Surface Roughness Prediction Model in Machining of Carbon Steel by PVD Coated Cutting Tools

The surface roughness model in the turning of AISI 1040 carbon steel was developed interms of cutting speed, feed rate and depth of cut using response surface methodology. Machining testswere carried out using PVD-coated tools under different cutting conditions. The surface roughnessequations of cutting tools when machining the carbon steels were achieved by using the experimentaldata. The results are presented in terms of mean values and confidence levels. The established equationshows that the feed rate was found to be a main influencing factor on the surface roughness. Itincreased with increasing the feed rate, but decreased with increasing the cutting speed and the depthof cut, respectively. The variance analysis for the second-order model shows that the interaction termsand the square terms were statically insignificant. However, it could be seen that the first-order effectof feed rate was significant while cutting speed and depth of cut was insignificant. The predictedsurface roughness of the samples was found to lie close to that of the experimentally observed oneswith 95% confident intervals.