铝合金/镀锌钢异种材料薄板的超声波点焊

Ultrasonic spot welding of aluminum alloy and galvanized steel dissimilar metals sheets

关键词:  超声波焊  铝合金  镀锌钢  接头强度  界面组织

Key words:  ultrasonic welding  aluminum alloy  galvanized steel  joint strength  interface microstructure

摘要:

为了实现铝合金和钢板的高效连接,对3003铝合金和镀锌钢板进行了超声波点焊. 研究了接头的显微组织特征、焊接参数对接头性能的影响以及焊缝区的温度变化过程. 结果表明,超声波焊接可以对3003铝合金与镀锌钢板进行有效连接;镀锌层被不规则挤出,铝合金与钢直接接触区形成了FeAl₃和Fe₂Al₅相;在一定范围内,随着焊接时间的增加,接头抗拉强度先增加后减小,其减小的原因是过长的焊接时间诱导显微组织演变;当焊接时间为240 ms,焊接压力为0.4 MPa时,获得接头的最大抗拉力为673.05 N;在文中试验条件下,焊接区最高温度达到390 ℃.

Abstract:

Ultrasonic spot welding of 3003 aluminum alloy to galvanized steel sheets was conducted to join aluminum and steel sheets with high efficiency. Microstructure characteristics of the joint, effects of the welding parameters on the joint properties, as well as temperature rise in the weld were studied. The results show that: (i) it was possible to ultrasonically weld 3003 aluminum alloy and galvanized steel sheets;(ii) zinc coating was extruded irregularly, direct contact of aluminum alloy and steel locally resulted in the formation of FeAl₃ and Fe₂Al₅ phases;(iii) joint strength increased when the welding time increased within a certain range and then decreased due to the welding time induced microstructure evolution, and a maximal fracture load of 673 N was obtained when the welding duration was about 240 ms and welding pressure was 0.4 MPa;(iv) the maximal temperature in the weld was about 390 ℃.