Фазовая диаграмма системы Fe-Y
К оглавлению: Другие диаграммы (Others phase diargams)
Fe-Y (Iron-Yttrium)
W. Zhang, G. Liu, and K. Han
[61Dom] investigated the entire Fe-Y system with 99% pure Y and 99.9% pure Fe.
[61Gsc] thought that the experimental technique employed in [61Dom] did not
justify showing the liquidus as a solid line, and [82Kub] made minor revisions
to phase stoichiometries to bring the diagram into accord with results from
more recent crystallographic studies. The assessed diagram is essentially the
diagram proposed by [61Dom], with the revisions of [82Kub].
There are four compounds in this system-Fe17Y2, Fe23Y6, Fe3Y, and Fe2Y-with
the first three compounds melting congruently. The compound Fe5Y with the
CaCu5 structure reported by [61Gsc] could not be confirmed by later
experiments [71Tay].
Hellawell reported that 1 at.% Y lowers the g/d Fe transformation temperature
by 3 C [61Gsc]. The effect of additions of Y on a/g Fe transformation is not
known [82Kub]. The terminal solid solubility of Y in Fe is less than 1 wt.% [
61Gsc]. The equilibrium solubility of Fe in Y is less than 0.1 at.%, although
as much as 3 at.% Fe could be dissolved interstitially in cph Y in rapidly
quenched Y-rich alloys [81Ten].
A g loop (similar to the Fe-Cr system) was reported by [61Dom] to exist at a
composition less than 1 wt.% Y. However, no further experimental information
is available. Such a g loop is not shown in the assessed diagram.
Fe17Y2 melts congruently at 1400 с 25 C [61Dom]. Two modifications exist-the
rhombohedral Th2Zn17 type and hexagonal Ni17Th2 type. Because samples annealed
at 1000 C for 15 days contained both types of Fe17Y2 and because splat-cooled
samples contained only the hexagonal type [66Bus], the Ni17Th2 type should be
considered the high-temperature modification of Fe17Y2.
Fe3Y melts congruently, whereas Fe2Y is formed peritectically. Fe2Y has a
small composition range, because a slight decrease of the lattice parameter (0.
0004 nm) was found between the 65.0 and 68.0 at.% Fe alloys after annealing at
870 C for 125 h [60Bea]. The compound was also found after annealing at 700
or 900 C [61Dwi].
[82Ten] investigated the crystallization of the metallic glass Fe0.32Y0.66,
prepared by levitation melting of high-purity components and splat cooling.
The crystallization of this glass occurs in two distinct steps associated with
the formation of cph Y and the Laves phase Fe2Y. A bcc form of elemental Y was
observed in Fe-Y alloys that were rapidly quenched by melt spinning, and the
compositions in which the bcc Y phase is formed are near the eutectic shown in
the Fe-Y phase diagram (34.6 at.% Fe) [82Ten].
The Curie temperature of Fe2Y was reported to be 535 K [61Gsc]. The Curie
temperature of Fe23Y6 is 481 K [86Chu], which is in good agreement with the
results of [79Bes] (478 K) and [84Her] (484 K). An Fe sublattice model
accurately describes the temperature dependence of the magnetization for
Fe23Y6; the calculated Curie temperature is 500 K [84Her].
60Bea: B.J. Beaudry, J.F. Haefling, and A.H. Daane, Acta Crystallogr., 13, 743
(1960).
61Dom: R.F. Domagala, J.J. Rausch, and D.W. Levinson, Trans. ASM, 53, 139-155 (
1961).
61Dwi: A.E. Dwight, Trans. ASM, 53, 479-500 (1961).
61Gsc: K.A. Gschneidner, Jr., Rare Earth Alloys, Van Nostrand Publishing,
Amsterdam (1961).
66Bus: K.H.J. Buschow, J. Less-Common Met., 11, 204-208 (1966).
71Tay: K.N.R. Taylor and C.A. Poldy, J. Less-Common Met., 27, 255 (1972).
77Bus: K.H.J. Buschow, Rep. Prog. Phys., 40, 1179-1256 (1977).
79Bes: M.J. Besnus, J.M. Bouton, and R. Clad, Phys. Status Solidi (a), 53, 351-
354 (1979).
81Ten: M. Tenhover, J. Phys. F, Metal Phys., 11, 2697-2670 (1981).
82Kub: O. Kubaschewski, Iron-Binary Phase Diagrams, Springer-Verlag, New York,
106-107 (1982).
82Ten: M. Tenhover, B.M. Clemens, and P. Duwez, J. Phys. F, Met. Phys., 12,
L167-L171 (1982).
84Bay: G. Bayer and W.E. Wallace, J. Phys. Chem., 88, 3220-3224 (1984).
84Her: J.F. Herbst and J.J. Croat, J. Appl. Phys., 55(8), 3023-3027 (1984).
86Chu: Y.C. Chuang, C.H. Wu, and Y.C. Chang, J. Less-Common Met., 118, 7-20 (
1986).
Submitted to the APD Program. Complete evaluation contains 1 figure, 4 tables,
and 32 references.
Special Points of the Fe-Y System