Do you mean having a blob of molten metal floating in a chamber? Surface tension means it won't keep a shape. (I guess you could make cheap ball bearings.) If you get around that, any time you touch the blob it would start rippling and ripples won't really damp out. Might make for some pretty sculpture if you can flash freeze it, but nothing of industrial value.

Unless you are trying to obliquely refer to casting, which should be pretty much identical with or without gravity/air. And still needs tooling to make the molds.

(And please don't say that the molten metal could be a feedstock for a printer. That would be a circular discussion.)

Um, but metal doesn't just freeze, right? There's a stage of plasticity while it cools during which you could feasibly sculpt with it.

Not saying it would necessarily be cost-effective, but it's an interesting idea.

Hey, you were the one who said molten :-)

I guess you meant something more like blacksmithing. Chamber could add heat by microwave induction. No air to oxidize the surface so you might be able to work trickier metals. We already have power hammers, we already have 6DOF manipulation tables. I'm not entirely convinced that a power hammer could do the work accurately enough, might want to use a milling machine for the final fitting.