Decelopment of and methods for ceramic coatings
J. G. Sun
26th Annual Conference on Fossil Energy Materials (2012)
Abstract
Three NDE imaging methods were evaluated for TBC life prediction – Laser backscatter (optical) .Not sensitivity to TBC life; may need IR laser to improve sensitivity – Mid-IR reflectance (optical) Good correlation to TBC life, although sensitivity is within a small range. Contamination, thickness limit, and failure level are remaining issues – Thermal multilayer analysis method (thermal) TBC life prediction model is based on conductivity reduction due to interface cracking.Preliminary data showed good potential for TBC life prediction.Effective conductivity for TBCs with depth-dependent conductivity variation needs to be defined and measured .Thermal TBC life prediction model could be more sensitive than optical because the "damage parameter" becomes larger in thermal (Dk) while smaller in optical (DR) when TBC is near failure. NDE methods for TBC life prediction are well developed; further evaluation for TBCs with various exposure conditions is needed.
Keywords:ceramic coatings;Plasma spray; Thermal barrier coatings
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