The impact of coating layers and additives on the performance of carbide tools when machining Inconel 718 superalloy

Abstract

Nickel based superalloys always considered as very difficult to machine materials due to their ability to retain high level of strength at elevated temperatures. In this work three different grades of cemented carbide tools with different geometries were used to machine nickel base, 718, superalloy in order to compare their individual performances and also to determine the optimum cutting conditions. Three cutting speeds have been used for each tool with fixed feed rate during the machining. The temperature dependence of the micro-hardness of the WC materials was investigated from room temperature up to 1000°C. The hot hardness results are correlated with the deformation mechanisms and micro-structural properties of the WC insert which control the response of the tool materials in service conditions.