机械合金化Fe_(60)Si_(40)体系的XAFS研究

XAFS Study on Fe_(60) Si(40) Alloy Processed by Mechanical Alloying

利用XAFS技术研究Fe60 Si40 二元合金体系中Fe原子周围配位环境随球磨时间的变化 .结果表明 ,球磨过程中 ,首先发生晶态α Fe和Si的晶格较大的畸变和颗粒破碎 ,致使Fe和Si原子近邻配位的无序度增大 ,进而Si原子通过活化的界面向Fe晶格扩散 ,形成亚稳的Fe3 Si和Fe5 Si3 替位固溶体 .

XAFS technique was used to study the local structure evolution with milling time around Fe atoms in Fe 60 Si 40 alloy prepared by mechanical alloying. The results show that during the mechanical milling process, the first stage is associated with the lattice deformation of crystalline α Fe and Si, so that the disorder degrees around Fe and Si atoms arise. Then the Si atoms diffuse into Fe lattice through the activated interface of grain boundaries. Finally Fe and Si are converted into metastable Fe 5Si 3 and Fe 3Si substitutional solid solutions.