Interactions between chemical ordering and magnetic transitions in ferromagnetic alloys.

铁磁合金中化学排序和磁转变之间的相互作用。

基本信息

批准号：
11450233
负责人：
KAINUMA Ryosuke
金额：
$ 9.34万
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：
1999
资助国家：
日本
起止时间：
1999 至 2000
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-11450233/
关键词：
PHASE SEPARATION ORDER-DISORDER TRANSITIONS MAGNETIC TRANSITION Fe-Al SYSTEM Fe-Ga SYSTEM Co-Al BASE SYSTEMS THERMODYNAMICS PHASE DIAGRAMS Fe-Si合金 Fe-Ga合金

项目摘要

It is known that magnetic transition influences order-disorder transitions in the Fe-base alloys which show both the chemical ordering and magnetic transition. However, there are very few papers quantitatively discussing the interactions between those transitions. In the present project, the order-disorder and magnetic transition temperatures in some Fe-base and Co-base alloys has been examined and the interaction between them was evaluated by thermodynamic calculation using the CALPHAD-type and BWG analysis.In order to investigate this topic, the Fe-X (X : Al, Rh, Ga and Si) systems and the Co-Al-X (X : Ti, Ni) systems had been selected. The obtained results are as follows :(1) The magnetic and chemical ordering transition temperatures in the Fe-X (X : Al, Rh, Ga, Si) binary alloys were determined by VSM, differential scanning calorimetry (DSC) and electric resistance (ER) measurements. In the case of some alloys showing the 1st order transitions, the phase equilibrium between the ordered and disordered phases were examined by X-ray microanalysis (XMA) and transmission electron microscopy (TEM). It was clarified by these examinations that the interactions between the magnetic and chemical orderings exist there in the Fe-Al and Fe-Ga systems.(2) The magnetic and chemical ordering transition temperatures in the Co-Al-X (X : Ti, Ni) ternary alloys were also determined by VSM and DSC measurements. The phase equilibrium between the B2 and D03 phases were examined by TEM observation.(3) On the basis of those experimental results, the phase equilibria in the Fe-Rh and Fe-Al binary systems were analyzed using the CALPHAD-type thermodynamic calculation. In conclusions, it was proposed that since the magnetic properties are strongly affected by the degree of order in the ordered phase, and the new thermodynamic model which takes into account the interaction between the magnetic and chemical orderings should be used for precisely describing the phase stability of phases.

众所周知，磁转变影响铁基合金中的有序-无序转变，铁基合金同时表现出化学有序性和磁转变。然而，很少有论文定量讨论这些转变之间的相互作用。在本项目中，研究了一些铁基和钴基合金的有序无序和磁转变温度，并使用 CALPHAD 型和 BWG 分析通过热力学计算评估了它们之间的相互作用。课题中，选择了Fe-X（X：Al、Rh、Ga和Si）系和Co-Al-X（X：Ti、Ni）系。所得结果如下：(1)采用VSM、差示扫描量热法(DSC)和电阻法测定了Fe-X(X：Al、Rh、Ga、Si)二元合金的磁有序转变温度和化学有序转变温度ER）测量。对于一些显示一级转变的合金，通过 X 射线微量分析 (XMA) 和透射电子显微镜 (TEM) 检查有序相和无序相之间的相平衡。通过这些研究阐明了Fe-Al和Fe-Ga体系中存在磁有序和化学有序之间的相互作用。(2)Co-Al-X(X:Ti, Ni)三元合金也通过VSM和DSC测量来测定。通过TEM观察检验了B2和D03相之间的相平衡。(3)基于这些实验结果，利用CALPHAD型热力学计算分析了Fe-Rh和Fe-Al二元体系中的相平衡。总之，提出由于有序相的有序程度强烈影响磁性能，因此应使用考虑磁有序和化学有序之间相互作用的新热力学模型来精确描述相稳定性的阶段。