Фазовая диаграмма системы Al-Ga

К оглавлению: Другие диаграммы (Others phase diargams)

Al-Ga (Aluminum-Gallium) J.L. Murray The equilibrium phases of the assessed Al-Ga diagram are (1) the liquid, L; (2) the fcc (Al) solid solution; and (3) complex cubic (Ga). The liquidus is well established from thermal analysis and from thermodynamic (emf and calorimetric) measurements, but the boundaries of the solid phases are not well established. The solubility of Al in (Ga) is very low. The maximum solubility of Ga in (Al) is approximately 9 at.%, but there are discrepancies among various investigations concerning the shape of the (Al) solidus curve. Because accurate thermodynamic data exist that agree with experimental liquidus measurements, thermodynamic calculations have been used as a tool for estimating the phase boundaries that have not been experimentally determined, such as the solvus curves, or where discrepancies exist, such as the (Al) solidus. The present diagram is based on a review of the work of [57Zol], [ 58Cla], [58Wil], [69Pre], and [79Esl]. Equilibria between the two solid phases also have not been investigated experimentally; the relevant temperatures are below room temperature. Because of this experimental difficulty, thermodynamic modeling is appropriate. In splat-quenched alloys, the metastable solubilities of Al in (Ga) and Ga in ( Al) were reported to be 8 at.% Al and 65 at.% Ga, respectively, based on X-ray data. Two metastable compounds, a› in the range of 66 to 82.5 at.% Ga, and f in the range of 86 to 88 at.% Ga, have been reported. 57Zol: H. Zoller, Metall, 11, 378-381 (1957) in German. 58Cla: J.W.H. Clare, J. Inst. Met., 86, 431-432 (1958). 58Wil: L.A. Willey, Alcoa Res. Lab., unpublished data, 1-3 (1958). 69Pre: B. Predel and D.W. Stein, J. Less-Common Met., 17, 377-390 (1969) in German. 79Esl: H. Eslami, J. de Franceschi, M. Gambino, and J.P. Bros, Z. Naturforsch. A, 34, 810-817 (1979). Published in Bull. Alloy Phase Diagrams, 4(2), Sep 1983. Complete evaluation contains 4 figures, 9 tables, and 22 references. Special Points of the Al-Ga System