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Gas-Atmosphere Crucible?


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I was wondering... Is there any way to buy/make a crucible fitted with a cap to contain an Argon atmosphere for melting?

Say, if I wanted to re-melt some Titanium scrap. To do so, I would need to exclude Oxygen and Nitrogen from the crucible placed in the foundry-furnace, as Titanium burns in air (readily combines with both Oxygen and Nitrogen at elevated temperatures.)

Vacuum would be ideal, but (would think) an Argon atmosphere should work. Can this be done? Anyone tried it?

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Casting Ti is generally far beyond the home shop capacity. Maintaining an inert atmosphere is one of the easy problems to solve by putting the entire furnace and molds in a controlled environment.

How are you going to generate enough heat? coal won't do it, heck oxy acet would barely do it maybe.

What are you going to use for a crucible? Commercially, crucibles are water cooled Ti themselves and this is a pretty trick as water doesn't stay water at those temps and both H and O will contaminate Ti. Still, there aren't any other coolants that'll do.

Lots of problems to casting Ti, please keep us posted if you give it a try. I have a few things I'd like to have cast in Ti and there's no way they're important enough to me to pay that kind of money. Like I have that kind of money in the first place.

Frosty

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Thanks Frosty. Appreciate the input.

The melting-point of Titanium is 3034 deg f. Wouldn't a ceramic-crucible survive that temperature?

I bought small laboratory crucibles many years ago, and one (albeit a tiny one) came with a crucible-lid. If I could enclose or (somehow) pump-in Argon to the crucible only, and maintain it, couldn't that work?

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My experience with Ti is limited to spinning and a little, very little tig welding some while back. Ti is pretty reactive and I think it will be contaminated by whatever the crucible is made of.

I do know some folk who do work with Ti quite a bit you might ask Jim, he does a LOT with it. No casting though, even though he has vacuum induction furnaces and more metallurgical knowledge than I could acquire if I were to start studying now.

His name is James Binnion and if you tell him Frosty sent you he MIGHT not charge you extra. ;) This is his site.

Unique Mokume Wedding Rings, Wedding Bands, Engagement Rings by James Binnion

Frosty

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Rio Grande Jewelry Supply may have a melting set up for you https://www.riogrande.com/home/index.aspx but it will be expensive if they have it. There are jewelers that specialize in casting that stuff so maybe one of the jeweler supply houses has a casting set up for sale. I know they have small electric melting furnaces for gold/silver with inert atmosphere, very expensive to buy. They have vacuum casting machine but don't remember seeing any with inert atmospheres.

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Appreciate the information and links. I have toured a "Real" Titanium Mill (Allegheny Wah Chang/Oremet in Albany, Oregon) and seen vacuum arc remelting furnaces in action.

I can't afford and don't plan to spend a fortune to try this out, as the quantities involved are fairly small; but, I just wondered what I might be up against, or would need to do, in order to attempt it.

8732.attach

8733.attach

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freon is inert...could use it as a coolant...highly toxic though...
i would imagine your biggest problem is going to be keeping the inert atmosphere contained AND inert...a simple lid on the crucible wont work...probably best left up to the professionals...but if you are going to give it a bash i'd love to hear how it goes :)

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Inert AND toxic? Nothing can be both. An inert element doesn't react with other elements under normal conditions. Gold for instance doesn't react under normal conditions.

Freon is far from inert, it isn't even an element, it's a flourocarbon and not actually toxic. Freon will kill you quick though by chemically binding to the hemoglobin in your blood far more readily than oxy can and thus suffocating you internally.

The worst an inert gas at room temp can do to you is suffocate you by replacing the oxy in the air. If you leave the concentration of inert gas, say argon or helium it flushes right out of your lungs and you recover. There's no chemical reaction going on if it's inert, it just displaces the air like water filling a glass would.

Here's another site of Jim's. He and Steve have been busy getting this process figured out and working. They're finally making sales. XPM Corporation Home

Frosty

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