Phase equilibria in the Ce-Co-Fe-system at 900 °C

• Published in: Journal of alloys and compounds 2018-10, Vol.765, p.644-649
• Main Authors: Fartushna, I., Mardani, M., Khvan, A., Cheverikin, V., Ivanov, D., Kondratiev, A., Dinsdale, A.
• Format: Article
• Language: English
• Subjects: Aqueous chemical equilibrium; Ce-Co-Fe system; Chemical compounds; Cobalt; Electron probe microanalysis; Electron probes; Experimental; Iron; Isothermal section; Liquid phases; Phase diagram; Phase diagrams; Phase equilibria; Phase transitions; Scanning electron microscopy; Solid solutions; Solidus; Temperature effects; X-ray diffraction
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2018.06.261

The Ce-Co-Fe phase diagram was investigated for the whole concentration range at 900 °C, using X-Ray diffraction (XRD), scanning electron microscopy (SEM) and electron probe microanalysis (EPMA). An isothermal section at this temperature was constructed. Two continuous solid solutions Ce2(Co,Fe)17 (Th2Zn17-type structure, hR57-R-3m) and Ce(Co,Fe)2 (MgCu2-type structure, cF24-Fd-3m), found by us both at the solidus temperatures and at 900 °C, contain 11 and 33.3 at.% Ce, respectively, due to mutual substitution of Fe and Co atoms. The liquid phase is present in the system at 900 °C. The isothermal section at this temperature is characterized by the five three-phase regions (αFe) + (αCo) + Ce2(Co,Fe)17, Ce5Co19 + CeCo5 + Ce2Co7, CeCo5 + Ce2(Co,Fe)17 + Ce2Co7, Ce2Co7 + Ce2(Co,Fe)17 + CeCo3 and CeCo3 + Ce2(Co,Fe)17 + Ce(Co,Fe)2 and associated two-phase fields. CeCo3 and Ce2Co7 show the widest homogeneity regions and dissolve up to 49 at.% and 21 at.% Fe respectively. The solubility of Fe in the other crystalline phases is smaller. •Phase equilibria in the Ce-Co-Fe system at 900°С were studied.•An isothermal section at this temperature was constructed.•Two continuous solid solutions Ce2(Co,Fe)17 and Ce(Co,Fe)2 form in this system.•CeCo3 and Ce2Co7 intermetallics have the widest homogeneity regions.