Measurement of micro-region elastic anisotropy in textured metal by laser-ultrasonics

Abstract

Measurement of elastic anisotropy in textured polycrystalline metals is very difficult, especially the nondestructive testing of the elastic anisotropy of micro-regions. In this paper, the angular dependence of surface acoustic wave velocity affected by texture in micro-regions is measured by the laser ultrasonic method, and a method for calculating elastic anisotropy based on angular dependence of surface acoustic wave velocity is discussed. The results show that the elastic anisotropy calculated by the angular dependence of the surface acoustic wave velocity fits well with the measured elastic anisotropy, and the elastic anisotropy in micro-scale regions can be characterized well by the laser ultrasonic method. In addition, a calculation model of the elastic modulus at different temperatures based on the elastic modulus at 25 °C is given, and the elastic modulus at different temperatures is also calculated, which fits well with the experiment results. This model can be used for nondestructive testing of the elastic modulus in micro-regions.