On the formation of metallic glass

TL;DR

This paper develops an analytical framework for understanding metallic glass formation, focusing on cooling rates, phase diagrams, and thermodynamics to improve glass-forming ability and develop better metallic glasses.

Contribution

It introduces a new analytical model for the cooling process, proposes a refined measure of glass-forming ability, and discusses thermodynamic principles underlying glass formation.

Findings

Derived determinants for cooling rate in metallic glass formation.

Proposed a more reasonable measure of glass-forming ability, ΔTrg.

Discussed thermodynamic laws governing glass transition.

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, we formulate the cooling process in an analytical way and figure out the determinants for cooling rate, and analyze the crystallization time with consideration of phase diagram. Based on the reduced glass transition temperature, Trg, for measuring the glass-forming ability (GFA), a more reasonable {\Delta}Trg is proposed. 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 supposed to underlie the physics for glass formation. These results may help understand the glass formation principally and develop new and robust MGs technically.