Nondestructive Material Characterization with Laser Ultrasound

A Remote Laser System for Material Characterization

For many years, new techniques have been developed to overcome the problems involved with the generation and detection of ultrasound in materials at high temperature [1,2]. A non-contacting technique is described using lasers to generate and detect ultrasound and which can be used to study the variation in acoustic velocity as a function of temperature. Results are presented for the change in l...

Direct Imaging of Anisotropic Material Properties using Photorefractive Laser Ultrasound

Anisotropic properties of materials can be determined by measuring the propagation of elastic waves in different directions. A laser imaging approach is presented that utilizes the adaptive property of photorefractive materials to produce a real-time measurement of the antisymmetric Lamb or flexural traveling wave mode displacement and phase. Continuous excitation is employed and the data is re...

Nondestructive Material Testing with Ultrasonics Introduction to the Basic Principles

Laser-flash-photolysis-spectroscopy: a nondestructive method?

Herein, we report the effect of the laser illumination during the diffuse-reflectance laser-flash-photolysis measurements on the morphological and optical properties of TiO2 powders. A grey-blue coloration of the TiO2 nanoparticles has been observed after intense laser illumination. This is explained by the formation of nonreactive trapped electrons accompanied by the release of oxygen atoms fr...

Fast Inversion Calculation for Full-field Measurement of Material Properties with Quantitative Laser Ultrasound Visualization System

This research employs a nondestructive, rapid, high accuracy and full-field material characterization platform which integrates quantitative laser ultrasound visualization system (QLUVS) with mechanical property mapping reconstruction algorithm. The QLUVS uses a pulsed laser generate acoustic waves with fast scanning mechanical to research two dimensional scanning goal and then detected with a ...