Nonparametric estimation of deformation relief

The present study is aimed at examining the possibilities of a nonparametric approach in evaluating the surface relief after plastic deformation. This method is consisted in using graphs of functions obtained on the basis of three-dimensional topographies as a criterion for estimating the surface. An analyzing the deformation relief was carried out on nickel single crystals with different crystallographic orientations of compression axis and faces. The samples were compressed at room temperature, the deformation relief was studied using scanning laser confocal microscopy. Nonparametric criteria (such as the function of ordinates and tangents of inclination angles distribution densities of profile and the autocorrelation function) is proposed to be used in the work to estimate the deformation relief on the single crystals surfaces. Through the autocorrelation function is shown that the organization of shear traces in the structural elements of the deformation relief of various types (meso- and macrobands, corrugated structures) leads to an increase of area with mutually consistent deformation. Based on the analysis of nonparametric criteria, the presence of one or several types of structural elements of the relief was identified in the deformation relief on the faces of the samples and their scale hierarchy was shown. The basic structural element of the deformation relief are the shear traces. Thus, a nonparametric (graphical) approach can be used as an additional method for researching the relief of a deformed surface.