Depth Detection of Internal Defects for Arc Additive Products Based on Laser Ultrasound

Abstract

Aiming at the problems of poor surface quality of additive products and difficulty of on-line detection of internal defects, the research of laser ultrasonic detection of internal defects for arc additive manufacturing test block was carried out. In order to ensure the accuracy of defect detection results, defect reflection method and synchronous movement of excitation source and receiving source way were adopted. The theoretical calculation, the simulation analysis and experimental results were contrasted, the propagation paths and detect wave type were determined. Defects in A sweeping reflection amplitude and defects in B scan reflected wave imaging were obtained respectively, according to the amplitude size and the imaging results. In depth of 10 mm, the internal defects 1 mm diameter were accurately detected, the influence laws of defect depth were obtained. The research results have a good reference value for the on-line detection of additive manufacturing.