Effect of oxygen impurity on long-term thermal stability of Zr-based metallic glasses below glass transition temperature
(1. State Key Laboratory for Mechanical Behavior of Materials,
Xi’an Jiaotong University, Xi’an 710049, China;
2. Construction Machinery School, Chang’an University, Xi’an 710049, China)
Xi’an Jiaotong University, Xi’an 710049, China;
2. Construction Machinery School, Chang’an University, Xi’an 710049, China)
Abstract: Long-term thermal stability of a series of Zr-based metallic glasses with different oxygen contents below their glass transition temperatures was compared based on their deductive continuous-heating-transformation diagrams created by using the corollary of Kissinger analysis method. It is found that the influence of oxygen on the long-term thermal stability of Zr-based metallic glasses exhibits at lower temperature is different from that on their short-term thermal stability presented at higher temperature. For each kind of the Zr-based metallic glasses, there is a critical heating rate, f c, which corresponds to a critical temperature, Tc. As heating rate is smaller than f c and onset devitrification temperature is below Tc, the glass with higher oxygen content will have longer incubation period for onset devitrification. The values of f c and Tc are related with the glasses’ reduced glass transition temperature Trg. The improving effect of oxygen impurity on the long-term thermal stability of Zr-based metallic glasses was discovered.
Key words: Zr-based metallic glasses; thermal stability; continuous heating transformation diagram; oxygen impurity