Фазовая диаграмма системы Al-Ho

К оглавлению: Другие диаграммы (Others phase diargams)


Al-Ho (Aluminum-Holmium) K.A. Gschneidner, Jr. and F.W. Calderwood The assessed phase diagram for the Al-Ho system is based primarily on the work of [66Mey]. There are two intermetallic compounds having congruent melting points: Al2Ho (1530 C) and AlHo2 (1018 C). Three other compounds are subject to peritectic decomposition. Al3Ho decomposes at 1087 C to the melt and Al2Ho. AlHo decomposes at 1115 C to the melt and Al2Ho, and Al2Ho3 decomposes at 994 C to the melt and AlHo. A eutectic occurs between Al and Al3Ho at about 1.8 at.% Al and solidifies at 650 C. Another eutectic occurs between Ho and AlHo2 at about 76 at.% Ho and solidifies at 976 C. A third eutectic exists between Al2Ho3 and AlHo2 at about 64 at.% Ho and solidifies at 984 C. AlHo2 has the orthorhombic Co2Si-type structure [71Bus]. Al2Ho3 has a tetragonal structure of the Al2Zr3 type, and AlHo has the orthorhombic AlEr- type structure [65Bus]. Al2Ho has the cubic Cu2Mg-type structure, and a hexagonal (rhombohedral) structure was reported for Al3Ho. 65Bus: K.H.J. Buschow, J. Less-Common Met., 8, 209 (1965). 66Mey: A. Meyer, J. Less-Common Met., 10, 121 (1966). 71Bus: K.H.J. Buschow, J. Less-Common Met., 24, 117 (1971). Published in Bull. Alloy Phase Diagrams, 9(6), Dec 1988. Complete evaluation contains 1 figure, 1 table, and 20 references. 1