Relation between ultrasonic scattering and microstructure of polycrystalline materials

Ultrasonic testing is a very common volumetric technique used in industry in order to detect and characterized defects. Within the framework of the maintenance of its nuclear power stations, Electricite de France (EDF) uses this technique on various components. In the case of polycrystalline materials, the scattering of the ultrasonic wave can result in an important attenuation of the signal and the appearance of structural noise. In the present study, we propose to analyze scattering noise in relation to the microstructure of the material. Both experimental and 2D finite elements modelling results are presented for different controlled structure of an homogeneous and isotropic Ni-based alloy.