Evaluation of thermal conductivity of thermal barrier coating by a laser flash method and a differential scanning calorimeter

Thermal barrier coating (TBC) is a key technology for using materials in high-temperature application. To understand exact mechanism of thermal transport across the surface to the bottom of the TBC deposited materials, an accurate measuring thermophysical quantities of each layer constituting TBC deposited material is very important and inevitable. However, it is very difficult to measure and evaluate thermophysical quantities in the form of thin film even at the level of several hundred micrometers in thickness, which is the reason that few experimental studies have been reported. In this study, we represent the effect of the TBC layer deposited on the nickel alloy on the heat transfer properties, i.e., thermal diffusivity, of the nickel alloy with temperature from 25 to 400 °C, which were understood by measuring and evaluating thermophysical quantities (thermal diffusivity, specific heat capacity, and thermal conductivity) of each layer constituting the TBC deposited material. This is the first report on the thermal diffusivity measurement of the TBC thin film deposited on a substrate by a laser flash technique based on an areal heat diffusion time method.