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Information × Registration Number 0218U005021, 0115U000692 , R & D reports Title Nonequilibrium thermodynamics of metals fragmentation and friction of spatially nonhomogeneous boundary lubricants between surfaces with nanodimensional irregularities popup.stage_title Head Oleksii Khomenko, Registration Date 06-02-2018 Organization Sumy State University popup.description2 The purpose of project is to further construct the theory of boundary friction, which describes the shear and thermodynamic melting of an ultrathin lubricant film, a nonequilibrium thermodynamic model of solid-state fragmentation, which occurs during severe plastic deformation (SPD), taking into account the influence of additive uncorrelated noise and the establishment of patterns of structural, tribological and kinetic phenomena in a thin film of the ice surface during the friction. The object of research is the ultra-thin lubricant film squeezed between atomic-smooth solid surfaces, the SPD method and the phenomenon of superplasticity. Methods: methods of nonequilibrium thermodynamics, evolutionary theory of phase transitions and the theory of elasticity, multifractal fluctuation analysis method, phase plane method, Lyapunov's first method and methods of computational mathematics. In the framework of the synergetic model of boundary friction, which describes the phase transitions in an ultrathin lubricant film, the friction processes of two atomically smooth and rough surfaces are investigated in the presence of an ultrathin lubricant layer between them. Allowance of the spatial inhomogeneity of the stress, strain, and temperature of the lubricant layers made it possible to describe the nontrivial non-Newtonian behavior of the lubricant shear viscosity. In the framework of nonequilibrium evolutionary thermodynamics, the process of metal fragmentation during the processing by SPD is investigated. In the approximation of a two-defect model taking into account both dislocations and grain boundaries, a phase diagram is constructed, which establishes the conditions for the formation of limiting structures of different types. The effect of additive uncorrelated noise of thermal and deformation fields on the softening of the ice surface during the friction is investigated. A phase diagram with ice regions is constructed and it is found that the friction region of ice is limited by comparatively low values of the temperature of the friction surfaces and the intensity of stresses and temperatures fluctuations on the ice surface. Product Description popup.authors Бойко Денис Володимирович Заскока Антон Миколайович Захаров Мирослав Владиславович Князь Ігор Олександрович Крекшин Денис Михайлович Ляшенко Яків Олександрович Трощенко Дар'я Сергіївна Хоменко Катерина Павлівна Хоменко Марія Олексіївна Ющенко Ольга Володимирівна popup.nrat_date 2020-04-02 Close