American Journal of Applied Sciences, vol.1, no.1, pp.12-17, 2004 (Peer-Reviewed Journal)
The surface roughness model in the turning of AISI 1040 carbon steel was developed in
terms of cutting speed, feed rate and depth of cut using response surface methodology. Machining tests
were carried out using PVD-coated tools under different cutting conditions. The surface roughness
equations of cutting tools when machining the carbon steels were achieved by using the experimental
data. The results are presented in terms of mean values and confidence levels. The established equation
shows that the feed rate was found to be a main influencing factor on the surface roughness. It
increased with increasing the feed rate, but decreased with increasing the cutting speed and the depth
of cut, respectively. The variance analysis for the second-order model shows that the interaction terms
and the square terms were statically insignificant. However, it could be seen that the first-order effect
of feed rate was significant while cutting speed and depth of cut was insignificant. The predicted
surface roughness of the samples was found to lie close to that of the experimentally observed ones
with 95% confident intervals.