Rheological Behavior of a New Amorphous Alloy (Al74Cu16Mg10)99,7Zr0.3

Abstract

A new amorphous alloy (Al₇₄Cu₁₆Mg₁₀)_99,7Zr_0.3 was prepared the applying a melt-spinning technique. Temperature dependence of viscosity of the alloy was determined using data from a PerkinElmer TMS2 thermo-mechanical analyzer processed according to a methodology based on the Free Volume Model (FVM). The strength of the alloy was calculated according to the Yang equation and the glass-forming ability was calculated according to the values of the Angell index m_A. The activation energy of crystallization and the activation energy of the glass transition were computed using data from differential scanning calorimetry and thermomechanical experiments respectively. The activation energy of crystallization Е_x = 168 ± 3.7 kJ/mol, was found to be higher than the activation energy of the glass transition Е_g = 156 ± 1.4 kJ/mol, which means a dominant contribution of the atomic transport barrier, compared to the nucleation barrier. The relatively high temperature interval of the supercooled melt state T_x-T_g = 32 K and the low viscosity values in the same range ƞ_(Тg) = 3.40E + 11 Pa.s and ƞ_(Тx) = 1.87E + 10 Pa.s would allow thermomechanical treatment of the alloy in the temperature range of supercooled melt.