Фазовая диаграмма системы Ni-Pb

К оглавлению: Другие диаграммы (Others phase diargams)

Ni-Pb (Nickel-Lead) P. Nash The Ni-Pb system is characterized by the presence of a monotectic and a eutectic, with no intermediate phases and very little solid solubility in the terminal solid solutions. The solid solubility of Pb in (Ni) is ~1.2 at.% [ 08Vos]. The assessed diagram is based on the thermal analysis of [07Por] and [08Vos] except for the liquid miscibility gap. The present diagram has been modeled on the basis of a regular solution for both phases. Two calculations were made- one with and one without excess entropy terms. The models reproduce the form of the diagram and the invariant reaction temperatures to within 3 C, but do not reproduce the liquidus well. An impurity solvus correlation for a number of solutes in Pb leads to the prediction of a minimum terminal solubility of ~0.01 at.% Ni in (Pb) [71Huf]. Addition of Pb to Ni raises the Curie temperature by about 5 C [08Vos]. [60Mil] determined the liquid miscibility gap tie lines at 1373 and 1430 C. Extrapolation of their data to 1340 C yields the accepted monotectic composition of 11.5 at.% Pb. Based on the data of [60Mil], graphical extrapolation of the (Ni) + L2 liquidus data to the monotectic temperature gives a composition of 57 at.% Pb. Microstructural work [85Bui] indicates that the low-temperature invariant reaction is a eutectic at 324 C [55Pel] and 0.46 at.% Ni [61Dav]. Because of liquid immiscibility, rapid quenching from the liquid is difficult. Formation of the NiPb phase with the AgNi-type structure has been reported after vapor deposition. 07Por: M.A. Portevin, Rev. M‚tall., 4, 814-818 (1907) in French. 08Vos: G. Voss, Z. Anorg. Chem., 57, 45-48 (1908) in German. 55Pel: E. Pelzel, Metall, 9, 692-694 (1955) in German. 60Mil: K.O. Miller and J.F. Elliot, Trans. AIME, 218, 900-910 (1960). 61Dav: T.R.A. Davey, Physical Chemistry of Process Metallurgy, AIME-TMS Conf., Vol. 7, 581-600 (1961). 71Huf: M.C. Huffstutler and W.S. Lindenberger, J. Inst. Met., 99, 352-353 ( 1971). 85Bui: T. Bui and P. Nash, unpublished work (1985). Published in Phase Diagrams of Binary Nickel Alloys, 1991, and Bull. Alloy Phase Diagrams, 8(3), Jun 1988. Complete evaluation contains 2 figures, 4 tables, and 21 references. 1