Finite Element Simulation of Laser-Synthetic Aperture Focusing Technique (SAFT) Detection of Additive Manufactured Parts

• Published in: Russian journal of nondestructive testing Vol. 59; no. 3; pp. 332 - 345
• Main Authors: Jiang, Yi, Han, Lei, Wang, Zhaoxin, Wang, Haitao, Shen, Zhongwen
• Format: Journal Article
• Language: English
• Published: Moscow Pleiades Publishing 01.03.2023; Springer Nature B.V
• Subjects: Acoustic Methods; Algorithms; Austenitic stainless steels; Characterization and Evaluation of Materials; Chemistry and Materials Science; Computer simulation; Defects; Finite element method; Imaging; Inclusions; Laser beam melting; Longitudinal waves; Materials Science; Mathematical models; Mechanical properties; Structural Materials; Synthetic apertures; internal defects of AM parts; synthetic aperture focusing technique; laser ultrasonic; non-estructive detection; ultrasonic imaging
• ISSN: 1061-8309; 1608-3385
• DOI: 10.1134/S1061830922601040

Selective laser melting (SLM) is an important method of additive manufacturing (AM). However, due to the large temperature gradient, defects such as pores and inclusions are easily visible during the printing process, affecting the forming quality and internal mechanical properties of the parts. This paper proposes a lase-SAFT detection method based on longitudinal wave to detect internal defects in additive parts. The mathematical model of the laser-SAFT algorithm is developed, and simulation research on the quantitative detection technique of AM 316L steel’s internal defects is conducted. A de-artifact approach based on wave mode and flight duration is presented to increase the accuracy of imaging results. The detecting impact of double-defect within the AM 316L steel is also modelled. Finally, the SAFT imaging of various locations and sizes of defects in the AM 316L steel, as well as the SAFT imaging detection of double-defect, are accomplished.