Performance evaluation of cemented carbide tools in turning AISI 1010 steel

In this paper, the performance of three cemented carbide cutting tools, two coated tungsten based cemented carbide — one with Al2O3 (black) outer layer and the other with TiN (golden), and an uncoated titanium based (silver grey) cemented carbide tool, with 80° — diamond insert shape were investigated during finish turning of AISI 1010 steel. The PCBNR tool holder, giving a side cutting edge angle of +15°, was used. Cutting tests were performed with constant depth of cut and at various cutting speeds and feed rates to investigate the performance of the tools under dry cutting conditions. Cutting forces and surface roughness were measured. The chips produced by the three type of tools during experimental trials were examined to determine the secondary shear zone, chip thickness and the angle of maximum crystal elongation. The tool which had the CVD with TiCN/TiC and PVD with TiN coating layer sequence performs best under the conditions tested, as lower forces with little variation were encountered, very good surface finish could be obtained and chips with minimum SSZ thickness could be produced, that contributed to low chip strain and therefore to low residual stresses on the workpiece surface.