Novel Thermosonic In-Process Nondestructive Evaluation of Additive Manufacturing Build

Metal additive manufacturing has become a new revolutionary for industrial manufacturing systems, providing a great potential for in-space servicing and manufacturing for NASArsquo;s mission. However, a primary challenge in this immature process is the lack of knowledge and controlling of the microstructure formation and evolution through this method, especially for the in-process interface between layers where defects are likely to be generated. Although after-process destructive inspection may provide information about the grainrsquo;s microstructure for the additively manufactured part, the after-process characterization does not reveal critical in situ information and thus the possibility for in situ correction. Therefore, any means to measure surface and buried defects in situ efficiently with a high spatial resolution would be highly desirable. To address this critical need, X-wave Innovations, Inc. (XII) proposes to develop an innovative optical-thermal-thermosonic-infrared (OTTI) imaging technology for the nondestructive, in-process inspection of critical flaws both on the layer surface and inside the welded build. The proposed NDE technique builds on the XII-developed multi-frequency thermosonic infrared technology, which is capable of detection of defects as small as micron-size. Combined with the optical and thermal imaging techniques, OTTI reveals unprecedented information in situ on defect formation between layers and microstructure evolution on the layers, which can lead to further in situ correction and control for the structure and quality of the building part during the additive manufacturing process.nbsp;