TPWJ, 2020, #9, 26-30 pages
Effect of local heat treatment on mechanical properties of welded joints of intermetallic of tial system produced by electron beam welding
L.M. Lobanov, E.A. Asnis, N.V. Piskun, E.L. Vrzhyzhevskyi And L.M. Radchenko
E.O. Paton Electric Welding Institute of the NAS of Ukraine
11 Kazymyr Malevych Str., 03150, Kyiv, Ukraine. E-mail: firstname.lastname@example.org
Welded joints of intermetallic β-stabilized alloy TiAl–Ti–44Al–5Nb–3Cr–1.5Zr (at.%) were investigated. Intermetallic
billets of 3 and 10 mm thickness were welded by electron beam welding. In order to prevent arising of cold cracks
in welded joints of titanium aluminide specimens of different thickness, the following postweld local heat treatment
using an electron beam was performed. The mentioned method of treatment is one of the most attractive to improve the
structure of ingot and reduce the level of residual welding stresses, which, in its turn, significantly increases mechanical
properties of the alloy. Static tensile tests were performed to evaluate the strength of welded joints. The specimens fractured
throughout the base material. The paper presents histograms showing the values of tensile strength (σt) of welded
joints produced during tensile tests for the specimens of different thickness with and without the use of local heat treatment
(lHT). It is shown that the use of local heat treatment increases tensile strength of the specimens of 3 and 10 mm
thickness, as compared to the specimens produced without lHT. In addition, the values of this index for welded joints
of different thicknesses, which are produced using this technique, are quite uniform. Comparative analysis of the results
of tensile tests and the results of microhardness studies was performed, which showed that fracture of the specimens
took place in the zone of lowering mechanical properties. The nature of fractures of different parts of welded joint was
studied, which confirmed that fracture occurs in the zone of brittle part of the specimen. It is known that mechanical
properties of welded joint are closely related to its structural state. During local heat treatment, an additional β0 (B2)
phase appears in the structure, which increases the ductility of the weld material, 14 Ref., 2 Tables, 9 Figures.
intermetallic alloy of TiAl system, electron beam welding, local heat treatment, mechanical tensile tests,
tensile strength, structural state, microhardness
1. Appel, F., Paul, J.D.H., Oering, M. (2011) Gamma titanium aluminide alloys. Sci. and Technol., WILEY-VCH, Weinheim. https://doi.org/10.1002/9783527636204
2. Kuchuk-Yatsenko, S.I., Zyakhor, I.V., Chernobaj, S.V. et al. (2015) Structure of β-TiAl joints in resistance butt welding with application of interlayers. The Paton Welding J., 9, 5-12. https://doi.org/10.15407/tpwj2015.09.01
3. Patterson, R.A. (1990) Titanium aluminide: electron beam weldability. Welding J., 1, 39-44.
4. Pflumma, R., Donchev, A., Mayer, S. et al. (2014) High-temperature oxidation behavior of multi-phase Mo-containing γ-TiAl-based alloys. Intermetallics, 53, 45-55. https://doi.org/10.1016/j.intermet.2014.04.010
5. Kulikovsky, R.A., Pakholka, S.N., Pavlenko, D.V. (2015) Prospects of industrial application of titanium aluminide in aircraft engine construction. Stroitelstvo, Materialovedenie, Mashinostroenie. Starodubov Lectures, 80, 369-372 [in Russian].
6. Xu, Q, Chaturvedi, MC, Richards, NL. (1999) The role of phase transformation in electron-beam welding of TiAl-based alloys. Metallurg. and Mater. Transact., A, 30A, 1717-1726. https://doi.org/10.1007/s11661-999-0171-0
7. Liu, J., Dahmen, M., Ventzke, V. et al. (2013)The effect of heat treatment on crack control and grain refinement in laser beam welded beta-solidifying TiAl-based alloy. Intermetallics, 40, 65-70. https://doi.org/10.1016/j.intermet.2013.04.007
8. Zamkov, V.N., Sabokar, I.K., Vrzhizhevsky, E.L. et al. (2005) Electron beam welding of γ-titanium aluminide. In: Proc. of Int. Conf. on Ti-2005 in CIS. Kiev, Naukova Dumka, 157- 164.
9. Chen, G.Q., Zhang, B.G., Liu, W., Feng, J.C. (2011) Crack formation and control upon the electron beam welding of TiAl-based alloys. Intermetallics, 19, 1857-1863. https://doi.org/10.1016/j.intermet.2011.07.017
10. Lobanov, L.M., Asnis, E.A., Piskun, N.V. et al. (2019) Investigation of stress-strain state of welded joints of the system TiAl intermetallics. The Paton Welding J., 11, 8-11. https://doi.org/10.15407/tpwj2019.11.02
11. Velikoivanenko, E.A., Milenin, A.S., Rozynka, G.F. et al. (2019) Prediction of cold cracking susceptibility of welded joints of γ-titanium aluminide based alloy in electron beam welding. Tekhnologicheskie Sistemy, 3, 59-66.
12. Pukhalskaya, G.V., Markov, I.B. (2016) Determination of mechanical properties in different zones of welded joints of titanium alloy VT3-1. Vestnik Dvigatelestroeniya, 1, 89-91 [in Russian].
13. Medvedev, A.Yu., Pavlini, S.P. (2012) Tensile tests of welded joints of titanium alloys performed by linear friction welding. Vestnik UGATY, 16, 7, 52, 68-71 [in Russian].
14. Nochovnaya, N.A., Panin, P.V. (2014) Analysis of residual macrostresses in welded joints of titanium alloys of different classes. Trudy VIAM, 5, 2 [in Russian]. https://doi.org/10.18577/2307-6046-2014-0-5-2-2
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