110 A、焊接电压为13.3 V、焊接速度为0.7 m•min-1时，得到了焊缝成形良好的铝钢焊接接头。当焊接电流为140 A、焊接电压为22.0 V、焊接速度为1.0 m•min-1时，镁钢焊缝成形良好。
显微组织分析表明：铝侧镀锌钢板的锌层部分与铝合金焊缝互熔较好，生成了部分固溶体和铝锌金属间化合物增强相，镁侧镀锌钢板的锌层部分与镁合金焊缝互熔较差，界面处生成一层镁锌金属间化合物。
力学测试结果表明：铝钢异种金属搭接接头和镁钢接头焊缝到钢母材显微硬度都呈上升趋势，铝钢接头界面处硬度约为HV 80，镁钢接头界面处硬度约为HV 70。镁铝间接搭接接头试样最大剪切结合强度为 22.3MPa，断裂均发生于镁侧熔合区，熔合区生成的大量金属间化合物是接头强度不高的主要原因。9049
关键词：铝镁异种接头 冷金属过渡焊 金属间化合物
毕业设计说明书（论文）外文摘要
Title Study on CMT technique to dissimilar metal between magnesium alloy and aluminum alloy based on galvanized steel sheet.
Abstract
In this paper, weld ability of dissimilar metal between AZ31B magnesium and 6061 aluminum based on galvanized steel sheet was studied to explore the reasonable process of indirect welding joint between Mg and Al.
The results of Aluminum steel and magnesium steel CMT process show that: when the welding current is 110A,voltage is 13.3V and welding speed is 0.7 m•min-1, excellent welded joint of aluminum steel is obtained. When the welding current, voltage and speed are 140A,22V and 1m•min-1,good magnesium steel weld seam is formed.
Microstructure analysis shows that: aluminum alloy and the zinc layer beside aluminum melt better, and reinforced phases as solid solution and aluminum zinc intermetallic compound are generated. Magnesium alloy and the zinc layer of galvanized steel beside magnesium melt much worse, with forming a layer of zinc magnesium intermetallic compound at the interface.
Mechanical tests show that: the hardness of the joints between aluminum and steel ,magnesium and steel shows the trend of rising, hardness of the interface between aluminum and steel is about HV80, and the joint of Mg and steel is about HV70. The maximum shear bonding strength of indirect lap joint of Mg and Al is 22.3MPa, and fracture occurrs in fusion zone of Mg side, because of large amounts of intermetallic compounds generated.
Keywords: Al-Mg dissimilar joints cold metal transfer intermetallic compounds
目 次
1 引言 1
1.1课题的意义 1
1.2铝合金与钢异种金属的焊接 1
1.3 镁合金与钢异种金属的焊接 3
1.4铝与镁异种金属焊接 6
1.5论文研究的内容 11
2试验材料及设备 12
2.1试样材料 12
2.2 试验设备 12
3 CMT焊接的工艺及试验方法 16
3.1研究方案与试验方法 16
3.2 基于镀锌板的铝、镁CMT焊接工艺试验研究 18
4焊缝成形及微观组织分析 20
4.1 焊缝成形分析 20
4.2焊缝接头金相分析 23
4.3扫描电镜与能谱分析 27
4.4本章小结 29
5、力学性能分析 30
5.1接头硬度分析 30
5.2接头的剪切强度分析 32
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