• CN:11-2187/TH
  • ISSN:0577-6686

机械工程学报 ›› 2020, Vol. 56 ›› Issue (6): 33-40.doi: 10.3901/JME.2020.06.033

• 铝合金与钢的焊接 • 上一篇    下一篇

扫码分享

铝-钢异质金属双光束激光焊接IMC层迁移行为及对界面性能的影响

袁锐1,2, 邓胜杰1,2, 崔海超1,2, 麻寕绪1,3, 芦凤桂1,2   

  1. 1. 上海市激光制造与材料改性重点实验室 上海 200240;
    2. 上海交通大学材料科学与工程学院 上海 200240;
    3. 大阪大学结合科学研究所 大阪 567-0047 日本
  • 收稿日期:2019-08-16 修回日期:2019-10-21 出版日期:2020-03-20 发布日期:2020-05-12
  • 作者简介:袁锐,男,1995年出生,硕士研究生。主要研究方向为钢/铝异质金属双光束激光熔-钎焊。E-mail:yr950411@sjtu.edu.cn;
    芦凤桂(通信作者),女,1975年出生,博士,教授,博士研究生导师。主要研究方向为焊接组织与材料性能关联性及其机理研究、焊接物理冶金过程建模。E-mail:lfg119@sjtu.edu.cn
  • 基金资助:
    国家自然科学基金资助项目(U1660101,51675336)。

Characterization on IMC Layer Migration and Interface Properties in Dual-beam Laser Welding of AA7075/DP590 Alloys

YUAN Rui1,2, DENG Shengjie1,2, CUI Haichao1,2, MA Ninshu1,3, LU Fenggui1,2   

  1. 1. Shanghai Key Laboratory of Materials Laser Processing and Modification, Shanghai 200240;
    2. School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240;
    3. Joining&Welding Research Institute, Osaka University, Osaka 567-0047, Japan
  • Received:2019-08-16 Revised:2019-10-21 Online:2020-03-20 Published:2020-05-12

摘要: 利用双光束激光熔-钎焊焊接方法开展了AA7075/DP590异质金属的连接,通过改变激光功率等焊接工艺发现熔钎焊接头显微组织中存在金属间化合物(Intermetallic compound,IMC)层脱离铝-钢界面整体迁移进入焊缝内部的特殊现象,迁移现象位于激光直接作用区域,数值模拟发现激光直接作用下的熔池剧烈流动驱动了IMC的迁移。对迁移部分IMC层物相表征分析发现,近铝-钢界面处发生迁移的IMC层形貌呈致密平板状,与铝-钢界面处IMC层相似,由η相组成;迁移深入焊缝内部的IMC层内有裂纹、断裂产生,由θ相组成,裂纹处存在铝焊缝组织长入,发生迁移的IMC层内部存在η相与θ相的过渡区。拉伸结果表明,IMC层迁移现象的出现会削弱焊接接头铝-钢界面处的强度,这是因为界面初生的IMC层薄弱,止裂能力差,所以控制IMC层迁移有利于提高接头力学性能。

关键词: 铝-钢异质金属, 双光束, 熔-钎焊, 金属间化合物(Intermetallic compound,IMC), 力学性能

Abstract: The joining of AA7075 aluminum alloy and DP590 steel are successfully conducted by dual beam laser welding brazing method. A unique phenomenon is found that the intermetallic compound (IMC) layer leaves Al/steel interface and migrates into welding seam. The migration of IMC layer only shows in the area where laser beam directly irradiates. Numerical simulation result shows the formation of such phenomenon is driven by the Marangoni Flow inside the welding pool induced by laser. It is found the migrated IMC layer near to Al/steel interface is composed of η phase and shows a compact flat morphology, which is similar to the IMC layer at Al/steel interface. On the contrary, the migrated IMC layer deep in welding seam is composed of θ phase and cracks are observed in such IMC layer with welding seam grows into cracks. There is a transition region for the η phase and θ phase inside the IMC layer. Tensile test results indicate that the migration of IMC layer will be harmful to the mechanical property of Al/steel interface because of the weak strength of newly-formed IMC layer. As a result, it’s better to avoid such phenomenon happening.

Key words: Al/steel dissimilar metals, dual beam laser, welding-brazing, intermetallic compound(IMC), mechanical properties

中图分类号: