Development and Practical Application of Coatings for Cutting Tools Using the Next-Generation PVD Method

AIP is one of the ion plating methods and widely used as a coating method for cutting tools. It produces a dense film but also generates droplets unavoidably. The droplets often negatively affect performance of cutting tools. HiPIMS is one of the sputtering methods that produces a dense and droplet-free film. However, the method has never been put to practical use in cutting tool applications. This is because HiPIMS has more process parameters than AIP, making it more difficult to control the coating. This study has investigated the effects of HiPIMS parameters on the microstructure and physical properties of the coatings. The longer the pulse duration, the higher the deposition rate, which is industrially advantageous. The high peak power density makes the films cubic, resulting in high hardness and compressive residual stress. An indexable milling tool coated with HiPIMS exhibited 1.1 times longer tool life and higher crater wear resistance than the one coated with AIP. A drill coated with HiPIMS exhibited a than 1.6 times longer tool life and less severe wear and weld marks than the one coated with AIP.