Maybe You Can Print in Metal

Let’s face it. Printing in plastic is old hat. It is fun. It is useful. But it isn’t really all that exotic anymore. The real dream is to print using metal. There are printers that handle metal in different ways, but they aren’t usually practical for the conventional hacker. Even a “cheap” metal printer costs over $100,000. But there are ways you can almost get there with a pretty garden-variety printer.

There’s no shortage of people mixing things into PLA filament. If you have a metal hot end and don’t mind wearing out nozzles, you can get PLA filament with various percentages of metal powder in it. You can get filament that is 50% to 85% metal and produce things that almost seem like they are made from metals.

[Beau Jackson] recently had a chance to experiment with a metal-bearing filament that has a unique twist. Virtual Foundry’s Filamet has about 10% PLA. The remaining material is copper. Not only do you have to print the material hot, but you have to print it slow (it is much denser than standard PLA). If it were just nearly 90% metal, that would be impressive, but nothing too exciting.  The real interesting part is what you can do after the print is complete. (If you don’t want to read, you can always skip to the videos, below.)

If you do nothing, you still wind up with a metal-like print. If you have access to a kiln, though, you can put  your part in at nearly 1000 degrees C along with the company’s proprietary “magic black powder.” This removes nearly all the PLA and leaves a completely (99.9%) metal object.

If you prefer, you can also sand and polish the material to bring out the metal appearance, which might be easier than slaving over a hot kiln. Either way, the results do look (and sound) like metal.

The company claims other metals are in development. This isn’t quite as awesome as having a printer that really spews molten metal, but it is a lot more affordable. Not that it is very cheap, mind you. A 750 g spool of material is $85. Sure beats electroplating, though.

 

31 thoughts on “Maybe You Can Print in Metal

      1. Metal injection molding uses powdered metal mixed with a polymeric carrier material, which is injected into molds using plastic injection molding machines. The resulting form is then debound using solvent to get rid of the carrier, and then sintered to densify the part.

        Percentages of material (plastic vs metal) and sintering temperatures are in the same ballpark for both processes. The main differences as I see them are (a) the lack of debind in the 3d printed stuff, and (b) the different method of producing the green form. I suppose this could be a brazing-like process as other commenters have mentioned, with a filler metal strengthening the part instead of proper sintering. But 1000 C seems pretty hot for that.

        Also, warpage is a serious challenge in MIM design too. So yeah, I think it is analogous.

    1. It may be soldered metal, not sintered. The black goop they pour around the object is some sort of fine sand which forms a mold around the object when it dries, and if it contains tin it will wick up through the pores left behind by the evaporating PLA.

      The result would be not quite bronze, but something along those lines. Shapeways employs the same method with their metal prints – the particles aren’t so much sintered but soldered together with some lower melting point metal.

  1. “If you prefer, you can also sand and polish the material to bring out the metal appearance, which might be easier than slaving over a hot kiln. Either way, the results do look (and sound) like metal.”

    What about the other qualities of metal?

    1. I’m curious how conducive unfired filament is. Thermal and electrically.
      Would be interesting to print 3D traces…
      Print an LED cube, leaving pauses to manually place the LEDs…

  2. This sounds like a similar technology to precious metal clay. In that case micronized silver or gold is mixed with an organic binder. It shapes like a modeling clay but when heated the binder burns off leaving only the metal itself in the same shape.

      1. It is a visual dead ringer for carbon black, although I’m not sure black would mix with water quite like that. More likely a proprietary mix of clay and black to get the water mix texture and fixing properties with the carbon to prevent firescale.

    1. I’ll bet it’s possible but the chip companies keep the tech under wraps.

      Need a 555?
      *prints a 555*
      *puts LED on it*
      *coats it with clear epoxy*
      Blink blink blink…

        1. Nothing wrong with that. Arduinos are becoming so mass produced and commonly available that it might soon be cheaper to just use an atmel chip and the oscillator on place of a 555 chip.

  3. Re: Not that it is very cheap, mind you. A 750 g spool of material is $85.

    That is actually not too ridiculous. Compare with solder, which is probably a much simpler material to make with a much larger market to drive economies of scale.

  4. I bought the sample pack from Virtual Foundry. I would advise against using this product. The 1.75 filament is quite brittle, it arrived in the box already broken into three separate coils. Loading it into my printer through a bowden tube caused more breaks which ruined one test print.

    I did get one completed print out of it, though, using VF’s recommended temperature and speed settings. The final object was just as brittle as the filament itself. Part of the object remained on the glass heat bed of my printer when I tried to remove it. Trying to do some sanding preparatory to polishing caused the object to break. I know of no kiln anywhere nearby that I can use to try making it solid metal.

    So far I am quite disappointed in this filament.

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