Determination of Cast-Metal Structures and Welded Joints After Electron-Beam Welding of the Intermetallic Titanium Alloys Ti−28Al−7Nb−2Mo−2Cr Obtained by Electron-Beam Melting Method
S. V. Akhonin, A. Yu. Severyn, V. Yu. Belous, V. A. Kostin, V. O. Berezos
E. O. Paton Electric Welding Institute, NAS of Ukraine, 11 Kazymyr Malevych Str., UA-03150 Kyiv, Ukraine
Received: 17.10.2023; final version - 28.11.2023. Download: PDF
The structure of the base metal and weld metal after electron-beam welding (EBW) of the intermetallic titanium alloy Ti−28Al−7Nb−2Mo−2Cr (wt.%) obtained by the electron-beam melting method is studied. The macrostructure of the Ti−28Al−7Nb−2Mo−2Cr alloy ingot is characterized by grains close to equiaxed with a grain size of 8–9 points. As shown, the microstructure of the cast metal of the Ti−28Al−7Nb−2Mo−2Cr alloy consists of a matrix bright $\gamma$-phase alternating with sections of a two-phase ($\gamma$ + $\alpha_{2}$) lamellar structure up to 50 µm in size, with a lamellae thickness of about 1 µm, and of the ordered $\beta$-phase, which forms a mesh pattern against the background of the matrix. As established, the intragranular structure of the metal of the welded joint after EBW with local heat treatment (LHT) differs from the structure of the base metal and consists of small (up to 20 µm) areas with a ($\gamma$ + $\alpha_{2}$) lamellar structure against the background of a light matrix $\gamma$-phase with a network of elongated particles of 30-80 µm long and 1-3 µm thick.
Key words: intermetallic titanium alloy, structure, phase, electron-beam melting, electron-beam welding.
URL: https://mfint.imp.kiev.ua/en/abstract/v46/i05/0415.html
DOI: https://doi.org/10.15407/mfint.46.05.0415
PACS: 06.60.Vz, 64.70.dj, 68.37.Hk, 81.20.Vj, 81.30.Bx, 81.30.Fb, 81.40.Wx
Citation: S. V. Akhonin, A. Yu. Severyn, V. Yu. Belous, V. A. Kostin, and V. O. Berezos, Determination of Cast-Metal Structures and Welded Joints After Electron-Beam Welding of the Intermetallic Titanium Alloys Ti−28Al−7Nb−2Mo−2Cr Obtained by Electron-Beam Melting Method, Metallofiz. Noveishie Tekhnol., 46, No. 5: 415—429 (2024) (in Ukrainian)