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Material choice for DMLS engagement ring

teachme

Aluminum
Joined
Apr 13, 2020
My material choices are:
•Cobalt Chrome
•Titanium(Ti6Al4V)
•Stainless Steel(17-4 PH)

I need a metal that won't fracture with the least resilience possible. To prevent the prongs from breaking or springing back.

(image for reference only)
Capture.PNG
 
Which of the 3 has the highest resilience? I need to bend it about 0.5 mm, and have it spring back
In that case, you want to make it from Titanium. That material will act like a spring. Very hard to form because it springs back into it's original shape. Titanium is also called memory metal for this reason.

I thought you were trying to form the prongs.
 
In that case, you want to make it from Titanium. That material will act like a spring. Very hard to form because it springs back into it's original shape. Titanium is also called memory metal for this reason.

I thought you were trying to form the prongs.
"Resilience" is not a mechanical property. Ductility and elasticity are. Do you want ductility, so you can form the prongs over the gem, or elasticity so you can spring them open and have them snap back?
I found an alternative design that would require spring-back of the prongs.
The last concern is fracturing - how far can I bend and at what thickness/geometry.
Also strength, will it be flimsy

Thank you for your help and advice!
 
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I found an alternative design that would require spring-back of the prongs.
The last concern is fracturing - how far can I bend and at what thickness/geometry.
Also strength, will it be flimsy

Thank you for your help and advice!
My thought is that if it's springy enough to snap the gem in, the gem will eventually fall out when it gets bumped. Traditionally, gem setting is done by deforming the material over the edge of the gem. The traditional material, gold, is about as malleable as it gets.

If you want to make a proper ring with 3D printing, you'll use a resin printer (DLP or STL) with lost-wax resin to make an original, then do a lost wax casting.
 
My thought is that if it's springy enough to snap the gem in, the gem will eventually fall out when it gets bumped. Traditionally, gem setting is done by deforming the material over the edge of the gem. The traditional material, gold, is about as malleable as it gets.

If you want to make a proper ring with 3D printing, you'll use a resin printer (DLP or STL) with lost-wax resin to make an original, then do a lost wax casting.
The ring will be split in the middle. So the individual prongs aren't flexing. The arrows show the direction of spring-back. And likewise reverse to flex open.
image_2022-10-14_194254000.png
 
The ring will be split in the middle. So the individual prongs aren't flexing. The arrows show the direction of spring-back. And likewise reverse to flex open.
View attachment 377215
It'll look nice when you finish it, and either the Ti or the 17-4 should work. But if it will flex enough to put it together, it will flex enough to come apart. It's up to you if you want to take that risk.
 
Oh boy. I sure wouldn't trust that to hold an expensive gemstone unless those top prongs go WAY further over the corner of the gem than it looks like they do. After you flex the band and install the stone I'd be finding some way to mechanically fasten the underside of that split. I've read that Ti can be soldered these days, but the hot ticket would be a small laser weld. @implmex
 
Oh boy. I sure wouldn't trust that to hold an expensive gemstone unless those top prongs go WAY further over the corner of the gem than it looks like they do. After you flex the band and install the stone I'd be finding some way to mechanically fasten the underside of that split. I've read that Ti can be soldered these days, but the hot ticket would be a small laser weld. @implmex
The prongs go ~0.6 mm past the diamond edge towards the center. Ill try extending them further, good idea. And I also considered mechanically bonding the split. Perhaps adding a few holes extending through both ends, and suturing with a metal wire. Not sure Id trust any soldering or welding so close to the diamond. Great ideas tho, appreciate the advice!
My last concern would be how flimsy the prongs are. I have minimal experience working with Ti
 
Oh boy. I sure wouldn't trust that to hold an expensive gemstone unless those top prongs go WAY further over the corner of the gem than it looks like they do. After you flex the band and install the stone I'd be finding some way to mechanically fasten the underside of that split. I've read that Ti can be soldered these days, but the hot ticket would be a small laser weld. @implmex
Almost all tension rings have a mini finding welded under the stone. Findings all have a hole dead center of stone for light magic to happen.
I do not know why, stone setters mostly use tig and not laser welders.
 
I've seen several tension mount rings with nothing under them, though all were very thick bodied vs. the one shown.
I don't know about 3d printing, but if you're willing to carve it out from a solid chunk, a titanium ring with traditional prongs is possible. That's how I made my wife's 12 years ago after not being able to find a jeweler willing to do it. After making 98% of it I had a jeweler cut the seat and set the stone. It went in fine and is still there all these years later, but he did mention it was a bit touchy getting it in. I'd be awfully grumpy if she lost the band, but we both think thinks made in a lab are cool, so the stone wouldn't be any great loss should the prongs ever let go.
 








 
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