Metallic 3D printing in micro/zero-gravity Jun 24, 2019 0:15:55 GMT
Post by doctorsquared on Jun 24, 2019 0:15:55 GMT
Jun 2, 2019 6:49:02 GMT anonymous said:How can additive manufacturing work for metals in orbit? The only way that I know of to "3D print" metals is with a power bed, but this requires gravity to keep the power flat on the base plate. I don't think that liquefying metal and printing it the same way as melted plastic filament is viable but I might be wrong. I found some mentions of it on Google but no explicit explanation of how it works.
There are a few other options:
Desktop Metal uses a FDM (Fused Deposition Manufacturing) process using plastic rods infused with the metal powder being used. Parts are printed on an FDM printer, the polymer is evaporated in a solvent bath (which could work in zero-g if kept under pressure or in a centrifuge), and then the remaining metal part is sintered in a furnace.
Admatec and Tethon3D have developed a DLP (Digital Light Processing) process that suspends the metal powder in a UV-curable polymer resin. A build plate is submerged in the resin tank and an LCD display covering a UV light source turns its pixels on and off the selectively cure the resin, layer by layer into the final part. It is then sintered in a sintering furnace to densify the part. This could work in zero-g since the printer could be rotated in a centrifuge or an inert atmosphere within the printer could be pressurized to help hold the resin bath in place.
Arcam AB (now owned by GE) and Chervona Hvilya melt a metal wire (fed similar to an FDM plastic filament) with an electron beam source to form metal parts that don't require sintering. This method is currently used by General Electric's aviation division to build turbine blades for jet engines and is better suited to building larger-scale components.
Other processes like metal injection molding or extrusion would also probably work in zero-g since those processes rely on pressure and fluid flow, rather than gravity to make it work.