Resonant Ultrasound Microscopy with Isolated Langasite Oscillator for Quantitative Evaluation of Local Elastic Constant

A resonant-ultrasound-microscopy method has been developed for measuring the local Young's modulus of a material. This method detects the effective Young's modulus through the resonance frequency of a langasite (La3Ga5SiO14) oscillator touching the specimen. Because the vibration of the oscillator is induced and detected with a solenoid coil in noncontacting, wireless, and electrodeless way, it is affected only by its contact with the specimen, achieving an absolute measurement. Elastic-constant mapping was performed on cross sections of a duplex stainless steel and a NbTi/Cu superconducting wire. Analysis with the static contact stiffness predicts the frequency change smaller than that measured, and the necessity of considering the dynamic contact stiffness is discussed.Ogi Hirotsugu, Tian Jiayong, Tada Toyokazu, et al. Resonant Ultrasound Microscopy with Isolated Langasite Oscillator for Quantitative Evaluation of Local Elastic Constant. Japanese Journal of Applied Physics, 2005, 44(6S), 4381. https://doi.org/10.1143/JJAP.44.4381