Carbon coatings: structure and functionality of a high-volume product

Abstract

Metal containing diamond like carbon coatings (Me-DLC) are well known for their excellent tribological properties. They have a great potential in the field of wear and friction reduction on precision components. The importance of this coating material is increasing continuously in a wide range of applications. However, the wear resistance of standard Me-DLC coatings is still markedly lower than that of pure diamond like carbon (DLC). Today, the deposition of pure DLC in an industrial scale as well as its adhesion are still on research. On the contrary, dc magnetron deposition techniques for Me-DLC coatings show excellent adhesion and have reached a high technological level. The aim of our work was to close the quality gap between Me-DLC and DLC, especially with respect to wear resistance. The preparation of the Me-DLC coatings were performed in an industrial batch coater by reactive dc magnetron sputtering in an argon acetylene mixture using Ti, W and WC/Co targets. A comparison of the deposition rates, wear and adhesion of the coatings deposited using the different targets is presented. Besides the coating properties, aspects like process stability and target costs will be discussed.