Фазовая диаграмма системы Re-Ti

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Re-Ti (Rhenium-Titanium) J.L. Murray The Ti-Re phase diagram has been studied only in one laboratory [58Sav, 59Sav, 69Sav] and only in limited composition and temperature ranges. In view of the limitations of the investigations and the difficulties intrinsic to working with this system, the phase diagram must be considered uncertain. [58Sav] determined melting temperatures by the "drop method." The solidus temperature was judged to be that temperature at which a hole in the sample completely filled with liquid. For Ti-rich compositions, the data, although scattered, define a (bTi) solidus between 1670 and about 2000 C. For the high melting temperatures at Re-rich compositions, the drop method provided only a rough estimate of the solidus. [59Sav] studied the (bTi)/(aTi) equilibria using metallographic, X-ray, and dilatometric methods. They also estimated the solubility of Re in (aTi) to be approximately 0.03 at.% at 750 C. In a study of the decomposition of metastable (bTi), [61Age] verified that a 6 at.% Re alloy lies within the two- phase (bTi) + (aTi) region at 400 C. Metastable phases are formed from (bTi) during quenching. In Ti-rich alloys, the cph phase (a›Ti) can form martensitically, and at slightly higher Re contents, an orthorhombic distortion of the cph structure (a›Ti) is formed. [ 58Bag] observed the orthorhombic (a›Ti) martensite in an as-quenched 2.8 at.% Re alloy. [59Sav] found that the bcc phase could be retained metastably during quenching in alloys containing more than 3.6 at.% Re; thus, martensitic start reaches room temperature at approximately that composition. The w phase is formed either during quenching of alloys of sufficient Re content that (aTi) is not formed during quenching, or during aging of metastable bcc alloys between approximately 300 and 450 C. [58Bag] observed w + (bTi) in an as-quenched 4 at.% Re alloy; in a 5.3 at.% Re alloy, only w phase was found. [61Age] produced w + (bTi) in a 6 at.% Re alloy during aging at 400 C. 58Bag: Yu.A. Bagariatskii, G.I. Nosova, and T.V. Tagunova, Dokl. Akad. Nauk SSSR, 122, 593-598 (1958) in Russian; TR: Sov. Phys. Dokl., 3, 1014-1018 (1958) . 58Sav: E.M. Savitskii and M.A. Tylkina, Zh. Neorg. Chem., 3(1), 815 (1958) in Russian; TR: Russ. J. Inorg. Chem., 3(1), 338-415 (1958). 59Sav: E.M. Savitskii, M.A. Tylkina, and Yu.A. Zotev, Zh. Neorg. Chem., 4(2), 702-703 (1959) in Russian: TR: Russ J. Inorg. Chem., 4(3), 319-320 (1959). 61Age: N.V. Ageev, O.G. Karpinskii, and L.A. Petrova, Zh. Neorg. Chem., 6(1), 251 (1961) in Russian: TR: Russ. J. Inorg. Chem., 6(1), 127-128 (1961). 69Sav: E.M. Savitskii, M.A. Tylkina, and O.Kh. Khamidov, Izv. Akad. Nauk SSSR, Met., (4), 200-208 (1969) in Russian; TR: Russ. Metall., (4), 130-135 (1969). Published in Phase Diagrams of Binary Titanium Alloys, 1987.Complete evaluation contains 1 figure, 4 tables, and 10 references. Special Points of the Ti-Re System