Nondestructive Evaluation of Thermal Barrier Coating Systems Using Ultrasonic Techniques

Abstract

Nondestructive Evaluation of Thermal Barrier Coating Systems Using Ultrasonic Techniques Binwei Zhang Nondestructive evaluation (NDE) as a diagnostic tool has been extensively used to inspect the integrity of structure members. In the energy sector, the premature failure of the protective Thermal Barrier Coating (TBC) covering the turbine blade can cause the structural metal base of the blade to be exposed at extremely high temperature fluids, thus reduce the service life. It is highly necessary that an NDE technique be developed for xii List of Pictures Picture 3.1 Spallation at one corner of WVU isothermal René N5 coupon after 400 hours of exposure……………………………………………………………………………….50 Picture 3.2 Spallation at one corner of WVU isothermal René N5 coupon after 450 hours of exposure……………………………………………………………………………….50 Picture 3.3 Spallation at one corner of WVU isothermal René N5 coupon after 500 hours of exposure……………………………………………………………………………….50 Picture 3.4 Spallation at one corner of WVU isothermal René N5 coupon after 550 hours of exposure……………………………………………….………………………………50 Picture 3.5 Failure Process along one edge of New René N5 coupon #1………..………55 Picture 3.6 Failure Process along Edge One of New René N5 coupon #2………………56 Picture 3.7 Failure Process along Edge Two of New René N5 coupon #2……………..57