Effects of high temperature ion implantation on titanium nitride coated carbide cutting tools

The effects of high temperature nitrogen and aluminum ion implantation and plasma implantation on titanium nitride coated carbide cutting tools are investigated. Aluminum implantation is used to enhance the high temperature oxidation wear resistance, and plasma nitriding and high-temperature ion implantation are used to further improve the surface microhardness and corrosion resistance. TiN films are deposited on carbide cutting tools by vacuum arc ion plating, in which a shutter plate is used to avoid line of sight transit of macro-particles from the cathode to the substrate. Nitrogen and aluminum ion implantation at elevated temperature (300-600°C) is then achieved in a multi-function ion implantation system. The effects of different substrate temperature, implantation dose and implantation energy on the surface properties are assessed. The corrosion measurements are carried out in a NaCl solution using electrochemical impedance spectroscopy. The oxidation resistance studies are carried out in air at 800°C using continuous and discontinuous method. The surface microhardness, crystal structure and microstructure are measured by microhardness measurement, XRD, SEM and AES. The process is applied to industrial cutting tools in the production line, and the results are reported in this paper.