Nanostructured SiC-Ni Composite Coatings Obtained by Electrodeposition-a Tribocorrosion Study

Abstract

The tribocorrosion properties of SiC (20nm) - Ni nanostructured coatings have been studied in pin on disc tribocorrosimeter connected with an electrochemical cell. The objectives of our study in principal is to fully understanding the tribocorrosion process kinetic and mechanism of modified surfaces by co-depositing nano silicon carbide particles with nickel. The samples with coating on a top of a cylinder were installed in a cell, containing the electrolyte and electrodes, and mounted on a pin-on-disc tribometer, with the working surface of the specimen facing upwards. The counterbody (pin) was a corrundum cylinder (7 mm in diameter), mounted vertically on a rotating head, above the specimen. The lower spherical end (radius = 100 mm) of the pin, was then applied against the composite surface (disc) with an adjustable normal force. When rotation was applied, the end of the pin draws a circular wear track (16 mm in diameter) on the working composite surface. Continuous friction tests were carried out. Different friction forces were applied during 10000 tours with a rotation speed of counterbody from 30 to 120 tours/min. Some features of these tests reproduce the wear conditions of composite coatings in real conditions. K2SO4 0.5M was used as corrosive and passivating electrolyte for tribocorrosion tests.