Фазовая диаграмма системы Bi-Cu

К оглавлению: Другие диаграммы (Others phase diargams)


Bi-Cu (Bismuth-Copper) D.J. Chakrabarti and D.E. Laughlin The equilibrium phases of the Cu-Bi system are (1) the liquid, miscible in all proportions; (2) the fcc solid solution, (Cu), with restricted solubility of Bi amounting to 0.003 at.% Bi at 800 C; and (3) the rhombohedral solid solution, (Bi), with negligible solubility of Cu. The assessed phase diagram for the Cu-Bi system is of the eutectic type with the eutectic point located close to pure Bi. The present diagram is based primarily on the work of [1897Hey], [52Kle], [62Nat], and [81Tas]. A metastable compound is reported at approximately Cu5Bi2 composition [ 60Cov], based on alloys made under vacuum from 99.999% Cu and 99.99+% purity Bi. The compound reportedly forms only at temperatures below ~300 C and in the absence of Cu nuclei, through precipitation from liquid Bi supersaturated with Cu. Thermodynamic modeling analysis by the present authors showed that the metastable miscibility gap of the liquid exists not far below the liquidus. The thermodynamic parameters of the liquid Cu-Bi alloys given by [Hultgren,B], including the near-symmetric parabolic variation of DmixH with composition, agree satisfactorily with the assessed phase diagram. Very close agreement of the assessed liquidus exists with the experimental liquidus when optimized calculations are used. 1897Hey: C.T. Heycock and F.H. Neville, Philos. Trans. R. Soc. A, 189, 25-69 ( 1897). 52Kle: O.J. Kleppa, J. Am. Chem. Soc., 74, 6047-6051 (1952). 60Cov: A.K. Covington, K. Groenwolt, and B.W. Howlett, J. Inst. Met., 89, 291- 292 (1960-1961). 62Nat: M.W. Nathans and M. Leider, J. Phys. Chem., 66, 2012-2015 (1962). 81Tas: P. Taskinen and J. Niemela, Scand. J. Metall., 10, 195-200 (1981). Published in Bull. Alloy Phase Diagrams, 5(2), Apr 1984. Complete evaluation contains 5 figures, 5 tables, and 39 references. 1