Fe-Pt-Au三元系950℃富Fe角等温截面的研究

摘要

In order to control the homogeneous distribution of fine L10-FePt nano-phase in a non- magnetic matrix, it is necessary to systematically study phase diagrams of Fe-Pt-X systems. In this work, phase relationships and equilibrium phase compositions in the Fe-rich corner of the Fe- Pt-Au ternary system at 950 ℃ were studied by both alloying method and diffusion couple technique using X-ray diffraction and scanning electron microscopy assisted with energy dispersive spectroscopy（SEM-EDS）, thus the isothermal section of Fe-rieh corner was constructed in this system at 950 ℃. The results showed that there exists a wide（y Fe ＋ aAu） and a narrow（ yFe ＋ L10-FePt）two-phase regions. The ,solubility of Au in the yFe phase increases from -4% to -15% with the addition of Pt, whereas the solubility of Fe in the aAu phase decreases rapidly. With the addition of Au, the solubility of Pt in the yFe phase decreases and the（ yFe ＋ L10-FePt） two-phase region remains unexpanded.%为了控制细小的L10-FePt纳米相均匀分布在非磁性基体中，有必要对Fe—Pt—x系的相图进行系统研究．通过合金法和扩散偶法，利用x射线衍射（XRD）、扫描电镜及能谱成分（SEM—EDS）分析确定了Fe—Pt—Au三元系950℃富Fe角处相平衡关系及各相平衡成分，从而建立了富Fe角的等温截面相图．结果表明，该等温截面存在成分范围很宽的（yFe＋aAu）两相区和成分范围很窄的（yFe＋LIn—FePt）两相区．Pt的加入使Au在7Fe中的固溶度从约4％提高到约15％（原子数分数），而大大降低了Fe在aAu中的固溶度；Au的加入使Pt在yFe中的固溶度降低，并且没有扩大（yFe＋L10-FePt）两相区．