Regulation of the structure and phase composition of titanium aluminides produced by zone melting

1Asnis, EA, 1Piskun, NV, 1Statkevich, II, 1Velikoivanenko, EA, 1Rozynka, GF, 1Milenin, AS, 1Bohaichuk, IL, 2Filatov, VE
1E.O. Paton Electric Welding Institute of the NAS of Ukraine, Kyiv
2G.S. Pisarenko Institute for Problems of Strength of the NAS of Ukraine, Kyiv
Dopov. Nac. akad. nauk Ukr. 2017, 6:36-45
Section: Materials Science
Language: Russian

A technology, combining the induction zone melting of intermetallides of the TiAl system and a subsequent heat treatment providing the cooling rate, which promotes the homogenization of the structure and mechanical characteristics along the ingot, has been developed. A mathematical model of the process is constructed, and the computing experiment is conducted, which showed that the homogenization of an intermetallic structure along the entire ingot length and the improvement of its mechanical characteristics require ensuring the cooling rates in the interval of 0.4—0.6 K/s. Investigation of the structure of an ingot produced by this process showed the presence of the platelike (γ + α2)-phase and the β0(B2)-phase in it. Heat treatment promotes an increase of the volume of the ordered cubic β (B2)-phase responsible for strengthening and ductility.

Keywords: heat treatment, intermetallide, mechanical properties, structure, zone melting
  1. Kazantseva, N. V., Grinberg, B. A., Demakov, S. L., et al. (2002). Microstructure and plastic strain of orthorhom bic aluminides Ti2AlNb. I. Formation of a polydomain structure. Fiz. metal. i metalloved., 93, No. 3, pp. 83-92 (in Russian).
  2. Kablov, E. N. & Lukin, V. I. (2008). Titanium- and nickel-based intermetallides for products of a new technique. Avtom. svarka, No. 11, pp. 76-82 (in Russian).
  3. Bochvar, G. A. & Salenkov, V. A. (2004). Study of alloys on the basis of titanium aluminide with orthorhombic structure. Tekhn. legk. splavov, No. 4, pp. 44-46 (in Russian).
  4. Bochvar, G. A. & Salenkov, V. A., Ponomareva, E. V. (2007). Influence of hardening modes on the structure and phase composition of Ti-Al-Nb intermetallic alloys with high content of niobium. Tekhn. legk. splavov, No. 1, pp. 62-65 (in Russian).
  5. Kumpfert, J. & Kaysser, W. A. (2001). Orthorhombic titanium aluminides: phases, phase transformations and microstructure evolution. Intern. J. Mater. Research, 82, pp. 128-134.
  6. Imaev, V. M., Imaev, R. M. & Khismatullin, T. G. (2008). Mechanical properties of Ti-43Al-7(Nb,Mo) - 0.2B (at. %) intermetallic alloy after a heat treatment. Fiz. metal. i metalloved., 105, No. 5, pp. 516-522 (in Russian).
  7. Zolotarevski, V. S. (1974). Mechanical testing of metals and properties of metals. Moscow: Metallurgiya (in Rus sian).
  8. Patent № u 201406203. Asnis Y. A., Piskun N. V., Statkevich I.I. et al. The method of thermal processing intermetallics titanium-aluminum system, Ukraine, patent owner Welding Institute. EO Paton NAS of Ukraine, appl. 05.06.2014. Publ. 10.12.2014r. Bull. No. 23 (in Ukrainian).