SOME STATISTICAL DISTRIBUTIONS, WHICH DESCRIBE THE NANOTOPOGRAPHY OF TECHNICAL SURFACES

Abstract

The nanotopography of engineering surfaces of machine parts made of high alloy heat-treated steel and electric silver after finishing mechanical treatment was studied. The probability density functions of the nanotopography parameters – the heights of peaks and the radii of curvature of their vertices – were experimentally determined. These parameters are necessary for theoretical description of processes of the contact interaction of engineering surfaces (exemplifying on surfaces of silver and steel). It is established that the distributions of the above mentioned nanoroughness parameters are essentially asymmetrical and are far from normal ones. It has been proved that for the studied surfaces the probability densities of the above mentioned nanoroughness parameters are adequately described by the beta-distribution. The validity of this conclusion is confirmed by the fitting criteria such as χ^2 (K. Pearson’s criterion) and Romanovsky’s criterion.

Keywords

• surface
• nanotopography
• parameters
• probability density
• beta-distribution
• fitting criteria