Фазовая диаграмма системы As-Au

К оглавлению: Другие диаграммы (Others phase diargams)


As-Au (Arsenic-Gold) H. Okamoto and T.B. Massalski In the assessed As-Au phase diagram, the gas phase is already involved in equilibria at low concentrations of Au in As at ordinary pressure. This eutectic-type diagram is based primarily on the work of [76Gat]. Because As is very volatile, As-Au alloys can be made only up to 19.2 at.% (8.3 wt.%) As in Au in open furnaces. The phase boundaries were calculated using the thermodynamic properties estimated from the eutectic relationship in the phase diagram and the assumed stability parameters for pure As and Au. The agreement between the experimental and calculated boundaries is very good. The eutectic temperature appears to be independent of pressure. The solid solubility of Au in (As) has not been determined, because of the high volatility of As. The solid solubility of As in Au was estimated to be about 0.2 at.% at 611C, but with no apparent solubility at 400C. Reported metastable phases are limited to orthorhombic eAs and the three types of amorphous phases of As (bAs, gAs, and dAs) [Pearson2]. 76Gat: B. Gather and R. Blachnik, Z. Metallkd., 67(3), 168-169 (1976) in German. Published in Phase Diagrams of Binary Gold Alloys, 1987, and Bull. Alloy Phase Diagrams, 5(1), Feb 1984. Complete evaluation contains 3 figures, 3 tables, and 6 references. 1