On the Fidelity of Replica of Roughness of Cutting Edges to the Machined Surfaces

In this paper, as one of the main factors generating roughness of machined surfaces, the fidelity of replica of roughness of cutting edges to the machined surfaces has been experi-mentally studied. It is assumed that the process of the roughness generation may constitute a linear system in which profiles of cutting edges and those of the machined surfaces can be shown as random signals of input and output respectively, and power spectrum, frequencygain characteristic, cross-correlation coefficient and depth of over-cut coefficient of these signals are calculated to appreciate the effect of machining conditions on the fidelity of replica. The experimental results in turning with cemented carbide tools show that the fidelity of replica depends on properties of work materials and cutting conditions. For example the fidelity of replica is high to copper, brass and duralumin but low to carbon steel, also high under small depth of cut with high speed. Judging from the results, it is considered that the fidelity of replica may be lowered by occurrence of built-up edge, tearing of work materials and others