Фазовая диаграмма системы B-Nb

К оглавлению: Другие диаграммы (Others phase diargams)

B-Nb (Boron-Niobium) Editor The B-Nb phase diagram is redrawn from [Elliott], which is based primarily on [ 59Now], with the following modifications. B6Nb5, in addition to BNb, was found by [90Bol]. This phase is added in the assessed diagram, but the reaction of its formation is unknown. The L = B2Nb + (bB) eutectic point was originally shown at ~1.4 at.% Nb and ~1850 C. Accordingly, the slope of the ( bB) liquidus was unrealistically steep (a thermodynamically possible initial slope is about -9 C/at.% at the steepest). If the eutectic temperature is increased without modifying the eutectic composition, the liquidus of B2Nb must have two unusual inflections. The assessed diagram is a compromise between the phase diagram of [Elliott] and thermodynamic requirements.-H.O. 49Nor: J.T. Norton, H. Blumenthal, and S.J. Sindeband, Trans. AIME, 185, 749- 751 (1949). 50And: L.H. Andersson and R. Kiessling, Acta Chem. Scand., 4, 160-164 (1950). 58Now: H. Nowotny and A. Wittmann, Monatsh. Chem., 89, 220-224 (1958) in German. 59Now: H. Nowotny, F. Benesovsky, and R. Kieffle, Z. Metallkd., 50, 417-423 ( 1959) in German. 90Bol: H. Bolmgren and T. Lundstrom, J. Less-Common Met., 159, L25-L27 (1990). 1