Strain Tolerant Thermal Barrier Coatings for Durable and Efficient Gas Turbines

Purpose and goal

The principal project goal was to evaluate and further develop strain tolerant thermal barrier coatings (TBCs) with lower thermal conductivity and better application flexibility to support the development of gas turbines in sustainable energy systems. Through extensive experimental work, important properties and better understanding of two types of strain tolerant TBCs targeted for use on different gas turbine components were obtained. Material data including thermal conductivity, thermal cyclic fatigue (TCF) life and erosion resistance were acquired.

Expected results and effects

Two promising ceramics for making EB-PVD TBCs were identified, which give better thermal isolation capability and TCF life than the baseline TBC. TBCs prepared by the PS-PVD technique were less satisfactory, as their resistance to erosion was poor and further tuning is needed. The obtained coating data and better understanding of benefits and limitations of the respective TBCs are important for formulation and execution of further work on developing strain tolerant TBCs. Their eventual implementation is expected to contribute to improved cyclic durable gas turbine performance.

Planned approach and implementation

The project was divided into two stages with respective tasks and deliverables. Considering results from Stage I, the focus of Stage II and thereby the deliverables were revised. Co-operation between the partners through project meetings and emails was important for the successful execution of the project. During the course of project, problems with external sample suppliers and outbreak of the COVID pandemic caused significant delay in obtaining test specimens needed in both stages. The extension granted by VINNOVA enabled us to complete all the tasks and achieve the project goal.