Comparative analysis over microstructural, mechanical properties and cutting performance of TiN, TiVN coatings deposited by magnetron sputtering on SiAlON ceramic tool insert

In this work, TiN and TiVN hard coatings were deposited by magnetron sputtering process on SiAlON cutting tools. FESEM and XRD were used to analyze the coating's microstructure and phase composition. The hardness of the coatings was measured through nanoindentation test and the adhesion of the coatings was determined using the scratch test. Turning tests were carried out on uncoated, TiN and TiVN coated cutting tools in D3 hardened steel turning under dry environment. Tool life, wear progression, and cutting force were investigated under different cutting parameters. Meanwhile, the wear patterns and mechanisms were studied. Surface roughness after machining and cutting temperature during machining were also recorded and analyzed during the experimentation work. Chips after every set of experiments were collected and their morphology study was done using FESEM. For cutting tools coated in TiN and TiVN, abrasion with grooves on the worn faces was the main wear mechanism. The results indicate a significant optimization in performance, with cutting forces minimized by up to 30 %, cutting temperatures reduced by 20 %, and machined surface roughness improved by 45 % when compared to the TiN coated cutting tool. The experimental findings showed that the TiVN-coated SiAlON cutting tool outperformed the uncoated cutting tool and the TiN coated SiAlON cutting tool in terms of cutting performance. This research additionally offers a comparative experimental behavior of coated cutting tools, along with an investigation into cutting performance, which is essential for advancing research and enhancing our understanding of machining hardened steels.