Metal filament is mostly fine metal powder held together by a polymer binder. It prints on an ordinary FDM printer, and the printed part, called a green part, is then heated in a kiln. The binder burns away and the metal particles fuse into a dense, all-metal part.
The workflow
- Print the green part on an FDM printer, typically with a hardened nozzle because metal-filled filament is abrasive.
- Embed the part in refractory ballast inside a crucible to support it during firing.
- Debind and sinter in a kiln on the manufacturer's firing schedule. Some metals also need a carbon or reducing atmosphere.
- Finish by sanding, polishing, machining or tapping like any metal part.
Plan for shrinkage
Parts shrink as the powder densifies, so models are scaled up before printing. Each material publishes its own shrinkage and firing schedule, and test coupons are the best way to dial in a new geometry.
What you can make
Stainless steel 316L and 17-4, copper, bronze, M300 tool steel, Inconel 718, high carbon iron, tungsten for radiation shielding, plus porcelain, silicon carbide and glass for ceramic parts.
What you need
A capable FDM printer, the filament, a sintering kiln, a crucible, refractory ballast and kiln paper. The getting-started bundles group the consumables so a first firing goes right.
