An estimation of thermophysical properties of layered materials by the laser-flash method

An investigation of two-layered and three-layered systems by the flash method has been carried out. Because of the behaviour of the material analysed, the theory considers two-layered and three-layered composites with the ideal thermal contact described by zero thermal contact resistance. The data reduction algorithm is introduced and results are given of an estimation of the thermal diffusivity of alumina (aluminium oxide, Al 2 O 3 ) on copper/alumina layers. An estimation of the thermal diffusivity of one layer requires, besides the knowledge of other relevant properties (density, heat capacity, and thickness of components), knowledge of the thermal diffusivity of the remaining layer(s). The way the error in the known thermal diffusivity influences the error in the unknown thermal diffusivity estimation is analysed. The proposed approach, which indicates error propagation and estimates the accuracy limits, is applied to a two-layered system.