Production of CuCrZr parts via the IR laser powder directed energy deposition through powder modification

Official URL: https://dx.doi.org/10.1016/j.apt.2025.105152

Additive manufacturing (AM) of copper-based alloys has gained massive attention from different industries due to their wide application in thermal management systems. However, processability of copper alloys remain challenging due to the high laser reflectivity and thermal conductivity. The aim of this work is to develop a cost-effective process for producing near defect-free parts from CuCrZr alloy via the laser powder directed energy deposition (LP-DED) technique. For this purpose, a thermal coating procedure was established and implemented in order to increase the laser absorptivity of this alloy by forming an absorptive layer around the powder particles, as well as increasing their surface roughness. The results showed that the combination of oxidation and nitriding procedures formed a stable and thick layer around the powder particles that can effectively improve the processability of this copper alloy and increase the density of the bulk specimens by increasing the melt pool stability. The optimized process parameters successfully resulted in near-fully dense bulk parts without using excessive input heat that could have damaged the optics and nozzle. The obtained microstructure from the bulk samples revealed finer grains for the treated powders due to the formation of coarser precipitates, which resulted in comparable mechanical properties.