TRANSIENT THERMAL RESPONSE OF PLASMA-SPRAYED ZIRCONIA MEASURED WITH THIN-FILM THERMOCOUPLES

A pulsed laser heat source method for measuring the transient thermal response of thin-film thermocouples (TFTCs) is shown to obtain results for the temperature jump and temporal response which are consistent with those predicted employing a simple model. Some deviation from this model is observed for the thinnest films on alumina, which has a very high thermal conductivity, and on Min-K 2000, which has a very low thermal conductivity. Poor adherence of the thin film to the substrates, the interface thermal conductance, is suggested to be the origin of this effect. The technique is determined to be sensitive to the thermal properties of the substrate on dimensions of the thermal diffusion lengths. This experimental method is preferable to calculations of the thermal response of the TFTCs based on bulk thermal data. It should prove useful as a method for characterizing in situ TFTCs, which may vary from batch to batch. © 1990.