Three-Sheet Spot Welds of 5052 Aluminum Alloy: Weld Growth and Failure Behavior

Abstract:

Resistance spot welding is used extensively in auto industry. Every commercial vehicle has 4000-5000 spot welds. The weld ability, performance, and reliability are therefore important issues in design. In this paper, we studied weld nugget formation and failure behavior of three-sheet 5052 aluminum alloy resistance spot welds. The Peltier effect between the Cu-Al (the electrode and the Al worksheet) to the nugget formation was noticed. The mechanical strength and fracture mode of the weld nuggets at the upper and lower interfaces were studied using tensile shear specimen configuration. Three failure modes were identified, namely, interfacial, mixed, and pull-out. The critical welding time and critical nugget diameter corresponding to the transitions of these modes were investigated. Finally, an empirical failure load formula for three-sheet weld similar to two-sheet spot weld was developed.

• Periodical: Applied Mechanics and Materials (Volume 782)
• Pages: 158-163
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.782.158
• Online since: August 2015
• Authors: Fu Yu Yan, Zhen Luo, Yuh J. Chao, San San Ao, Yang Li, Xue Tuan Cui
• Keywords: 5052 Aluminum, Failure Behavior, Resistance Spot Welding, Three Sheets, Weld Growth Mechanisms

References

[1] Gould, J. E. An examination of nugget development during spot welding using both experimental and analytic techniques. Welding Journal. 1987; 66 (1): 1- 10.

[2] Zhang, W. H., Qiu, X. M., Sun, D. Q., Han, L. J. Effects of resistance spot welding parameters on microstructures and mechanical properties of dissimilar material joints of galvanised high strength steel and aluminum alloy. Science and Technology of Welding and Joining. 2011; 16 (2): 153-161.

DOI: 10.1179/1362171810y.0000000009

[3] Khan, J. A., Xu, L., Chao, Y. J. Prediction of nugget development during resistance spot welding using coupled thermal-electrical-mechanical model. Science and Technology of Welding and Joining, 1999; 4 (4): 201-207.

DOI: 10.1179/136217199101537789

[4] Shen, J., Zhang, Y. S., Lai, X. M., Wang, P. C. Modeling of resistance spot welding of multiple stacks of steel sheets. Materials and Design. 2011; 32: 550-560.

DOI: 10.1016/j.matdes.2010.08.023

[5] Drebushchak, V. A. The Peltier Effect. Journal of Thermal Analysis and Calorimetry. 2008; 91 (1): 311-315.

[6] Li, B. Q. Research on the numerical simulation of the process for aluminum alloy resistance spot welding and energy analysis. Ph.D. dissertation. 2002; Tianjin, Tianjin University.

[7] American Welding Society. Test Methods for Evaluating the Resistance Spot Welding Behavior of Automotive Sheet Steel Materials. 2012; AWS D8. 9M: (2012).

[8] Zhou, M., Zhang, H., Hu, S. J. Relationships between quality and attributes of spot welds. Welding Journal. 2003; 82 (4): 72-77.

[9] Rivett, R. M. Factors affecting the quality of resistance spot welds. Ph.D. dissertation. 2002; Cardiff, Wales, University of Wales.

[10] Sawhill, J. Furr, S. Spot weldability tests for high-strength steels. SAE paper 810352. (1981).

DOI: 10.4271/810352

[11] Chao, Y. J. Ultimate strength and failure mechanism of resistance spot weld subjected to tensile, shear, or combined tensile/shear loads. ASME Journal of Engineering Materials and Technology. 2003; 125 (4): 125-132.

DOI: 10.1115/1.1555648