Wear Mechanism Maps for Titanium Nitride Coatings Deposited on Copper and Brass with Electroless Nickel Interlayers

Copper and its alloys are a widely used group of engineering materials that find application in fields where their properties allow them to excel. Surface engineering is a term that refers to the use of various technologies used to modify a surface, leading to desirable properties at the surface. This may be done by an overlay coating or a diffusion-type (surface hardening) process. The practice of surface engineering as a means of improving the corrosion properties of copper is well established. The improvement of wear resistance of copper by these means is however less ascertained. In the current study, titanium nitride has been coated onto copper and brass with electroless nickel (EN) interlayers. Scratch adhesion tests were performed and the results interpreted via a profilometer and microscopic examination. Recommendations have been made as to appropriate nickel interlayer thicknesses for a given degree of wear resistance as reflected in the coating failure mechanism, by way of the so-called 'wear mechanism map'.