Planar Non-Uniformity of Regular and Partially Regular Microreliefs and Method for Its Evaluation

Based on the analysis of grooves of regular and partially regular microreliefs formed on flat surfaces, the relationship between the geometric parameters of the grooves of their microreliefs, which ensures their regularity, was revealed. The functionality of the existing parameter for assessing the oil capacity of the surface of the relative area of the grooves of the microrelief was analyzed. It was proved that the parameter—the relative area of the grooves of the microrelief—is insensitive to their distribution on the plane. A new graph-analytical method for determining the planar heterogeneity of the distribution of the area of the grooves of the microreliefs was developed. A numerical parameter—the coefficient of planar heterogeneity, which determines the uniformity of the distribution of the area of the grooves on the plane, was also substantiated. The effectiveness of the new approach was demonstrated and proven. Graphs of longitudinal and transverse planar heterogeneity of the main forms of the grooves of the microreliefs were constructed, which will eliminate the need to obtain complex analytical dependencies to determine the area of these grooves. By analyzing the graphs of planar heterogeneity, numerical values of the heterogeneity coefficient were determined—a parameter that characterizes the homogeneity of microrelief grooves in the axial and interaxial directions. It is proposed to search for optimal placement schemes of adjacent microrelief grooves on the plane based on the analysis of their planar heterogeneity coefficients. This will ensure an increase in the plane heterogeneity coefficient from 0.69 to 0.97 for the triangular shape of the grooves, from 0.87 to 0.83 for the sinusoidal and from 0.46 to 0.69 for the groove shape in the form of a truncated cycloid, with the same relative areas of the microrelief.