ABSTRACT
The application envelope of thermal spray coatings (flame spraying, plasma spraying, D-gun spraying and high-velocity oxy-fuel spraying) can be widened significantly by eliminating the various inherent defects associated with them through suitable post-processing routes like microwave irradiation. The electromagnetic waves directly interact with material at atomic/molecular level and result in volumetric interaction inside the deposited coatings. This results in the generation of intense heat in a very fast manner inside the coatings. The internal heating phenomenon associated with microwave heating results in unique properties inside the thermal-sprayed coatings, which is not possible with other processing routes like laser treating and suitable heat treatment of the thermal spray coatings. In this chapter, the application of microwaves in treating various thermal spray coatings has been discussed with suitable examples. The properties of the microwave-treated and as-sprayed coatings are discussed in a chronological manner in this chapter. The results indicate that the microwave processing of material is an efficient technology for treating the thermal spray coatings. The microwave-treated coatings have significantly improved properties than the as-sprayed coatings.
