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

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.