Abstract
In this paper, damage assessment for TBC sprayed combustor in a land-based gas turbine is shown based on analytical method. Firstly, TBC damage examination for 20000hours-used combustor was conducted with a visible inspection and SEM micro-observation. The visible examination indicated that TBC damages such as crack and delamination were not occured. However, SEM observation showed that a lot of micro-cracks parallel to the coating interface were distributed in the liner and duct especially. TBC damage assessment method in consideration with thermal-stress based damage such as crack initiation and ceramic coating spalling was proposed. The proposed method was applied to evaluate TBC remaining life in the 20000 hours-used combustor. It was shown that current TBC has more long life and will keep good condition in-service in spite of including micro-cracks in ceramic coating layer.
