Start-up supported by ESA TIWARI scientific instruments succeeded in 3D printing complex geometries using pure copper material with its RAPTOR Bonded Filament Extrusion (FFF) 3D Printer, obtaining high density, oxygen-free copper parts. Examples of these high resolution parts are shown in the images above and below. They include heat exchangers, which were designed using nTopology, simulated via SimScale, and manually optimized for performance.

Copper has long been on the wish list of AM adopters and its potential use for heat exchangers, due to its high thermal conductivity, has been well documented. However, processing pure copper in powder or filament form has proven to be extremely difficult.

Recent developments in copper AM have successfully deployed green lasers for the production of 3D printed copper parts by powder bed laser fusion (L-BPF). However, improving the surface finish for demanding applications may require additional machining / post-processing and this may affect the post-processing purity of copper parts. With FFF parts can be printed with a layer thickness of approximately 50 µm. After sintering, the roughness due to the thickness of the layer tends to be even lower due to shrinkage. Additionally, parts can be manually polished to a green state, further reducing the cost associated with post-processing.

TIWARI’s EAM technology is suitable for the cost-effective production of ceramic and metal parts using Fused Filament Manufacturing (FFF) technology. The process uses specially fabricated bonded metal or ceramic filaments that are shaped into the desired geometry using specially developed in-house FFF printers. The printed “green parts” can then be machined to include additional detail in the parts and improve the surface finish, after which they are then heat treated at high temperature to remove the binder and sinter the part. RAPTOR produces metal and ceramic parts with a relative density of over 99%.

TIWARI currently supports both metals including copper, stainless steel (316L and 17-4PH), titanium (Ti6Al4V) and ceramics including alumina (Al2O3), silicon carbide (SiC ), silicon nitride (Si3N4), tungsten-cobalt carbide (WC-Co), zirconia (ZrO2), molybdenum disilicide (MoSi2). TIWARI also carried out a qualification campaign for its metals and ceramics in collaboration with ESA.