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5, 6, 7, 8! Heat makes metal congregate!

A project log for Bound metal deposition printing at (lab)

Using filament and/or metallic resin and then casting if I get really desperate. Basically just trying to print metal

Ahron WayneAhron Wayne 04/16/2021 at 22:293 Comments

Here's a quick pick of all of these, plus some earlier trials: 

As we can see, we have had some success! Let's go through this, shall we:

Attempt #5:

Leave uncovered for first step, with some carbon on top.


30 mins to 204. Hold for 2 hours. 2.5 hours to 484. Hold for 3 hours. Let cool down.   

Add more carbon. Cover. 

5.5 hours to 1018.  2 hours to 1074. Hold for 3 hours. 

VIOLA! 

Metal parts! The cube, the I beam, and the "head". Totally solid, with a smooth shiny texture, and a nice clink when you drop them! Progress! 

They look like this close up:

I'm sure you know of the LadyBug Beefy scanning project if you know of this one, but if you don't, check it out. I use a digital microscope and a CNC-type setup to take lots of pictures and stitch them together. 

We can see just how much this has shrunk. (a lot). The letters on one or two sides are just barely visible, while the Z axis one is completely gone. But it's roughly flat on the bottom, so some shape has been preserved. The I beams faired even better but definitely still with drooping for the part that wasn't being supported by the aluminum oxide refractory. 

At the same time the density and strength for these is great. I would be totally happy if I could get this density and strength for a functional part. We're not quite there yet though, as you will see.


Attempt #6 

Same temperature profile as attempt #5, but in one cycle adding carbon beforehand, uncovered, in a much small and fancier oven. Result:

Nothing was left. Not even an oxidized part like #1. Carbon was completely gone, too. I'll investigate this oven later, since it's high quality, but for now I'll stick to my current oven.

#7: 

Leave uncovered for first step, with some carbon on top.

30 mins to 204. Hold for 2 hours. 2.5 hours to 484. Hold for 3 hours. Let cool down.   

Add more carbon. Cover. 

5.5 hours to 1018.  2 hours to 1060 (14 less than #5). Hold for 3 hours. 

So I ran the second cycle for this one and I actually let it ran twice by accident. It got about an hour through the second sintering hold at 1060 before I stopped it. Turns out "cycle 2" does not mean it can store more than one cycle, but rather, it just does it twice. Whoops.

And yet this one turned out to be the best yet in terms of holding features!



Check it out! It's my head! In solid copper! I mean, it looks like a little shrunk, but that makes sense because on one side it was hollow (weird scan). So yeah! Woot! 

I really should have measured all dimensions before making this post, whoops, and I will once the process is more stable. But look at that I beam! And the cube! Almost every feature was preserved --- marks from pulling it off the build plate, overhung strings, and so on. This would make some great miniatures. 

My only gripe was that the density was clearly not maximum un, for instance, the I beam. And I want that. For functional parts, it is going to be necessary. And so I reran at just higher temp to try and reach that sweet spot:

#8 

Leave uncovered for first step, with some carbon on top.

30 mins to 204. Hold for 2 hours. 2.5 hours to 484. Hold for 3 hours. Let cool down.   

Add more carbon. Cover. 

5.5 hours to 1018.  2 hours to 1064 (4 more than #7). Hold for 3 hours.

This one was intermediate, but unfortunately, not just "better":

Before printing:

 After sintering, before cleaning with HCl ( have to make a video of that --- it's like magic, really)

Monsters! Eek! No face but in kind of head shape is really scary :(

It's definitely intermediate... so how to prevent it from sagging? One option is maybe to use that lower temperature but to raise the holding time. Another is to hold for a few hours at the lower temperature, then slowly raise to the higher temperature after it's had time to settle. But there's already such a long raise temperature time... I'm not sure. I'll have to try. 

But I'd consider this a success. Let's see if we can get some more! 

Update: We got some more! 

Discussions

Paul McClay wrote 04/19/2021 at 02:44 point

Metal. Sweet.

And kinda like the transporter failure in the original Star Trek movie... You sure you want to use your head for 'exploratory' iterations? :) 

  Are you sure? yes | no

Ahron Wayne wrote 04/19/2021 at 02:56 point

Was it the one where my head is squished and skinny, where it's been hideously disfigured,  melted into a blob, burnt to a crisp, or just crumbled away as ash? 

  Are you sure? yes | no

Paul McClay wrote 04/20/2021 at 07:00 point

Yes.

Although I think it's the one in the middle that, considered as a deformation of 'head', seems most ... evocative.

  Are you sure? yes | no