Chemical vapour deposition of polycrystalline diamond films on high-speed steel

Highly wear resistant polycrystalline diamond films can be deposited on numerous substrate materials by activated chemical vapour deposition (CVD) processes. Process technology for CVD diamond has mainly been developed on cemented carbide or other ceramic tools at deposition temperatures well above 700 deg C. In applications like dry cutting of lightweight materials CVD diamond tools have demonstrated high performance. To utilize the excellent tribological properties of diamond for steel components and tools, we developed diamond coating process technology for high speed steel using deposition temperatures below 550 deg C and interlayers. The reduced deposition temperature and the diffusion barrier interlayer make sure, that the steel substrate keeps its hardness. The interlayers also improve the adhesion by compensating in part the high thermally induced stresses and increasing the carrying capacity of the coated tools and components.