Powder Functionalization Of Pure Cu With Ag For Improved PBF-LB/M Processability

The Powder Bed Fusion- Laser Beam (PBF-LB) of pure Cu pose significant challenges due to the high laser-reflectivity and thermal-conductivity of this metal. Near-IR lasers are widely considered not suitable for processing Cu, unless high power is employed, limiting the accessibility to Cu. In this work, we investigate a disruptive approach to improve Cu processability by using a low-power (200 W) near-IR PBF-LB/M system, which is based on the Ag-coating of Cu particles that were heat-treated at 500°C/600°C to promote diffusion at the coating interface. Pure Cu and coated powder were processed by PBF-LB/M to produce bulk samples. Microstructure analysis was performed by SEM, EDX, and XRD. It was observed that the Ag layer has a positive effect on the laser processability of Cu. Almost fully dense materials (>98%) were achieved due to the formation of a Cu-Ag eutectic network able to heal pores and defects during solidification.