On Mechanism of generating Surface Roughness (3rd Report) : Characteristic Roughness according to Material

Abstract

We have also considered the internal factor of generating roughness. One is abnormal roughness accompanying the built-up edge. In estimating it the partial correlation coefficient r_{i i+1-18} is used in order to get rid of the effect of roughness of edge from two adjoining profiles. Similarity of forms of generating built-up edge is more remarkable in oil cutting and shallow cutting. The order is the following ; -copper, brass, mild steel, hard steel, and cast iron. The other is auto-generating roughness which has certain characteristic waves in its profile according to the material. Correlogram and spectrum density are used to estimate them. Copper has only a non-periodic component, brass and hard steel have each one kind of wave, mild steel and cast iron have respectively two kinds of wave. It is caused by lack of uniformity in strength and size of the crystal grains.