Additive Gaussian Noise Effect on Phase Diagram of Metal’s Fragmentation Modes during Severe Plastic Deformation

Author(s) A.V. Khomenko , D.S. Troshchenko , Ya.O. Kravchenko , M.A. Khomenko
Affiliations

Sumy State University, 2, Rimsky Korsakov Str., 40007 Sumy, Ukraine

Е-mail o.khomenko@mss.sumdu.edu.ua
Issue Volume 9, Year 2017, Number 3
Dates Received 15 May 2017; revised manuscript received 14 June 2017; published online 30 June 2017
Citation A.V. Khomenko, D.S. Troshchenko, Ya.O. Kravchenko, M.A. Khomenko, J. Nano- Electron. Phys. 9 No 3, 03045 (2017)
DOI 10.21272/jnep.9(3).03045
PACS Number(s) 05.70.Ln, 61.72.Mm, 62.20.F –, 61.72.Lk, 64.30.Ef, 81.30. – t, 05.10.Gg, 74.40. + k
Key words Grain Boundary, Dislocation (8) , Phase Transition (4) , Phase Diagram, Internal Energy, Additive Noise, Fragmentation (2) .
Annotation Based on nonequilibrium evolutionary thermodynamics the process of solid fragmentation during the processing by methods of severe plastic deformation is investigated. The description of the forming defect structures is carried out by approach of the two-defect model taking into account the density of grain boundaries and dislocations, which define the formation of fine grained structure and a limit of plastic flow. Considering additional terms in the expansion of internal energy and taking into account the additive noise of basic parameters we describe more accurately the self-consistent behavior of structural defects in the process of the formation of limiting submicrocrystalline or nanocrystalline structures. The phase diagram is constructed. It determines the regions of realization of various types of limiting (stationary) structures depending on both the noise intensity and elastic strain. It is established that with an increase of both the fluctuations intensity and the values of elastic strains the size of grains in limiting structures decreases. The conditions of simultaneous existence of two limiting (stationary) structures that correspond to the regime of the phases formation with different grain sizes are found.

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