Mass-transfer kinetics, structure, and tribological properties of coatings deposited on steel in Ar or N2+O2 by electro-spark alloying using Cr3C2-NiAl electrodes

Abstract

Abstract Multicomponent coatings were obtained by electro-spark alloying using Cr3C2-NiAl electrodes, in air and in argon medium at direct and opposite polarity. Cr3C2-NiAl electrodes were manufactured by self-propagating high temperature synthesis. Mass transfer kinetics was determined by gravimetric method. The structure and composition of the coatings were evaluated by scanning electron microscopy and energy-dispersive analysis methods. Friction coefficient was measured using pin-on-disk test. Roughness parameters and wear tracks were studied by optical profilometry. It was found that the opposite polarity in combination with a protective environment is optimal in terms of growth rate, structure and tribological properties. The coatings obtained by the best regime had a relatively low roughness (Ra=4 jm), high wear resistance and a low friction coefficient at the level of 0.18.