Characterization of Ni-Cr coating failures deposited on CW614 substrate using friction coefficient evolution

Laboratoire des Systèmes Electromécaniques (LASEM), École Nationale d’Ingénieurs de Sfax (ENIS), Université de Sfax, B.P.W3038, Sfax, Tunisie
mouradchokribenjemaa@gmail.com

Received: 29 October 2012
Accepted: 12 June 2013

Abstract

In this study, characterization of the total wear of coatings by the friction coefficient evolution of nickel-chromium (Ni-Cr) coatings is presented. The device used is a developed ball-on-disc tribometer. The samples tested in this study are brass discs (CW614) coated with Ni-Cr layers sliding against a steel ball. The effect of normal load, sliding velocity and substrate roughness on the wear of coatings is studied. An optical microscope (OM) and energy dispersive spectroscopy (EDX) are used to confirm the coating failures. The results show that the total wear of Ni-Cr coatings is related to the sliding distance. However, an increase in normal load and/or sliding velocity increases the total wear of the coating, whereas the reduction of the substrate roughness reduces the coating failures and increases their service behavior.