Фазовая диаграмма системы Ag-Pr

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Ag-Pr (Silver-Praseodymium) K.A. Gschneidner, Jr. and F.W. Calderwood The Ag-rich portion of the assessed phase diagram for the Ag-Pr system is drawn from data reported by [74Del] and includes some features from [78Sta] and [78Mul]. The temperatures for the melting points and transformations in the pure metals have been adjusted to agree with the accepted values. The a = b transformation for Ag2Pr as reported by [78Mul] is included. From ~30 at.% Pr to pure Pr, average values are used for the various invariant points. For the Ag-rich section (0 to 30 at.% Pr), the temperatures are from [74Del]. [74Del] reported the following phases: Ag5Pr (peritectic formation at 830 C), Ag51Pr14 (congruently melting at 1033 C), Ag2Pr (peritectic formation at 847 C), and AgPr (melting point, 932 C). Three eutectics were observed: (Ag)- Ag5Pr (804 C, 9.2 at.% Pr), Ag2Pr-AgPr (805 C, 39.5 at.% Pr), and AgPr-(Pr) ( 578 C, 77.9 at.% Pr). The phases Ag5Pr and Ag51Pr14 occur in the Ag-rich portion of the diagram; the latter phase has a composition range of between 21.5 and 25 at.% Pr. The calculated solubility of Pr in Ag was reported to be 0.05 at.% [70Gsc]. Addition of Ag to Pr reduces the a = b transformation temperature from 795 to 652 C at about 96 at.% Pr by a monotectic reaction (bPr = aPr + L). The addition of Ag to Pr lowered the a = b transformation temperature from 795 с 5 C for Pr to 652 с 5 C for the solid solution containing about 4 с 1. 5 at.% Ag. Maximum solubility of Ag in (aPr) was about 1 с 0.5 at.% at 652 C. 70Gsc: K.A. Gschneidner, Jr., O.D. McMasters, D.G. Alexander, and R.F. Venteicher, Metall. Trans., 1, 1961-1971 (1970). 74Del: S. Delfino, A. Borsese, R. Capelli, and R. Ferro, J. Less-Common Met., 35, 31-37 (1974). 78Mul: A.M. Mulokozi, I. Stapf, and E. Gebhardt, J. Less-Common Met., 57, 39 ( 1978). 78Sta: I. Stapf and E. Gebhardt, J. Less-Common Met., 58, 47-53 (1978). Published in Bull. Alloy Phase Diagrams, 6(1), Feb 1985. Complete evaluation contains 3 figures, 1 table, and 18 references. 1