Observations on the structure, hardness and adhesion properties of a selection of multicomponent refractory element nitride coatings

In recent years, the introduction of titanium-based nitride and carbide coatings has led to a marked improvement in the tribological behaviour and service life of many engineering components such as cutting tools and metal forming dies. Although TiN performs satisfactorily, increasing demands from manufacturing industries have driven the development of thin coatings to optimised performance. Coatings are being sought with, inter alia, improved hardness and wear resistance. In this context, attention has been focussed on a number of advanced multi-component nitride coating systems based on, or incorporating, refractory element additions. Thus the use and incorporation of refractory and semi-refractory elements such as Al, Zr, Cr or V promises to provide coatings with higher hardness and improved wear resistance due to the formation of novel complex structures. In the present investigation, a wide selection of single and multi-component coatings (TiN, CrN, ZrN, TiAlN, TiAlVN, TiCrN, TiZrN and TiCN) have been deposited onto high speed steel substrates, using the technique of unbalanced magnetron sputtering. This paper presents data on the structure, hardness and adhesion properties of these coatings. The implication of these results is then discussed.