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MATERIALS SCIENCE
ArticleName Thermal stability of rolled semi-finished products from metastable β-titanium alloy VT47
DOI 10.17580/tsm.2024.04.06
ArticleAuthor Shiryaev A. A., Zavodov A. V., Avtaev V. V., Nochovnaya N. A.
ArticleAuthorData

Federal State Unitary Enterprise “All-Russian Scientific-Research Institute of Aviation Materials” of National Research Center “Kurchatov Institute” (NRC “Kurchatov Institute” – VIAM), Moscow, Russia

A. A. Shiryaev, Senior Researcher, Candidate of Technical Sciences, e-mail: shiryaev_aa84@mail.ru
A. V. Zavodov, Senior Researcher, Candidate of Technical Sciences , e-mail: zavodovad@gmail.com
V. V. Avtaev, Senior Engineer, e-mail: darkee@mail.ru
N. A. Nochovnaya, Counselor to Director General, Doctor of Technical Sciences, e-mail: nochovnaya_viam@mail.ru

Abstract

The article presents the results of thermal stability investigation for the structure and mechanical properties of rolled semi-finished products from metastable β-titanium alloy VT47 after hardening heat treatment and subsequent thermal exposure with the application of tensile stresses. It has been established that the change in the mechanical properties of the VT47 alloy during thermal exposure at tensile stresses close to the values of the longterm strength limit is due to the development of twinning processes in the secondary α phase lamellae. This is also actual for semi-finished products with 12 mm thickness wherein the formation of TiCr2 nano-sized particles with lamellar morphology is observed in microvolumes of residual β phase, the particles belonging to the group of Laves phases (type C36). During the analysis of the mechanical properties after long-term exposure, a high correlation relationship (R2 ≥ 0.89) was established between the yield strength (σ0,2), integral work of destruction (W), uniform tensile elongation (δu) and stress applied during thermal exposure (σ350). The studies have shown that the application of stresses not higher than 0.7...0.8 of σ100350 during thermal exposure at a temperature of 350 оС allows to retain a high level of the VT47 alloy plasticity. Based on the obtained results, it follows that the VT47 alloy has a high level of bulk thermal stability of mechanical properties (without taking into account the effect of surface oxidation) under load during thermal exposure within the recommended values, approximately corresponding to the level of the alloy creep strength values at the selected temperature. The level of mechanical properties thermal stability of the alloy VT47 corresponds to that of the metastable β-titanium alloys VT32 and VT35, and significantly exceeds the characteristics of the first generation metastable β-titanium alloy VT15.

This work was carried out as part of the implementation of complex scientific direction 9.2 “Titanium-based materials with regulated β structure” (“Strategic directions for the development of materials and technologies for their processing for the period until 2030”).

keywords Metastable β-titanium alloys, rolled semi-finished products, hardening heat treatment, microstructure, mechanical properties, thermal stability, Laves phase.
References

1. Kolli R. P., Devaraj A. A review of metastable beta titanium alloys. Metals. 2018. Vol. 8. pp. 1–41.
2. Santhosh R., Geetha M., Nageswara Rao M. Recent developments in heat treatment of beta titanium alloys for aerospace applications. Transactions Indian Institute of Metals. 2017. Vol. 70 (7). pp. 1681–1688.
3. Nochovnaya N. A., Shiryaev A. A., Andrianov A. N., Davydova E. A. Variability of hardening phase morphology and topology in pseudo-β-titanium alloys quenched for β-structure. Metallurgist. 2021. No. 6. pp. 43–50.
4. Moiseev V. N. Beta-titanium alloys and prospects for their development. MiTOM. 1998. No. 12. pp. 11–14.
5. Ilyin A. A., Kolachev B. A., Polkin I. S. Titanium alloys. Composition, structure, properties: Directory. Moscow: VILS—MATI, 2009. 520 p.
6. Kablov E. N., Putyrsky S. V., Yakovlev A. L., Krokhina V. A. et al. Study of resistance to fatigue failure of stampings from high-strength titanium alloy VT22M, manufactured with final deformation in (α+β)- and β-areas. Titan. 2021. No. 1 (70). pp. 26–33.
7. Titanium and titanium alloys. Fundamentals and applications. Ed. by Leyens C., Peters M. Germany : Wiley—VCH, 2003. 513 p.
8. Aleksandrov V. K., Anoshkin N. F., Belozerov A. P. Semi-finished products from titanium alloys. Moscow: VILS, 1996. 581 p.
9. Panin P. V., Zavodov A. V., Lukina E. A. Effect of thermal exposure on microstructure evolution and mechanical properties of cast beta-solidifying TiAl-based alloy doped with Gd. Intermetallics. 2022. Vol. 145. 107534.
10. Voitovich R. F., Golovko E. I. High-temperature oxidation of titanium and its alloys. Kyiv: Naukova Dumka, 1984. 69 p.
11. Layner D. I., Slesareva E. N. On the influence of some alloying additives on the oxidation of titanium. Tsvetnye Metally. 1962. No. 2. pp. 70–76.
12. Hauffe K. Oxidation of Metals. N.Y. : Plenum Press, 1965. 452 p.
13. Bania P. Next generation titanium alloys for elevated temperature service. ISIJ International. 1991. Vol. 31, No. 8. pp. 840–847.
14. Boyer R. Aerospace applications of beta titanium alloys. JOM. 1994. No. 6. pp. 20–23.
15. Phase transformations in titanium and its alloys. Ed. by McQuillan M.A. USA : The Institute of Metals, 1963. 104 p.
16. Panin P. V., Nochovnaya N. A., Kablov D. E., Alekseev E. B. et al. Practical guide to metallography of alloys based on titanium and its intermetallic compounds: textbook. edited by E. N. Kablov. Moscow: VIAM, 2020. 200 p.
17. Nochovnaya N. A., Shiryaev A. A. Influence of heat treatment modes on the mechanical properties and structure of the experimental composition of high-strength pseudo-β-titanium alloy. Proceedings of VIAM: electron. scientific and technical magazine. 2018. No. 6. Art. 03.
18. Markovsky P. E., Ikeda M. Influence of alloying elements on the aging of economically alloyed metastable titanium beta-alloys. Materials Science. 2013. Vol. 49, No. 1. pp. 85–92.
19. Kablov E. N., Nochovnaya N. A., Shiryaev A. A., Gribkov Yu. A. Highstrength titanium-based alloy and a product made of high-stre ngth titanium-based alloy. Patent RF, No. 2569285. Applied: 29.12.2014. Published: 20.11.2015. Bulletin. No. 32.
20. Kablov E. N., Nochovnaya N. A., Shiryaev A. A., Davydova E. A. Study of structural-phase transformations in pseudo-β-titanium alloys and the influence of the cooling rate from the homogenization temperature on the structure and properties of the VT47 alloy. Part 1. Proceedings of VIAM: electron. scientific and technical magazine. 2020. No. 6-7. Art. 01. URL: http://www.viam-works.ru. Access date: 14.02.2023.
21. GOST 1497—84. Metals. Tensile test methods. Introduced: 16.07.1984.
22. GOST 9651—84. Metals. Tensile test methods at elevated temperatures. Introduced: 01. 01.1986.
23. GOST 3248—81. Metals. Creep test method. Introduced: 01.07.1982.
24. GOST 10145—81. Metals. Long-term strength test method. Introduced: 01.07.1982.
25. Nochovnaya N. A., Shiryaev A. A., Sharapkin D. S. Complex of mechanical and operational properties of rolled billets made of pseudo-β titanium alloy VT47. Aviation materials and technologies. 2022. No. 3(68). pp. 50—59.
26. Baumann W., Leineweber A. Solid solubility by anti-site atoms in the C36 – TiCr2 laves phase revealed by single-crystal X-ray diffractometry. Journals of Alloys and Compounds. 2010. Vol. 505. pp. 492–496.
27. Headley T. J., Rack H. J. Phase transformation in Ti –3 Al – 8V – 6 Cr – 4 Zr – 4 Mo. Metallurgical transactions A. 1979. Vol. 10А. pp. 909–920.
28. Chen W., Lin Y. C., Zhang X., Zhou K. Balancing strength and ductility by controllable heat-treatment twinning in a near β-Ti alloy. Journal of Materials Research and Technology. 2020. No. 9(3). pp. 6962–6968.
29. Li Y., Fang H., Sun S., Zhang X. et al. Refinement of αs phase and formation of nano-twins of Ti – 7 Mo – 4 Al – 3 Nb – 2 Cr alloyed by Zr element. Journal of Materials Research and Technology. 2022. Vol. 21. pp. 3343–3356.
30. Beyerlein I. J., Zhang X., Misra A. Growth twins and deformation twins in metals. Annual Review of Materials Research. 2014. Vol. 44. pp. 329–363.
31. Kolachev B. A., Livanov V. A., Elagin V. I. Metal science and heat treatment of non-ferrous metals and alloys. Moscow: Metallurgy, 1972. 480 p.
32. Glazunov S. G., Moiseev V. N. Titanium alloys. Structural titanium alloys. Ref. ed. Corresponding member USSR Academy of Sciences A. T. Tumanov. Moscow: Metallurgy, 1974. 368 p.
33. Donachie M. J. Titanium. A technical Guide. ASM International, 1988. p. 469.
34. Zhang X. D., Evans D. J., Baeslack W. A., Fraser H. L. Effect of long term aging on the microstructural stability and mechanical properties of Ti – 6 Al – 2 Cr – 2 Mo – 2 Sn – 2Zr alloy. Materials Science and Engineering A. 2003. Vol. 344. pp. 300–311.
35. Lin H. C., Wang L. M. Improved mechanical properties of Ti – 15 V –3 Cr – 3 Sn – 3 Al alloy by electron beam welding process plus heat treatments and its microstructure evolution. Materials Chemistry and Physics. 2011. Vol. 126. pp. 891–897.
36. State diagrams of double metallic systems: a reference book in 3 volumes/edited by N. P. Lyakishev. Moscow: Mashinostroenie, 1997. Vol. 2. 1024 p.
37. Ding C., Liu C., Zhang L., Deng Y. et al. Microstructure and tensile properties of a cost-affordable and ultrahigh-strength metastable β titanium alloy with a composition of Ti – 6 Al – 1 Mo – 1 Fe –6.9 Cr. Journal of Alloys and Compounds. 2022. Vol. 901. 163476.
38. De Angelis R. J., Huang Y. H., Sargent G. A. Formation of a TiCr2 intermetallic compound in a beta titanium alloy. Scripta Metallurgica. 1974. Vol. 8. pp. 339–342.
39. Rack H. J. Grain boundary embrittlement in a beta titanium alloy. Metallurgical Transactions A. 1975. Vol. 6A. pp. 947–949.
40. Gross K. A., Lamborn I. R. Some observations on decomposition of metastable beta-phase in Titanium-Chromium alloys. Journal of The Less-Common Metals. 1960. Vol. 2. pp. 36–41.
41. Chen K. C., Allen S. M., Livingston J. D. Factors affecting the roomtemperature properties of TiCr2-base Laves phase alloys. Materials Science and Engineering A. 1998. Vol. 242. pp. 162–173.
42. Honeycombe R. Plastic deformation of metals. Moscow: MIR, 1972. 408 p.
43. Novikov I. I., Rozin K. M. Crystallography and crystal lattice defects. Moscow: Metallurgy, 1990. 336 p.
44. El-Aty A. A., Xu. Y., Guo X., Zhang S. H. et al. Ch Strengthening mechanism, deformation behavior, and anisotropic mechanical properties of Al – Li alloys: A review. Journal of Advanced Research. 2018. Vol. 10. pp. 49–67.
45. Dzunovich D. A., Alekseev E. B., Panin P. V., Lukina E. A. et al. Structure and properties of sheet semi-finished products from deformable intermetallic titanium alloys of different classes. Aviation materials and technologies. 2018. No. 2 (51). pp. 17–25.
46. Kablov E. N. Marketing of materials science, aircraft engineering and industry: present and future. Director of Marketing and Sales. 2017. No. 5—6. pp. 40–44.

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