Kinetics of crystallization in continuously cooled BMG

Abstract

Nucleation kinetics of bulk metallic glass (BMG) alloy has been studied. Understanding the kinetics of crystal nucleation in continuously cooled liquid is very important since the crystallization is the only event to prevent the transformation of continuous cooled liquid to amorphous phase. In this study, DTA data have been analyzed together with the heterogeneous nucleation theory to give an accurate estimation of the nucleation temperatures for various cooling rates as well as prediction of crystallization behavior. Continuous cooling transformation (CCT) and time temperature transformation (TTT) diagrams of Zr41.2Ti13.8Cu12.5Ni10Be22.5 alloy were calculated. Calculated critical cooling rate R-c of Zr41.2Ti13.8Cu12.5Ni10Be22.5 alloy was 1.7 K/s, which is in good agreement with the experimental value. Our approach can be applied to the analyses of crystallization kinetics of continuously cooled BMG alloys with a wide range of critical cooling rates. (c) 2005 Elsevier B.V. All rights reserved.