As the science and technology of additive manufacturing (AM) advance, an increasing number of safety-critical aerospace components will be manufactured by AM. Specific NASA missions with AM components include the Artemis Program's Orion Spacecraft and the Space Launch System, with Boeing as prime contractor. While AM has many benefits, there is a gap in the availability of reliable techniques to qualify the finished parts. Reliable qualification is especially important for safety-critical aerospace applications, as only parts that can be fully inspected can be certified for flight. In a previous NASA SBIR project, we demonstrated the feasibility of filling this gap by applying laser ultrasonic testing (LUT) for nondestructive evaluation of each AM deposited layer in real time as it is formed. This in-line inspection qualifies the part layer-by-layer, directs defect removal during the manufacturing process, and ensures qualified finished parts that require no further testing. In this proposal we describe a new type of laser ultrasonic sensor that will greatly improve the state of the art in inspection performance, leading to improved suppression of mechanical and acoustical disturbances. This performance improvement will in turn enable the implementation of a simpler and more agile beam setup and probe design. At the start of the project, we will be at TRL 3; at the end of the project, we will be at TRL 4. Potential NASA Applications (Limit 1500 characters, approximately 150 words): Additive manufacturing is finding broad applications by NASA and its contractors for the fabrication of high-value, safety-critical components. The enhanced in-line AM inspection system described in this proposal will enable the production of fully qualified AM parts to be used in the Orion Spacecraft and the Space Launch System. The inspection technology described in this proposal is aligned with the NASA Space Technology Roadmaps, and addresses needs described in the recent NASA memorandum "Nondestructive Evaluation of Additive Manufacturing." Potential Non-NASA Applications (Limit 1500 characters, approximately 150 words): Aside from space, industries that are adopting additive manufacturing include military and commercial aviation, automotive and consumer products. Aircraft engine suppliers have been investing heavily in capacity for AM parts manufacturing. Key high-value components such as injection nozzles are found multiple times in a turbine engine. The use of AM will reduce engine weight and cost. Duration: 6
