Fabrication of artificial defects using 3D printing for non-destructive testing applications

• Main Author: Lee, Kai Ling
• Other Authors: Xiao Zhongmin
• Format: Final Year Project
• Language: English
• Published: Nanyang Technological University 2021
• Subjects: Engineering::Aeronautical engineering
• Online Access: https://hdl.handle.net/10356/150487
• Institution: Nanyang Technological University

In non-destructive testing, test parts are traditionally manufactured using conventional manufacturing technology for training purposes. In this study, the use of ultrasonic technique will be carried out to consider the feasibility of a specimen with an artificial defect manufactured using additive manufacturing instead of conventional manufacturing technology. Specifically, this study will investigate the nature of selective laser melting additively manufactured AlSi10Mg. Only one specimen with an uncommon sub-surface defect was fabricated due to budget and time constraint. The defect was designed to challenge the limitations of ultrasonic testing when it comes to detecting unusual-looking (jagged) defect. Microscopic testing was performed on the printed specimen to assess the accuracy of additive manufacturing technology. Ultrasonic ‘A’ and ‘C’ scans were calibrated in accordance with the characteristics of the printed specimen before the tests were carried out to ensure better accuracy. A dimensional analysis has been for all experiments conducted for this research. Ultrasonic ‘A’ scan is successful in locating the top of the defect but failed to determine the exact characteristics (shape) of the defect. Also, the 6 dB drop technique was found to be ineffective in accurately measuring the width of the defect. On the other hand, ‘C’ scan was successful in locating the height, length and width of the defect with very small deviation. Likewise, it was unable to accurate plot out the jagged shape of the defect. This study suggested that fabricating sample specimens for non-destructive testing applications using additive manufacturing in place of conventional manufacturing method is impractical.