Effects of Tool Wear on Subsurface Deformation of Nickel-based Superalloy

Increased demand of energy efficiency for the components used in aerospace and energy industries requires high efficiency and low cost in the production of component made of nickel-based superalloy, such as aged Inconel 718. With use of whisker reinforced ceramic cutting tool in finishing machining process, higher cutting speed and higher production efficiency can be reached accordingly. However, surface integrity of the part produced by this process still needs to be studied due to the high demand of surface quality. The paper analyses the effects of tool wear on subsurface deformation of nickel-based super-alloy in finishing turning. The objective is to understand the nature of subsurface deformation under the influence of tool wear for prediction of the surface integrity in machined components based upon the machining conditions and material behaviours that give rise to them. Machined samples were studied under a Backscattered electron microscope to distinguish the subsurface features produced by the machining. The electron back scatter diffraction (EBSD) was also used to quantify the depth of deformation zones in the subsurface after the machining.