Using Methods of Analysis of Optical Images of Friction Surfaces of Ti-Al-N Based Coatings for Assessing Accumulation of Damage and Diagnostics of Failure in Tribological Tests

The processes of damage accumulation and failure in thin ceramic coatings based on the Ti-Al-N system deposited on ductile steel and brittle sitall substrates have been investigated during tribological tests under dry friction conditions. Fractal analysis was carried out to quantitatively assess damage to friction surfaces, as well as Fourier and wavelet analysis of their images obtained using optical microscopy. It is shown that the spectral analysis (Fourier and wavelet analysis) make it possible to reveal an unambiguous correlation between the quantitative parameters obtained and the rate of wear of coatings at the stage of steady wear. At the same time, the fractal dimension provided an estimate of the dynamics of accumulation of damage at the run-in stage but did not allow one to be produced at the stage of steady-state wear.