On the heterogeneous microstructure and strengthening mechanisms in a laser welding AZ80 magnesium alloy

Yu Liu; Gaoming Zhu; Yaqi Wang; Zhifeng Xin; Ning Hao; Wei Huang; Sangbong Yi; Dietmar Letzig; Ulrich Lienert; Jie Wang; Xiaoqin Zeng

doi:10.1038/s41598-024-73767-0

On the heterogeneous microstructure and strengthening mechanisms in a laser welding AZ80 magnesium alloy

Sci Rep. 2024 Oct 3;14(1):22993. doi: 10.1038/s41598-024-73767-0.

Authors

Yu Liu¹, Gaoming Zhu^{2

3}, Yaqi Wang⁴, Zhifeng Xin⁵, Ning Hao⁵, Wei Huang⁵, Sangbong Yi⁶, Dietmar Letzig⁷, Ulrich Lienert⁸, Jie Wang⁹, Xiaoqin Zeng¹⁰

Affiliations

¹ National Engineering Research Center of Light Alloy Net Forming & State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, Shanghai, 200240, China.
² National Engineering Research Center of Light Alloy Net Forming & State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, Shanghai, 200240, China. [email protected].
³ Institute of Material and Process Design, Helmholtz-Zentrum Hereon, 21502, Geesthacht, Germany. [email protected].
⁴ Shanghai Key Laboratory of Materials Laser Processing and Modification, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China.
⁵ Consumer & SMB Notebook Development Center, Lenovo (Beijing) Ltd., Beijing, 100094, China.
⁶ School of Materials Science and Engineering, Kumoh National Institute of Technology, Gyeongbuk, 39177, South Korea.
⁷ Institute of Material and Process Design, Helmholtz-Zentrum Hereon, 21502, Geesthacht, Germany.
⁸ Deutsches Elektronen-Synchrotron (DESY), 22607, Hamburg, Germany.
⁹ National Engineering Research Center of Light Alloy Net Forming & State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, Shanghai, 200240, China. [email protected].
¹⁰ National Engineering Research Center of Light Alloy Net Forming & State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, Shanghai, 200240, China. [email protected].

Abstract

This study investigates the microstructural characteristics and mechanical properties of a laser welded AZ80 magnesium alloy. The welding process led to the formation of coarse-grained fusion zone (FZ), where a secondary phase formed continuous network. Mg₁₇Al₁₂ precipitation and coarsening of grain boundaries occurred in the heat affected zone. The welded joint exhibited excellent mechanical properties with a yield strength of 202 MPa and a joint efficiency of 92%. The microstructure analysis via EPMA and EBSD in conjunction with synchrotron X-ray diffraction analysis reveals that precipitates and increased dislocation density in the fusion zone are primary strengthening mechanisms for the laser welded AZ80 Mg alloy.

Keywords: Laser welding; Magnesium alloy; Mechanical properties; Synchrotron X-ray diffraction.

Grants and funding

52301018/National Natural Science Foundation of China