Kinetics of Glass Transition of Zr₄₁Ti₁₄Cu_12.5Ni₁₀Be_22.5 AlloySolidified in a Drop Tube

Droplets of Zr₄₁Ti₁₄Cu_12.5Ni₁₀Be_22.5 glass-forming alloy with different sizes are solidified in a drop tube containerless process. The glass transition temperature T_g of Zr₄₁Ti₁₄Cu_12.5Ni₁₀Be_22.5 glassy spheres solidified with different cooling rates is investigated by using a differential scanning calorimeter. It was found that all the amorphous spheres show an increase of T_g with the heating rate. The glassy spheres have a unique value for glass transition activation energy E_g= 435.50kJ/mol, which is independent of cooling rate q. The insensitivity of T_g to q is interpreted by an extension of the free volume model for flow.