r/metallurgy • u/LegateDamar • 2d ago
Labs that can determine liquidus and solidus of exotic alloys?
I work at a foundry and we need to pour an alloy of roughly
33% chromium 16% tungsten 0.2% carbon 0.5% manganese 1% aluminum Balance nickel
I've reached out to a few universities with materials characterization labs and some independent labs with no success. Anyone have any suggestions?
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u/Badger1505 Heat Treatment, Mo-Si-B alloy oxidation in a previous life 2d ago
We used to that capability at UW-Madison when I was working on my master's. A few challenges you're going to have with that is the reactivity of those metals, the vapor pressure of Cr, and the high melting point. I'm guessing any lab would need to use a crucible of MgO or yttria... So it's going to take some specialized equipment.
I'd recommend reaching out to them if you haven't to see if they still have that capability.
Edit: while I was there, I was actually trying to measure the liquidus and solidus of Ti-6-4. Used a tungsten cup with yttria powder to suspend the sample. Got about 6 cycles out of it before the sample got wise to us and got out and destroyed the crucible and sample carrier... $5k shot in an instant.
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u/NeoOzymandias 1d ago
If you wanted a ballpark number just to get an idea, then you could always try CALPHAD.
If you don't have access to Pandat or Thermo-Calc, then you could use pycalphad with the COST507 database. COST507 won't be, uhhh, overly accurate. But it'll give you a starting point for free if you have some command line skills.
https://pycalphad.org/docs/latest/ https://gist.github.com/bocklund/c4714ddbc0500c78e6fe255a763e7550
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u/FerroMetallurgist Iron and Steel Foundry Work since 2007 2d ago
My first call would be to Element, in Wixom Michigan.
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u/CuppaJoe12 2d ago
Are you looking for an official certification, or is a rough estimate OK?
Grab some platinum rhodium thermocouples and melt a sample in a high temperature furnace. Air cool, and there will be an inflection in the cooling curve at the liquidus and solidus, as well as any solid-solid phase transformations.
If you are looking for a certification, then high temp DSC is the way to go. It will be expensive. Some labs might market the service as TGA (thermo gravimetric analysis) because these capabilities are often combined in one machine.
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u/TheEverDistant 1d ago
If you just need a rough idea of the phase diagram ,using a thermodynamic calculation software like Thermocalc or FactSage may get you most of the way there. It depends if their databases have any data for that alloy system.
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u/FerrousLupus 2d ago
If you want I can DM you 3 universities I've worked at that have this capability, but the tool you're looking for called a differential scanning calorimeter (DSC).
You could also look a publications to see which groups have this data, and contact them.
Cost will probably run you about $1k to hire a university lab to perform the measurement for you. The trick is that these instruments tend to be more specialized and thus owned and operated by an individual professor rather than the "materials research facility" or something.
If I were still in school I could probably have run your data for free if there were scientific merit in it. Or at a different school it was owned by a common lab, external user cost would probably be $50-100/hr + $50-150 for a pan.
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u/LegateDamar 1d ago
Send em over! We've got the funds if it's the difference between a scrap casting and shippable product
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u/Cydonia-Oblonga 2d ago
Where are you based? I know two groups who might be able to do it... But they are here in Europe.
Do you already have the alloy and can you provide a sample or do they have to mix it themselves?
As others have said search for differential scanning calorimetry, differential thermal analysis.
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u/phasechanges 2d ago
Try doing a search for labs that do differential scanning calorimeter (DSC) testing. A quick google brought up a few for me.