Detection of Defects in Solidified Layers within Laser-based Powder Bed Fusion using Active Thermography

During the metal-based additive manufacturing process "laser-based powder bed fusion" (Short: PBF-LB/M) even minor deviations from the required process conditions, e.g. changes in the layer thickness or a reduction in the inert gas flow, can lead to defects and thus negatively affect the quality of the components. In the field of non-destructive testing, heat flow thermography is an established method for detecting defects close to the surface. In this paper, a method to investigate the potential of non-destructive testing by means of a laser as an excitation source for active thermography and the results for the material 1.4404 are presented.