Modeling ultrasonic noise and attenuation in elongated duplex polycrystalline materials

Abstract : The interaction between ultrasonic waves and the polycrystalline microstructure of metals leads to structural noise and attenuation, which can cause significant losses in detection performances. Taking these phenomena into account in UT simulation can help designing suitable inspection procedures. It is possible to model them based on the intrinsic scattering coefficients of a material. Expressions of this coefficient valid for duplex elongated materials and for any mode and scattering direction are given in this communication. Structural noise from a titanium alloy was computed based on these expressions and is compared to measurement.