权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Electromagneto-thermo-mechanical functional ferromagnetic shape memory alloy

电磁热机械功能铁磁形状记忆合金

基本信息

批准号：
09450043
负责人：
TAKAGI Toshiyuki
金额：
$ 7.94万
依托单位：
TOHOKU UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1997
资助国家：
日本
起止时间：
1997 至 1999
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09450043/
关键词：
Ferromagnetic shape memory alloys Shape Memory alloys Heusler alloys Martensitic transformation Ferromagnetic Xray diffraction Shape memory effect Nonstoichiometry 非科学量論ホイスラー型ホイスラ-型

项目摘要

We investigate a novel ferromagnetic shape memory alloy, Ni-Mn-Ga system, which has the shape memory effect induced by external magnetic field in addition to temperature and stress changes. We have obtained electromagneto-thermo-mechanical properties of this alloy that are important for the application of this alloy to actuators.For the bulk materials we have evaluated the material properties of this alloy changing the methods of heat treatment and fabrication procedures, and we have obtained the following results.1. Martensitic transformation temperatures and Curie points change for different Ni contents against the Mn. This change was verified by a differential scanning calorimeter (DSC) as well as magnetic properties and resistivity measurements.2. NiィイD22.18ィエD2MnィイD20.82ィエD2Ga shows a strange magnetic property that the structural transition and magnetic transition coincides at a certain temperature.3. The material made by an arc melting method was found brittle. We applied a spark plasma sputtering (SPS) method to this material and demonstrated that material properties were improved by this method.4. The alloy made by the SPS shows four times larger Young's modulus than that of the alloy made by an arc melting method.5. We measured the temperature dependency of the Young's modulus of this alloy fabricated by the SPS and found that the modulus changes with structural transitions of this alloy.For thin films we confirm the shape memory effect at certain film thickness and quench conditions made by a sputtering method. In this special heat treatment the crystal grain size becomes larger and the shape memory effect occurs when the temperature coincides with the transition temperatures measured by DSC. The shape memory effect of this film was demonstrated first in the world.

研究了一种新型的铁磁形状记忆合金Ni-Mn-Ga系，该合金在外加磁场的作用下，除了温度和应力的变化外，还具有形状记忆效应。我们获得了该合金的电磁-热-机械性能，这对于该合金在致动器上的应用是非常重要的。对于块体材料，我们通过改变热处理方法和制备工艺来评估该合金的材料性能，并得到了以下结果。马氏体相变温度和居里点随Ni含量的变化而变化。通过差示扫描量热仪（DSC）以及磁性能和电阻率测量验证了这种变化. Ni掺杂D22.18锰掺杂D2 Mn掺杂D20.82锰掺杂D2 Ga在一定温度下表现出结构转变与磁性转变相一致的奇异磁性.发现通过电弧熔化方法制成的材料是脆性的。采用放电等离子体溅射（SPS）方法对该材料进行了制备，并证明了该方法对材料性能的改善.由SPS制备的合金显示出比由电弧熔炼方法制备的合金大四倍的杨氏模量。测量了SPS制备的合金的杨氏模量随温度的变化，发现其模量随结构转变而变化。对于薄膜，我们证实了溅射法制备的合金在一定膜厚和淬火条件下的形状记忆效应。在这种特殊的热处理过程中，当温度与DSC测量的转变温度一致时，晶粒尺寸变大，并且发生形状记忆效应。该薄膜的形状记忆效应在世界上首次得到证实。