Measurement of Young's modulus of thermal barrier coatings at elevated temperature utilizing an impact exciting method with a dropping steel ball

Abstract

In the high temperature technology such as a gas turbine of the power generation system, thermal barrier coatings are necessary for making greater heat-resistance materials. In this study, Young's modulus of thermal barrier coating was measured under the elevated temperature environment up to 1000°C. The rectangular section bar specimens which have two-layer coating consisting of a metallic bond coat and a ceramic top coat were used in the experiment. Young's modulus of each layer material was calculated from the natural frequency of the specimen applying the multi-layer beam theory for the flexural free vibration. It was found that the Young's modulus of top coat decreased with temperature rise and was affected to the heat hysteresis during heating and cooling processes.