Фазовая диаграмма системы Ac-Pt

К оглавлению: Другие диаграммы (Others phase diargams)


Ac-Pt (Actinium-Platinum) D.E. Peterson The assessed Ac-Pt phase diagram was estimated by correlation with the La-Pt phase diagram [Moffatt]. There have been no experimental phase studies of the Ac-Pt system. Six intermetallic compounds are expected to form, along with the eutectic, four peritectic, and two congruent reactions. There should be very little mutual solid solubility of the elements; however, AcPt2 will probably exhibit a wide homogeneity range. Terminal eutectic compositions were calculated, assuming that the liquid behaves as an ideal solution and that there is negligible mutual solid solubility of the elements. The same approach was used to calculate the lowering of the melting point, described by [85Ven]. The Ac and Pt melting points are from [Melt]. Temperatures for the eutectic reactions involving Ac and Pt were assumed to be 200 and 160 C lower than the respective melting points of the elements, in analogy to the La-Pt system. The resulting eutectic compositions calculated were at 16 and 92 at.% Pt, respectively. 85Ven: M. Venkatraman, J.P. Neumann, and D.E. Peterson, Bull. Alloy Phase Diagrams, 6(5), 413-414 (1985). Published in Bull. Alloy Phase Diagrams, 10(4a), Sep 1989. Complete evaluation contains 1 figure, 1 table, and 2 references. 1


Экспериментальные данные отсутствуют. В работе [1] предполага­ется, что диаграмма состояния Ac-Pt подобна диаграмме состояния La—Pt. В системе можно ожидать образование соединений Ac7Pt3, Ac3Pt2, AcPt, Ac3Pt4 (AcPt2) и AcPt5, а также наличие эвтектического взаимодействия между (Ac) и Ac7Pt3 и между AcPt5 и (Pt) (рис. 2).

При этом составы эвтектических точек, полученные расчетным путем, равны приблизительно 16 и 92 % (ат.) Pt, а температуры эвтектических реакций по приблизительной оценке на 200 и 160 °С ниже, чем температуры плавления Ac (1051 0C) и Pt (1769 0C), соответственно [2]. В системе также предполагается наличие эвтектики Ac3Pt4 + (AcPt2).

1. Peterson D.E.// Bull. Alloy Phase Diagrams. 1989. V. 10. N 4a. P. 471—472.