Solid State Welding between CPTi and AZ31B Magnesium Alloy by Friction Stirring

Abstract:

This paper described an experimental study on the friction stir welding of dissimilar metal between commercially pure titanium (CPTi) and magnesium alloy AZ31B (Mg). Butt-welds produced at various tool rotation speeds were evaluated by the observation of the weld surface appearance, X-ray radiographic test, tensile test, SEM and EDX analysis. The main results obtained are as follows. Butt-joint welding of the CPTi plate to the Mg plate was easily and successfully achieved. The ignition of Mg occurred during welding at the tool rotation speeds over 1200rpm. The fragments of CPTi existed in a continuous form in Mg matrix. The tool rotation speed of 1200rpm attained the maximum tensile strength of a joint, which was about 75% of that of Mg base metal. Fracture occurred at the weld interface in most joint. EDX analysis revealed that Al in the Mg diffused into CPTi through the weld interface and MgO existed at the interface. It seems that the decrease in Al concentration in the Mg and MgO formation around the weld interface caused the low tensile strength of the joints.

• Periodical: Materials Science Forum (Volumes 539-543)
• Pages: 3856-3862
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.539-543.3856
• Online since: March 2007
• Authors: H. Tanabe, Takehiko Watanabe, Y. Abe, A. Yanagisawa
• Keywords: CPTi, Dissimilar Metal, Friction Stir Welding (FSW), Joining, Magnesium Alloy, Tensile Strength

References

[1] C. J. Dawes� and� W. M. Thomas, Welding Journal, 75-3(1996), pp.41-45.

[2] H. Okamura, K. Aota and M. Esumi, Journal of Japan Institute of Light Metals, 50 (2000), p.166. (in Japanese).

[3] K. Nakata, S. Inoki, Y. Nagano, T. Hashimoto, S. Johgan and M. Ushio, Journal of Japan Institute of Light Metals, 51(2001), pp.528-533. (in Japanese).

DOI: 10.2464/jilm.51.528

[4] K. Katoh, H. Tokisue, T. Kitahara, Journal of Japan Institute of Light Metals, 55- 6(2005) , pp.59-64. (in Japanese).

[5] S. Hirano, K. Okamoto, M. Doi, H. Okamura, M. Inagaki and Y. Aono, Journal of the Japan Welding Society, 21-4(2003), pp.539-545. (in Japanese).

[6] T. Watanabe, A. Yanagisawa and H. Takayama, Journal of the Japan Welding Society, 22-2(2004), pp.141-148. (in Japanese).

[7] T. Watanabe, H. Takayama, A. Yanagisawa and S. Konuma, Journal of The Japan Welding Society, 23-4(2005).

[8] M. Fukumoto, M. Tsubaki, Y. Shimoda and T. Yasui, Journal of The Japan Welding Society, 22-2(2004), pp.309-314. (in Japanese).

[9] The Japan Magnesium Association, A handbook of magnesium, Kallos Publishing, (2000), p.298. (in Japanese).

[10] T. B. Massalski et al, Binary Phase Diagrams, ASM, 1996, CD.

[11] The Japan Magnesium Association, A handbook of magnesium, Kallos Publishing, (2000), p.115, p.256. (in Japanese).

[12] The Japan Magnesium Association, Magnesium Manual, (1999), p.126. (in Japanese).