化学镀锡层对镁铝异种金属超声波焊接的影响

发布时间：2018-04-22 09:35

本文选题：镀锡层 + 镁铝异种金属　；参考：《材料科学与工艺》2017年02期

【摘要】：为提高镁铝异种金属超声波焊接接头强度,预先在铝合金表面镀锡后进行镁铝异种金属超声波点焊,并对接头的微观组织和力学性能进行分析.研究表明:无镀锡层的镁铝超声波焊接接头界面出现了大量的Mg_3Al_2和Mg_(12)Al_(17)相,其接头的最大拉伸剪切强度为27.5 MPa;含镀锡层的铝镁超声波焊接结合区由镁锡反应扩散层、残余锡层和铝锡反应扩散层组成,其中,铝锡反应层是固溶体层,镁锡反应层主要是过饱和的固溶体基体及弥散析出的中间相Mg_2Sn,其接头的最大拉伸剪切强度为32.9 MPa.镀锡层的加入有效阻止了镁铝的相互扩散,抑制了硬脆的Mg-Al系金属间化合物的生成,提高了镁铝超声波焊接接头强度,与镁铝超声波焊接相比最大拉伸剪切强度提高了19.6%.
[Abstract]:In order to improve the strength of magnesia aluminum dissimilar metal ultrasonic welding joint, the supersonic spot welding of magnesium aluminum dissimilar metal was carried out after tin plating on the aluminum alloy surface, and the microstructure and mechanical properties of the joint were analyzed. The results show that there are a large number of Mg_3Al_2 and Mg-Si-12AlP17) phases at the interface of the joint without tin coating, and the maximum tensile shear strength of the joint is 27.5 MPA, and the bonding zone of Al-Mg ultrasonic welding joint with tin coating is composed of magnesium-tin reactive diffusion layer. The residual tin layer and the Al-Sn reactive diffusion layer are composed of the Al-Sn layer, the Al-Sn layer is the solid solution layer, and the magnesium-tin reactive layer is mainly the supersaturated solid solution matrix and the dispersed precipitated mesophase mg _ 2Sn.The maximum tensile shear strength of the joint is 32.9 MPA. The addition of tin coating can effectively prevent the diffusion of magnesium and aluminum, inhibit the formation of hard and brittle intermetallic compounds of Mg-Al system, and improve the strength of joint of ultrasonic welding of magnesium and aluminum, and the maximum tensile shear strength is increased by 19. 6% compared with that of ultrasonic welding of magnesium and aluminum.
【作者单位】：江西省机器人与焊接自动化重点实验室(南昌大学机电工程学院);
【基金】：国家自然科学基金资助项目(51265035)
【分类号】：TG174.4;TG453.9

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