Diamonds

[unclesyd]

Just interesting:
Just saw a program on TV concerning the manufacture of artificial diamonds by the Gemesis Corporation.
They have a pressure vessel who’s forming chamber is under 850,000 psi at some unknown shell temperature.
The construction is essentially sphere halves with a 12" or better spherical working chamber that uses an enormous clamping wedge ring, similar to the Graylok or Taperlok. If there was a gasket/seal between the two halves it sneaky. It looks like the pressure on the diamond forming chamber is developed by using segmented conforming anvils/spherical wedges and the force on the anvils might be developed due to thermal expansion of same. The anvils fit like some of the stack puzzles you see around. I been playing around on how they keep the some components from seeing forces that exceed the compressive strength of the material. I imagine that the forces are similar to that developed with the diamond anvil high pressure devices.
They have numerous machines as they make quite a few carats per week and it takes 87 hours per two carat stone.

I though I might ask what codes were used in the construction of the vessels.

A two carat colored stone daimond goes for about $3700.

 

[metengr]

unclesyd;
Interesting article. Just in time for Valentines Day. Any chance we could get a group discount on diamonds?

I would guess these vessels could be fabricated under ASME Section VIII, Div 3 or perhaps they could fall under a State Special - design by analysis.

 

[unclesyd]

I think we would have to figure how to cut the diamond up without losing too much material for our pocket books, mine in particular. My wife was willing to take the rejects. I told her that the reject would go good with Sapphires I recovered from our thermal reduction furnace after temperature excursion.

The company is located in Florida so your are probably correct in the design by analysis approach.

On the show they also made a volumetric comparison of the Hope Diamond to the supposed lineage stones, the French Blue and the L Diamond. It work out that this could and probably was the lineage. Even though there was considerable carat weight lost between the different cuts there was never enough material to make sister stones.

 

[JStephen]

While they are under this much pressure, the diamonds are a solid, not a liquid or gas, right? In other words, this isn't necessarily a "pressure vessel" as normally used.

If I'm not mistaken, you can exceed the compressive strength of the material, provided that it is a uniform pressure, IE, in all directions...like hydrostatic?

 

[unclesyd]

I assume that is what they achieved with the this design and any volumetric change is directed inward toward the gem forming capsule due to the spherical shaped working chamber. Kinda sorta like an implosion without the gas pressure.

One thing I didn't mentioned is the MOC of the inner working components though relatively large didn't appear to be that heavy by the way they were handled.