Фазовая диаграмма системы Be-Pt

К оглавлению: Другие диаграммы (Others phase diargams)


Be-Pt (Beryllium-Platinum) H. Okamoto and L.E. Tanner Available information on the Be-Pt phase diagram is fragmentary. Intermediate phases reported are (1) Be12Pt (Mn12Th type); (2) Be5Pt (AuBe5 type); (3) Be21Pt5 (Ni5Zn21 type); (4) BePt (CsCl type); and (5) BePt15 (?). Of these, the latter three may need further examination for confirmation. The assessed phase diagram is partly based on comparison with the Be-Pd system. The existence of the two Be-rich phases, Be12Pt and Be5Pt, seems to be well established by X-ray diffraction of single crystals and powders [58Bat]. The latter phase is likely to have some homogeneity range, because variations in lattice parameters were observed. Diffusion couple measurements by [75Mat] suggested that a phase exists with up to 60 wt.% Pt (6.5 at.% Pt) and is stable at 1000 and 1100 C, but unstable at 900 C. This phase would appear to correspond to Be12Pt. In addition, [75Mat] found two other distinguishable phases having compositions of 85 to 87 wt.% (20.7 to 23.6 at.%) Pt and 93 to 94 wt.% (38 to 42 at.%) Pt; the former was believed to correspond to Be21Pt5 ( 19.2 at.% Pt). 58Bat: F.W. von Batchelder and R.F. Raeuchle, Acta Crystallogr., 11(2), 122 ( 1958). 75Mat: M.P. Matveyeva, R.M. Volkova, I.D. Marchukova, and A. E. Mirkin, Izv. Akad. Nauk SSSR, Met., (5), 196-202 (1975) in Russian; TR: Russ. Metall., (5), 156-160 (1975). Published in Phase Diagrams of Binary Beryllium Alloys, 1987, and Bull. Alloy Phase Diagrams, 8(4), Aug 1987. Complete evaluation contains 1 figure, 3 tables, and 15 references. 1