Laser-based ultrasound detects defect-producing features in metal 3D printingLawrence Livermore Nati
Laser-based ultrasound detects defect-producing features in metal 3D printingLawrence Livermore National Laboratory (LLNL) researchers have developed a new all-optical ultrasound technique capable of performing on-demand characterization of melt tracks and detecting formation of defects in a popular metal 3D printing process. In a paper published by Scientific Reports, lab researchers propose a diagnostic using surface acoustic waves (SAW), generated by laser-based ultrasound, that can reveal tiny surface and sub-surface defects in laser powder bed fusion (LPBF) metal 3D-printing. The team reported the system they developed can effectively and accurately evaluate laser melt lines—the tracks where the laser liquifies metal powder in LPBF printing—by scattering acoustic energy from melt lines, voids and surface features that can be quickly detected. The team validated the findings using optical microscopy and X-ray computed tomography (CT).“We hope that this work demonstrates the potential for an all-optical ultrasound system capable of rapid, on-demand in situ characterization of LPBF processes and powders,” said LLNL engineer and principal investigator David Stobbe. “The demonstrated laser-based ultrasound, surface acoustic wave system showed excellent sensitivity to surface and near-surface features, including breaks in the LPBF melt line, metal surface splatter and subsurface air voids.”Read more. -- source link
#materials science#science#acoustics#defects#3d printing#metals#ultrasound#lasers