Abstract
A non-destructive method for evaluating the heat resistance of thermal barrier coatings (TBCs) on gas turbine blades has been developed This method is based on active thermography using carbon dioxide laser heating. The position of the laser beam is controlled by the robot arm and the laser beam heats the topcoat surface. The surface temperature is measured by an infrared camera. Subsequently, three-dimensional analysis of the unsteady heat conduction under the practical condition derives an expression for the relationship between the heat resistance and the topcoat surface temperature. The heat resistance of TBCs is estimated by substituting the measured temperature for the expression. In this report, this method was applied to a gas turbine blade, and the TBC heat resistance at 70% height of the blade was evaluated. The results showed that the estimated error of the TBC heat resistance is within 4%.
