CVD diamond deposition under atmospheric conditions on steel with a silicon intermediate layer

In order to realize dry metal forming, the requirements of the surface layer, e.g. to load-bearing capacity and tribological properties are increasing. Therefore, the feasibility of chemical vapour deposition (CVD) of diamond onto tool steel 1.2379 under atmospheric conditions without a vacuum chamber is investigated, so that there is no limit according to the size of the tool. For the deposition of CVD diamond coatings, a laser-based plasma CVD process combined with a physical vapour dep-osition (PVD) process is used. It is shown that a PVD silicon layer serves as diffusion barrier for the subsequent deposition of a CVD diamond layer. The diffusion barrier as well as the CVD diamond layer is analysed by laser microscope meas-urements, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. The crystal structure of the diamond films is verified by Raman spectroscopy and laser microscope measurements. To visualize the coating system, a focused ion beam is used to generate a cross-section. The local deposition of a CVD di-amond layer onto tool steel without the need for a vacuum chamber is evidenced by these investigations.