Volumetric texture measurement of HCP metals from diffuse wave fields

Crystallographic texture in polycrystalline materials, such as in Hexagonal Close-Packed metals, strongly influences their mechanical and physical performance. Texture commonly develops during thermomechanical deformations that engineering metal components undergo during manufacturing, yet accurate bulk texture characterisation remains challenging, especially in components with curved geometries. This paper introduces a non-destructive ultrasonic methodology that combines Green’s function reconstruction from diffuse wave fields with ultrasonic texture inversion to enable volumetric texture characterisation in such components. Finite element simulations were employed to investigate and optimise the diffuse field generation process, assessing different phased array excitation strategies, including non-steered, beam-steered, and phase-shifted modes, with emphasis on improving the reconstruction accuracy of the longitudinal wave component. Directional wave velocities extracted from the reconstructed Green’s functions were processed using an established ultrasonic texture inversion framework to determine the bulk crystallographic texture. The reconstructed texture shows strong agreement with Electron Backscatter Diffraction measurements, demonstrating the accuracy of the proposed approach. The presented methodology extends ultrasonic bulk texture characterisation to curved components and broadens the applicability of ultrasonic techniques for non-destructive evaluation in engineering applications.