A crystal chemical approach to the formulation of self-lubricating nanocomposite coatings

In recent years, design or formulation of superhard coatings with self-lubricating properties has become one of the hottest research topics in the field of tribological coatings. In particular, the production of new coating architectures based on nano-composite or -layered morphologies has become very popular, especially for dry machining or high-temperature sliding bearing applications. In such applications, these coatings can lead to the formation of self-lubricating tribofilms that reduce friction and wear. In this paper, a crystal chemical model is presented to account for the formation of such low-shear and hence low-friction tribofilms. In support of this model, recent experimental findings of various research groups are also provided. The major benefit of this model is that it may provide a scientific means to better design and formulate future tribological coatings that provide not only superior wear resistance but also sufficient lubricity during dry machining or sliding applications. (c) 2005 Published by Elsevier B.V.