Hard turning of Inconel DA 718 using PVD nanocomposite coatings for carbide insert: performance improvement and Three-Dimensional tool wear assessment

Several current studies revolve around manufacturing components made by Inconel 718, one of the most used superalloys for crucial applications in modern aerospace and automotive industries, because its mechanical, chemical and physical properties lead to a complex and expensive machining of the material. The purpose of this research is to test PVD nanocomposite coatings for carbide tools made by Ti-Al-Cr nitrates in a Si-based amorphous matrix for turning direct-aged Inconel 718, under different cutting conditions. According to the results of a developed analytical model for optimization and the current usage in industry, a range of cutting speeds have been experimentally tested. Tool wear evaluation and data analysis of efficiency parameters have been performed to determine the condition allowing costs reduction and productivity improvements. The tool wear modes and mechanisms have been investigated by optical, Focus-Variable and scanning electron microscopes, in order to get information about flank wear as well as 3D-volume wear. The traditional mono and the three-dimensional methodologies for defining the tool wear have been compared to find a correlation between the end of tool life limits. Thanks to the wide range of data, a predictive model for flank wear has been developed. Furthermore, since the 3D wear resembled to grow exponentially, a fitting model has been formulated to prove this tendency.