Investigation of low-reflective ZrCN–PVD-arc coatings for application on medical tools for minimally invasive surgery

Medical tools for minimally invasive surgery are often used under difficult environmental conditions. If the surgeons have to work with a microscope, the operating area must be brightly lit. Reflection and scattering of light from tool-surfaces disturb the visual field. To decrease this kind of disturbance, the tools can be covered by a dark PVD thin film. In the present study, the properties of low-reflective PVD-arc coatings of ZrCN were considered in comparison to TiCN. Different pure metal targets of zirconium and titanium were utilized in a reactive arc-coating process. The coating device was an industrial PVD engine of the HTC 1000/4 ABS type. Caused by the purpose of aimed investigations the engine merely operated in the arc-coating-mode. Amounts of carbon and nitrogen in the layers were steered by systematic changes of gas flow parameters from batch-to-batch. Substrate temperature and bias voltage were held at constant levels. Besides some mechanical and optical properties, aspects of biocompatibility of ZrCN on stainless steel AISI 304 were focused on. Summarizing the obtained results with regard to questions of biocompatibility, all of the investigated thin films have fulfilled the requirements for short-term applications to the human body.