Improvement of microstructure and mechanical properties of AZ61 Mg alloys subjected to rapid cooling friction stir welding

ABSTRACT

Conventional friction stir welding (FSW) AZ61 Mg alloy weld usually exhibits an Al supersaturated α-Mg solid solution with an intense basal texture, resulting in an unsatisfactory strength and ductility. In this work, rapid cooling FSW was conducted on the AZ61 Mg alloy to improve the microstructure and mechanical properties of the weld. A fine grain structure with dislocations, β-Mg₁₇Al₁₂ particles, and {10-12} twins was obtained in the weld. Additionally, the particle stimulated nucleation induced dynamic recrystallisation and {10-12} twinning induced dynamic recrystallisation contribute to the reduction of the basal texture intensity. The mechanical properties of the weld were improved due to the synergistic effects of the dislocations, β-Mg₁₇Al₁₂ particles, and {10-12} twins.

KEYWORDS:

• Mg alloy
• friction stir welding
• microstructure
• strength
• ductility

Acknowledgements

The authors would like to deeply appreciate the support from the Jiangsu University of Technology for providing the FSW equipment. Author N. Xu would like to thank Professor Hidetoshi Fujii in Osaka University for his valuable idea during this work.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Correction Statement

This article has been republished with minor changes. These changes do not impact the academic content of the article.

Additional information

Funding

This work was supported by Natural Science Foundation of Jiangsu Province: (Grant Number BK20211067); National Natural Science Foundation: [Grant Number 51805145]; Fundamental Research Funds for the Central Universities: [Grant Number B200202229]; Changzhou Science and Technology Program: [Grant Number CJ20200076]; Postgraduate Research & Practice Innovation Program of Jiangsu Province: [Grant Number KYCX21_0469]; ‘Qing Lan’ Project of Jiangsu Province.