Study and understanding of ageing, recycling and plasma treatment of an aluminium alloy powder for additive manufacturing by Laser Powder Bed Fusion (L-PBF) – APR2-POWDER

The aim of the "APR2-POWDER" project is to provide solutions to major industrial challenges encountered in the field of laser powder bed fusion (L-PBF) additive manufacturing. These challenges include the storage of reactive powders such as aluminium and the recycling of powders after laser melting.

The study of aluminium powder storage requires a more fundamental scientific approach based on the observation and understanding of phenomena occurring at the surface scale of aluminium powder particles. Fine powders tend to adsorb ambient moisture, causing chemical reactions with the formation of oxide and hydroxide compounds on the surface of particles. The effect of the laser on this powder can induce various problems in the produced parts, such as increased oxygen content and/or the formation of hydrogen porosities. We will rely on state-of-the-art surface characterization techniques to correlate microscale and nanoscale phenomena with the macroscopic behaviour of the powder.

One of the innovations of the project is the use of inductive plasma treatment of powders to improve the surface state of particles, reduce moisture uptake and facilitate storage. We will also use this technique to treat the powders used in L-PBF laser melting to recondition them to meet initial specifications for direct reuse in the manufacturing cycle.

In terms of industrial interest, this project aims to propose optimal methods for the storage and reconditioning of aluminium powders with limited technical constraints (storage conditions and handling procedures) and reduced environmental impact. The use of the potential of inductive plasma treatment for powder reconditioning for direct reuse will constitute a promising new w ay for the recycling of aluminium powders in L-PBF additive manufacturing.