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
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