> I don't actually understand how Markforged and BASF can print with a material that obviously becomes runny at about 250°C, and yet retains its shape while in the sintering furnace at 1300°C. It would be good to learn more about how this works.
A blind guess: the original filament has a resin to make the metal powder flow, that becomes viscous at certain temperatures. Perhaps this resin could be volatile and evaporate at temperatures below its viscous temperature.
Or maybe it could be quickly burned off by supplying extra oxygen (so that burning temperature isn't high and there's not enough time for the piece to deform).
In any case you could probably introduce some kind of automatic software correction for the deformation to the piece. As noted in the article this has some limitations/drawbacks, like limiting some geometries you can achieve (and requiring careful knowledge/control of your process).
The binder is something like PLA, and it binds powdered metal. The metal particles are quite small.
The low percentage basically puts plenty of metal into contact with other metal. This tends to hang together fairly well.
There is a process shrink, and it can be something on the order of 20 percent.
The 3D printed "Green" part is actually substantial. It can be machined, polished, drilled, etc...
One trouble area is support materials. Putting filament containing metal onto a support filament, like HIPS, can work. HIPS on top of metal generally doesn't.
One can use the same base polymer for both over and under support, but that can be difficult to remove. Often the metal filament itself is used. This is messy, can be difficult, but does generally work for most geometries.
The metal part can "wick" other metals during sintering too. Making a bronze with a copper "green" part with the other metal present in the oven works better than one might think.
I have yet to find a great use, other than art pieces and or simple metal shapes that could be machined at lower cost and difficulty.
A blind guess: the original filament has a resin to make the metal powder flow, that becomes viscous at certain temperatures. Perhaps this resin could be volatile and evaporate at temperatures below its viscous temperature.
Or maybe it could be quickly burned off by supplying extra oxygen (so that burning temperature isn't high and there's not enough time for the piece to deform).
In any case you could probably introduce some kind of automatic software correction for the deformation to the piece. As noted in the article this has some limitations/drawbacks, like limiting some geometries you can achieve (and requiring careful knowledge/control of your process).