Levels of topography in mechanics of precision joints

摘要

Characterizing even very smooth surfaces it is necessary to take into account multilevel structure oftopography. By methods of stylus profilometry and atomic force microscopy (AFM) roughness ofhard magnetic disk substrates textured under different regimes was measured. It is shown that themethods reflect various levels of roughness with overlapping ranges of wave lengths. Quantitativeparameters for each roughness level suitable for the subsequent modeling of an actual contact zonewere determined. To reduce influence of the roughness' long-wave components on the reliefparameters at a small-scale level, computer processing of the AFM-images was performed. For thedescription of the actual contact area hybrid two-level model was offered. The Greenwood-Williamson scheme using the profilometry data and complemented by the account of superficialforces influence was used at a microlevel. Computer simulation of a contact on a database of AFM-image of a surface was used at submicrolevel. Influence of the contact area discreteization at amicrolevel on a degree of submicroasperities deformation was taken into account. Visualization ofthe real contact area was performed. Distinctions in the operational characteristics of surfacesdepending on their texturing modes was shown.