Comparative Study of Theoretical and Practical Surface Roughness Profiles Produced in Turning

An ideal surface produced in machining has typical roughness due to these feed marks which can be modeled and quantitatively predicted from the geometry of the cutting tool and its relative path or feed rate. The associated mechanism of surface generation can be termed as deterministic and intrinsic to the process. However the real or practical surface has considerable variation from the ideal theoretical surface which can be visualized but cannot be mathematically modeled. The basic geometry of roughness profile consists of ridges and furrows, which follow the angles of side cutting edge, end cutting edge and their intersection which may be sharp pointed or radiused. The plastic flow due to ploughing action of the cutting tool results in the swelling at the flanks which can be radially upward or axially backward or side flow. The factors which can affect cutting forces and plastic flow have therefore been selected for study viz. depth of cut, rake angle, work material properties, cutting fluid and cutting speed. The response parameters are surface roughness profile and its characteristics . In this paper , relative characteristics of theoretical and practical surface roughness profiles are compared and the corresponding Fourier spectra is presented.