Effect of cutting edge preparation on tool performance in hard-turning of DF-3 tool steel with ceramic tools

This study presents an experimental investigation on turning hardened DF-3 tool steel (similar to 58HRC) with PVD-TiN coated mixed ceramic. We focused on the effect of chamfer and honed edge geometry on tool wear, tool life, cutting forces and surface finish of the machined workpiece. The effects of the process parameters on performance characteristics were investigated using ANOVA. It was found that longer tool life was recorded with chamfered edge geometry at various cutting conditions. The typical damage observed as flank and crater wear for ceramic tools and abrasive wear was found as the main mechanism. The optimal cutting speed was 155 m/min, with which a tolerable tool life and volume of material removal was obtained for both edges geometry. Finer machined surface was left by chamfered tool with feeds and speeds in the range of 0.125-0.05 mm/rev and 155-210 m/min, respectively; also, cutting forces decrease with increased cutting speed. The obtained consequence of cutting forces shows that tool wear has a considerable effect on cutting forces and greater forces values recorded with honed tools.