The conditions of the coincidence between viscosity obtained by the heating rate dependence of glass transition and the measured viscosity for amorphous alloys

The conditions of the coincidence between viscosity η^τ(T) obtained by the heating rate dependence of glass transition and the measured viscosity η(T) are studied. It is found that G_η(T)/G₀ can be used to judge the degree of the coincidence between η^τ(T) and η(T), where G_η(T) and G₀ are η(T)/τ_trans(T) (transition time) and η₀/τtrans 0(the pre-exponential factor of η(T) and τ_trans(T)), respectively. η^τ(T) will be the same with η(T) in whole temperature range when G_η(T)/G₀ equals 1; Conversely, η^τ(T) will depart from η(T) when G_η(T)/G₀ does not equal 1. The greater the difference between G_η(T) and G₀ is, the greater the degree of underestimate or overestimate for η(T) is. The reason why ideal glass transition temperature T_g⁰ and strength parameter D_q obtained by T_g^onset(q_H) with three unrestricted fitting parameters depart from ideal glass transition temperature T^η 0 and strength parameter D_η obtained by viscosity results from the constant A_q of T_g^onset(q_H) equation is excessively less than the constant (VG_ηΔT_g)/N_Ah, where N_A, h, V, G_η and ΔT_g are Avogadro’s constant, Planck’s constant, the molar volume, a scaling factor and the width of the glass transition region.