Friction Stir Welding between Dissimilar Metalswith Circular Weld Line

Abstract:

Hybrid metallic structure, which is composed of aluminum alloy as a representative of light metal and steel as that of high strength metal, has been paid attention remarkably in these days, especially in the transportation vehicle industry from the energy saving viewpoint. To perform the hybrid structure, friction stir welding FSW has been recognized to be an effective way for the welding between dissimilar metals, like between steel and Al alloy. Based on our previous findings on the butt welding between dissimilar metals with straight weld line, welding between dissimilar metals with circular weld line has been tried to open a new application field of FSW. The objective of this research is to get a fundamental finding on the welding between dissimilar metals with circular weld line and to clarify the effect of material character of Al alloy and tool design on the FSW between dissimilar metals. Typical results obtained in this study are summarized as follows: 1) Macroscopic defects often observed at the bottom part of the welding in case of ADC12 material. It indicates that insufficient stirring was given in the stirring zone due to the higher thermo-mechanical property of ADC12. 2) Tensile strength of the specimen welded with scroll shoulder tool was 266 MPa, while that with flat shoulder tool was 161 MPa. Tensile strength of the weld joint was improved by a factor of 1.65 by introducing the scroll onto the tool shoulder with normal thread probe. 3) High performance defect free ADC12/S45C weld structure with circular weld line could be fabricated by the tool with combination of scroll shoulder and thread probe.

• Periodical: Key Engineering Materials (Volumes 622-623)
• Pages: 501-507
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.622-623.501
• Online since: September 2014
• Authors: Masahiro Fukumoto*, Hiroki Mizushima, Toshiaki Yasui
• Keywords: ADC12, Butt Welding, Circular Weld Line, Dissimilar Metal, FSW, Joint Strength, Tool Design

References

[1] K. Tanaka, M. Kumagai and H. Yoshida, Dissimilar joining of aluminum alloy and steel sheets by friction stir spot welding, J. of Japan Institute of Light Metals, 56-6 (2006) 317-322.

DOI: 10.2464/jilm.56.317

[2] T. Morita, A. Sakamoto, S. Mabuchi and T. Iizuka, Strength and formability of friction stir welded aluminun alloy with cold rolled steel, J. of the Society of Materials Science, Japan, 58-4 (2009) 317-322.

DOI: 10.2472/jsms.58.317

[3] K. Ohishi, M. Sakamura, K. Ohta and H. Fujii, Novel dissimilar spot welding of aluminum alloy and steel sheets by friction stirring, Quarterly J. of Japan Welding Society, 32-1 (2014) 1-7.

DOI: 10.1080/09507116.2014.921088

[4] M. Fukumoto, Y. Shimoda, M. Tsubaki and T. Yasui, Butt welding between dissimilar metals by friction stirring, Proc. of Int. Symposium on FSW, Metz (2004) CD.

[5] T. Yasui, Y. Shimoda, M. Tsubaki and M. Fukumoto, Welding of aluminum and steel by friction stir diffusion process, Materials Science Forum, 446-452 (2004) 433-436.

DOI: 10.4028/www.scientific.net/msf.449-452.433

[6] T. Yasui, Y. Shimoda, M. Tsubaki and M. Fukumoto, Friction stir welding between aluminum and steel with high welding speed, Proc. of Int. Symposium on FSW, Metz (2004) CD.

DOI: 10.4028/www.scientific.net/msf.449-452.433

[7] T. Yasui, Y. Shimoda, M. Tsubaki, and M. Fukumoto, Welding properties between 6063 aluminum and S45C steel by friction stir, Proc. of ISOPE, Seoul (2005) CD.

DOI: 10.1533/wint.2006.3580

[8] T. Yasui, T. Ishii, M. Tsubaki, M. Fukumoto, Macrostructure of butt weld between aluminum and steel by friction stirring, Proc. of Int. Symposium on FSW, Montreal (2006) CD.

[9] M. Fukumoto, Friction stir welding between dissimilar materials, J. of Light Metal Welding, 49-10 (2011) 383-389.