Feed-Forward Controls for Laser Powder Bed Fusion Based Metal Additive Manufacturing

The research objective of the proposed work is to demonstrate a prototype of a feed-forward control (FFC) system for the laser powder bed process to produce higher quality AM builds. The FFC will compensate for the systemic variability arising from the statistics of the additive layer, powder bed, and thermal phenomena. The compensation will be performed in near-real time on a full set of laser processing parameters. The proposed work will implement FFC as three subsystems to correct for the layer, powder bed, and thermal variability, respectively. The output of FFC for layer and powder bed variability will be input for FFC for thermal variability. The disturbance signals will be measured using VIS, SWIR, MWIR sensors and a 3D laser scanner. The sensors are selected to meet the cadence and resolution requirements for FFC, which will be performed on a layer-by-layer (L-L), track-by-track (T-T), and point-by-point (P-P) basis. Custom optics will be fabricated in order to enable cross-calibration of sensor data and improve the quality of FFC algorithms. A Navy component of current interest will be utilized to demonstrate build quality improvement using FFC.