Dry sliding tribological behavior of Cr coatings electrodeposited in trivalent chromium sulphate baths

In this study, tribological properties of Cr coatings obtained from Cr(III) sulphate baths with complexing agents (formate-urea, glycine and oxalate) prepared on 316Ti stainless steel have been investigated. Surface morphology and wear scar and debris were examined by scanning electron microscopy. The surface microhardness of the different coatings was performed to determine the mechanical properties of the coatings. Cr coatings phase composition was identified by X-ray diffraction. To assess the tribological behavior of the coatings, dry sliding wear test against a 100Cr6 steel ball was performed with a ball on flat configuration. Investigation of friction coefficient has shown that Cr coatings deposited in Cr(III) baths have better tribological properties as compared to those of Cr coatings deposited in Cr(VI) baths. Heat treatment (at 400 degrees C and 600 degrees C) of Cr coatings deposited in Cr (III) baths deteriorates their tribological properties i.e. the friction coefficient increases. Attempts have been made to describe the wear mechanisms of Cr coatings by observing wear tracks. (C) 2017 Elsevier B.V. All rights reserved.