Фазовая диаграмма системы Co-Cu

К оглавлению: Другие диаграммы (Others phase diargams)


Co-Cu (Cobalt-Copper) T. Nishizawa and K. Ishida The assessed phase diagram for the Co-Cu system is based on a composite of data [37Has, 58Nak, 59Liv, 66Old, 72Bru, 78Kau, 80Has, 82Tas]. This diagram is somewhat different from the diagram of [Hansen], especially in the solidus, which exhibits a remarkable retrogression. The Curie temperature of Co is 1121 C and is lowered by the addition of Cu. The magnetic transition is represented by a dash-dot line, and the intersection of the Curie temperature and the (aCo) solvus occurs at 1050 C and 9.5 at.% Cu. The metastable liquid miscibility gap was studied by supercooling [58Nak]. The critical temperature for mixing is 90 C below the liquidus at the equiatomic composition. [63Kle] also studied direct quenching from the liquid alloy, in which a single-phase solid solution was obtained in the ranges 0 to 25 and 85 to 100 at.% Cu. Martensitic transformation takes place in the Co-rich phase. The cph (eCo) phase can form martensitically during quenching. The martensite start temperature is lowered by the addition of Cu. According to [77Nik], specimens containing 8 to 10% Cu transform to a complex crystalline phase (e›) with a 126-layer rhombohedral lattice below room temperature. The e› martensite is transformed to e martensite with a cph lattice as a result of plastic deformation. Experimental determinations of thermodynamic properties relevant to the phase diagram were done in liquid [65Dok, 77Igu, 81Tim, 82Tas] and solid [69Den] phases, and the phase diagram was calculated by [78Kau] and [80Has]. 37Has: U. Haschimoto, J. Jpn. Inst. Met., 1, 19 (1937) in Japanese. 58Nak: Y. Nakagawa, Acta Metall., 6, 704 (1958). 59Liv: J.D. Livingston, Trans. AIME, 215, 566 (1959). 63Kle: W. Klement, Jr., Trans. AIME, 227, 965 (1959). 65Dok: R.N. Dokken and J.F. Elliott, Trans. AIME, 233, 1351 (1965). 66Old: C.F. Old and C.W. Haworth, J. Inst. Met., 94, 303 (1966). 69Den: W.A. Dench and O. Kubaschewski, High Temp.-High Pressures, 1, 357 (1969) . 72Bru: F.J. Bruni and J.W. Christian, Mater. Sci. Eng., 9, 241 (1972). 77Igu: Y. Iguchi, Y. Tozaki, S. Ban-ya, and T. Fuwa, J. Iron Steel Inst. Jpn., 63, 953, (1977). 77Nik: B.I. Nikolin, Fiz. Met. Metalloved., 43, 591 (1977) in Russian; TR: Phys. Met., Metallogr., 43(3), 177 (1977). 78Kau: L. Kaufman, Calphad, 2, 117 (1978). 80Has: M. Hasebe and T. Nishizawa, Calphad, 4, 83 (1980). 81Tim: L. Timberg, J.M. Toguri, and T. Azakami, Metall. Trans. B, 12, 275 ( 1981). 82Tas: P. Taskinen, Z. Metallkd., 73, 445 (1982). Published in Bull. Alloy Phase Diagrams, 5(2), Apr 1984. Complete evaluation contains 5 figures, 4 tables, and 35 references. 1