Structure, mechanical and tribological properties of nitrogen-containing chromium coatings prepared by reactive magnetron sputtering

摘要

Cr{sub}{1-x}N{sub}x coatings were deposited by magnetron sputtering at a substrate temperature of 200℃ onto AISI 316 stainless-steel substrates immersed in an Ar/N{sub}2 plasma. The goal of this investigation was to study the influence ofnitrogen content on the structural, mechanical and tribological properties of the Cr{sub}{1-x}N{sub}x coatings (with x being in the range of 0-0.4). The coating composition and microstructure were evaluated utilizing glow discharge optical emissionspectroscopy and glancing angle X-ray diffraction, whereas the morphology was evaluated by scanning electron microscopy. Knoop microhardness, scratch adhesion, pin-on-disc sliding, ball-on-plate impact and abrasive wheel wear tests were performed toevaluate the mechanical and tribological properties. The presence of Cr, Cr{sub}2N, CrN (and mixtures of these phases) has been identified and related to the film composition. For Cr{sub}{1-x}N{sub}x, coatings with x≤0.16 only theαCr phase could bedetected. A progression towards a denser microstructure was found with increasing nitrogen content up to x = 0.29, associated with an increase in hardness from 700 up to 2400 HK{sub}0.025. Cr{sub}{1-x}N{sub}x coatings with x =0.10-0.16 showed goodadhesion and the best abrasive and pin-on-disk sliding wear resistance, together with less crack development around the indentation area (and thus improved toughness) in impact tests after 50 000 impacts, against both steel and cemented tungsten carbideballs. The hardest coating (Cr{sub}0.71N{sub}0.29) performed best in terms of reducing the resulting impact indentation volume.