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In the paper, we consider the tangential contact of single microasperities of the interacting surfaces the mechanical characteristics of which are close to the characteristics of typical rail steels. Using computer simulation by the method of discrete elements, we study the influence of the parameters of adhesive interaction of both external and internal surfaces on the regime of wear of asperities. It has been established that with increasing adhesion work, the wear regime changes from slipping (low wear) to grinding or brittle fracture of asperities (high wear), and this change is of threshold nature. An empirical sigmoid dependence of the location of the boundary between the two wear regimes (namely, the threshold value of the adhesive stress) on the value of the material hardening coefficient has been established. It is shown that the logistic nature of this dependence is due to the competition of two mechanisms of elastic strain energy dissipation, which determine the wear regime. These are plastic deformation and adhesion of the contacting surfaces. Special discussion is devoted to the influence of the scale factor on the threshold values of the mechanical characteristics of the material which provide the change of the wear regime.

The applicability of a tribospectral analysis to the detection of nanoscale inhomogeneities and discontinuities at the nanocoating-substrate interface has been substantiated theoretically. The approach put forward in this work is based on the measurement of the counterbody sliding resistance force coupled with an analysis of its frequency spectrum. A theoretical study on the potentialities and limitations of nanotribospectroscopy has been performed with the use of a computer simulation by the method of movable cellular automata. The results of the investigation have shown, among other things, the possibility to estimate a number of parameters of nanoscale discontinuities (characteristic spacing, linear size, etc.). To obtain reliable information on the defect structure and spacing, nanotribospectroscopy must be supplemented by other diagnostic methods. The design of a prototype nanotribospectrometer with spatial resolution up to 8 nm is described. Applications of the examined approach as a promising nondestructive-testing technique for assessment of nanostructured coating and surface layer damage are discussed.