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MMH compatibility with Ti-3Al-2.5V

MMH compatibility with Ti-3Al-2.5V

MMH compatibility with Ti-3Al-2.5V

(OP)
Does anyone know where I can find chemical compatibility of MMH (MonoMethyl Hydrazine) with Ti-3Al-2.5V?

RE: MMH compatibility with Ti-3Al-2.5V

NASA, since it is a hypergolic related to many rocket fuels.
They have publications that cover material compatibility.

= = = = = = = = = = = = = = = = = = = =
Plymouth Tube

RE: MMH compatibility with Ti-3Al-2.5V

Hey kev,

As usual, you have checked Eckhardt's book? If the data for that specific alloy and fuel is not in there, you might call directly to RRC (now Aerojet) up in Redmond, as they have done an awful lot of compatability testing. You may have to spend a little money (or at least sound willing to do so) to get them to send you a report, but I'd give 50/50 odds that they have tested that combo. From memory, the 6Al-4V alloy is pretty compatible (i.e. is what they use for neat hydrazine tanks) and so is pure Ti, so the alloy you list should be fine. Can you say why you need to know - i.e. what duration of contact and what temperature you are looking at, and whether you are worried about fuel degradation or alloy degradation?

RE: MMH compatibility with Ti-3Al-2.5V

(OP)
Thanks btrueblood. What is Echardt's book's full title? The alloy will be subject to Monomethylhydrazine Fuel or Nitrogen
Tetroxide MON-3 Oxidizer between 60-100°F. We had Ti-6-4 originally specified, but may need to specify Ti-3-2.5 as an alternative due to material shortage.

RE: MMH compatibility with Ti-3Al-2.5V

Kev,

Hydrazine and Its Derivatives, by Eckhardt Schmidt. Apparently now in 2nd edition, and grown to 2 volumes:

http://www.amazon.com/Hydrazine-its-Derivatives-Pr...

A good aero university library should have a copy...but then, a decent spacecraft shoppe ought to have one too ;)

The MON-3 is trickier, but I think the preferred tankage is still titanium.

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