ISSN (print) 1995-2732
ISSN (online) 2412-9003


download PDF


Problem Statement (Relevance): When zirconium and titanium alloys are used in nuclear power and space industries, it is necessary that they could perform well under heavy duty regimes. It is known that the meta-stable baric ω-phase, which forms in the above materials under severe loading, is characterised with higher density, hardness and brittleness compared with the stable α-phase. To minimize the embrittlement factor of the ω-phase and to prevent fracture in structures made of both pure metals and Zr/Ti alloys, it is necessary to look into the stability of the metastable ω-phase as observed after severe loading. Objectives: The objective of this study is to understand what structural transformations take place in sample zirconium pseudo-single crystals subjected to loading in the Bridgman chamber as the temperature increases from room temperature to 300 °C. Methods Applied (Experiments): With the help of electron beam crucible-free zone melting, original samples of iodide pseudo-single crystal of α-Zr were derived. Disk samples were subjected to plastic deformation in hard-alloy Bridgeman anvils at 8 GPa and the angular speed of ω=1.0 RPM. The tests were conducted at room temperature and at 70, 100, and 300 °C. The anvil turn angle was φ=1080 degrees. The structural phase state of the deformed zirconium samples was analysed through electron microscopy (with a JEM-200CX microscope) and X-ray diffraction (with a DRON-3 diffractometer in the monochromatic CuKα-radiation). Findings: The tests showed that after the loading was stopped and the test samples cooled down from the 70, 100, and 300 °C to room temperature, the ω-phase partially persisted in all the samples, despite the dynamic and post-dynamic recrystallisation processes observed. These tests were also first to prove that 70°C works as a stabilisation temperature for the metastable ω-phase. Practical Relevance: The results obtained may be used to predict the structural durability of equipment used in aerospace and nuclear industries.


Pseudo-single crystal of zirconium, deformation, high quasi-hydrostatic pressure, α → ω phase transitions.

Lada Yu. Egorova – PhD (Eng.), Senior Researcher

Physical Metallurgy Laboratory, Mikheev Institute of Metal Physics, Ural Branch of the Russian Academy of Sciences.

Yulia V. Khlebnikova – PhD (Eng.), Lead Researcher

Physical Metallurgy Laboratory, Mikheev Institute of Metal Physics, Ural Branch of the Russian Academy of Sciences.

Aleksandr M. Patselov – PhD (Physics & Mathematics), Senior Researcher

High-Pressure Physics Laboratory, Mikheev Institute of Metal Physics, Ural Branch of the Russian Academy of Sciences.

Vitaly P. Pilyugin – PhD (Physics & Mathematics), Lead Researcher

Head of High-Pressure Physics Laboratory, Mikheev Institute of Metal Physics of the Ural Branch of the Russian Academy of Sciences.

1. Frost P.D., Parris W.M., Hirsch L.L., Doig J.R., Schwartz C.M. Isothermal transformation of titanium-chromium alloys / Trans. Asm. 1954. 231 p.

2. B.S. Hickman. The formation of omega phase in titanium and zirconium alloys: A review. Journal of Materials Science. June 1969, Volume 4, Issue 6, pp. 554–563.

3. K. Sikka, Y. K. Vohra and R. Chidambaram. Omega phase in materials. Progress in Materials Science. 1982. Vol. 27, pp. 245-310. DOI:10.1016/0079-6425(82)90002-0

4. Orientation Relations During the α-ω Phase Transition of Zirconium: In Situ Texture Observations at High Pressure and Temperature/H.-R. Wenk, P. Kaercher, W. Kanitpanyacharoen, E. Zepeda-Alarcon and Y. Wang// Рhysical review letters. PRL 111, 195701 (2013). DOI:10.1103/PhysRevLett.111.195701

5. Experimental constraints on the phase diagram of elemental zirconium/Jianzhong Zhanga, Yusheng Zhao, Cristian Pantea, Jiang Qian, Luke L. Daemen, Paulo A. Rigg, Robert S. Hixson, Carl W. Greeff, George T. Gray III, Yunpeng Yang, Liping Wang, Yanbin Wang, Takeyuki Uchid. Journal of Physics and Chemistry of Solids 66 (2005) 1213–1219. DOI: 10.1016/j.jpcs.2005.03.004

6. K. Edalati, Z. Horita, S. Yagi, E. Matsubara. Allotropic phase transformation of pure zirconium by high-pressure torsion. Materials Science and Engineering A. 523 (2009) рр. 277–281. DOI: 10.1016/j.msea.2009.07.029

7. Hongxiang Zong, Dezhen Xue, Xiangdong Ding and Turab Lookman. Phase transformations in Titanium: Anisotropic deformation of ω phase. Journal of Physics: Conference Series. 2014. V.500. P. 112042. DOI: 10.1088/1742-6596/500/11/112042/

8. Cerreta E. K., Escobedo J. P., Rigg P. A., Trujillo C. P., Brown D. W., Sisneros T. A., Clausen B., Lopez M. F., Lookman T., Bronkhorst C. A., Addessio F. L. The influence of phase and substructural evolution during dynamic loading on subsequent mechanical properties of zirconium. Acta Materialia. 2013. V. 61. P. 7712–7719. DOI: 10.1016 / j.actamat.2013.09.009

9. Alshevsky Yu.L., Kulnitsky B.A., Konyaev Yu.S., Roytburd A.L. Reversible martensitic ω↔α transformation in Ti and Zr. Doklady Akademii nauk [Proceedings of the Academy of Sciences], 1985, vol. 285, no. 3, pp. 619–621. (In Russ.)

10. G. T. Gray, C. E. Morris, and A. C. Lawson. Omega phase formation in titanium and titanium alloys, in Titanium '92: Science and Technology, ed. F. H. Froes and I. L. Caplan (Warrendale, PA, Minerals Metals & Materials Society), pp. 225–232 (1993).

11. Azhazha V.M., Vyugov P.N., Lavrinenko S.D., Lindt K.A., Mukhachev A.P., Pilipenko N.N. Tsirkoniy i ego splavy: tekhnologii proizvodstva, oblasti primeneniya: obzor [Zirconium and its alloys: Production & application: Review]. Kharkov: Kharkov Institute of Physics and Technology National Science Center, 1998, 89 р. (In Russ.)

12. Degtyarev M.V., Voronova L.M., Chashchukhina T.I., Pilyugin V.P., Resnina N.N. Structural evolution of nickel during high-pressure shear deformation at 150°. FMM [Physics of metals and metallography], 2017, vol. 118, no. 3, pp. 270–277. (In Russ.)

13. Khlebnikova Yu.V., Sazonova V.A., Rodionov D.P., Vildanova N.F., Egorova L.Yu., Kaletina Yu.V., Solodova I.L., Umovа V.M. Formation of macro- and microstructure during beta-alpha transformation in zirconium single crystals. FMM [Physics of metals and metallography], 2009, vol. 108, no. 3, pp. 267–275. (In Russ.)

14. Egorova L.Yu., Khlebnikova Yu.V., Pilyugin V.P. How the deformation ratio influences the structural evolution of zirconium single crystals under pressure shear strain. Pisma o materialakh [Letters on materials], 2016, vol. 6, pp. 237–242. (In Russ.)

15. Chernyaeva T.P., Gritsina V.M. Characteristics of hcp metals defining their behavior under mechanical, thermal and radiation effects. Voprosy atomnoy nauki i tekhniki [Problems of nuclear science and technology], 2008, No. 2, Ser. Fizika radiatsionnykh povrezhdeniy i radiatsionnoe materialovedenie [Series: Physics of radiation damage and radiation materials science], (92), pp. 15–27. (In Russ.)

16. Gorelik S.S., Dobatkin S.V., Kaputkina L.M. Rekristallizatsiya metallov i splavov: monografiya [Recrystallization of metals and alloys: monograph]. Moscow: MISIS, 2005, 432 p. (In Russ.)

17. Zolotorevsky V.S. Mekhanicheskie svoystva metallov. Uchebnik dlya vuzov. 3-e izdanie pererabotannoe i dopolnennoe [Mechanical properties of metals. Textbook for university students. 3rd revised edition]. Moscow: MISIS, 1998, 440 p. (In Russ.)

18. Svoystva elementov: sprav. izd. [Properties of elements: Handbook]. Ed. by M.E. Dritsa. Moscow: Metallurgiya, 1985, 672 p. (In Russ.)

19. A. Rabinkin, M. Talianker and O. Botstein. Cristallography and a model of the α→ω phase transformation in zirconium. Acta Metallrgica. 1981, v. 29, pp. 691–698.

20. P.B. Hirsch, A. Howie, R.B. Nicholson,
D.W. Pashley, M.J. Whelan. Elektronnaya mikroskopiya tonkikh kristallov [Еlectron microscopy of thin crystals]. Ed. by L.M. Utevsky. Moscow: Mir, 1968, 573 p. (In Russ.)