On the formation of metallic glass

Abstract

The high cooling rate needed for preparing the metallic glass (MG) makes the nonequilibrium nature of glass formation more prominent and requires a better quenching technique than ever before. Here, the cooling process is formulated analytically to reveal the determinants for cooling rate, and the crystallization time with consideration of phase diagram is calculated. Based on the reduced glass transition temperature, T_rg, for measuring the glass-forming ability (GFA), a more reasonable ΔT_rg is presented. Glass transition, especially in ever glass whose ground state is of glass, is discussed in terms of thermodynamics for phase transition. A fundamental law concerning the changing rate of entropy in a closed system is proposed to underlie the physics for glass formation. These results may help understand the glass formation principally and develop new and robust MGs technically.