bereal511
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Platinum/Tungsten alloy
I was looking into purchasing some platinum/tungsten 24 gauge wiring for the catalytic conversion of ammonia to nitric oxide. I know there have been
several problems with this process in making nitric acid, but I've been quite interested in it for a while. Anyway, I would like to know two things:
if the tungsten within the alloy would still oxidize in the presence of oxygen and nitric oxide at 500 - 800 degrees celcius and if the wire can be
bent without snapping.
As an adolescent I aspired to lasting fame, I craved factual certainty, and I thirsted for a meaningful vision of human life -- so I became a
scientist. This is like becoming an archbishop so you can meet girls.
-- Matt Cartmill
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Fleaker
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IIRC tungsten/platinum alloys are rather hard and as such, brittle somewhat simliar to Pt/Ir alloys (where iridium is the hardening agent). It will
not be easily bent. Also, I do believe there would be oxidation of the tungsten at that temperature. Try platinum gauze/wire or maybe Pt/Ir.
What is the percentage of tungsten in the alloy? Is it all you have been able to find, or perhaps a choice based on economy?
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bereal511
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The alloy is 8% tungsten. More or less based on economy, but if I did have the money, where could I find platinum gauze or wiring for a price range
between $20 - $50? At this point, I'm completely broke.
As an adolescent I aspired to lasting fame, I craved factual certainty, and I thirsted for a meaningful vision of human life -- so I became a
scientist. This is like becoming an archbishop so you can meet girls.
-- Matt Cartmill
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Fleaker
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At that price range...I can not even suggest a place. You might ask for samples from some places and pretend like you're interested in buying a few
thousand square foot  Otherwise, good luck. I don't know how much you plan to
buy, but platinum anything is expensive b/c a.) it's $900/oz b.) amazingly hard to fabricate, and c.) it comes from a lab supplier!
I suggest Alfa Aesar and Advent research materials. Wa Chang might have something though.
BTW, 8% tungsten should be fine...you should definitely consider boiling the wire in concentrated sulfuric acid which should remove the tungsten from
the surface at least IIRC it will.
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Nick F
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Find a small jeweller's shop, and ask them who they buy their metals from. Explain that you want to buy a small amount for a chemistry experiment. And
if their supplier only sells large quantities, ask if you can buy what you need from the jeweller. They'll probably be happy to help, although I doubt
that you will have luck at any larger shops...
Or just keep searching on the internet or wherever for suppliers to the jewellery trade. When I was looking for silver I found a great place here in
the UK that sells GW platinum (5% Cu) in various forms, all at £22.40/gram. They do wire from 0.5mm to 6mm, sheet from 0.55mm to 3.2mm thick and
tubes from 1.6mm to 5mm OD. And there's no minimum order!
And you can make a little go a long way if you dissolve it (aqua regia), soak a solution onto activated carbon (fish section of your local pet
shop...) and heat it to get the metal back.
Also, look in the chemistry section at forum.4hv.org, there's a topic about "methanol and platinum" which uses some platinised ceramic fibre out of a
"Jon E handwarmer" as a catalyst. Could be a good OTC source.
Edit: also look out for catalytic attachments for the ends of small gas torches, the wire mesh in them is probably platinum or some other member of
the group. Maplin's sells them in the UK, Radioshack probably would too.
[Edited on 30-12-2005 by Nick F]
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jpsmith123
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| Quote: | Originally posted by bereal511
The alloy is 8% tungsten. More or less based on economy, but if I did have the money, where could I find platinum gauze or wiring for a price range
between $20 - $50? At this point, I'm completely broke. |
I've bought both gold and platinum wire from Hoover and Strong. They have pure Pt as well as various alloys.
My guess is that the alloy you have will work for what you want to do, but if not, you can go here and get something better:
http://www.hooverandstrong.com/mill/roundwire_specs.htm
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neutrino
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You could always go to your local jewler, buy a small Pt band, and hammer it out to a foil. These things aren't that expensive ($35US for mine) and
are usually 1.5g of pure Pt or some malleable alloy.
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bereal511
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See, I've gone to a few jewelry stores around here, and they all say that their platinum bands would never be in my price range. I even asked my
friend whose parents own a jewelry shop, but I suppose they're just not exactly the most helpful people. Maybe they're trying to cheat me or
something >_<. Thanks for the Hoover and Strong link though jpsmith123, I'll look into it.
As an adolescent I aspired to lasting fame, I craved factual certainty, and I thirsted for a meaningful vision of human life -- so I became a
scientist. This is like becoming an archbishop so you can meet girls.
-- Matt Cartmill
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