Nondestructive Evaluation with Laser Ultrasound of Powder Bed Fusion Printed Metal Parts

Abstract

Introduction/Purpose Many of the main advantages of 3D printing metal components, for example the possibility to manufacture components of high geometriccomplexity in small series, typically make the nondestructive quality control difficult and resource intense. A number of published studies haveproposed in-process quality control of the component, as it is built layer by layer, as a possible general approach solution to this difficulty. Previousstudies have also indicated that the non-contact nondestructive testing method laser ultrasound might be an applicable method to conduct such anin-process nondestructive evaluation of 3D printed components. Methods In this work laser ultrasonic nondestructive evaluation of both electron beam and laser beam powder bed fusion printed metal parts isdemonstrated. Nickel-base and Stainless Steel samples are evaluated both from a machined surface and, in order to simulate the in-process setup,from the as-printed top surface. Results The laser ultrasonic evaluation results are compared to results from other material characterization methods. Designed artificial defects as well asprocess material anomalies could be detected with the proposed laser ultrasonic evaluation, both when the evaluation was performed from the asprintedtop surface as well as from the machined surface. Conclusions We conclude that laser ultrasound can be utilized to detect material anomalies of interest in powder bed fusion printed metal parts. Furtherresearch is required in order to better understand and improve the capability and reliability of the nondestructive evaluation method.QC 20190930</p