David Maass

Dave Maass has focused on developing insitu inspection and closed loop control methods for LPBF. Flightware work uses very high resolution profilometry of the melt layer after formation to assess quality of the solidified melt at the layer stage. This work has been funded by NASA, the Defense Logistics Agency and the Air Force over five programs. Current Air Force work focuses on the role of Spatter in the generation of AM flaws. Using profilometry, Spatter particles welded to the current melt layer can be reliably detected, located and measured. Statistical distributions of Spatter height, length and width confirm they can be surprising frequent and large, with heights often reaching 3 to 4 times the melt layer thickness. Welded Spatter can disrupt powder spreading and melting of subsequent layers, which then can lead to flaws such as pores and regions of porosity. In this program we use discrete Saptter information to repair and minimize each Saptter layer-by-layer via closed loop control. Mr. Maass has four decades experience in aerospace certification, structures, materials, processes and quality assurance with a recent focus on LPBF. He holds a BS and MS in Aeronautics and Astronautics from MIT and six patents.