Non-destructive thermal property measurements of an APS TBC on an intact turbine blade

Terahertz dielectric properties of plasma-sprayed thermal-barrier coatings

“…In addition, with the growth of an oxide layer (called thermally grown oxide, TGO) between the ceramic top and metallic bond layers, the two layers delaminate at the interface, which leads to spallation of the ceramic layer [5,6]. Thus, inspection techniques that can assure the reliability of TBCs by evaluating the degree of sintering and detecting delamination at the interface are becoming important [7,8].…”

Differential phase of photothermal emission analysis for thermal property measurement of thermal barrier coatings

“…Although both methods can measure coating properties on coupon samples, measurements on an actual engine blade has only been demonstrated in the open literature with PopTea [12]. Additionally, PopTea has been used to investigate the consequence of service related changes to coatings thermal properties resulting from high temperature exposure [13] and foreign material infiltration [14].…”

Thermal diffusivity of TBC: Results of a small round robin test and considerations about the effect of the surface preparation and the measuring approach

“…2 For the sake of simplicity and for guaranteeing a higher robustness of the inversion procedure, since the thermal properties of metallic bondcoat and the metallic substrate usually differ negligibly, it is a common practice to use a two layer model [14,[21][22][23][24][25][26][27][28][29][30]. Relative thermal diffusivity increase Fig.…”

“…the heating and temperature detection confined to the same side of the sample) such as Pulsed Photothermal Technique [21], Time Resolved Infrared Radiometry (TRIR) [22], Thermal Waves Interferometry (TWI) [23] and PopTea [24,25], have demonstrated their ability to measure the thermal diffusivity on TBC deposited onto substrates without any special requirement on the sample size and geometry. In particular, measurements on real components have been recently reported [25,26].…”