Why not Low Melting Temperature Metal Alloy Printing?

[LesHall 95]

This morning I thought I'd write a little April fool's post about a printing in metal breakthrough that allows enthusiast and hobbyist FFF printers to print with metal.  Then as I Googled the topic, searching for believable "evidence" of such, I looked up "Pot Metal" and was led to links of low temperature alloys used for prototyping and casting.  They tend to be pricey and can be harmful to health so they must be handled with care, and with adequate care they can be cast into molds.  

These metals have a melting temperature of 62C or lower.  FFF print heads print up to 250C or 300C max.  So why not print with some sort of mixture of these metals?

Maybe they would be too thin and would plate the nozzle then puddle on the glass bed?  If so, then would it be possible to mix these metals in powder form with a low temperature substrate such as a food product like pasta or whatever to hold the metals together in a matrix then burn off the food or let insects eat it away or something!

Bug Pasta Prints!

Haha or use water soluble matrix to hold the metal in place?  I dunno what I'm talking about obviously, just wondering out loud (in textual form) why we can't print in metal when we have metal alloys that melt in our nozzles.  

...oh, and happy April Fool's Day!

Les

Edited April 1, 2016 by Guest

[LesHall 95]

Maybe we could print a mold of PVA, pour in the molten metal, then wash away the PVA with water? That could be one way of printing with metal for making electronic circuits or jewelry items.

Les

[madesolid 0]

Give it a try! From my experience the alloys in the low melting point metals tend to form a coating of oxidation on their surface that makes depositing and bonding the next molten layer difficult or impossible without a flux or printing under inert atmosphere. Most of the low melting point alloys in use today tend to also be quite brittle. Conductive circuit traces, always in fashion, would be a good use case here. If you do happen to run some experiments, post pics!

cheers,

~lance

[madesolid 0]

For the metal powder/binder compositions. Jewelry metal 'clay' is what this brings to mind immediately. Yes, in fact, what you're proposing with the powdered metal filament+binder, is in line with powder metallurgy techniques used today.

A combination of brass powder and PVA binder worked well for us, we made sheets of the stuff for LOM style printing. Benefits of using PVA is that you can really load up the metal powder and as the water evaporates you get a very dense material. PVA smells horrible when burning the binder out, but it's cheap, environmentally benign, and readily available.