Фазовая диаграмма системы Be-Pu

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Be-Pu (Beryllium-Plutonium) H. Okamoto, L.E. Tanner, and D.E. Peterson The assessed phase diagram for the Be-Pu system is based on the experimental work of [59Sch], (modified by [67Ell]). The phase diagram proposed by [55Kon] has not been accepted. The equilibrium phases are (1) the liquid, L; (2) the terminal solid solution, (Be); (3) the compound Be13Pu; and (4) the terminal solid solution, (Pu). The assessed liquidus is based on the present thermodynamic model, which adopts the experimental enthalpy of formation of Be13Pu and approximately represents the tentative liquidus of [67Ell]. If the L = Be13Pu + (ePu) eutectic is about 630 C [67Ell], there must be sizable (~2 at.%) solubility of Be in (Pu). This solubility range is plausible because the Be solubility in (gU) is about the same, where (ePu) and (gPu) have the same structure and the Be-Pu and Be-U phase diagrams are similar. [67Ell], on the other hand, reported that the microstructure of Pu-rich alloys showed no evidence of a eutectic structure (unpublished data). Further study is needed to resolve the inconsistency. Because some variation in the lattice parameter of Be13Pu was observed by [ 55Cof] and [56Run1], a measurable homogeneity range was predicted by [55Cof]. [ 56Run2] presented cursory evidence for a miscibility gap between Be and Be13Pu based on crystalline size arguments. This possible miscibility gap was also cited by [59Sch]. 55Cof: A.S. Coffinberry and F.H. Ellinger, in Proceedings of the International Conference on the Peaceful Uses of Atomic Energy, Vol. 9, Geneva, 138-146 ( 1955). 55Kon: S.T. Konobeevsky, in Proceedings of the International Academy of Science of the USSR on the Peaceful Uses of Atomic Energy, Chemical Science Volume, Geneva, 362 (1955) in Russian; TR: U.S. At. Energy Comm. AEC-Tr-2435, Pt. 2, 207-214 (1956); Met. Abstr., 24, 153 (1956). 56Ell: F.H. Ellinger, Trans. Metall. AIME, 206, 1256-1259 (1956). 56Run1: O.J.C. Runnalls, Can. J. Chem., 34, 133-145 (1956). 56Run2: O.J.C. Runnalls and R.R. Boucher, Can. J. Phys., 34, 949-958 (1956). 59Sch: F.W. Schonfeld, E.M. Cramer, W.N. Miner, F.H. Ellinger, and A.S. Coffinberry, in Progress in Nuclear Energy, Metallurgy and Fuels, Ser. V, Vol. 2, H.M. Finniston and J.P. Howe, Ed., Pergamon Press, New York, 579-599 (1959). 60Akh: V.V. Akhachinskii and L.M. Kopytin, At. Energy (USSR), 9(6), 504-505 ( 1960) in Russian; TR: Sov. J. At. Energy, 9(6), 1051-1053 (1960); TR: Kernenergie, 4(6), 519-520 (1961) in German. 67Ell: F.H. Ellinger, C.C. Land, and K.A. Gschneidner, Jr., in Plutonium Handbook, Vol. 1, O.J. Wick, Ed., Gordon and Breach, New York, 191-247 (1967). 84Ste: G.R. Stewart, Z. Fisk, J.L. Smith, J.O. Willis, and M.S. Wire, Phys. Rev. B, 30(3), 1249-1252 (1984). Published in Phase Diagrams of Binary Beryllium Alloys, 1987. Complete evaluation contains 2 figures, 3 tables, and 22 references. 1