Porosity Evaluation of Additive Manufactured Parts: Ultrasonic Testing and Eddy Current Testing

Abstract

This study was conducted to investigate the effectiveness of ultrasonic testing (UT) and eddy current testing (ECT) for the porosity evaluation of additive manufactured (AM) parts. AM samples containing different levels of porosity were fabricated at varying laser scanning speeds. The porosity of each sample was evaluated through scanning acoustic microscopy, which was adopted as reference. For UT, the ultrasonic velocity and ultrasonic attenuation coefficient were measured with an ultrasonic contact transducer using the traditional pulse-echo method. For ECT, the electrical conductivity was measured using an eddy current electrical conductivity meter. The relationship between the measured parameters and the porosity content showed that an increase in the porosity content decreased the ultrasonic velocity, increased the ultrasonic attenuation coefficient, and decreased the electrical conductivity. UT was preferred in terms of measurement sensitivity, whereas ECT facilitated a simple setup and high inspection speeds.