Thermal Characterization of Anisotropic Materials at High Temperature Through Integral Methods and Localized Pulsed Technique

Abstract

New applications in aerospace or energy industries require the development of new materials at high temperature exhibiting high anisotropic properties. Their thermal characterization requires the development of specific experimental benches. In this article, a new experiment is presented which allows one to estimate through only one experiment the three diffusivities of an orthotropic material at high temperatures without the need of vacuum. The estimation procedure is very fast and accurate due to using, on the one hand, integral transforms that allows one to get rid of the spatial distribution of the flash energy, and on the other hand, an infrared camera that provides a large amount of experimental data. And thanks to the use of a nonlinear parameter estimation and estimations made directly on Fourier transforms of the temperature field, the heat flux stimulation is no longer necessary to be Dirac in time. To validate the method and the experimental facility, measurements were performed on a Ti–6Al–4V alloy from room temperature up to $$1000\,^{\circ }\text{ C }$$ . In addition, particular attention has been paid to the thermal coupling that can appear between the low conducting materials and the air, and a criterion has been established to determine if the in-plane thermal diffusivity measurements can be affected or not.