In-situ monitoring and quality control for in-space additive manufacturing using laser acoustical resonance spectroscopy

摘要

The paper describes and demonstrates a non-destructive evaluation method that can perform in space, in situ, and postproduction inspection for metallic and non-metallic products of additive manufacturing. The method, which is based upon measuring the vibrational spectrum of an object and using it as a unique acoustical signature is capable, not only of detecting defects and flaws, but also doing this in situ. The method combines Laser Doppler vibrometry with acoustical resonance spectroscopy to extract acoustical information from exposed layers during the printing process to characterize the part at any stage during its manufacture. Component samples with intentional defects were printed and correlated with vibrational signatures. In future work we plan to develop the necessary hardware and software to adapt and integrate the inspection system into commercial printing machines. The resulting machine will feature in situ monitoring of typical parts while being printed in the machine.