PENELOPE: A New Solution for Insitu Monitoring and Defect Removal in L-PBF

A new Laser Powder Bed Fusion (LPBF) prototype for in-situ monitoring of defects and in-situ and in-line flaw removal has been developed and patented in Politecnico di Milano (Italy). This prototype allows one to identify a defective layer thanks to an innovative in-situ monitoring approach that combines image and video-image data in the visible and infrared ranges. When the alarm is issued, the layer containing the defect is removed in-situ and in-line, thanks to a novel self-repairing system acting as a grinder on the powder bed. After this removal step, the following layers are additively produced starting from the healed height. By comparing specimens obtained with and without the intermediate layer removal, this preliminary study aims to investigating the feasibility of the methodology, showing that no discontinuity is introduced in the part by the novel in-line removal operation. This solution is conceived to enable novel zero-defect and first-time-right capabilities in additive manufacturing.