What alternatives to computed tomography for inspection of additive manufacturing parts with channels

Abstract

Non-destructive inspection of parts with small diameter channels is a major challenge. Additive Manufacturing (AM) offers many advantages compared to the traditional subtractive manufacturing process for the manufacturing of these complex structures. Thales, Safran and ArianeGroup joined forces to find a way to inspect parts with small diameter channels by technics other than X-ray computed tomography. LNE and Institut de Soudure (French welding institute) worked with them to identify, propose and test non-destructive techniques capable to detect flaws and cavities containing unfused powder unique to the powder-bed fusion AM process category. This paper will present some results of this project called FA- Canalsafe®. Artificial defects created on mock-ups will be described. Some results and limitations on eddy current testing and on visual endoscopy will be discussed. Finally, some recommendations on NDT implementation will be proposed.