Фазовая диаграмма системы Ca-Pu

К оглавлению: Другие диаграммы (Others phase diargams)

Ca-Pu (Calcium-Plutonium) K.M. Axler and D.E. Peterson Very few studies of the Pu-Ca system have been published. The assessed phase diagram is based on review of the experimental data [59Sch, 61Sch, 68Ell] and was obtained by thermodynamic modeling. The elements appear to be immiscible in both the solid and liquid states. The boundary of the miscibility gap was estimated. Ca metal has a (fcc) and b (bcc) allotropes. [59Smi] reported that cph and low symmetry forms were stabilized by impurities, but were not observed in the most pure Ca examined. [83Cha] lists the temperatures of 443 C for the a to b transition and 842 с 2 C for the Ca melting point. The six Pu allotropes are a (primitive monoclinic), b (bc monoclinic), g (fc orthorhombic), d (fcc), d› (bct), and e (bcc). [83Oet] measured the transformation temperatures for b to a (125 с 1 C), g to b (215 с 1 C), and d to g (320 с 1 C). [81Rol] determined the d› to d (463 с 2 C), e to d› (483 с 4 C), and L to e (640 с 2 C) temperatures. A precise determination of the solid solubilities has not yet been reported. An effort to experimentally define the shape of the miscibility gap is required to fully characterize the Pu-Ca system. 59Sch: F.W. Schonfeld, et al., Progress in Nuclear Energy, Series V, Vol. 2, Pergamon Press, New York, 597-599 (1959). 59Smi: J.F. Smith and B.T. Bernstein, J. Electrochem. Soc., 106, 448 (1959). 61Sch: F.W. Schonfeld, in The Metal Plutonium, A.S. Coffinberry, and W.N. Miner, Ed. The University of Chicago Press, 251 (1961). 68Ell: F.H. Ellinger, W.N. Miner, D.R. O'Boyle, and F.W. Schonfeld, Constitution of Plutonium Alloys, Los Alamos National Laboratory Report LA- 3870, 17 (1968). 81Rol: C.E. Rolan and G.F. Gallegos, J. Therm. Anal., 21, 159-161 (1968). 83Cha: M.W. Chase, Bull. Alloy Phase Diagrams, 4(1) 124 (1983). 83Oet: F.L. Oetting and R.O. Adams, J. Chem. Thermodyn., 15, 537-554 (1983). Published in Bull. Alloy Phase Diagrams, 10(4a), Sep 1989. Complete evaluation contains 1 figure, 2 tables, and 8 references. 1