Effect of Oxygen on Microstructure Evolution and Glass Formation of Zr-based Metallic Glasses

The effect of oxygen on the microstructure evolution and glass formation of Zr-based bulk metallic glasses (BMGs) was studied in detail. It was found that oxygen did not form oxides or dissolve in glass matrix, but induced the precipitation of α-Zr which has the high affinity and solubility of oxygen in the Zr-based bulk metallic glass (Zr-BMG). With the precipitation of α-Zr, the remaining melts contain much lower oxygen content and have strong glass formation, resulting in the formation of α-Zr/BMG composite. The findings provide an important insight into the mechanism of the oxygen on glass formation, and give us a useful guideline to avoid the oxygen detrimental for designing new BMGs.