Phase equilibrium in the cerium-poor Ce–Ni–Cu system

• Published in: Journal of alloys and compounds 2007-06, Vol.436 (1), p.161-169
• Main Authors: Wang, J., Pisch, A., Flükiger, R., Jorda, J.L.
• Format: Article
• Language: English
• Subjects: Ce–Ni–Cu; Cross-disciplinary physics: materials science; rheology; Equilibrium phase diagram; Exact sciences and technology; Isoplethic section; Materials science; Phase diagrams and microstructures developed by solidification and solid-solid phase transformations; Phase diagrams of metals and alloys; Physics; Polythermal section; Solid solution
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2006.11.012

In the framework of preparing metallic substrates for high temperature superconductors of the second generation, the Ce–Ni–Cu system in Ce-poor field has been studied by means of DTA/TG, X-ray diffraction, SEM with EDX attachment and optical microscope. For the solid state equilibrium, the existence of a continuous solid solution Ce(Ni 1− x Cu x ) 5 has been confirmed and it was found that this solid solution extends in poor Ce compositions. No ternary phase could be evidenced in the investigated field. CeCu 6 was found to dissolve up to 5 at.% Ni. The cerium solubility in the (Ni,Cu) solid solution is less than 0.5 at.%. At high temperatures, for the equilibrium implying a liquid phase, a ternary eutectic reaction L ↔ Ce(Ni,Cu) 6 + Ce(Ni,Cu) 5 + (Ni,Cu) occurs at T = 871 °C for Ce 0.10Ni 0.07Cu 0.83, i.e for a Ce composition 1 at.% higher than in the binary systems. Finally, the polythermal section of the system has been estimated and the isoplethic sections with the 16.7 at.% Ce, 14.3 at.% Ce and 9 at.% Ce are proposed.