Crystallization kinetics and induced magnetic properties of bulk (Fe,Co)-Zr-Nd-B metallic glass

来源期刊：中国有色金属学报(英文版)2004年第5期

论文作者：李福山 张涛 关绍康 沈宁福

文章页码：840 - 845

Key words：nanocrystallization; kinetics; bulk Fe-based metallic glass; magnetic properties

Abstract: Crystallization kinetics and phase transformation of bulk Fe₆₄Co₇Zr₆Nd₃B₂₀ metallic glass were studied by X-ray diffractometry (XRD), differential scanning calorimetry (DSC) and transmission electron microscopy (TEM). Based on the Kissinger analyses, the activation energies for the nucleation and growth during the first, second and third crystallization-stages of the metallic glass are determined to be 294, 475 and 365 kJ/mol, respectively, and the activation energy for the glass transition is determined to be 1 242 kJ/mol. The Johnson-Mehl-Avrami (JMA) analysis under the isothermal condition reveals that the crystallization process is a three-dimensional controlled growth of nuclei at a constant nucleation rate. The crystalline grains are in the size of less than 50 nm after the selected annealing treatments. In the completely crystallized state, the alloy exhibits the maximum coercivity (H_c) of 34.8 kA/m and corresponding energy product of 11 kJ/m³.