LAUSR

In this work, we investigated the cavitation, abrasion and corrosion resistance of vacuum arc coatings Ti-Cr-N. Nanostructured coatings with a thickness of 10 μm were deposited on AISI 430 steel substrates from filtered plasma flow using Ti-Cr cathodes containing 23 and 32 wt.% Cr at nitrogen pressure from 0.12 to 0.67 Pa. Nanocrystalline (nc) or amorphous-nanocrystalline (a/nc) coatings based on cubic solid solution (Ti1-x,Crx)N with chromium content from x = 0.11 to x = 0.25, CSZ size in the range of 6…14 nm and different axial textures were tested. The coatings had a high hardness of 31…46 GPa, however, changes in the cathode composition and/or nitrogen pressure during deposition affected the chromium content in the coatings and their structure, which altered their protective properties. Nevertheless, all the studied coatings effectively protected the steel substrate during testing. Nc coatings with a low Cr content of 11…13 at.% and a hardness of 30…33 GPa shown the best cavitation wear resistance. The reduction in the crystallites size of the solid solution (Ti1-x,Crx)N and the formation of the [110] texture contributed to the improvement of cavitation resistance. Coatings with a high Cr content of 18…24 at.% had the best abrasion resistance, besides the a/nc structure with a high hardness of about 46 GPa had certain advantages, but it showed the worst results in cavitation and corrosion tests. The nc(Ti0.87Cr0.13)N coating with a [111] texture and a hardness of 33 GPa proved to be the most corrosion-resistant, although it had the worst resistance to abrasive wear. The appearance of the anodic polarisation curve for this coating differs from other specimens and has a secondary passivated region. It has been shown that optimizing the deposition parameters during the synthesis of coatings with a high Cr content of about 25 at.% allows for further improvement of the abrasive or corrosion resistance of coatings with a/nc and nc structures, respectively. With regard to the comprehensive protection of steel products from cavitation, abrasion and corrosion, the use of nanocrystalline coatings appears to be the most appropriate.