Self-healing ceramic coatings

In the development of functional ceramic coatings for future applications, self-healing ability is a key property. This chapter aims to briefly review the development of self-healing ceramic coatings (SHCCs). Some important applications of SHCCs, such as the thermal/environmental barrier coatings (T/EBCs) for the aircraft engine's turbine blades, are explained inclusively. During the operation of the turbine, the T/EBCs' surface is susceptible to being cracked by foreign object debris or by thermal shock; thus, self-crack healing ability is necessary. The ceramic coatings can be structured with healing agent materials (such as silicon carbide), which react with oxygen at high temperatures to form oxide, whose volume expansion helps to seal the surface cracks. This ability of SHCCs can improve the reliability and service lifeof gas turbine blades. In addition, other important applications of SHCCs (friction surface, oxidation protection) are also introduced. The perspective of SHCCs is discussed in the last sections of the chapter.