Фазовая диаграмма системы Cu-Fe

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Cu-Fe (Copper-Iron) L.J. Swartzendruber The assessed Fe-Cu phase diagram is based primarily on the experimental data of [14Rue], [17Rue], [24Han], [30Tam], [35Nor], [36Mad], [57Hel], [58Nak], [ 60Wri], [61Qur], and [66Boc] and has been obtained by thermodynamic modeling. The equilibrium phases are (1) the liquid, L; (2) the fcc Cu-rich solid solution, (Cu) (often called the e phase); (3) a high-temperature Fe-rich bcc solid solution, (dFe); (4) an intermediate-temperature Fe-rich fcc solid solution, (gFe); and (5) a low-temperature Fe-rich bcc solid solution, (aFe). The assessed liquidus is based primarily on the measurements of [36Mad], [ 58Nak], [57Hel], and [80Lin] and on the thermodynamic calculations of [77Kub] , [80Has], and [84Chu]. Many early measurements of the Fe-Cu liquidus [14Rue, 17Rue] reported the presence of a liquid miscibility gap. However, a number of subsequent investigations reported that the mutual solubility in the liquid might depend on the presence of impurities, especially carbon. The situation was considerably clarified by [36Mad] and [38Iwa]. In particular, [38Iwa] found that no liquid phase separation occurs if the alloys contain less than 0. 02 to 0.03 wt.% C. They also reported that additions of 1 wt.% Al, Ni, Pb, Sn, or Zn caused no liquid segregation in 50 wt.% Cu alloys. [50Smi] confirmed the effect of C, finding insignificant segregation for alloys containing 0.1 or less wt.% C and clear segregation for 0.2 or more wt.% C, with most of the C contained in the Fe-rich liquid. [34Smi] also reported liquid segregation in a 50 wt.% Cu alloy with approximately 1 wt.% Si. A miscibility gap for supercooled liquids was determined experimentally by [ 58Nak], whose results are in substantial agreement with the thermodynamic calculations of [84Chu]. The earlier data require correction to IPTS-68. In addition, correction to the reference points for pure Fe and pure Cu is often needed. This correction contains considerable uncertainty and is to some extent arbitrary. The data points in the assessed diagram have been corrected by linear interpolation. The error limits assigned to these measurements vary with the experimental data. Addition of Cu to Fe tends to stabilize the fcc structure and to lower the melting temperature, restricting the range of (dFe) stability. The measurements of [08Sah], [14Rue], [36Mad], [38Iwa], and [57Hel], corrected to IPTS-68 and to the reference points of 1538 C for the melting temperature of pure Fe, when combined with the thermodynamic calculations of [84Chu], give a maximum solubility of Cu in (dFe) of 6.7 с 1 at.% Cu at the (dFe) + L <259> ( gFe) 1485 с 10 C peritectic point. At the peritectic, (dFe) is in equilibrium with (gFe), containing 7.2 с 1 at.% Cu and L containing 11.5 с 1 at.% Cu. As shown by the measurements of [80Lin] and the thermodynamic calculations of [ 80Has] and [84Chu], Cu exhibits a retrograde solubility of (gFe), reaching a maximum solubility of 12 с 2 at.% Cu at approximately 1410 C. The maximum solubility of Cu in aFe is 1.88 с 0.5 at.% Cu at the eutectoid temperature of 850 с 5 C. The maximum Fe solubility in (Cu) is 3.5 с 0.5 at.% Fe at the peritectic temperature of 1096 с 5 C. Below the eutectoid temperature (850 C), Fe forms large coherent clusters in the fcc Cu matrix. In an alloy containing 2.7 at.% Fe, [56Den] found that coherent iron precipitates could not be easily transformed to the stable bcc form by thermal treatment alone, but the transformation is readily accomplished by plastic deformation. [57New] also found evidence that the Fe precipitate first forms as coherent platelets parallel to the [111] planes of the matrix lattice. Loss of coherency can be obtained by cold working or by charged particle irradiation [56Den]. Magnetic [61Ber] and M”ssbauer [70Ben] measurements show that before the formation of coherent precipitates very small superparamagnetic clusters (the so-called g2 Fe) are formed. [65Kle] has demonstrated that very rapid quenching can produce solid solutions containing up to approximately 7 at.% Fe. M”ssbauer effect studies [69Lah] indicate that bcc Cu-rich clusters precede precipitation of the fcc (Cu) in (dFe). Measurements of the M”ssbauer isomer shift at room temperature for dilute Fe in (Cu) were made by [65Edg] up to 20 GPa (200 kbar). No transitions were detected. According to [17Rue], the Curie temperature of (aFe) saturated with Cu is 10 C lower than that for pure aFe. A linear decrease with Cu concentration is consistent with the measurements of [64Kne]. The effect of Cu additions to Fe on the coercive force and remanence of iron was investigated by [50Rai], who observed a maximum coercive force of about 120 Oe and a maximum remanence of about 0.9 T. The saturation moment of Fe atoms in (Cu) is 2.85 mB [67Hur], and a Curie- Weiss law is obeyed at high temperatures [39Bit]. Isolated Fe atoms in (Cu) undergo a spin compensation with a Kondo temperature of approximately 29 K [ 72Ede]. Coherent metastable gFe precipitates in (Cu) are antiferromagnetic with ~0.75 mB/atom and a N‚el temperature of approximately 67 K [82Rhy]. 08Sah: R. Sahmen, Z. Anorg. Allg. Chem., 57, 9-20 (1908) in German. 14Rue: R. Ruer and R. Klesper, Ferrum, 9, 257-261 (1914) in German. 17Rue: R. Ruer and F. Goerens, Ferrum, 4, 49-61 (1917) in German. 24Han: D. Hanson and G.W. Ford, J. Inst. Met., 32, 335-361 (1924). 30Tam: G. Tammann and W. Oelsen, Z. Anorg. Allg. Chem., 186, 257-288 (1930) in German. 34Smi: C.S. Smith, J. Inst. Met., 54, 251 (1934). 35Nor: J.T. Norton, Trans. AIME, 116, 386-394 (1935). 36Mad: W.R. Maddocks and C.E. Claussen, Iron Steel Inst. Spec. Rept., (14), 97- 124 (1936). 38Iwa: K. Iwase, M. Okamoto, and T. Amemiya, Sci. Rept. Tohoku Imp. Univ., 26, 618-628 (1938). 39Bit: F. Bitter and A.R. Kaufman, Phys. Rev., 56, 1044-1051 (1939). 43And: A.G. Andersen and A.W. Kingsbury, Trans. AIME, 152, 38-47 (1943). 50Rai: H. Rainer, Metall, 4, 416-420 (1950) in German. 50Smi: C.S. Smith and E.W. Palmer, Trans. AIME, 188, 1486-1499 (1950). 56Den: J.M. Denney, Acta Metall., 4, 586-592 (1956). 57Hel: A. Hellawell and W. Hume-Rothery, Philos. Trans. R. Soc. London A, 249, 432-433 (1957). 57New: J.B. Newkirk, J. Met., 9(10), 1214-1220 (1957). 58Nak: Y. Nakagawa, Acta Metall., 6, 704-711 (1958). 60Wri: H.A. Wriedt and L.S. Darken, Trans. AIME, 218, 30-36 (1960). 61Ber: C. Berghout, Z. Metallkd., 52, 179-186 (1961) in German. 61Qur: A.H. Qureshi, Z. Metallkd., 52, 799-813 (1961) in German. 64Kne: E.F. Kneller, J. Appl. Phys., 35(7), 2210-2111 (1964). 65Edg: C.K. Edge, R. Ingalls, P. Debrunner, H.G. Drickamer, and H. Frauenfelder, Phys. Rev., 138(3A), A729-A731 (1965). 65Kle: W. Klement, Trans. AIME, 233, 1180-1182 (1965). 66Boc: A.A. Bochvar, A.S. Ekatova, E.V. Panchenko, and Y.F. Sidokhin, Dokl. Akad. Nauk SSR, 174, 863-864 (1966) in Russian. 67Hur: C.M. Hurd, Phys. Rev. Lett., 18, 1127-1129 (1967). 69Lah: S.K. Lahiri, D. Chandra, L.H. Swartz, and M.E. Fine, Trans. AIME, 245, 1865-1868 (1969). 70Ben: L.H. Bennett and L.J. Swartzendruber, Acta Metall., 18, 485-498 (1970). 72Ede: A.S. Edelstein, Phys. Rev. Lett., 29(22), 1522-1524 (1972). 77Kub: O. Kubaschewski, J.F. Smith, and D.M. Bailey, Z. Metallkd., 68, 495-499 (1977). 80Has: M. Hasebe and T. Nishizawa, Calphad, 4(2), 83-100 (1980). 80Lin: P.A. Lindquist and B. Uhrenius, Calphad, 4, 193-200 (1980). 82Rhy: J.J. Rhyne, Bull. Alloy Phase Diagrams, 3(3), 401-402 (1982). 84Chu: Y.Y. Chuang, R. Schmid, and Y.A. Chang, Metall. Trans. A, 15, 1921-1930 (1984). Submitted to the APD Program. Complete evaluation contains 2 figures, 4 tables, and 102 references. Special Points of the Fe-Cu System