Vision-based in-situ monitoring system for melt-pool detection in laser powder bed fusion process. (August 2021)

• Record Type: Journal Article
• Authors: Le, Trong-Nhan; Lee, Min-Hsun; Lin, Ze-Hong; Tran, Hong-Chuong; Lo, Yu-Lung
• Is Part Of: Journal of manufacturing processes. Volume 68:Part A(2021)
• Page Start: 1735
• Page End: 1745
• Publication Date: 2021-08
• Subjects: L-PBF -- In-situ monitoring -- Melt-pool measurement -- IN718 -- SS316L; Production management -- Data processing -- Periodicals; Manufacturing processes -- Periodicals; Procestechnologie; Productietechniek; Production -- Gestion -- Informatique -- Périodiques; Fabrication -- Périodiques; Manufacturing processes; Production management -- Data processing; Periodicals; 670.5
• DOI: 10.1016/j.jmapro.2021.07.007
• Languages: English
• ISSNs: 1526-6125

Abstract

Abstract: A low-cost, lateral off-axis non-IR imaging system is proposed to inspect the melt-pool in the Laser Powder Bed Fusion (L-PBF) processing of IN718 powder and stainless steel 316 L powder. In the proposed system, a perspective transformation method is applied to transform the captured side-view image into a top-view image and the melt-pool boundary is then determined based on an inspection of the gray-level intensity profile of the captured image and its first derivative. For the IN718 L-PBF process, the measurement results obtained for the melt-pool width and melt-pool length vary by no more than 13% and 3%, respectively, from the experimental results reported in the literature. For the SS316L, the measured melt-pool width is within 6% of the ex-situ measurements obtained by optical microscopy, while the melt-pool length differs by no more than 9% from the numerical predictions. Overall, the results show that the proposed system provides a viable means of detecting potential build failures during the L-PBF process and improving the yield of the fabrication process as a result.