Electromigration Effects During Resistance Brazing of Zn–Al/Al System
Liquid filler metals often experience electromigration (EM) effects during resistance brazing due to the high current density, which can affect the microstructure of the joint and reduce its strength. However, to date, few studies have investigated this effect. Here, a Zn–Al alloy filler metal was used to braze 6063 Al alloys using direct-current resistance brazing. We clearly observed that EM occurred and analyzed its effect on the microstructures and morphology of joints. Al atoms migrated from the negative side to the positive side under a combined effect of the electric field and chemical gradient, while Zn atoms migrated in the opposite direction due to a back stress gradient. Further, growth of a solid solution layer at the positive side was inhibited by the back stress gradient, which also promoted growth of a similar layer at the negative side.
Keywordsaluminum alloy direct-current resistance brazing electromigration effect back stress
This work was supported by National Natural Science Foundation of China (No. 51465032).
Compliance with Ethical Standards
Conflict of interest
The authors have no conflict of interest to declare.
- 2.J. Zhang, J. Yang, L. Liang et al., A molecular dynamics investigation of the micro-mechanism for vacancy formation between Ag3Sn and βSn under electromigration. Mol. Phys. 116(5), 1–8 (2018)Google Scholar
- 4.Y. Wang, Y. Yao, A theoretical analysis of the electromigration-induced void morphological evolution under high current density. Acta Mech. Sin. (English Series) 33(5), 1–11 (2017)Google Scholar
- 13.L. Xu, J.H.L. Pang, Combined thermal and electromigration exposure effect on SnAgCu BGA solder joint reliability, in Electronic Components and Technology Conference, 2006. Proceedings, (IEEE, 2006)Google Scholar
- 14.S. Ou, K.N. Tu, A study of electromigration in Sn3.5Ag and Sn3.8Ag0.7Cu solder lines, in Electronic Components and Technology Conference, 2005. Proceedings, vol. 2 (IEEE, 2005), pp. 1445–1450Google Scholar
- 16.G.Q. Wei, H.L. Lin et al., Effect of electromigration and isothermal aging on interfacial microstructure and tensile fracture behavior of SAC305/Cu solder joint. China Weld. 25(03), 42–48 (2016)Google Scholar