A Note on “Surface Roughness Prediction Model in Machining of Carbon Steel by PVD Coated Cutting Tools”

An article published in this journal by Sahin and Motorcu^[1] developed a surface roughness model based on the response surface method, multiplicative-logarithmically linearized approach for determination of the cutting parameters in turning of AISI 1040 carbon steel. Their published results for the surface roughness show that it appears Sahin and Motorcu^[1] have obtained wrong constants (C, m, n, p), thereby resulting in incorrect solutions for the surface roughness prediction model. This note works through the solutions to show how Sahin and Motorcu^[1] incorrectly handled the published prediction model constants to their solution. The established predictive model shows that the surface roughness increases with the increase of feed rate but decreases with cutting speed and depth of cut.