Calculation of the Viscosity of Zr-and Fe-based Metallic Glass Alloys with Thermodynamics Method

Based on quasiregular model and Miedema model,a new thermodynamics method to evaluate the viscosity of glass alloys was provided by using the easily obtained parameters such as onset melting temperature,glass transition temperature and the cooling rate.With this model the viscosity of Zr-and Fe-based metallic glass alloys was calculated and the computed results agree well with the empirical one.The results show that,at a given temperature,viscosity increases with the addition of new component,and a higher viscosity will be obtained with the increase of the supercooling;to Zr-Al-Cu and Zr-Al-Ni,the highest viscosity locates in the composition range of xZr=0.375~0.8625,xCu=0~0.400 and xZr=0.375~0.8571,xNi=0~0.357,respectively,and to the Zr-Ni-Al-Cu system with 66.67% Zr,the highest viscosity is obtained in the region of xAl= 0.632~0.809,xNi=0.145~0.245;Fe-Nb-B alloys have a higher viscosity in xNb=0.325~0.9375,xB=0.0625~0.675;for Fe-Si-B the favorite composition to form glass is in xSi=0~0.521,xB=0.5124~0.9375.