Influence of process parameters on properties of chromium oxide deposited by reactive HiPIMS

Chromium oxide coatings appear to be a potentially attractive material since its good tribological properties at high temperature. Coatings were prepared by reactive high power impulse magnetron sputtering (HiPIMS). Coating depositions were carried out on cold work and hot work tool steel samples. To achieve ion bombardment of the growing coating, bias on the substrate or positive kick on the sputtering target were applied. The impact of these methods on the structure and properties of the coating was then investigated. The surface and cross-section of coatings were examined by scanning electron microscopy (SEM). The structure of the coatings was studied using X-ray diffraction (XRD). The influence of the coating process on surface roughness and the presence of coating defects was further studied using phase shifting interferometry and optical light microscopy. Tribological tests were performed using the pin-on-disc method at room temperature and high temperature using Al 2 O 3 counterbodies. During tests at high temperatures, the coatings exhibited low wear and stable friction, predisposing them to use in applications at elevated temperatures.