Thermodynamic properties and metastability of bulk metallic glasses

Abstract

Glasses are formed if upon cooling of a melt below the glass transition temperature crystal nucleation and growth are avoided. Recently, multi-component alloys with deep eutectic temperatures have been developed which allow the formation of a metallic glass during slow cooling of the melt. These so-called bulk metallic glasses can be produced with several cubic centimeters (cm3) dimensions and have excellent properties making them suitable as a superior engineering material. Moreover, for these amorphous alloys crystallization can be avoided over a broad temperature–time window not accessible so far for metals. As such, the relevant thermodynamic properties of the metastable glassy and undercooled liquid states can be directly measured below and above the glass transition temperature, respectively. The obtained data gives new insight into the fundamental aspects regarding the stability of undercooled liquids and the nature of the glass transition.