Fe-Nb-Si三元体系相平衡研究  

Phase equilibrium investigation of the Fe-Nb-Si ternary system

作　　者：聂玉崧 闻安东 章立钢[1] 邓子旋 刘立斌[1] NIE Yusong;WEN Andong;ZHANG Ligang;DENG Zixuan;LIU Libin(School of Material Science and Engineering,Central South University,Changsha 410083,China)

机构地区：[1]中南大学材料科学与工程学院,长沙410083

出　　处：《粉末冶金材料科学与工程》2022年第1期13-23,共11页Materials Science and Engineering of Powder Metallurgy

基　　金：国家磁约束核聚变能发展研究专项(2018YFE0306100)。

摘　　要：硅钢具有高矫顽力、低磁导率、大电阻系数等优点,被广泛应用于制造变压器和电机的铁芯材料。添加Nb元素可以提升硅钢的电磁性能,同时细化晶粒,提高力学性能。对Fe-Nb-Si三元合金研究应用的基础是三元相图的研究,本工作通过X射线衍射分析(XRD),扫描电子显微镜(SEM)和电子探针显微分析(EPMA/WDS)等表征手段,对Fe-Nb-Si三元体系1 173 K和1 073 K下的相平衡进行了分析研究。两个温度下均测得了11个三相平衡区,发现三种三元化合物τ_(2)(Fe Si_(2)Nb_(2))、τ_(5)(Fe_(4)Si_(7)Nb_(4))、τ_(6)(FeSiNb)。1 173 K和1 073 K下,Nb在η相(Fe_(5)Si_(3))中的最大固溶度分别约为1.6%(摩尔分数,%,下同)和0.5%,Fe在αNb_(5)Si_(3)的最大固溶度分别约为5.8%和4.9%,Si在Fe_(2)Nb中的最大固溶度分别为24.3%和25.2%,Si在μ(FeNb)中的最大固溶度分别为13.4%和11.3%。本工作完善了Fe-Nb-Si三元体系的相图信息,为后续开发新型硅钢提供了理论依据。Because of high coercivity,low permeability and large resistivity,silicon steel is widely used in the manufacture of iron core materials for transformers and various motors.On the basis of silicon steel,the addition of Nb element can improve the electromagnetic properties of silicon steel,and at the same time refine the grains and improve its mechanical properties.The research and application of Fe-Nb-Si ternary alloy is based on the study of ternary phase diagram.X-ray diffraction (XRD),scanning electron microscopy (SEM) and electron probe microanalysis (EPMA/WDS)were used to analyze the Fe-Nb-Si ternary system at 1 173 K and 1 073 K.The following phase equilibrium was experimentally investigated.The results show that 11 three-phase equilibrium zones are measured at two temperatures,and three ternary compoundsτ_(2)(Fe Si_(2)Nb_(2))、τ_(5)(Fe_(4)Si_(7)Nb_(4))、τ_(6)(FeSiNb) are found.Themaximum solid solubility of Nb inηphase (Fe_(5)Si_(3)) is about 1.6%(mole fraction,%,the same below) at 1 173 K and 0.5%at 1 073 K.The maximum solid solubility of Fe in αNb_(5)Si_(3) is about 5.8% at 1 173 K and 4.9%at 1 073 K.The maximum solid solubility of Si in Fe_(2)Nb is24.3%at 1 173 K and 25.2%at 1 073 K.The maximum solid solubility of Si inμphase (FeNb) is up to 13.4%Si at 1 173K and only about 11.3% at 1 073 K.This work improves the phase diagram information of the Fe-Nb-Si ternary system and provides a theoretical basis for the subsequent development of new silicon steel.

关 键 词：Fe-Nb-Si体系 相平衡 固溶度 等温截面 

分 类 号：TG113.14[金属学及工艺—物理冶金]