Quantitative thermal diffusivity imaging of disbonds in thermal protective coatings using inductive heating

Abstract

An inductive heating technique for making thermal diffusivity images of disbonds between thermal protective coatings and their substrates is presented. Any flaw in the bonding of the coating and the substrate shows as an area of lowered values in the diffusivity image. The benefits of the inductive heating approach lie in its ability to heat the conductive substrate without directly heating the dielectric coating. Results are provided for a series of samples with fabricated disbonds, for a range of coating thicknesses.