3d printing Ti?

SimonGH

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Westbrook CT
So the other discussion is the application.

You're caught in a horrible sea state and things are bad enough that it's time to deploy a drogue to stop you from being capsized by enormous waves.

Is that really the time to be thinking "gee, i'm glad I saved 1lb and went with that 3D printed titanium part, just hope it doesn't crack under the strain of holding my boat against these waves"

Or would you prefer to have something a bit heavier that you know for sure will hold up the displacement of your boat?

Sometimes you need to choose the right material / process for the application...

 

solosailor

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I know there are places you can send drawings and they will 3d print a Ti part.  My question is how good quality is the Ti part? Is it 'just like machined'? Would you use it in high load application?  . . . or is it a bit crap?  Anyone have direct experience with this?
Well I've been printing prototypes and then sent to be CNC machined at a service bureau, not made from additive manufacturing (3D printing).

 

SimonGH

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Westbrook CT
It is definitely an evolving technology and the advancements are really cool.

No arguments that its great for certain applications (trust me, we're doing it a lot at work). 

I just don't think it's a great method for this particular application...

 

SloopJonB

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Are they sintered? i.e. properties the same in all directions.

(as opposed to forged/rolled metal parts which have a linear grain structure)
That raises a question I have had about printing metal parts.

It seems to me that any printed metal must be a form of sintering - how does its strength compare to forged - cast - rolled metal?

 

DDW

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I don't know that the laser fused method is the same as sintering. The parts come out near designed dimensions, supposed to be match the density and properties of cast metal. In the 3D sintering processes there is significant shrinkage involved, and the densities are somewhere in the 95% range according to manufacturer's literature. These are the processes that deposit metal in a plastic binder which is burned away by the sintering oven.

Not that sintered metal is useless either, gears, connecting rods, all kinds of fairly demanding applications are done that way. 

You can actually experiment yourself pretty cheaply. BASF makes a 316 filled filament printable by an ordinary 3D FMD type printer, and has a network of sintering service bureaus. It is very reasonably priced. 

 

SloopJonB

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I don't know that the laser fused method is the same as sintering.
Hence the "form of sintering" comment.

A printer couldn't provide the heat & pressure required for true sintering but fusing powdered metal together in a printer seems to be a cousin of the process.

 

DDW

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The two basic processes seem to be laser fusing a thin layer of powder repetitively, and depositing a metal powder filled plastic followed by cooking in a sintering oven. While I'm not a metallurgist, it seems to me that it would be surprising if the results were the same. I'd guess that melting a layer of metal powder with a laser into the last layer would be similar to casting. In contrast, the metal filled plastic version is printed and then cooked in a sintering oven, but not to the melting point as the part would then collapse into a puddle. In an industrial sintering process, the part is held in form with a mold at high pressure during this process, in the 3D sintering world the part is free standing. It shrinks by about 20% in linear dimension during the process. The vendors of this process claim "close to" cast properties, so not equal to. 

Somewhere in between is the possibility of an investment cast part using a plastic 3D printed form for the investment. There you get a true cast part, and the cost seems much less - currently - than 3D printing metal. For machinable parts, CNC is much less still. 

 

DDW

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Yes - the confusing bit is it is commonly called laser sintering. But seems like a lot different process at a glance anyway. 

 

DDW

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No, but it is only about $0.5M for a small machine. Put it on the CC. There are a couple of used ones on eBay right now in the $150 - 250K range. 

Not that I would impulse buy one anyway, but another issue is the care and feeding is expensive even if the machine is free.

 

Zonker

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I did see a 3D printed Inconel exhaust header (rotary engine). It was a thing of beauty. But obviously not required to take high loads, just high temps.

 

gewoon ik

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Flora
Damen printed a ships propeller out of NiCu.

And I believe a dutch company printed a cranehook recently (but have to look up who or what).

Was more showcase than everything else, I don't believe it was cheaper than the traditional methode. But they are going to test them (propeller is already in use).

 

bilbobaggins

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a piece to join two bridles to a highly loaded series drogue rode - somewhere between a 'delta plate' and a 'ring with cross bars' - but bit more complex (FEA) to have most strength with least weight.  Could be done easily in steel but trying to make lighter.  Dont think we want to weld Ti for such an application - so I was just wondering it there was a Ti printing possibility.  There are various other options, vut I was just curious if this was an actual possibility.
The 'arboriculture'/'commercial rigging' industry has come up with some devices of interest. Here's one. There's a US manu doing something similar.

Then there are the excellent DMM shrouded thimbles...
 

Rplate.jpg

thimble.jpg

 

estarzinger

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The 'arboriculture'/'commercial rigging' industry has come up with some devices of interest. 
we ended up being uncreative and machined in H1150

the arbor crowd tends to have lower working loads than we were looking for and the commercial lifting guys tend to not be very elegant

I was hoping to do something really nice with printed Ti but testing proof's of concepts was a road too far.  I do have another little project where they are probably up for more experimenting and testing - might give it a go there.

 
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