Tailoring degradation-resistant thermal barrier coatings based on the orientation of spontaneously formed pores: From retardation to self-improvement

Abstract

Thermal barrier coatings (TBCs) endow metal components with exceptional endure capability to withstand high temperatures over their bearable limits. Thus, TBCs are indispensable in a wide range of applications related to high temperatures. However, the thermal barrier performance degrades by at least 50% during service, which remains a critical challenge for these coatings. Herein, degradation-resistant TBCs were achieved using composited structures. Thermal insulation 2D pores were spontaneously formed during thermal exposure. Moreover, the degree of resistance was optimized from 20% to 50% by tailoring the orientation of the 2D pores. Thus, the thermal barrier performance was self-improved. A detailed examination suggests that scale-progressive healing of the initial pores is primarily responsible for the degradation mechanism. Analysis of the orientation of the spontaneously-formed 2D pores on thermal resistance reveals that this accounts for the self-improved thermal barrier performance. These results will guide the advanced design of TBCs for future applications.