Friction stir spot welding (FSSW) is a solid-state joining process and a rapidly growing dissimilar material welding technology for joining metallic alloys in the automotive industry. Welding tool shape and process conditions must be appropriately controlled to obtain high bonding characteristics. In this study, FSSW is performed on dissimilar materials AA5052-H32 aluminum alloy sheet and SPRC440 steel sheet, and the influence of the shape of joining tool and tool insertion depth during joining is investigated. A new intermetallic compound is produced at the aluminum and steel sheets joint. When the insertion depth of the tool is insufficient, the intermetallic compound between the two sheets did not form uniformly. As the insertion depth increased, the intermetallic compound layer become uniform and continuous. The joint specimen shows higher values of tensile shear load as the diameter and insertion depth of the tool increase. This shows that the uniform formation of the intermetallic compound strengthens the bonding force between the joining specimens and increases the tensile shear load.

1. Introduction
2. Experimental
3. Results and Discussion
    3.1. 용접부 미세조직
    3.2. 인장전단하중
    3.3. 미소경도
4. Conclusion
Acknowledgement
References

• 안수호(부산대학교 융합학부) | Su-Ho An (Graduate school of convergence science, Busan 46241, Republic of Korea)
• 정영근(부산대학교 융합학부) | Young-Keun Jeong (Graduate school of convergence science, Busan 46241, Republic of Korea) Corresponding author