Thermal diffusivity of homogeneous and coated materials in the temperature range between room temperatur and 1000 C

A short description of an instationary measurement method (flash diffusivity) for investigation of thermal diffusivity is given. Measurements of temperature dependent thermal diffusivities of homogeneous and coated materials have been carried out in the temperature range between room temperature and 1000 degree C. Investigate materials are technically pure molybdenum, the nickel superalloy IN 617 and coated IN 617. From the known thermal diffusivities of the substrate and the measurements performed on coated samples (coating: NiCrAlY plus Substrate: IN 617), the thermal diffusivity of the coating has been determined. In order to check and improve the accuracy, a finite differences computation has been carried out, using the measured thermal diffusivities for the substrate and coating. The diffusivity of the coating has been adjusted in such a way, that an optimum agreement between the computed and measured values for the coated samples is achieved.