Фазовая диаграмма системы Co-Fe

К оглавлению: Другие диаграммы (Others phase diargams)

Co-Fe (Cobalt-Iron) T. Nishizawa and K. Ishida The assessed phase diagram for the Co-Fe system is based on the work of [41Ell] , [53Har], [66Lor], [67Asa], [70Fis], [70Pre], [75Nor], [77Oye], and [77Pap]. The g/d equilibrium was determined by thermal analysis [53Har] and magnetic susceptibility measurements [70Fis]. The temperature of the g/d transformation of pure Fe is increased by the addition of Co. The temperature of the a (bcc)/g (fcc) transformation in Fe is also increased by Co, which indicates that Co stabilizes austenite near the A4 point and stabilizes ferrite near the A3 point. The a/g equilibrium was determined by [ 69Stu], [70Fis], [75Nor], and [41Ell]. The effect of Co on the a (bcc) <259> e (cph) transformation of Fe at room temperature has been studied under high pressures. The transformation pressure increases with the addition of Co to Fe between 0 and 50 wt.% Co [66Lor, 77Pap] . The equiatomic alloy of Fe and Co undergoes the order-disorder transformation at 730 C, and the ordered phase a› exists over a considerable range on either side of the stoichiometric composition [67Asa, 77Oye]. The transformation temperature is increased with increasing pressure. In studies on supercooling of austenite on the Fe-rich side, it was well established that the martensitic transformation temperature depends on the cooling rate. The kinetics of this transformation can be attributed to several different processes of interaction between the interface and impurities [81Mir] . The martensitic transformation temperature of Co is markedly decreased by the addition of Fe. A metastable h phase with a double cph structure is formed in Co-rich alloys. The h phase was detected in the surface layer of Co-(2 to 5 %) Fe alloys as a result of cavitation-erosion [71Woo]. Using high-temperature X-ray diffraction and heat capacity measurements, [74Ono] showed that this phase is also formed during isothermal soaking or slow cooling in the range 1.5 to 4.8 at.% Fe. 41Ell: W.C. Ellis and E.S. Greiner, Trans. ASM, 29, 415 (1941). 53Har: G.B. Harris and W. Hume-Rothery, J. Iron Steel Inst., 174, 212 (1953). 66Lor: T.R. Loree, C.M. Fowler, E.G. Zukas, and F.S. Minshall, J. Appl. Phys., 37, 1918 (1966). 67Asa: H. Asano, Y. Bando, N. Nakanishi, and S. Kachi, Trans. Jpn. Inst. Met., 8, 180 (1967). 69Stu: H. Stuart and N. Ridley, Br. J. Appl. Phys., Ser. 2, 485 (1969). 70Fis: W.A. Fisher, K. Lorenz, H. Fabritius, and D. Schlegel, Arch. EisenhЃttenwes., 41, 489 (1970). 70Pre: B. Predel and R. Mohs, Arch. EisenhЃttenwes., 41, 143 (1970). 71Woo: D.A. Woodford and H.J. Beattie, Metall. Trans., 2, 3223 (1971). 74Ono: T. Onozuka, S. Yamaguchi, M. Hirabayashi, and T. Wakiyama, J. Phys. Soc. Jpn., 37, 687 (1974). 75Nor: A.S. Normanton, P.E. Bloomfield, F.R. Sale, and B.B. Argent, Met. Sci., 9, 510 (1975). 77Oye: J.A. Oyedale and M.F. Collins, Phys. Rev. B, 16, 3208 (1977). 77Pap: D. Papantonis and W.A. Bassett, J. Appl. Phys., 48, 3374 (1977). 81Mir: D.A. Mirzaev, M.M. Shteinberg, T.N. Pomomareva, B.Y. Bylskii, and S.E. Karzunov, Fiz. Met. Metalloved., 51, 364 (1981) in Russian; TR: Phys. Met. Metallogr., 51(2), 116 (1981). Published in Bull. Alloy Phase Diagrams, 5(3), Jun 1984. Complete evaluation contains 10 figures, 3 tables, and 128 references. 1