Coatings are routinely used as protective barriers against abrasion, chemical attack,
hydro-thermal variations and to improve aesthetics. Currently, most of these coatings are
in the micrometer range. New materials and techniques are being developed to develop
nano-meter thick coatings that are durable and generate less heat due to reduced friction.
Coatings could be self-cleaning and self-healing. In most cases the performance of these
coatings are evaluated using experimental techniques. The major parameters evaluated
are: durability of coatings under various exposure conditions, abrasion resistance, friction
resistance, high temperature resistance and electrical characteristics. Performance of the
(coating) film and the interface between the film and the parent material play important
role in the overall durability of the system. The authors believe that analytical models are
needed to predict the performance of various types of coatings, so that optimum design
approaches can be developed. The models could become quite complex because of the
interaction of the coating-film with the parent material through the interface. For most
cases, the mechanical properties of parent surfaces and some of the available coating
materials are known. But very little is known about the performance of the interface
under mechanical, hygrothermal and magnetic forces. For the nano coatings, the
properties of the coatings themselves need investigation.