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

By adding 2 at.% Al element in Zr50Cu50 binary glass-forming alloy, we obtained Zr50Cu48Al2 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 Zr50Cu48Al2 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 Zr50Cu48Al2 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.