Defect visualization in billets by time reversal of scattered waves from defects

Abstract

There are several defect inspection methods for billets using ultrasound. One of the methods is pulse transmission with computerized tomography, and this method enables the visualizion of defects in billets. However, this method requires many paths to visualize. Therefore, we propose a method of time reversal of scattered waves from defects, which enables the visualization of defects with fewer paths. In this paper, we show the flow of our method and describe our experiment for evaluating the method. As a result, the image of defects visualized by our method is clearer than those of defects visualized by simple back-propagation methods. In addition, our method enables visualization of defects with fewer paths.