Фазовая диаграмма системы Cu-Nd

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Cu-Nd

Cu-Nd (Copper-Neodymium) P.R. Subramanian and D.E. Laughlin The equilibrium phases of the Cu-Nd system are (1) the liquid, L, with no miscibility gaps; (2) the fcc terminal solid solution, (Cu), with negligible solid solubility of Nd in (Cu); (3) the Nd-rich bcc terminal solid solution, ( bNd), based on the equilibrium phase of pure Nd between 863 and 1021 C and with negligible solid solubility of Cu in (bNd); (4) the Nd-rich dcph terminal solid solution, (aNd), stable below 863 C and with negligible solid solubility of Cu in (aNd); (5) the orthorhombic intermediate phase Cu6Nd, stable up to the congruent melting temperature of 910 C; (6) the hexagonal phase Cu5Nd, stable up to the peritectic temperature of 870 C; (7) the orthorhombic phase Cu4Nd, stable up to the peritectic temperature of 845 C; ( 8) the orthorhombic phase Cu2Nd, stable up to the congruent melting temperature of 840 C; and (9) the most Nd-rich intermediate phase CuNd, stable up to the peritectic melting temperature of 675 C. The assessed phase diagram is based primarily on the work of [83Car], with minor modifications in the liquidus in the vicinity of the congruent points at 910 and 840 C, to conform to thermodynamic rules for construction of congruent inflection points. [83Car] reported the high-temperature formation of Cu7Nd2 at 825 C, with its subsequent decomposition at 785 C. This phase could not be retained at room temperature under any circumstances. The presence of Cu7Nd2 is not corroborated by [84Lak], although the diagram of [84Lak] indicates the presence of thermal arrests near 830 C as well as near 785 C. It is therefore possible that Cu7Nd2 is a metastable phase, which exists only within a limited temperature range. 83Car: M.M. Carnasciali, G.A. Costa, and E.A. Franceschi, J. Less-Common Met., 92, 97-103 (1983). 84Lak: C. Laks, J. Pelleg, and L. Zevin, J. Less-Common Met., 102, 23-28 (1984) . Published in Bull. Alloy Phase Diagrams, 9(3a), Aug 1988. Complete evaluation contains 2 figures, 5 tables, and 19 references. Special Points of the Cu-Nd System