A revised model for predicting surface roughness in turning

The objective of this paper is to demonstrate how tribological interactions at the interface between the chip and the tool control the surface roughness generation in finish turning with a single-point tool. It was assumed that one of the major sources which cause visual differences between the theoretical and natural surface roughness is relatively strong adhesion at the rake-chip interface. By considering this exceptional tribological effect, expressed mathematically in the form of the condition for the transition from ploughing to micro cutting, the minimum undeformed chip thickness was estimated. Consequently, the theoretical surface roughness was calculated based on Brammertz's formula. From the obtained data it is evident that the proposed methodology results in a better evaluation of the natural surface roughness produced by turning.