Thermal conductivity of EB-PVD thermal barrier coatings evaluated by a steady-state laser heat flow technique

The thermal conductivity of electron beam-physical vapor deposited (EB-PVD) ZrO2-8 wt.%Y2O3 thermal barrier coatings was determined by a steady-state laser heat flux technique. Thermal conductivity change kinetics of the EB-P VD ceramic coatings were also obtained in real time, at high temperatures, under the laser high heat flux, long-term test conditions. The thermal cond uctivity increase due to micro-pore sintering and the decrease due to coati ng micro-delaminations in the EB-PVD coatings were evaluated for grooved an d non-grooved EB-PVD coating systems under isothermal and thermal cycling c onditions. The coating failure modes under the high heat flux test conditio ns were also investigated. The test technique provides a viable means for o btaining coating thermal conductivity data for use in design, development, and life prediction for engine applications. (C) 2001 Elsevier Science B.V. All rights reserved.