Smart tribological coating

Abstract

Materials that can adapt their characteristics favorably to relevant external factors are defined as smart materials. The term “smart tribological coatings” defines a class of coatings that are capable of responding to their environment while offering an advantageous functionality while preserving their tribological property. The latest approach in coatings is to manipulate the material and structural composition of the deposition at submicron scales to develop functional architecture. This sequential fabrication of submicron layers featuring unique material compositions and topography result in unique and exotic properties suitable for the development of smart coatings. Several such smart coating architectures have been conceived and investigated by researchers that are summarized in this study. Notable examples of such coatings include sensing, self-healing, self-lubricating, self-cleaning, and bioactive systems. Surface architectures with enhanced and novel functionalities such as self-stratifying, super-insulating and thermochromic are also emerging and are likely to become part of the smart coating portfolio. This article starts by briefly introducing the primary concepts associated with smart tribological coatings along with their functionalities. The different types of coating structures and their smart characteristics are discussed in subsequent sections. Altogether, the article brings together the various concepts in smart tribological coatings that offer significant potential for a range of functional applications.