Study of Effect of Machining Parameters on Surface Finish and Noise Patterns for Machining EN 19 Steel with PVD TiN Coated Mixed Ceramic Inserts in CNC Turning Operation

Abstract

The surface finish of a product is one of the most important factors in determining the quality of the surface of the product. For long, research on optimisation of machining parameters and other inputs, to find ways to achieve the best surface finish has been done for a variety of materials. In this study, hard turning of EN 19 alloy steel is done using PVD TiN coated mixed ceramic (Al2O3+TiCN) inserts on a CNC turning centre under wet lubrication conditions to investigate the effect of machining parameters on surface roughness. The turning operations are performed for different combination of cutting parameters viz. cutting velocity, feed and depth of cut. The combinations of these three parameters for experimental runs are obtained using full factorial design of experiments and thereafter, ANOVA is applied to find the effect of those parameters on surface roughness. Additionally, noise generated during the cutting operation is also studied keeping in mind the health hazards of high noise levels on the workers. Frequency spectrum analysis is also done to find out the frequency range in which highest sound levels are obtained. An attempt has been made to find a possible correlation between the two responses, surface roughness and noise. Optimum parameters have been determined for the best surface finish under said machining conditions and also for lowest noise generated if that may be the requirement, without compromising much with the surface finish.