Ni-Mn基Heusler合金的显微结构调控及性能研究  

Study on Microstructure Regulation and Properties of Ni-Mn-Based Heusler Alloys

作　　者：黄文洋 郭文辉 龚勇 李俊沛 陈云龙 缪雪飞 

机构地区：[1]南京理工大学材料科学与工程学院,江苏 南京

出　　处：《材料科学》2025年第2期250-256,共7页Material Sciences

摘　　要：Ni-Mn基Heusler合金因其磁–结构相变特性表现出多种功能特性,如磁热效应、磁阻效应与磁场诱导形状记忆效应等,受到广泛关注。本文针对其中的Ni-Mn-In合金展开研究,利用定向凝固技术,制备得到了具有强织构的样品,并利用扫描电子显微镜、X射线衍射仪、差热扫描量热仪等仪器,对样品的显微结构、相变行为以及性能变化进行了深入研究。研究表明,在室温下样品为L21立方奥氏体,且定向凝固后得到了织构。通过对喷铸与定向凝固样品的相变行为进行分析,发现定向凝固后相变温度显著上升(从约170 K升高至约200 K),居里温度则基本保持不变。同时,定向凝固样品的相变宽度更窄,即相变更剧烈,相变的热滞后行为也得到显著改善(从19.8 K降低至12.5 K)。此外,对定向凝固样品的热膨胀性能进行了测试:在升温奥氏体相变过程(215~230 K)中,沿生长方向(LD)发现了显著的负热膨胀现象,热膨胀系数αL = −259.6 ppm/K,而垂直于生长方向(ND)则呈现正热膨胀行为,热膨胀系数高达452.7 ppm/K,远高于喷铸样品的173.9 ppm/K。综上所述,定向凝固方法对Ni-Mn-In合金的相变行为起到显著调控作用,并成功在该体系合金中获得了负热膨胀性能。Ni-Mn-based Heusler alloys have attracted widespread attention due to their magnetic-structural phase transition characteristics, which exhibit various functional properties such as the magnetocaloric effect, magnetoresistance, and magnetic-field-induced shape memory effect. This paper focuses on the Ni-Mn-In alloy, where directional solidification technology was used to prepare samples with strong texture. The microstructure, phase transition behavior, and performance changes of the samples were thoroughly studied using instruments such as scanning electron microscopy, X-ray diffraction, and differential scanning calorimetry. The research shows that at room temperature, the sample is in the L21 cubic austenite phas

关 键 词：Ni-Mn-In合金 定向凝固 一级相变 负热膨胀 

分 类 号：TG1[金属学及工艺—金属学]