HIGH-LAMBDA
Additive manufacturing of metal optics and optical framing components made of highly thermally conductive materials, "high-lAMbda"
Demonstrator made of pure copper by laser-assisted powder bed fusion.
Subproject:
Additive manufacturing of highly thermally conductive components using tailored laser radiation
The aim of the project is laser-assisted powder bed fusion (L-PBF) of highly thermally conductive materials. Laser-based 3D printing based on such extraordinary materials is particularly challenging due to the fact, that a large fraction of the applied laser energy is lost to areas of the already fabricated and therefore densified highly conducting 3D part. This effect alters the induced temperature during the processing extremely yielding an accumulated occurrence of lack of fusion defects. This problem cannot be easily solved by increased laser power due to the fact, that this would lead to severe fluctuations of the melt zone diameter yielding strongly reduced processing precision.
In the case of diamond-based composites, higher laser powers are particularly problematic, as high peak temperatures lead to burning (coking) of the diamond particles and a destruction of the material, respectively. In order to solve this problem, a new approach based on ultrashort laser pulse (USP) welding is applied. The use of USP radiation allows highly confined melting of the material, whereas the overall thermal load can be significantly reduced, and an permanently increased fabrication precision is achieved.
Fabricated highly conductive pure copper turbines based on laser assisted powder bed fusion (laser 3D printing).
Image: Univ. Jena, IAP