Superplasticity and Phase Transitions in Nanocrystalline Aluminum Alloys

Klepikov Viacheslav F. Professor, Dr. Sci. (Phys.– Math.), Corresponding Member of the National Academy of Sciences of Ukraine, Director of Institute of Electrophysics and Radiation Technologies National Academy of Sciences of Ukraine;
Lytvynenko Volodymyr V. Dr. Sci. (Tech. Science), Deputy Director of Institute of Electrophysics and Radiation Technologies National Academy of Sciences of Ukraine;
Bryukhovetsky Vasyl’ V. Dr. Sci. (Phys.– Math.), Head of Department, Institute of Electrophysics and Radiation Technologies National Academy of Sciences of Ukraine;
Babich Artem V. PhD (Phys.– Math.), Scientific Secretary of Institute of Electrophysics and Radiation Technologies National Academy of Sciences of Ukraine.
Poyda Andrey V, PhD (Phys.– Math.), Senior Researcher, Institute of Electrophysics and Radiation Technologies National Academy of Sciences of Ukraine.
Keywords:
superpasticity, nanostructured alloys, mechanical and radiation treatment, phase transitions, supersymmetry
Abstract:
The goal of the project is to study the features of the nanoscale structure formation in aluminum alloys through the treatment with mechanical and radiation impacts. Optimal temperature and speed conditions of superplastic deformations for nanostructured technical and model aluminum alloys will be determined. The kinetics of phase transitions  and the most typical structural transformations, which take place during superplastical flow of nanocrystal materials will be studied. Additionally, a theory of superpasticity and phase transitions in nanostructured materials will be developed .
Project Idea:
Using combined impact of a strong plastic deformation and a pulsed beam of relativistic electrons allows one to transform a microstructure of a sample to a nanoscale structure. A polycrystal during a superplastic deformation is a strained medium which consists of 3 phases, namely a crystal phase, a cavity phase, and a phase with grain boundary layers. Various inorganic materials (metals, alloys and ceramics) can show superplastic effects under various thermal and speed conditions. Nanocrystalline alloys show superplastic effects if they are in nonequilibrium state and if there are phase transitions which lead to formation of the metastable liquid phase. The liquid phase generation on the grain boundaries and on the interfaces causes the development of the superplastic states. The presence of the liquid phase in the nanocrystalline alloys structure leads to the significant changes of the alloys’ structural states, which impacts the deformation and accommodation processes.   Detailed study of the structural states’ changes under various conditions allows one to identify  the physical processes which are responsible  for the superplastic deformation and to ascertain physical nature of the superplasticity.
A list of organizations that are ready to join the project (if any)
Karazin Kharkiv National University, Kharkiv, Ukraine; KIPT Kharkiv, Ukraine.
Scientific novelty:
Study of superplastic behavior of nanostructured materials allows one to improve our knowledge about the physical nature of the superplasticity, which is not  clear enough yet. One of the main problems is that microscopic theory of superplastisity has not been formulated yet. There are only various phenomenological theories of superplastisity, and descriptions of superplastisity of different types of materials demand using different phenomenological approaches. In order to formulate microscopic theory of superplastisity, we are going to carry out a set of experiments on various aluminum alloys. The goal of the experiments is to specify features of superplastic transformations. Theoretical description of superplasticity needs appropriate theory of phase transitions which takes into  account a possibility of existence of several control parameters. Such theory has a lot in common with theory of modulated structures. We are going to modify existing theories of phase transitions in order to describe superplasticity on nanoscale. New theory of phase transitions with spontaneous supersymmetry breaking will be proposed. Taking into  account spontaneous supersymmetry breaking will allow us to describe new types of modulated structures, which may appear under superplastic transformations.
 List of the most significant publications in the international journals included in the Scopus database (if any):

  1. V.V. Bryukhovetsky R.I. Kuznetsova, N.N. Zhukov, V.P. Poida and V.F. Klepikov Liquid-phase nucleation and evolution as a cause of superplasticity in alloys of the Al-Ge system, Phys. Stat. Sol. (a). – 2005. – V.202, N.9. – P. 1740-1750.
  2. V.F. Klepikov, V.Yu. Korda, S.V. Berezovsky, A.S. Molev,  L.P. Korda On importance of higher non linear interactions in the theory of type II incommensurate system, Physica B. – v.425 –   2013. – p.31-33.
  3. V.V.Bryukhovetskii, V.P.Poida, D.E.Pedun, A.V.Poida, R.V.Sukhov, A.L.Samsonic, V.V. Litvinenko Structural changes during superplastic deformation of high strength alloy 1933 of the Al-Mg-Zn-Cu-Zr system, Phys. Met. Metallogr.- V.114. – №9. – 2013. -p.779-788
  4. V.P. Poida, V.V. Bryukhovetskii, A.V. Poida, R.I. Kuznetsova, V.F. Klepikov, and D.L. Voronov Morphology and mechanisms of the formation of fiber structures upon high-temperature superplastic deformation of aluminum alloys, Phys. Met. Metallogr. V.103, 414–423 (2007).
  5. 5. V. Bryukhovetskii, V.P. Poida, A.V. Poida, R.I. Kuznetsova, K.A. Mahmoud, and D.E. Pedun Phase transformations and structural changes in the course of the high_temperature superplastic deformation of aluminum alloys, Phys. Met. Metallogr. – 2010 – V.110. – p 588–596.
  6. V.V. Bryukhovetskii, A.V. Poida, V.P. Poida, and Yu.V. Kolomak Thickness of grainboundary liquid phase and its effect on the mechanism of superplastic deformation Phys. Met. Metallogr. – 2011. –V.112. – p. 526–534

    7. (2011).

  7. V.V. Bryukhovetskii, V.P. Poida, A.V. Poida Mechanical Properties and Structural Changes during Superplastic Deformation of 6111 Aluminum Alloy, Metallofiz. Noveishie Tekhnol. – 2009. – V31. p – 1289–1302.
  8. V.V. Bryukhovetskii, V.P. Poyda, A.V. Poyda, R.I. Kuznetsova, Kaafarani Ali Mahmoud, and
  9. E. Pedun Phase Transformations and Structural Changes in the Course of the High Temperature Superplastic Deformation of Aluminum Alloys, Phys. Met. Metallogr. 2010. – V110. – p 588–596.
  10. A.V.Babich, S.V.Berezovsky, V.F. Klepikov Spatial modulation of order parameters and critical dimensions, International Journal of Modern Physics B.- 2008.- V.22, №7.- Р.851-857.
  11. A.V. Babich, L.N. Kitcenko, V. F.Klepikov. Critical dimensions of systems with joint multicritical and lifshitz-point-like behavior // Modern Physics Letters B, Vol. 25, No. 22 (2011) 1839-1845.

Expected results:
New data on temperature and speed conditions of appearance of superplasticity in nanostructured aluminum alloys; information on influence of  the structure evolution during the deformation  on the superplastic flow development; data on thermoactivative superplastic deformation parameters; information on the development of grain boundary sliding during high-temperature superplastisity phase. Influence of electronic pulsed irradiation on the formation of the grain structure and on the  superplastisity features will be studied. Mechanism of the formation and development of fibers under the condition of high-temperature superplastic deformation of nanostructured aluminum alloys will be specified. Theory of dynamic phase transitions based on gauge field theory will be formulated. An expansion of the theory of critical phenomena   in case  of inhomogeneous space phases will be proposed.  New kinds of models which describe phase transitions with spontaneous SUSY breaking will be studied.

Contacts:
Babich Artem, Scientific Secretary of Institute of Electrophysics and Radiation Technologies National Academy of Sciences of Ukraine.
Correspondent Address: 61002,  ul. Chernyshevskogo 28, a/ya 8812, Kharkiv, 61002 Ukraine
Email: ntcefo@yahoo.com
Phone: +380632617917
 
Contacts:
Babich Artem, Scientific Secretary of Institute of Electrophysics and Radiation Technologies National Academy of Sciences of Ukraine.
Correspondent Address: 61002,  ul. Chernyshevskogo 28, a/ya 8812, Kharkiv, 61002 Ukraine
Email: ntcefo@yahoo.com
Phone: +380632617917