Фазовая диаграмма системы Np-Pu

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Np-Pu (Neptunium-Plutonium) R.I. Sheldon and D.E. Peterson The Np-Pu system is characterized by the very high solubility of Np in (aPu) and (bPu), with maximum values of 96 and 85 at.% Np, respectively. These solubilities decrease with decreasing temperature, but the exact locations of the phase boundaries are uncertain because of contradictory and nonreproducible X-ray results. The extremely high solubility of Np in the monoclinic a and b phases of Pu is unique among the Pu alloy systems. The assessed phase diagram is based primarily on the work of [61Mar], with review of the pertinent literature [61Poo, 68Ell]. gNp and ePu are completely miscible, but the solubilities of Np in (gPu), (dPu) , and (d›Pu) are limited to about 2 at.% by the presence of an intermediate intermetallic phase, h. The h phase extends from 51 to 97 at.% Pu, decomposing by the eutectoid reaction h = (bPu) + (gPu) at 288 C, and forming by the peritectoid reaction (gNp,ePu) + (bPu) = h at 508 C. The solubility of Pu in (aNp) increases with decreasing temperature, but the phase boundary becomes uncertain below 170 C. The solubility of Pu in (bNp) increases with increasing temperature, but this phase boundary is also uncertain. 61Mar: P.G. Mardon, J.H. Pearce, and J.A.C. Marples, J. Less-Common Met., 3, 281-292 (1961). 61Poo: D.M. Poole, M.G. Bale, P.G. Mardon, J.A.C. Marples, and J.L. Nichols, Plutonium 1960, E. Grison, W.B.H. Lord, and R.D. Fowler, Ed., Cleaver-Hume Press, Ltd., London, 267-280 (1961). 68Ell: F.H. Ellinger, W.N. Miner, D.R. O'Boyle, and F.W. Schonfeld, Los Alamos Nat. Lab. Rep. LA-3870, Los Alamos, NM (Dec 1968). Published in Bull. Alloy Phase Diagrams, 6(3), Jun 1985. Complete evaluation contains 1 figure, 3 tables, and 13 references.