Previously, it was not possible to melt copper for complex 3D printed parts using an infrared laser.

The Fraunhofer Institute for Material and Beam Technology IWS in Dresden, Germany, has designed a green laser with wavelength much shorter than the typical infrared laser to melt copper powder during additive manufacturing. It enables new production approaches that previously could not be achieved with pure copper.

New AM system completely melts pure copper powder

“Previous experiments repeatedly showed that infrared (ʎ = 1064nm) laser beam sources of up to 500 watts are not efficient enough to completely melt copper,” explains Samira Gruber, who supervises the project as a research assistant at Fraunhofer IWS.

Only 30 per cent of the energy used reaches the copper material – the rest is reflected. With the green laser (ʎ= 515nm) at a maximum of 500 watts, the copper powder absorbs more than 70 per cent of the energy, and melts completely, which in turn permits its application in additive manufacturing.

Complex copper parts can be manufactured layer by layer

“Additively manufactured copper parts are superior to many aluminium solutions due to a higher volume-specific conductivity. This is particularly interesting wherever small designs and high performance are required,” says Elena Lopez, head of the additive manufacturing department at Fraunhofer IWS.

Complex components made of pure copper and copper alloys can now be built via AM for aerospace and automotive industries, and the efficiency of electric motors and heat exchangers can be increased. For example, more efficient and compact heat sinks for future power electronics can be manufactured, as well as particular individual coils for electrical drives in satellites, cooling systems in space propulsion systems, and many other parts.

https://www.iws.fraunhofer.de/en/pressandmedia/press_releases/2020/presseinformation_2020-07.html