Evaluation of additive manufacturing in fabricating ultrasonic calibration blocks

• Main Author: Tan, Derrick Chun Hong
• Other Authors: Brian Stephen Wong
• Format: Final Year Project
• Language: English
• Published: 2018
• Subjects: DRNTU::Engineering
• Online Access: http://hdl.handle.net/10356/74524
• Institution: Nanyang Technological University

Ultrasonic calibration blocks are currently being manufactured inefficiently, often through repeated trial and error. This project aims to evaluate the use of additive manufacturing in fabricating ultrasonic calibration blocks. Multiple defect blocks were additively manufactured by selective laser melting and were subjected to ultrasonic tests and computer tomography scans. An internal defect was also exposed to verify the authenticity of the non-destructive test results. The experimental results revealed that the additively manufactured internal defects were geometrically accurate, and are detectable from the conducted ultrasonic tests and computer tomography scans. However, it is also found that the internal defects can have a very rough surface. As it is currently impossible to improve the surface roughness of the additively manufactured internal defect due to technological limitations, it is concluded that additive manufacturing is not ready to replace current manufacturing methods of fabricating ultrasonic calibration blocks. Additive manufacturing has the potential to produce realistic defects in NDT calibration blocks, which can help to improve the reliability of NDT in the working industry. Therefore, the author believes that additive manufacturing has great potential in becoming a replacement to current manufacturing methods. It is possible that future technological advancements might enable the designs of defect blocks to be improved and selective laser melting can be further developed to handle miniscule surface roughness. Alternatively, other additive manufacturing methods can be considered in the production of the defect blocks.