EFFECT OF MINOR Al ADDITION ON GLASS-FORMING ABILITY AND THERMAL STABILITY OF Zr–Cu BINARY ALLOY

Abstract

By adding 2 at.% Al element in Zr 50 Cu 50 binary glass-forming alloy, we obtained Zr 50 Cu 48 Al 2 glassy rods with diameter larger than 3 mm. The reduced glass transition temperature, parameter γ and the critical section thickness obtained from the differential scanning calorimetry (DSC) traces indicate the better glass-forming ability (GFA) of Zr 50 Cu 48 Al 2 bulk metallic glass (BMG). The super-cooled liquid region and the continuous heating transformation diagram constructed from Vogel–Fulcher–Tammann fitting of crystallization temperature illustrate the enhanced thermal stability of the Zr 50 Cu 48 Al 2 BMG. The mechanism of effect of minor Al addition on GFA was investigated in more detail from Angell's fragility concept and from the thermodynamic point of view respectively.