Characterisation and performance of coated SiAlON cutting tools for Inconel 718 machining

Physical vapor deposition (PVD) with High Power Impulse Magnetron Sputtering (HiPIMS) presents a highly promising surface modification approach for the performance enhancement of SiAlON cutting tools in the machining of Nickel-based superalloys alloys, which are renowned for their challenging machinability. This study systematically investigates the coating roughness, microstructural characteristics, and cutting performance of HiPIMS-coated SiAlON tools in Inconel 718 milling. The deposited multilayer coatings were comprehensively analysed using advanced characterisation techniques, including scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). Cutting tests were carried out with different tool geometries and machining conditions, as well as coated and uncoated tools—factors that highly influence tool's performance. The HiPIMS coating demonstrated improved thermal stability and reduced susceptibility to diffusion-related deterioration—factors that are critical in managing the high temperatures encountered in superalloy machining. These results underscore the potential of HiPIMS technology to significantly extend tool longevity and enhance machining efficiency, establishing it as a viable solution for high-performance manufacturing sectors. • Coated SiAlON tools studied for high-speed machining of Inconel 718 superalloy • Coating effectiveness depends on tool geometry; improved performance for RPGN 090300. • Wear mechanisms include adhesion, notch wear, chipping, and built-up edge formation. • No significant diffusion wear detected; material transfer confirmed by EDS analysis • Coated tools enable high material removal rates at speeds ≥800 m/min with optimization.