[FrostKiwi]

Those are solved issues.

> oxidation at high temperatures

SLM machines typically use an Argon gas chamber. DED machines use an Argon gas shield.

> It’s more typical to print copper alloys than pure copper.

In the context of modern SLM, it depends on your definition of "pure" and "alloy". During the process, a bit of resin to is mixed into the powder and heat treated in a final step to get to 99.9% pure copper.

edit: Just fixed up my knowledge. Indeed alloys are typically used (99% copper with things like Chrome added on depending on use-case), tough the pure copper can be used with higher laser power.

[ju-st]

Printing pure copper (99.9%) is possible since years with SLM process using lasers with an appropriate wavelength

[tbenst]

Any references for 99.9% density with SLM copper? My understanding is that pure copper SLM printing is less frequently done as doesn’t work well with the infrared lasers on most machines, requires high heat & speed, and has more porosity than other alloys. It’s also hard to print so that it’s strong, conductive and heat stable.

I think there’s still quite active research in the area, though, and no doubt there’s a lot going on that I don’t know! https://www.sciencedirect.com/science/article/pii/S026412752...

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10861549/

[ju-st]

Sorry I wasn't talking about density but the copper content of a powder which is printable. Googling a bit I found this presentation from 2022 showing that a density of 99.5% for pure copper is possible although at half the productivity of a copper alloy https://www.coppercouncil.org/wp-content/uploads/2022/02/TS2...

[FrostKiwi]

> doesn’t work well with the infrared lasers

The copper use-case is what kick-ed off an industry-wide race towards offering blue laser as an option. There is more than just wavelength that goes into printing good copper results, but that is a major factor.