Study of Effect of Advanced PVD coating on Drilling of Nickel-Based Super Alloy Inconel 825

Abstract

The drilling process of Inconel 825, a nickel-based superalloy, is very challenging due to the material properties, the operating conditions and the high quality requirements. Moreover because of its low thermal conductivity, heat is concentrated near the tool tip and unable to dissipate causing tool wear. The current study investigates the influence of advanced PVD coating on the tool in terms of its performance during drilling of nickel based superalloy Inconel 825. A cutting force model is developed and forces and torque is predicted for different parameter settings. Systematic comparisons are made between the drilling performance of coated and uncoated carbide tools by taking into account the surface roughness, thrust force and torque utilizing analytical model, simulation and experiments. Force and torque are found to be less in case of coated tool compared to uncoated counterpart. Surface finish was better at higher cutting speed for PVD coated tool. Chip thickening is observed because of the constraints exerted on the free flow of the chip in drilling. This chip resistance force is reduced using the coated tool as the results show.