Discrimination between over-thickness and delamination of thermal barrier coatings by apparent thermal effusivity thermographic technique

When the delamination extent of thermal barrier coatings (TBC) is over a sufficiently large area to assess the adhesion of coatings, Pulse thermography (PT) is an effective technique, but often the distinction between delamination and TBC over-thickness is very difficult to determine. In this work, a recently developed algorithm based on apparent thermal effusivity has been applied to automatically distinguish between delamination and over-thickness during the inspection of a serviced gas turbine TBC-coated vane.