J. Mater. Sci. Technol. ›› 2020, Vol. 44: 48-53.DOI: 10.1016/j.jmst.2019.10.018

• Research Article • Previous Articles     Next Articles

In-situ surface transformation of magnesium to protect against oxidation at elevated temperatures

Yuecun Wanga, Meng Lia, Yueqing Yanga, Xin’ai Zhaoa, Evan Mab*(), Zhiwei Shanb*()   

  1. a Center for Advancing Materials Performance from the Nanoscale (CAMP-Nano) & Hysitron Applied Research Center in China (HARCC), State Key Laboratory for Mechanical Behavior of Materials, Xi’an Jiaotong University, Xi’an, 710049, China
    b Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, 21218, MD, USA
  • Received:2019-08-08 Revised:2019-09-25 Accepted:2019-10-07 Published:2020-05-01 Online:2020-05-21
  • Contact: Evan Ma,Zhiwei Shan

Abstract:

The native oxide thin scale on magnesium (Mg) surface appears continuous and crack-free, but cannot protect the Mg matrix from further oxidation, especially at elevated temperatures. This thermal oxidation process is witnessed in its entirety using a home-made in-situ heating device inside an environmental electron transmission microscope. We proposed, and verified with real-time experimental evidence, that transforming the native oxide scale into a thin continuous surface layer with high vacancy formation energy (low vacancy concentration), for example MgCO3, can effectively protect Mg from high-temperature oxidation and raise the threshold oxidation temperature by at least two hundred degrees.

Key words: Magnesium, Thermal oxidation, In-situ E-TEM, Carbonation, Oxidation inhibition