Influence of process parameters on stability, surface roughness, and defect formation in wire laser additive manufacturing at high deposition rate

The wire-based laser additive manufacturing (WLAM) process enables the large-scale production of metallic components with complex geometries. To ensure the integrity of the produced parts, it is essential to assess the quality of the printed material. For this purpose, this study is divided into three parts. The first part focuses on the stability of single-wire deposition using an instrumented test bench. The second part investigates the overlap ratio between successive passes, aiming to minimize surface roughness and ensure optimal printing of the 3D structure. The third part aims at characterize the macroscopic defects observed in 3D structures under various parameter sets. The study on single beads deposition reveals the existence of a stable domain, based on geometric stability and observations of the laser-material interaction. The second study determines the minimum surface roughness and the optimal layer height for different printing conditions, while also highlighting the relationship between surface quality and the wetting angle. The analysis of macroscopic defects across various parameter sets shows a strong correlation between the type of defect and the manufacturing conditions. This study identifies a stable WLAM operating window enabling high deposition rates with good geometric repeatability, though internal defects may still occur.