Bi-Modal Technology for In-situ Defect Detection in Additively Manufactured Parts

A bi-modality approach is proposed to offer in-situ assessment on the AM deposition layer porosity levels. By leveraging High-Speed Hyperspectral Imaging (HSI) and Phase-Shifting Vibrometry (PSV). We aim to provide real-time assessments on the newly deposited AM layer by monitoring, with improved accuracy, the temperature and emissivity of the build material melt pool. Furthermore, the proposed PSV monitors how acoustic waves’ phases vary over the AM layer and offer assessments on the underlying porosity of the AM layer. The information gathered can ultimately be fed into the growth processes of the AM part and offer in-situ rectification of any potential defects like pin holes and porosity. Proven successful, the proposed technology can enhance greatly the confidence on the quality of the grown AM part. Feasibility studies are to be carried out in the Phase I program in which AM samples of varying porosity levels are to be grown, evaluated by the proposed technology, and corroborated by X-ray Ct scans. Finally, failure testing will be conducted on the AM samples to correlate their strength/reliability with findings from the proposed bi-modal technology. Approved for Public Release | 20-MDA-10643 (3 Dec 20)