Geometric and hardness characterization of additively manufactured copper using bound powder extrusion with thermal sintering

“Recent advancements now allow for high thermal conductivity metals
such as copper to be additively manufactured and will allow for the applications
of the technology to be broadened in the field of heat transfer. In this study, copper
samples were additively manufactured using a bound powder extrusion process
and then characterised in terms of hardness, porosity, mass, volume shrinkage and
surface roughness. It was found that this additively manufactured material has a
significantly reduced hardness when compared to pure copper and a porosity of
between 32-38%. During the manufacturing process a mass loss of up to 8% and
a volume loss of up to 28% was seen compared to the original printed part. The
surface roughness (Ra) on the sides of the sample was 14 µm while the tops and
bottoms of the sample had a surface roughness 8 µm, both significantly higher
than parts produced with traditional machining processes. Designers of heat
exchangers that makes use of bound powder extrusion will thus have to
compensate for geometry changes between the initial print and final part as well
as reduced hardness (and likely strength). Greater porosity and roughness of their
parts will also have to be considered, which in some cases like boiling can be an
advantage, while in convective heat transfer may be disadvantage.”

Full paper published to MATEC Web of Conferences in 2024 https://www.matec-conferences.org/articles/matecconf/pdf/2024/18/matecconf_rapdasa2024_07017.pdf