Microstructure and high-temperature tribological properties of TiSiN-Ag coatings deposited by multi-arc ion plating

The TiSiN-Ag coatings were deposited on 304 stainless steel by multi-arc ion plating. The composition and structure of the coating were characterized by scanning electron microcopy, X-ray diffraction, X-ray photoelectron spectroscopy and transmission electron microscope, respectively. The hardness was tested using nanoindentation. The tribological behavior of the coating was investigated at room temperature, 350 °C, 550 °C and 750 °C, respectively. Ag presented as the nanosize clusters and metallic silver, and they were embedded in amorphous Si 3 N 4 and nanocrystalline TiN. The results show that the TiSiN-Ag coating containing Ag concentration (~ 8.66 at.%) has the excellent frictional behaviors in the high temperature (> 550 °C), which is correlated with the diffusion of metallic Ag and the formed oxidation. Temperature plays a crucial role to drive the silver lubrication.