Фазовая диаграмма системы Ti-Y

К оглавлению: Другие диаграммы (Others phase diargams)


Ti-Y (Titanium-Yttrium) J.L. Murray The assessed Ti-Y phase diagram is the result of thermodynamic calculations and reproduces the input phase diagram data within the experimental uncertainty. [60Lov] determined invariant temperatures by differential thermal analysis and estimated liquidus temperatures by optical pyrometry. The results were quite scattered. [61Bar] determined invariant melting temperatures by the incipient melting technique, liquidus compositions by chemical analysis of the equilibrated liquid, solid solubilities by microscopy, and the effect of Y on the (bTi) <259> (aTi) transition by thermal analysis. Both the Ti and the Y used to make alloys were rich in interstitial impurities, particularly oxygen. [62Lun] produced microscopic evidence that the (bY) <259> (aY) reaction with the liquid is of the catatectic type. The solubilities of Y in (aTi) and (bTi) were found to be about 0.1 and 0.2 at.% at the eutectoid temperature (870 C) by metallography. The Y used by [62Lun] contained 1750 ppm (by wt.?) of oxygen and 1000 ppm (wt.?) Zr, and the melting temperature of Y was reported as 1552 C, compared to the accepted value of 1522 C [81Gsc]. [68Bea] verified the catatectic reaction and determined the Y-rich part of the diagram by thermal analysis. They used distilled Y that was very pure with respect to nonmetallic impurities. 60Lov: B. Love, WADD Tech. Rep., Part I, 60-74 (1960). 61Bar: D.W. Bare and O.N. Carlson, Trans. ASM, 53, 1-11 (1961). 62Lun: C.E. Lundin and D.T. Klodt, Trans. AIME, 224, 367-372 (1962). 68Bea: B.J. Beaudry, J. Less-Common Met., 14, 370-372 (1968). 81Gsc: K.A. Gschneidner, Jr. and F.W. Calderwood, IS-RIC-PR-1, Rare-Earth Information Center, Iowa State Univ., Ames, IA (1981). Published in Phase Diagrams of Binary Titanium Alloys, 1987. Complete evaluation contains 2 figures, 4 tables, and 7 references. Special Points of the Ti-Y System