Surface modification of metal substrates by coatings has remained a
challenging research topic because of the conflicting demands for various properties.
Functionally graded coatings (FGCs) have recently attracted the attention of
researchers all over the globe owing to their mechanical, electrical, thermal and
tribological characteristics in a variety of advanced engineering applications. These
coatings are usually characterized by low porosity, good adhesion and base material
compatibility, which includes temperature and geometry. However, coatings often
experience some problems like variable thermal expansion coefficient (TEC) as
compared to their base metals. Thus, to overcome this issue, the functionally graded
material (FGM) layers may be employed. Hence, the purpose of this chapter is to
describe a general idea of FGM coatings, including classifications of production
methods and their diverse applications
Keywords: Functionally graded coating, Mechanical and tribological properties, Process parameters, Thermal spray.
