Phase Equilibrium and Phase Separation in quaternary Fe-Al-Co-Ti B2 ordered compound

四元 Fe-Al-Co-Ti B2 有序化合物的相平衡和相分离

基本信息

批准号：
11650678
负责人：
KOZAKAI Takao
金额：
$ 2.3万
依托单位：
Nagoya Institute of Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1999
资助国家：
日本
起止时间：
1999 至 2001
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-11650678/
关键词：
DO_3 ordered phase B2 ordered phase transmission electron microscopy A2+B2+DO_3 three-phase field microstructure spinodal decomposition precipitation on interface Heusler phase D0_3規則相 A2+B2+D0_3 3相分離二相分離三相分離三相スピノーダル分解 B2金属間化合

项目摘要

Phase equilibrium and phase separation process in Fe-Al-Co-Ti quaternary alloy system had been investigated by means of transmission electron microscopy.When more than 2at%Ti was added into Fe-20at%Al-20at%Co alloy, DO_3(L2_1) ordered phase was stabilized at the temperature over 973K and thereby two kinds of two-phase coexistence fields, (A2+DO_3) and (B2+DO_3) appeared. In particular in the Fe-Al-Co-2at%Ti and the Fe-Al-Co-3at%Ti alloys three-phase coexistence field was newly found. It was found from the chemical analysis by energy dispersion X-ray spectroscopy (EDS) of the constitutive phases in the phase-separated microstructures that the three-phase field was at the temperature range from 1030K to 1075K and most of Ti element was distributed into DO_3 phase and A2 phase does not contained Ti.When the alloy being within the three-phase field was decomposed from B2 single phase, the phase decomposition occurred at the following three steps: First, the B2 alloy decomposed into A2 and B2 phases and so-called mottled structure was formed. Second, DO_3 ordered particles precipitated within the B2 ordered domains and thereby the morphology of microstructure changed to the anisotropic periodic structure. At the final stage, cubic particles of the B2 and DO_3 phases aligned along <100> direction in the A2 matrix. These phase separation processes are able to be qualitatively explained by the 2-dimensional computer-simulation.

已经通过传输电子显微镜研究了Fe-Al-CO-TI四氢元合金系统中的相位平衡和相位分离过程。当将超过2AT％的Ti添加到Fe-20at％al-20AT％CO合金中时，DO_3（L2_1）阶相中的相位均在973k和两种+两种情况下（A2）（a）（l2_1）的阶段（l2_1）稳定下来。（B2+DO_3）出现。特别是在Fe-Al-CO-2AT％Ti和Fe-Al-CO-3AT％Ti合金三相共存场中新发现。 It was found from the chemical analysis by energy dispersion X-ray spectroscopy (EDS) of the constitutive phases in the phase-separated microstructures that the three-phase field was at the temperature range from 1030K to 1075K and most of Ti element was distributed into DO_3 phase and A2 phase does not contained Ti.When the alloy being within the three-phase field was decomposed from B2 single phase, the phase decomposition occurred at以下三个步骤：首先，形成了分解为A2和B2相的B2合金以及所谓的斑驳结构。其次，do_3排序的颗粒在B2有序域内沉淀，从而使微观结构的形态变为各向异性周期性结构。在最后阶段，B2和DO_3相的立方颗粒沿A2矩阵中的<100>方向对齐。这些相分离过程能够通过二维计算机模拟来定性地解释。