Abstract
Magnesium is the lightest structural metal, and alloying with lithium makes it even lighter. However, multi-phase Mg-Li alloys typically undergo rapid corrosion, and their strength decreases at room temperature due to natural age-softening. Here, we engineer a rapidly degrading dual-phase Mg-Li-Al alloy to be durable via friction stir processing followed by liquid CO2 quenching. The best performing alloy has a low electrochemical degradation rate of 0.72 mg·cm−2· day−1, and high specific strength of 209 kN·m·kg−1. We attribute this electrochemical and mechanical durability to its microstructure, which consists of a refined grain size of approximately 2 µm and dense nanoprecipitates. This microstructure suppressed the formation of the detrimental AlLi phase, and an aluminium-rich protective surface layer also formed. This processing route might be useful for designing lightweight and durable engineering alloys.
| Original language | English |
|---|---|
| Article number | 18 |
| Number of pages | 10 |
| Journal | Communications Materials |
| Volume | 3 |
| Issue number | 1 |
| DOIs | |
| Publication status | Published - 6 Apr 2022 |
Bibliographical note
Funding Information:The authors are grateful for financial support from the Australian National University (ANU) Futures Scheme, Japan New Energy and Industrial Technology Development Organization (NEDO) Innovation Structural Materials Project (Future Pioneering Projects), National Natural Science Foundation of China (Grant No. 52035005), and Swedish Research Council and the Royal Swedish Academy of Engineering Sciences. We acknowledge the use of facilities at the ANU Centre for Advanced Microscopy, Monash Centre for Electron Microscopy, Nodes of Microscopy Australia, and Monash X-ray Platform. Z.R. Zeng acknowledges the assistance of FIB and TEM from Dr. Frank Brink and Dr. Felipe Kremer, and help with processing XPS data from Mr Chengkai Sun, and helpful discussion with Dr. Yuanming Yan.
Funding Information:
The authors are grateful for financial support from the Australian National University (ANU) Futures Scheme, Japan New Energy and Industrial Technology Development Organization (NEDO) Innovation Structural Materials Project (Future Pioneering Projects), National Natural Science Foundation of China (Grant No. 52035005), and Swedish Research Council and the Royal Swedish Academy of Engineering Sciences. We acknowledge the use of facilities at the ANU Centre for Advanced Microscopy, Monash Centre for Electron Microscopy, Nodes of Microscopy Australia, and Monash X-ray Platform. Z.R. Zeng acknowledges the assistance of FIB and TEM from Dr. Frank Brink and Dr. Felipe Kremer, and help with processing XPS data from Mr Chengkai Sun, and helpful discussion with Dr. Yuanming Yan.
Publisher Copyright:
© 2022, The Author(s).