A unique technique for studying friction force in the same contact geometry under atmospheric and vacuum conditions has been created and applied.
-Discovered triboinduced products sorbed by composite polymeric materials for structural purposes
- Conditions of adhesion onset in friction pairs polymeric composite Ф4К20-alloyed steel have been studied. An expression for determining the value of the limiting load corresponding to the setting was obtained
-The method of artificial bases is improved by means of substantiation of application of simple and the most exact tools for wells cutting. Measurement of the size of the wells is carried out by a digital microscope equipped with a program for the recognition and exact determination of the size of images of any shape.
-The peculiarities of abrasion of multilayered sliding bearing liners were investigated. Dependences of wear intensity and hardness of layers of materials on abrasive grain size and other factors are obtained.
-A technique of vibroacoustic control (VAC) of wear intensity with the help of vibrograph SM-21, to estimate the mean square value of vibration acceleration is developed. It is proved, that wear of friction pairs is characterized by level of acceleration in a high-frequency band of a spectrum of 2 - 10 kHz. Dependences of the mean square value of acceleration on roughness and a mode of testing of samples are received. SAC algorithms for predicting the time of friction knot development by the reduction trend of the RMS value of acceleration in dB have been developed and verified.
-A simplified algorithm for volumetric wear by the "block-on-ring" method (chord method) based on the Taylor series with recalculation by the new law to linear wear resistance taking into account the specific pressure
-The correlation between the wear characteristics and the hardness of the examined material according to the Mohs scale θ and the "block-on-ring" method was established. The developed method of wear estimation taking into account the hardness level is confirmed by test data of different materials, including the composite of polytetrafluoroethylene filled with ultradispersed diamond
- A new relation suitable for determination of heat flow distribution coefficient for friction pairs with considerably different values of heat conductivities was elaborated.
-The generalized mathematical model of the law of friction of sliding of the solid bodies, allowing to describe dependence of force of friction on loading at the spontaneous changes of states of frictional contact, caused by the complex physical and chemical and mechanical processes is developed.
- A generalized formula for the calculation of the classical friction coefficient under conditions of spontaneous changes of friction contact states, allowing to describe analytically the principal scheme of change in the classical friction coefficient.
-The mathematical model describing dynamics of change of force of friction at presence of one or more transitive processes caused by spontaneous changes of a frictional contact condition under the influence of certain physical and chemical processes is developed. By means of the given model it is possible to define intensity of change of force of friction, dynamics of change of work and impulse of force of friction, and also integral average values of the given tribological characteristics.
For the first time the generalized mathematical model describing all characteristic sections of a classical curve of wear dynamics: the section of running-in, the section of normal wear and the section of limiting wear is developed. The given mathematical model, at various values of parameters entering into it, allows to describe six types of laws of wear dynamics, concrete knots of a friction.
-Regularities of friction force dynamics during super slow motion of smooth steel surfaces are revealed and their correspondence with the developed mathematical model of friction characteristics dynamics is established. The absence of stationary values of friction force, characteristic for higher sliding speeds, has been established. It is shown that the developed generalized mathematical model of the sliding friction law is satisfied for the case of friction at super slow motion.
-To determine the value of temperature on the polymer-steel tribocontact surface the equation taking into account friction coefficient and wear coefficient has been developed. The tribotechnical criterion allowing to determine the temperature range of formation of polytetrafluoroethylene transfer films has been proposed.
- It has been shown by calculation and experiment that polytetrafluoroethylene filling leads to increasing the value of glass transition temperature from minus 120 0C corresponding to polytetrafluoroethylene to plus 150 0C, which is one of the reasons for increasing the wear resistance of composites based on polytetrafluoroethylene.
pectrometric method has been used to systematically study the thermal stability of submicron films of various polymers. Approaches to the analysis of changes in the shape of the thermodestruction spectra of polymers and polymer-fullerene composite systems have been developed. Models of fullerene binding to macromolecules have been constructed, which may determine the decrease of macromolecule thermostability.
- The products of polymer tribo-destruction in vacuum were studied by mass spectrometry. The products characteristic of tribo destructions not appearing under purely thermal influence on the polymer have been established.
-It is shown that the presence of adhesion creates modified layers around the filler particles. Calculated ratios for determining the proportion of unmodified polymer in the composite depending on the concentration and dispersity of the filler have been obtained.
-Computer simulation of the structures formed by a dispersed filler in polymer matrices using the technology of dry mixing of the composite components with subsequent molding and the technology of introduction of the filler in the matrix melt was carried out.
-The division of the filler structures into spatial and random structures has been proposed. The distinctive parameters of such structures that depend on the size and concentration of the filler have been established.
-Mathematical expressions for calculation of structural parameters of polymer composites with disperse filler of micro and nanosize that determine the loading of matrices have been developed. The value of matrix loading is used in the relations for predicting the surface strength of composites under shear deformation conditions.
-A physical model of wear of polymeric materials in the form of mathematical expression linking wear coefficient with loading parameters, in which a structural parameter of the material is introduced, is obtained. The adequacy of the obtained expression has been checked from the position of nonequilibrium thermodynamics.