Empirical Determination of Roughness Parameters Using Wiper Tool Inserts in Finish Turning of AISI 4140

The surface finishing resulting from metal cutting processes is associated with the surface texture and integrity. Texture can be quantified by roughness parameters as Roughness Average (R-a), Total Roughness (R-t), Maximum Surface Depth (R-y) and Surface Depth (R-z) which are directly related to cutting magnitudes and tool characteristics. This work assesses empirically the roughness generated by wiper cutting tools in dry finishing turning operations of AISI 4140 steel. By keeping a constant cutting speed and using depths of cut greater than 2/3 of the cutting tool radius (r(epsilon)), four feed rates (f) are used with three r(epsilon), both combined in a way to ascertain the equations which allows the evaluation of R-a, R-t, R-y and R-z values. In order to determine the equations for roughness prediction a multiple linear regression method in function of f and r(epsilon) is applied, showing good agreement with experimental results. Also, achieved results allows to prove the effectiveness of wiper tools to generate excellent surface finish without grinding operations and consequently showing that its use can increase significantly the material removal rate without compromising the surface roughness in high feed rate operations.