Thermal barrier coatings (TBCs) are indispensable in the design of hot section components for advanced gas turbines. In particular, yttria stabilized zirconia (YSZ) layers fabricated by electron beam physical vapor deposition (EB-PVD) are suited for high performance applications. The principal reason is their superior tolerance against thermomechanical fatigue due to the unique columnar grain structure. The characteristics of the deposition process and the equipment are briefly explained. In the EB-PVD process, the processing conditions, such as preheating temperatures or rotation speeds of the substrates, strongly influence the microstructures and the crystallographic orientations of the layers. Therefore, controlling these aspects is the key issue to develop the durable TBC layers with excellent functions including thermal insulation. Finally, the state-of-the-art researching prospects concerning the new materials instead of YSZ are surveyed.
- Crystallographic orientation
- Electron beam physical vapor deposition
- Gas turbine
- Thermal barrier coating