Processing Effects on Microstructural Charcteristics and Properties of Reactively Ion‐Plated Titanium Nitride Coatings

Abstract

The effects of key processing parameters on the resulting microstructure and mechanical properties of thin TiN coatings, reactively ion‐plated on polished aluminum and steel substrates, were investigated experimentally. A deposition procedure was established and a processing scheme for reactive ion plating was developed. Optimization of processing conditions was achieved by means of controlling the principal ion‐plating parameters to prevent the growth of species different from TiN, evaporant poisoning, and variations in the coating thickness. Emphasis was placed on identifying the effects of critical independent and dependent processing parameters, such as the rf power density, the deposition rate, and the coating thickness, on the TiN microscopic morphology, crystal structure, surface roughness, microhardness, and deformation behavior arising under static and sliding contact loads. Results from various testing and characterization methods revealed that deposition of hard, strongly adherent, and relatively smooth TiN coatings possessing dense microstructures of fine equiaxed grains with a preferential (200) texture can be accomplished under certain ionplating conditions.