Фазовая диаграмма системы Co-Mn

К оглавлению: Другие диаграммы (Others phase diargams)

Co-Mn (Cobalt-Manganese) K. Ishida and T. Nishizawa The assessed Co-Mn phase diagram is based primarily on the work of [57Hel], [ 71Tsi], and [82Has]. The equilibrium phase are (1) the liquid, L; (2) the fcc terminal solid solutions, (aCo) and (gMn); (3) the cph solution, (eCo); (4) the Mn-rich bcc solution, (dMn); (5) the solid solution, (bMn); (6) the cubic phase with a complex structure, (aMn), based on the allotropic form of pure Mn below 727 C; and (7) the s phase formed at about 50 at.% Mn below 545 C. The assessed phase diagram shows the miscibility gap in (aCo) phase along the Curie temperature, which is based on the thermodynamic calculation by [82Has]. This magnetically induced phase separation was confirmed by [81Ind]. The (gMn) phase cannot be retained by quenching pure Mn, but transforms to the face-centered tetragonal g› phase [Pearson1]. [49Sch] reported that the (g›Mn) single phase was formed by quenching from the high-temperature solid field of (gMn) phase. (g›Mn) phase was also formed in the composition range of 91 to 100 at.% Mn by splat quenching from the melt [ 75Gud]. The metastable (gMn) phase was found in specimens obtained by rapid solidification in the range of 60 to 88 at.% Mn [75Gud]. The (aCo)/(eCo) martensitic transformation temperatures were examined by [ 70Mas], who found that both the transformation temperatures on heating (As) and cooling (Ms) decrease with increasing Mn content. The (aCo) and (eCo) phases are ferromagnetic. The magnetic transition from ferromagnetic to antiferromagnetic in (aCo) phase occurs near 30 at.% Mn at room temperature [70Mat]. The N‚el temperature of pure (aMn) is about 95 K [ 56Kas]. [76Wil] reported the effect of Co on the N‚el temperature of (aMn) using electrical resistivity measurements. The change in N‚el temperature for 1 at.% Co is about 26 K. 32Has: U. Haschimoto, Kinzoku-no-Kenkyu, 9, 64-65 (1932) in Japanese. 33Kos: W. K”ster and W. Schmidt, Arch. EisenhЃttenwes., 2, 121-126 (1933) in German. 49Sch: A. Schneider and W. Wunderlich, Z. Metallkd., 40, 260-263 (1949) in German. 56Kas: J.S. Kasper and B.W. Roberts, Phys. Rev., 101, 537-544 (1956). 57Hel: A. Hellawell and W. Hume-Rothery, Philos. Trans. R. Soc. (London) A, 249, 417-459 (1957). 70Mas: H. Masumoto, S. Sawaya, and M. Kikuchi, Trans. Jpn. Inst. Met., 11, 171- 175 (1970). 70Mat: M. Matsui, T. Ido, K. Sato, and K. Adachi, J. Phys. Soc. Jpn., 28, 791 ( 1970). 71Tsi: K. Tsioplakis and T. G”decke, Z. Metallkd., 62, 680-681 (1971) in German. 72Ada: K. Adachi, K. Sato, M. Matsui, and S. Mitani, IEEE Trans. Magn., 8, 693- 695 (1972). 75Gud: V.N. Gudzenko and A.F. Polesya, Izv. Akad. Nauk SSSR, Met., (5), 192- 195 (1975) in Russian. 76Wil: W. Williams and J.L. Stanford, J. Magn. Magn. Mater., 1, 271-285 (1976). 81Ind: G. Inden, Calphad, 5, 152 (1981). 82Has: M. Hasebe, K. Oikawa, and T. Nishizawa, J. Jpn. Inst. Met., 46, 577-583 (1982) in Japanese. 83Nis: T. Nishizawa and K. Ishida, Bull. Alloy Phase Diagrams, 4(4), 387-390 ( 1983). Published in Bull. Alloy Phase Diagrams, 11(2), Apr 1990. Complete evaluation contains 8 figures, 9 tables, and 38 references. 1