Characterization of texture in hexagonal materials using a line focus acoustic microscope

A line focus acoustic microscope (LFAM) was used to measure the angular distribution of longitudinal surface skimming waves in Zr-2.5% wt. Nb samples exhibiting orthorhombic macroscopic symmetry. Using the information from longitudinal wave scans obtained on three principal planes, the authors attempt to determine as much information as possible about the five independent texture coefficients, W/sub lmn/, without any prior knowledge of the single-crystal elastic constants. In general, it is found that only ratios of the texture coefficients and the isotropic longitudinal velocity component can be determined from the ultrasonic measurements, when performed on hexagonal materials with orthorhombic macroscopic symmetry. The results are averaging method independent and do not require any information about the density of the material.<
>