Фазовая диаграмма системы B-Cr

К оглавлению: Другие диаграммы (Others phase diargams)


B-Cr (Boron-Chromium) P.K. Liao and K.E. Spear The assessed phase diagram for the Cr-B system is based primarily on the results of [69Por], [72Por], and [76Guy], with modifications based on the data of [68And]. The system consists of six intermetallic compounds (Cr2B, Cr5B3, CrB, Cr3B4, CrB2, and CrB4) and the terminal solid solutions-bcc (Cr) and rhombohedral (bB). The existence of several other reported borides, such as Cr4B, Cr3B2, and CrB6, have been ruled out and/or remain uncertain, and these are not included in the assessed diagram. The liquidus temperatures for compositions greater than 80 at.% B on the B- rich side of the system are rather uncertain, and the invariant temperatures are uncertain to the extent of с30 to 50 K. The solubility of B in (Cr) has been reported to be approximately 0.7 at.% B at 1100 C by [Shunk], which is consistent with the value of 0.6 at.% reported by [71Bor] for a temperature of ~1527 C. [69Por] reported the maximum solubility of Cr in (bB) to be approximately 2 at.%, which was confirmed by [ 70And] using X-ray diffraction data. 68And: S. Andersson and T. Lundstrom, Acta Chem. Scand., 22(10), 3101-3110 ( 1968). 69Por: K.I. Portnoi, V.M. Romashov, and I.V. Romanovich, Poroshk. Metall., (4), 51-57 (1969). 70And: S. Anderson and T. Lundstrom, J. Solid State Chem., 2, 603-611 (1970). 71Bor: M.L. Borlera and G. Pradelli, Metall. Ital., 63, 61 (1971). 72Por: K.I. Portnoi and V.M. Romanshov, Poroshk. Metall., (5), 48-56 (1972). 76Guy: C.N. Guy and A.A. Uraz, J. Less-Common Met., 48, 199-203 (1976). Published in Bull. Alloy Phase Diagrams, 7(3), Jun 1986. Complete evaluation contains 2 figures, 3 tables, and 35 references. Special Points of the Cr-B System