A Mini-review on Non-destructive Techniques for Additive Manufactured Metal Parts

Worldwide the additive manufacturing technology is used on large scale, on different fields of application, not only when unique parts are needed. Therefore, the manufacturing process must be carried out based on a clear procedure and work instructions, the traceability of the entire process must be assured and acceptance criteria must be settled. A big role in the entire quality control chain is the test methods used to characterize the metallic parts fabricated. This article aims to provide an updated mini-review on the non-destructive testing (NDT) approaches used to identify defects related to the powder-based additive manufacturing (AM) technologies. The mini-review aim is to provide an overview on different NDT methods suitable for different types of manufacturing related flaws and defects. In the carried out study, several factors were taken into consideration, such as: laser power, scan speed, layer thickness, hatch distance, powder feed rate, powder size distribution, and powder particles surface chemistries. All this process parameters and powder characteristics have impact on microstructural features of AM components (e.g., grain size, texture, etc.) and are the cause of defects appearance. After reviewing the NDT approaches, a good practice short guide is presented in the paper.