Enhancement of Tribological Behavior of ZrCN Coating

This paper focuses on tribological behavior of ZrCN coating on bearing steel substrates DIN 17230, 100Cr6 / 1.3505, fulfilling also roughness and adherence requirements. Two strategies are followed to achieve a reduction of coefficient of friction. Initially, a low roughness coating by using Physical Vapour Deposition (PVD sputtering process) is developed. At this stage, PVD conditions guarantying adherence step and avoiding drops generated during that process are achieved. A second strategy consisting of application of several polish post-processes is proposed. These polish post-processes pretend to reduce roughness keeping, at the same time, a proper adherence. Different post-process durations and conditions are analysed to achieve positive adherence results. Coated bearing samples obtained from the application of these two strategies are tested in friction test rigs. These tests concluded that there is not a significant improvement of friction performance by applying ZrCN coatings compared to bearing baseline.