Фазовая диаграмма системы Al-Nb

К оглавлению: Другие диаграммы (Others phase diargams)

Al-Nb (Aluminum-Niobium) U.R. Kattner The assessed phase diagram for the Nb-Al system is based on [66Lun], [ 68Sve], [76Yer], [80Jor], and [88Mur]. Although the liquidus and reaction temperatures have not been precisely established, the data are in general qualitative agreement. The existence of the three intermediate compounds and the solid-solid phase boundaries of (Nb), Nb3Al, and Nb2Al are well established. The Nb-Al system is a relatively simple system with six phases: the liquid, L; the bcc (Nb) solid solution, which dissolves up to ~21.5 at.% Al at 2060 C; Nb3Al, with a maximum homogeneity range from 18.6 at.% Al below 1500 C to 25 at.% Al at 1940 C; Nb2Al, with a maximum homogeneity range from 30 at.% Al below 1500 C to 42 at.% Al at 1590 C; NbAl3, with a narrow homogeneity range with a width of ~1 at.%; and the fcc (Al) solid solution with extremely limited solubility of Nb. The Nb3Al phase is a superconducting compound with a transition temperature of 18.6 K. 66Lun: C.E. Lundin and A.S. Yamamoto, Trans. AIME, 236, 863-872 (1966). 68Sve: V.N. Svechnikov, V.M. Pan, and V.I. Latiesheva, Metallofizika, 2, 54-61 (1968) in Russian. 76Yer: V.N. Yeremenko, Ya.V. Natanzon, and V.I. Dybkov, J. Less-Common Met., 50, 29-48 (1976). 80Jor: J.L. Jorda, R. Fluekiger, and J. Muller, J. Less-Common Met., 75, 227- 239 (1980). 88Mur: J.L. Murray, private communication of data from L.A. Willey, 1988. Submitted to the APD Program. Complete evaluation contains 1 figure, 2 tables, and 8 references. Special Points of the Nb-Al System