Фазовая диаграмма системы Cu-Sr

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Cu-Sr (Copper-Strontium) D.J. Chakrabarti and D.E. Laughlin The equilibrium phases of the Cu-Sr system are (1) the liquid; (2) the fcc solid solution, (Cu), with negligible solubility of Sr; (3) the bcc solid solution, (bSr), with negligible solubility of Cu and stable down to ~547 C; ( 4) the fcc solid solution (aSr), with negligible solubility of Cu and stable below ~547 C; (5) the hexagonal stoichiometric phase Cu5Sr, stable between 845 and approximately -28 C; and (6) the hexagonal stoichiometric phase CuSr, stable at all temperatures below 586 C. The assessed Cu-Sr phase diagram is based on the data of [71Bru]. The Sr used by [71Bru] was purified by distillation. The purity of Sr and Cu used was 99.8 and 99.999%, respectively. Cu and Sr are virtually insoluble in one another in the solid state and are soluble in all proportions in the liquid state. The intermediate phases Cu5Sr and CuSr are formed by peritectic reactions at 845 and 586 C, respectively. Because the Cu-Sr phase diagram is reasonably well established, the equilibrium boundaries between the coexisting phases can be used to derive expressions for the thermodynamic conditions of the different phases. Such expressions were used by the present authors to reproduce the phase boundaries and to calculate the regions of the phase diagram that have not been determined experimentally. Agreement between calculated and experimental results for select portions of the phase diagram is very good, suggesting good consistency between the thermodynamic parameters of the different phases, as derived from the phase diagram. 71Bru: G. Bruzzone, J. Less-Common Met., 25, 361-366 (1971). Published in Bull. Alloy Phase Diagrams, 5(4), Aug 1984. Complete evaluation contains 2 figures, 5 tables, and 14 references. Special Points of the Cu-Sr System