Interfacial analysis by optical monitoring of layer level multi-material parts fabricated via Powder Bed Fusion–Laser Beam

This experimental work aims to contribute to the development of Powder Bed Fusion–Laser Beam (PBF-LB) processes for the fabrication of multi-material structures by studying the interfacial characteristics using an off-axis optical monitoring system and relating in-situ results with metallurgical and mechanical properties of built parts. The study was developed employing an innovative approach for intralayer multi-material fabrication by PBF-LB, based on the use of a partitioning system in the powder chamber. Image analysis was used to extrapolate information needed to describe possible contamination effects between powders, the size of the interface and the presence of metallurgical defects. Chemical, metallographic and statistical analyses were also carried out to study the interface between the two materials of the samples and to support the results from optical monitoring. The results showed that the optical monitoring system enables real-time verification of the required quality parameters during the joining of different materials with PBF-LB processes.