Фазовая диаграмма системы Ni-W

К оглавлению: Другие диаграммы (Others phase diargams)

Ni-W (Nickel-Tungsten) S.V. Nagender Naidu, A.M. Sriramamurthy, and P. Rama Rao The assessed Ni-W phase diagram, characterized by three intermediate phases, is based primarily on the work of [40Ell], [73Wal], and [74Pou]. According to [40Ell], the solubility of W in (Ni) decreases from the maximum solubility of 17.5 at.% at 1495 C, the eutectic temperature, to 16.4 at.% at the peritectoid temperature of 970 C. The major decrease in the (Ni) solid solution occurs from 16.4 to 13.1 at.% W between 970 and 800 C. A smaller change in the solubility occurs from 13.1 to 11.8 at.% W between 800 and 500 C. [81Koz] reported the solubility values of Ni in (W) for different temperatures, revealing that the solubility decreases from 0.6 at.% Ni at 1927 C to 0.05 at.% Ni at about 1187 C. However, the solubility value of 0.46 at.% Ni for 1640 C was adjusted to 0.3 at.% Ni at 1495 C in the assessed diagram. The Curie temperature in the (Ni) phase was found to decrease with increasing W content. The data assessed by [Hansen] are accepted in this evaluation and are incorporated in the assessed diagram, except that the Curie temperature of Ni was modified to 355 C, the presently accepted value [84Nas]. The formation of NiW2 is extremely sensitive to the presence of even traces of oxygen in the system [74Pou]. 40Ell: F.H. Ellinger and W.P. Sykes, Trans. ASM, 28, 619-643 (1940). 73Wal: J.M. Walsh and M.J. Donachie, Jr., Metall. Trans., 4, 2854-2855 (1973). 74Pou: K.E. Poulsen, S. Rubaek, and E.M. Langer, Scr. Metall., 8, 1297-1300 ( 1974). 81Koz: L. Kozma and J. Labar, High Temp.-High Pressures, 13, 521-527 (1981). 84Gab: A. Gabriel, thesis, Univ. Grenoble, France (1984). 84Nas: A. Nash and P. Nash, Bull. Alloy Phase Diagrams, 5(5), 446-450 (1984). 85Gab: A. Gabriel, H.L. Lukas, C.H. Allibert, and I. Ansara, Z. Metallkd., 76( 9), 589-595 (1985). Published in Phase Diagrams of Binary Nickel Alloys, 1991, and J. Alloy Phase Diagrams, 2(1), Jan 1986. Complete evaluation contains 4 figures, 9 tables, and 46 references. Special Points of the Ni-W System