遮熱コーテイングのせん断弾性係数の高温下における測定システムの開発

抄録

Thermal barrier coatings are necessary for making greater heat-resistance materials based on metal substrate. In this study, a test system to measure elastic moduli, modulus of longitudinal elasticity E, of shear elasticity G and/or Poisson's ratio μ, is developed and its availability is experimentally confirmed. The longitudinal modulus (Young's modulus) E of thermal barrier coating was measured under the high 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. E values of each layer were calculated from the natural frequency of the specimen applying the multi-layer beam theory for the flexural free vibration. In this system, the natural frequencies of both bending mode and torsional mode of vibration can be measure easily by impact sound of one specimen. So that the natural frequency fT of torsional mode was measured by FFT analysis of different impact sounds obtained from a variety of impact point on the specimen at a room temperature. The experimental results are compared with the results of FEM analysis for the natural frequencies of each mode of vibration.