A consideration for estimating the characteristics of three dimensional texture of engineering surface.

This paper describes the method to estimate the texture of engineering surface. First of all, the indexes which discriminate between the isotropic surface and the anisotropic surface are derived from the second and the fourth order surface spectral moments. The following two are clarified by using the indexes mentioned above.(1) The points and regions which discriminate between the isotropic surface and the anisotropic surface are determined by calculating the Mahalanobis' generalized square distance. (2) The engineering surface is divided into three regions, that is the isotropic, the quasiisotropic and the anisotropic surfaces, respectively. Moreover, two indexes which discriminate between the isotropic surface and the quasiisotropic surface are derived. It is also shown that these indexes can be calculated simply and rapidly by using three variables, that is, the mean number of peaks, the mean number of zero crossings and the centre-line average height. For example, in applications, the texture of the surface of dull-finished cold rolling steel strip is analyzed.