Self-Healing Coatings in Extreme Environments

Abstract

The safety and longevity of materials is put to test in harsh environments. Conventional coating materials cannot fulfill the requirements of long term protection as they cannot repair themselves. Thus, damages that self-heal on coating have become a subject of research. This article systematically reviews the three primary kinds of selfhealing surface namely stimulus-responsive, ceramicbased high-temperature and organic-inorganic composite nature-inspired types of self-healing surface, their healing mechanisms, material innovations, and performance improvements. In particular, the stimulus-reactive types are effective in healing under a mild environment; the ceramic-based high-temperature types can be used in ultrahigh temperature (above 1500°C) with the capability of oxidation; and the nature-inspired composite types can be used in complex multi-field coupling environment. Nevertheless, the discipline continues to encounter such problems as a lack of environmental flexibility and challenges in developing translation. This paper attempts to summarize the developments, evaluate the challenges and present references to how high-performance self-healing coating can be designed and implemented in the future.