Enhancement of oxidation resistance of the supercooled liquid in Cu-Zr-based metallic glass by forming an amorphous oxide layer with high thermal stability

In the present study, we propose that the formation of amorphous oxide layers with an enhanced thermal stability can significantly improve the oxidation resistance of metallic glass in the supercooled liquid (SCL) state. Addition of a small amount of Be (2 at.%) in Cu46Zr46Al8 widens the SCL region and simultaneously improves the oxidation resistance of the SCL. For Cu46Zr46Al8, the initial amorphous oxide completely transforms into the crystalline oxide far below the glass transition temperature during continuous heating, while for Cu45Zr45Al8Be2, the amorphous oxide remains after heating up to the SCL region, thus significantly improving the oxidation resistance of the SCL.