A novel paradigm for feedback control in LPBF: layer-wise correction for overhang structures

In laser powder bed fusion (LPBF), it is common practice to select process parameters achieve high density parts starting from simple geometries such as cubes or cylinders. However, additive manufacturing usually adopted produce very complex geometries, where should be tuned locally, depending on the local features processed. fact, geometrical features, overhangs, acute corners, and thin walls may lead over- under-heating conditions, which result in inaccuracy, roughness, volumetric errors (i.e., porosity) even job failure due surface collapse. This work proposes a layer-wise control strategy improve precision of overhanging regions using coaxial melt pool monitoring system. The melt-pool images acquired at each layer are used control-loop adapt locally next order minimize defects. particular, duty cycle controllable parameter correct energy density. presents main architecture proposed approach, experimental procedure that need applied design parameters. was tested AISI 316L stainless steel an open LPFB platform. results showed solution constant observed via heated area size second onward, leading significant improvement accuracy 5 mm-long bridge geometries.