Kinetic study of non-isothermal crystallization in Al80Fe10Ti5Ni5 metallic glass

Abstract

This study investigated the crystallization behavior of a kinetically metastable Al80Fe10Ti5Ni5 amorphous phase. The Al80Fe10Ti5Ni5 amorphous phase was synthesized via the mechanical alloying of elemental powders of Al, Fe, Ti, and Ni. The microstructures and crystallization kinetics of the as-milled and annealed powders were characterized using X-ray diffraction, transition electron microscopy, and non-isothermal differential thermal analysis techniques. The results demonstrated that an Al80Fe10Ti5Ni5 amorphous phase was obtained after 40 h of ball milling. The produced amorphous phase exhibited one-stage crystallization on heating, i.e., the amorphous phase transforms into nanocrystalline Al-13(Fe,Ni)(4) (40 nm) and Al3Ti (10 nm) intermetallic phases. The activation energy for the crystallization of the alloy evaluated from the Kissinger equation was approximately 538 +/- 5 kJ/mol using the peak temperature of the exothermic reaction. The Avrami exponent or reaction order n indicates that the nucleation rate decreases with time and the crystallization is governed by a three-dimensional diffusion-controlled growth. These results provide new opportunities for structure control through innovative alloy design and processing techniques.