Friction Stir Spot Welding (FSSW) is a solid-state welding technology that is rapidly growing in the automotive industry. Achieving superior welding characteristics requires the proper selection of tool geometry and process conditions. In this study, FSSW was performed on dissimilar materials comprising AA5052-HO/hot-melt aluminum alloy sheets and Steel Plate Cold Rolled for Deep Drawing Use(SPCUD) steel sheets. The effects of tool geometry, plate arrangement, and tool plunge depth on the welding process were investigated. At the joint interface between the aluminum alloy and the steel sheet, new intermetallic compounds (IMCs) were observed. As the plunge depth increased, thicker and more continuous IMC layers were formed. However, excessive plunge depth led to discontinuous layers and cracking defects. An analysis of the IMCs revealed a correlation between the IMC thickness and the shear tensile load. Furthermore, compared to the conventional Al-Top arrangement, the St-Top arrangement exhibited reduced deformation and superior shear tensile load values. These findings indicate that plate arrangement significantly influences the mechanical properties of the joint.

1. Introduction
2. Experimental Procedure
3. Results and Discussion
    3.1. 두께 변형
    3.2. 전단인장하중
    3.3. 용접부 미세조직
4. Conclusion
Funding
Conflict of Interest
Data Availability Statement
Author Information and Contribution
Acknowledgments
References

• 박시선(부산대학교 융합학부) | Si-Seon Park (Graduate School of Convergence Science, Pusan National University, Busan 46241, Republic of Korea)
• 정영근(부산대학교 융합학부) | Young-Keun Jeong (Graduate School of Convergence Science, Pusan National University, Busan 46241, Republic of Korea) Corresponding author