In Situ Inspection of Additive Manufactured Metallic Parts Using Laser Ultrasonics

Additive manufacturing (AM) is a very promising technique for rapid, low-cost production of aircraft parts directly from a CAD file. AM is especially appealing for complex parts that would be costly or impossible to fabricate by machining or casting. At the current time there are no reliable, cost-effective techniques to qualify the finished parts. Several government studies have noted this gap and urged increased efforts to develop improved techniques for part qualification. In this project we will demonstrate the feasibility of applying laser ultrasonic testing to evaluate each deposited layer in real time during the build process. This in-line inspection has the benefit of part qualification layer-by-layer, ensuring finished parts that require no further testing. In Phase I we will team with Penn State Applied Research Laboratory, which will supply samples with well characterized defects and give general technical guidance. We will then optimize the beam configuration for the best sensitivity to these defects, and also develop signal processing algorithms to enhance the defect detection threshold and collect size information. In Phase II a prototype in-line inspection system will be developed and tested on a production machine.