Abstract :
Most engineering materials are multiphase polycrystalline aggregates displaying macroscopic anisotropy (texture). The texture influences a number of very important material properties, such as its drawability, strength, etc. Recently, ultrasound was used to characterize the texture in single-phase materials, such as polycrystalline Fe, Al, Cu (cubic) or Ti, Zr Mg (hexagonal). However, in practice the materials are often composed of several different phases, e.g., α-hexagonal and β-cubic grains. In this paper the author attempts to characterize the texture in multiphase materials, composed of an arbitrary number of cubic and/or hexagonal phases, employing angular variation of phase velocity of bulk longitudinal, Rayleigh surface waves and other ultrasonic modes. Measurements were performed in two-phase zirconium samples composed of about 90-95% α-hexagonal and 5-10% β-cubic grains, using a fine focus acoustic microscope. The texture coefficients determined ultrasonically were compared to those measured by neutron scattering technique
Keywords :
acoustic microscopy; texture; ultrasonic materials testing; zirconium; Rayleigh surface waves; Zr; bulk longitudinal modes; cubic-hexagonal materials; fine focus acoustic microscope; line focus acoustic microscope; macroscopic anisotropy; multiphase materials; multiphase polycrystalline aggregates; texture characterisation; two-phase materials; ultrasonic modes; Acoustic measurements; Aggregates; Anisotropic magnetoresistance; Iron; Material properties; Surface acoustic waves; Surface texture; Ultrasonic imaging; Ultrasonic variables measurement; Zirconium;