Фазовая диаграмма системы Ti-Zr

К оглавлению: Другие диаграммы (Others phase diargams)

Ti-Zr (Titanium-Zirconium) J.L. Murray [82Auf] uncovered several inconsistencies in the details of the phase boundaries. The congruent b to a transition was previously placed at 545 C [ 66Far, 71Cha]. (bTi,bZr) and (aTi,aZr) are referred to as b and a in the present evaluation. However, preliminary dilatometric studies [77Etc] indicated that for a 50 at.% alloy the b to a transition occurred near 600 C. Thermodynamic data tend to support the diagram of [82Auf]. Incipient melting determinations were made by [39Fas], [51Hay], and [69Rud]. The solidus data [69Rud] were used as input for thermodynamic calculations, and his value for the congruent melting temperature was accepted. For the congruent a/b transformation temperature, the dilatometric and microcalorimetric work of [77Etc] and [87Auf] is used. b can transform martensitically to the cph phase (a›) across the entire composition range [70Hua]. Martensite transformation temperatures were determined by [52Duw], [60Gri], [70Hua], [77Etc], and [82Auf]. [70Hua] measured the start temperatures of the b to a transformation on cooling and on heating. At the congruent composition, they were found to be 475 and 645 C, respectively. [60Gri] and [52Duw] found the minimum martensitic start temperature to be about 485 C. 39Fas: J.D. Fast, Rec. Trav. Chim., 58, 973-983 (1939). 51Hay: E.T. Hayes, A.H. Roberson, and O.G. Paasche, U.S. Bur. Mines Rep. Invest. No. 4826 (1951). 52Duw: P. Duwez, J. Inst. Met., 80, 525-527 (1952). 60Gri: V.N. Gridnev, V.I. Trefilov, and V.N. Minakov, Dokl. Akad. Nauk SSSR, 134(6), 1334-1336 (1960) in Russian; TR: Sov. Phys. Dokl., 5(6), 1094-1096 ( 1960). 66Far: P.A Farrar and S. Adler, Trans. AIME, 236, 1061-1064 (1966). 69Rud: E. Rudy, Tech. Rep. AFML-TR-65-2, Part V, Wright Patterson Air Force Base (1969). 70Hua: Y.C. Huang, S. Suzuki, H. Kaneko, and T. Sato, Sci. Technol. Appl. Titanium, Proc. Int. Conf., R.I. Jaffee, Ed., 691-693 (1970). 71Cha: D. Chatterji, M.T. Hepworth, and S.J. Hruska, Metall. Trans., 2, 1271- 1272 (1971). 77Etc: J. Etchessahar and J. Debuigne, M‚m. Sci. Rev. M‚tall., 74(3), 195-205 ( 1977). 82Auf: J.P. Auffredic, E. Etchessahar, and J. Debuigne, J. Less-Common Met., 84, 49-64 (1982). Published in Phase Diagrams of Binary Titanium Alloys, 1987. Complete evaluation contains 4 figures, 4 tables, and 22 references. Special Points of the Ti-Zr System