Correlation between thermal stability and <i>β</i> relaxation of La–Ce–Al–Co–Ga bulk metallic glasses

Abstract

The thermal instability of metallic glasses hinders their application and thermoplastic processing, and, at present, how to improve the thermal stability is a scientific topic worthy of further study. This paper, through the studies of a [(La0.7Ce0.3)65Al10Co25]100−xGax model system, reveals three correlations between β relaxation of metallic glasses and their thermal stability, stating that (1) the ratio of the β relaxation intensity to the α relaxation intensity, E″β/E″α, is positively correlated with the glass transition temperature, Tg; (2) at a fixed frequency, the ratio of the β relaxation temperature to the α relaxation temperature, Tβ/Tα, is positively correlated with the supercooled liquid region width, ∆Tx = Tx − Tg; (3) ∆Tx is negatively correlated with the β relaxation activation energy, Eβ. These identified relationships between β relaxation and the thermal instability of metallic glasses deepen the understanding of factors influencing the glass stability and offer a viable strategy to enhance the thermal stability of metallic glasses by regulating the β relaxation process.