Proceedings of SerbiaTrib '13

Serbian TribologySocietySERBIATRIB ‘1313 th International Conference onTribologyKragujevac, Serbia, 15 – 17 May 2013Faculty of Engineeringin KragujevacEQUILIBRIUM STATE FORMATION FEATURES OFSURFACE LAYERS OF MACHINE PARTSVyacheslav F. Bezjazychnyj, Alexander N. SutyaginFederal State-Financed Educational Institution of High Professional Education “P. A. Solovyov Rybinsk State AviationTechnical University”, Rybinsk, Yaroslavl region, Russian Federation,e-mail: technology@rgata.ruAbstract: The article describes the problem of forming the equilibrium state of surface layer of friction units.The possibility of taking into account the parameters of the lubricant in the mathematical model of therelationship of the wear rate with the equilibrium parameters of surface layer of parts is considered.Possibility of technological support equilibrium parameters of surface layer of machine parts is discussed.Keywords: friction, wear rate, surface layer, machining, quality parameters, equilibrium state.1. INTRODUCTIONPractice of exploitation of machines andmechanisms shows that one of the major causes offailures of various kinds of equipment is thedestruction of its parts or wear. Destruction andwear usually begins with working surfaces, so thestate of the last often becomes the dominant factorin determining the reliability and durability ofmanufactured equipment.Study the wear of machine parts friction unitsindicate that the transition to the normal process ofwear most of them are directed to change theirinitial geometry.During the break-in such quality parameters ofmachine parts undergo significant changes asprofile deviation, waviness, roughness of theirsurfaces, as well as the physical and mechanicalcharacteristics of the surface layer. If time and thewear are large enough, the stable steady state isreached tribosystem when the geometry of partssurfaces becomes conformal.2. THE STUDIED PHYSICAL MODELResearch the wear can provide a theoreticaljustification of the possibility of existence of stablereproducing geometric shapes of surfaces and theirphysical and mechanical properties in wear processin the given conditions of relative motion andloading.This rationale is based on the fundamentalprinciples of thermodynamics of dissipativesystems, which tribosystem are.Such systems can exchange with other systemsand the environment energy and mass (eg, massworn out particles), so stationary statescharacterized by a constant gradient of entropy canoccurΔS = S° – S = const, (1)where S°– entropy of the equilibrium state of thesystem; S – instantaneous entropy of the system.In the steady state, all the processes of heat andmass transfer are independent of time, asdetermined by the configuration of the system onlyin general terms and conditions on its borders.Tribosystem exhibit properties of selforganizationconsist of to consistently reproducethe macroscopic space-time structures that can existonly through the exchange of flows of energy(matter).Under self-limitation created by nature, astribosystem located on the border of artificialdevices and natural systems, and the selforganizationcan arise from a chaotic state, that is,the initial conditions do not matter, and therunning-in period, of course, increases anddecreases life of the friction units.The equilibrium state of the surface isdetermined by the minimum of its free energy,which may differ from the minimum of surface,13 th International Conference on Tribology – Serbiatrib’13 195