[AR] Re: New Al Alloy
- From: Keith Henson <hkeithhenson@xxxxxxxxx>
- To: arocket@xxxxxxxxxxxxx
- Date: Wed, 30 Oct 2013 13:21:16 -0800
On Wed, Oct 30, 2013 at 12:44 PM, George Herbert
<george.herbert@xxxxxxxxx> wrote:
> Extrusion plants aren't exactly cheap, Keith...
That's why the :-)
> And the mold design for closed forms (hollow tubing, etc) is nontrivial...
True. Spin casting is about all that would make sense for a small
production run.
> I am enamored of 5059 for welded structures, and some of the people here
> have used it. I'm lusting after trying some friction stir welded + aged
> 7075-T4 -> T5.
>
> But for most of us those are fairly silly optimizations most of the time.
I don't seem to have it any more, but for years I carried around a
piece of aluminum sheet metal that I made by vapor deposition.
> I'm looking at this new alloy...
Heh. Every tried to turn a 6061 casting before heat treatment? It
acts like chewing gum in the lathe. Wife had to put up with it baking
in the oven for a few hours before I could machine the casting.+
Keith
> -george
>
>
>
>
> On Wed, Oct 30, 2013 at 1:31 PM, Keith Henson <hkeithhenson@xxxxxxxxx>
> wrote:
>>
>> "if I didn't have to start w/ an ingot."
>>
>> All you need is an extrusion plant. :-)
>>
>> On Wed, Oct 30, 2013 at 12:04 PM, Bill Claybaugh <wclaybaugh2@xxxxxxxxxx>
>> wrote:
>> > If one wants to replace 6061, look to 2095, 2199 and the like. If it
>> > were
>> > available as tube, Al-Li could replace my existing 6061-T6 solid rocket
>> > tube
>> > with 1/2 the wall thickness and accordingly 1/2 the weight...and a
>> > little
>> > more propellant as a bonus. Even at current prices, I would make that
>> > trade
>> > if I didn't have to start w/ an ingot.
>> >
>> > Bill
>> >
>> > Sent from my iPhone
>> >
>> > On Oct 30, 2013, at 15:34, Nathan Mogk <nm8911@xxxxxxxxx> wrote:
>> >
>> > What interested me is not the slightly higher strength, but the fact
>> > that it
>> > was higher strength on an alloy that is specifically intended to replace
>> > 6061. Whether that translates to rockets/tanks is yet to be seen on
>> > specific
>> > properties. The release did mention wear resistance as a driving
>> > requirement.
>> >
>> >
>> > On Wed, Oct 30, 2013 at 12:10 PM, Jonathan Goff <jongoff@xxxxxxxxx>
>> > wrote:
>> >>
>> >> Nathan,
>> >>
>> >> There are already several alloys with more than 16.5% higher strength
>> >> than
>> >> 6061-T6. The questions for rocket stuff is thermal conductivity,
>> >> solidus,
>> >> high temperature strength, etc. Not just raw room-temperature strength.
>> >> For
>> >> instance 7068-T6 has a yield strength of almost 100ksi (vs ~40ksi for
>> >> 6061),
>> >> and has 190ish W/m*K thermal conductivity (compared to like 160ish
>> >> W/m*K).
>> >> But it's solidus is only something like 485C (compared to 560ish C for
>> >> 6061), which means its high temperature strength/creep characteristics
>> >> are
>> >> probably quite a bit worse than 6061.
>> >>
>> >> If this is a 6xxx series alloy with good thermal conductivity, and
>> >> similar
>> >> solidus to 6061, it might be a good replacement. Ultimately, it would
>> >> be
>> >> interesting to see someone do a detailed thermal analysis of a rocket
>> >> engine
>> >> using some of the various potential aluminum alloys to see which
>> >> combination
>> >> of factors really matters most. I have some hunches, but not being
>> >> actively
>> >> in the rocket world anymore I don't really have the time to
>> >> investigate.
>> >>
>> >> Would be really interested if someone wanted to do some sort of
>> >> simplified
>> >> analysis though and publish it on aRocket though!
>> >>
>> >> ~Jon
>> >>
>> >>
>> >> On Wed, Oct 30, 2013 at 1:03 PM, Nathan Mogk <nm8911@xxxxxxxxx> wrote:
>> >>>
>> >>> Apparently Alcoa recently unveiled a new alloy for use in truck wheels
>> >>> that is 16.5% stronger than 6061. This may be an interesting alloy for
>> >>> rockets when they let it into the market. There wasn't any real detail
>> >>> in
>> >>> the press release that I saw, and they didn't mention (and I didn't
>> >>> look up)
>> >>> what heat treatment of 6061 they are comparing with.
>> >>>
>> >>> Here is the press release
>> >>>
>> >>>
>> >>> http://www.asminternational.org/portal/site/www/NewsItem/?vgnextoid=3a23ccc1c26e1410VgnVCM100000621e010aRCRD
>> >>>
>> >>>
>> >>
>> >
>>
>
>
>
> --
> -george william herbert
> george.herbert@xxxxxxxxx
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