Фазовая диаграмма системы Cu-Si

К оглавлению: Другие диаграммы (Others phase diargams)

Cu-Si (Copper-Silicon) R.W. Olesinski and G.J. Abbaschian The equilibrium phases of the Si-Cu system are (1) the liquid, L; (2) the terminal solid solution, (Si), with negligible solubility of Cu; (3) the terminal solid solution, (Cu), with a maximum solubility of 11.25 at.% Si at the peritectoid temperature of 842 C; (4) the intermediate phases h, h›, h› ( high-temperature h with the rhombohedral structure melting congruently at 859 C, rhombohedral h› and orthorhombic h› remaining stable in the temperature ranges 467 to 620 C and below 570 C, respectively); (5) the cubic intermediate phase, e, which decomposes peritectoidally around 800 C; (6) the tetragonal intermediate phase, d, which is stable in the temperature range 710 to 824 C; (7) the cubic intermediate phase, g, which decomposes peritectoidally at 729 C; (8) the bcc intermediate phase, b, which is stable in the temperature range 785 to 852 C; and (9) the cph intermediate phase, k, which is stable from 552 to 842 C. The assessed phase diagram is based on evaluation of the work of [07Rud], [28Smi], and [29Smi], and [40Smi] and was obtained by thermodynamic optimization of the experimental data. Cu dissolves interstitially in (Si). The solid solution is retrograde, with a maximum solubility of 0.002 at.% Cu between 1200 and 1300 C. The (Cu) solubility curve shows a maximum solid solubility of 11.25 at.% Si at the peritectoid temperature of 842 C. [50Bar] reported that a metastable faulted phase, g›, developed on quenching or cold working of alloys containing between 89.4 and 91.4 at.% Cu, in the region of supersaturated (Cu). The new phase transformed to (Cu) only upon heating above the recrystallization temperature. [66Dah] showed that the metastable phase precipitating from the supersaturated (Cu) is structurally similar to k, and it can be designated as k›. The precipitates are coherent with the parent (Cu) phase across close-packed planes. The equilibrium g phase forms from k› in the second stage of decomposition of the supersaturated ( Cu). Rapidly solidified phases obtained by means of splat cooling were tentatively examined by [69Gie], who reported suppression of e and g phases on splat cooling to room temperature and postulated extended homogeneity ranges of h and d. Amorphous Si-Cu films were obtained in an unspecified composition range by [ 70Bos], using electron beam evaporation techniques. The films were reported to crystallize around 200 C. 07Rud: E. Rudolfi, Z. Anorg. Chem., 53, 216-227 (1907) in German. 28Smi: C.S. Smith, J. Inst. Met., 40, 359-370 (1928). 29Smi: C.S. Smith, Trans. AIME, 83, 414-439 (1929). 40Smi: C.S. Smith, Trans. AIME, 137, 313-329 (1940). 50Bar: C.S. Barrett, Trans. AIME, 188, 123-135 (1950). 66Dah: S.D. Dahlgren, W.F. Flanagan, and D.H. Polonis, Trans. AIME, 236, 1071- 1077 (1966). 69Gie: B.C. Giessen, Development in the Structural Chemistry of Alloy Phases, Plenum Press, New York, 227-281 (1969). 70Bos: J.R. Bosnell and U.S. Voisey, Thin Solid Films, 6, 161-166 (1970). Published in Bull. Alloy Phase Diagrams, 7(2), Apr 1986. Complete evaluation contains 3 figures, 4 tables and 61 references. Special Points of the Si-Cu System