Comparison of surface roughness and residual stresses induced by coated carbide, ceramic and CBN cutting tools in high speed facing of Inconel 718

Abstract

Inconel 718 is the most important and frequently used alloy for the manufacture of a wide variety of aerospace gas turbine components. However, the properties of the alloy, make machining difficult and troublesome. HSM using coated carbide, ceramic and CBN cutting tools is one of the feasible methods in improving the productivity. While improving the productivity, it is also essential to meet the surface integrity requirements. In this paper, the performance of coated carbide, ceramic and CBN cutting tools in the high speed facing of age hardened Inconel 718 have been compared (in terms of their surface roughness and residual stresses) at their respective optimum cutting conditions. PVD-TiAIN coated carbide and CBN cutting tools generated compressive residual stresses. The PVD-TiAIN coated cutting tool, which costs lower (only 4-5% of the cost of a CBN cutting tool) makes it more attractive for machining of Inconel 718.