Acoustic properties of standard specimens for the line-focus-beam ultrasonic material characterization system - synthetic silica glasses

摘要

Bulk acoustic properties of four kinds of synthetic silica glass specimens as standard specimens to calibrate the line-focus-beam ultrasonic material characterization (LFB-UMC) system are measured with high accuracy around 23℃. All the specimens with highly elastic homogeneity are made by the direct method through the hydrolysis of ultra-high-purity SiCI4 in an oxygen-hydrogen flame. Accurate values of the acoustic properties of longitudinal and shear velocities, and densities are obtained, although the effective figures are dominated mainly by the measurement accuracy of the specimen thickness. Some significant differences in the acoustic properties and the thermal coefficients of both longitudinal and shear velocities among the specimens are detected. The difference might be due to different amounts of impurities such as hydroxyl and chlorine ions incorporated and some differences in thermal history during the production process. And, it is shown that the LFB-UMC system is calibrated with higher accuracy for the leaky surface acoustic wave propagation characteristics of the synthetic silica glass specimens.