Decomposition of pre‐existing Au–P clusters induced in situ α‐Fe grains uniformization in Fe–P‐based nanocrystalline alloys
Minhao Han, Cheng Sun, Guoguo Xi, Yang Meng, Qiang Luo, xiaodong yu, Wenfeng Zhang, Hao Liu, Hongjie Xu, Tao Zhang
Abstract
Abstract In Fe‐based amorphous‐/nanocrystalline ribbons, the uniformization and refinement of α‐Fe grains are key aspects for optimizing their soft magnetic and mechanical properties. Herein, the Fe–P–C–B nanocrystalline alloy system was selected for investigation. We produced as‐spun ribbons with pre‐existing nanocrystals through melt‐quenching and then obtained a well‐distributed α‐Fe nanocrystalline structure through annealing below the first crystallization onset temperature (633 K), resulting in excellent magnetic properties (saturation magnetization of 1.65 T and coercivity of 1.6 A·m −1 ), ultra‐wide annealing temperature window (from 613 to 733 K), and extremely high annealing stability (up to 480 min at 633 K). Furthermore, we propose a new in situ two‐step mechanism for the uniformization of α‐Fe nanocrystals, which is separately induced by the decomposition of the Au–P clusters and the pre‐existing α‐Fe nanocrystals during annealing. This work underscores the crucial significance of micro‐alloying via metastable clusters primarily influenced by metal‐phosphide interactions in the process of refining α‐Fe nanocrystals. Furthermore, it introduces a new principle for optimizing the comprehensive properties of Fe‐based amorphous/nanocrystalline alloys.