Multilayered Coatings by Thermal Spray for High-Temperature Applications

Thermal Barrier Coatings (TBCs) play an increasingly vital role in improving efficiency and performance of high-temperature components in energy and aerospace industries. In recent years, materials such as Gadolinium Zirconate (GDZ)-based TBCs have become emerging contenders for conventional TBCs (based on Zr-stabilized systems) since these materials have low-thermal conductivity and excellent ability to withstand extreme chemical environments at high temperature. Another approach to increasing efficiency, performance, and lifetime is related to the development of Ceramic Matrix Composites (CMC) for the fabrication of components. In recent years, several efforts have been put into basic research with the aim of identifying strategies to enhance the performance of current high-temperature engine protective coatings. Notably, multilayered TBCs and the emergent EBCs have been the focus of attention on three aspects for the enhancement of protective coatings: i) the optimization of multilayered TBC/EBC architecture, ii) assessment of the damage of TBC/EBC subjected to thermal cycling and molten silicates attack, and iii) exploration of candidate materials for the fabrication of novel coatings. This chapter has the goal of illustrating new engineering professionals seeking to explore this topic and providing a compilation of key information about recent advances in this coating technology.