Effects of shot peening on microstructure, thermal performance, and failure mechanism of thermal barrier coatings

Abstract

Shot peening might be a potential technology to optimize the interface microstructure, plays a critical role on failure behaviors, of thermal barrier coatings (TBCs). It remains a significant challenge to understand the influence of shot peening on microstructure, oxidation resistance, and thermal shock life. In this work, the Y 2 O 3 -stabilized ZrO 2 TBCs have been deposited by EB-PVD. The phase, microstructure, thermal performance, and failure mechanism of TBCs have been systemically investigated after shot peening. The shot peening process can improve the planeness of interface and reduce the formation of the cauliflower-liked microstructure in TBCs. After shot peening, the TBC coatings exhibit relatively good isothermal oxidation resistance and high thermal shock life due to the optimization of TGO growth and the thermal stability. The phase transformation, TGO growth, and cracks extension might give rise to the failure of TBCs. This work might guide the investigation of the improvement of interface microstructure and failure behaviors.

An Oxide Growth-Coupled Viscoplasticity Model and Its Application to Interfacial Stress Analysis near an Air Hole within a Thermal Barrier Coating

“…The bond coat in TBCs, typically composed of MCrAlY, is rich in aluminum. During prolonged exposure to high-temperature environments, oxygen anions diffuse inward through the TC and react with aluminum cations from the BC, resulting in the formation of α-Al 2 O 3 , the primary component of TGO [21]. Previous research has extensively simulated TGO growth, but few studies consider air holes and the creep-plasticity interaction [22][23][24][25][26][27][28].…”