Research examines the best ways to monitor defects in additive manufacturing
BROOKLYN, New York, Monday, September 19, 2022 — Additive manufacturing (AM) — commonly referred to as 3D printing — involves manufacturing processes that depend on a set of user-defined optimized parameters. Monitoring and controlling these processes in real time can help achieve operational stability and repeatability to produce high quality parts. By applying in-situ monitoring methods to AM procedures, defects in printed parts can be detected.
In a new review in the journal Elsevier Materials & Design, Nikhil Gupta, professor of mechanical and aerospace engineering and director of the Composite Materials and Mechanics Laboratory at NYU Tandon, and Youssef AbouelNour, doctoral student under Gupta’s supervision, examine the application of the two imaging and acoustic methods for the detection of subsurface and internal defects.
Imaging methods consist of visual and thermal monitoring techniques, such as optical cameras, infrared (IR) cameras and X-ray imaging. Data is abundant as many studies have been conducted proving the reliability of the imaging methods in the monitoring of the printing process and the construction area, as well as in the detection of defects.
Acoustic methods rely on acoustic sensing technologies and signal processing methods to acquire and analyze acoustic signals, respectively. Raw acoustic emission signals can be correlated to particular defect mechanisms using feature extraction methods. In their review, Gupta and AbouelNour discuss the processing, representation and analysis of data acquired in situ from imaging and acoustic methods. They also introduce ex situ testing techniques as methods for verifying results obtained from in situ monitoring data.
Among their revelations:
- In-situ process monitoring methods can create a closed-loop AM process capable of correcting and controlling faults, to ensure process stability and repeatability
- Integrating monitoring and machine learning methods into the AM process can help continuously assess the quality of material deposition and develop intervention methods to correct defects in situ.
- And the use of X-ray computed tomography can lead to a thorough evaluation of defects, as well as an assessment of the quality of in situ monitoring methods.
- Integrating quality monitoring methods with manufacturing methods eliminates the need to perform quality assessment separately, which can save considerable time.
Additionally, Gupta was honored this year as a member of ASM International, a global organization of more than 20,000 members. The organization recognized Gupta for his “pioneering contributions to the science and technology of lightweight polymer and metal matrix composites” and his outstanding dedication to educating the public about scientific discoveries.