Need to know about outdated alloy... Alcoa 142-T63 Bohn Y-2 3

[RoarkS]

Howdy, my google kungfu has failed me. I have an old (late 1930's) print for a sand cast engine component that calls out Material: Alcoa 142-t63/Bohn Y-2 Heat treat:30000 min tensile, 2-3% elongation, appx 70 brinell.

I tried an email to Alcoa ingot division but it has been the better part of a month.

Anyway I need to be able to make this part. I'm guessing A356 will be more than fine... but I'm not 100% sure. I can't imagine that an outdated alloy from 1938 would have better properties.

Closest thing I have been able to find is out of my ASM Metals Handbook 1939 edition that lists Alcoa No.142-T61 and T571 and Ingot No.142... lists it as an Al-Cu-Ni-Mg alloy.

Anyway when it comes down to it for PMA, I have a licensing agreement with the type certificate holder, with the original blueprints... but am worried that I can’t claim identicality because of the change of alloy.

If anyone has any thoughts either on the alloy itself for making me feel better about Identicality due to licensing I would love to hear about it.

 

[btrueblood]

Hmmm....this link might help, it's apparently a data sheet for Alum. alloy 142 published in 1952:

http://www.asminternational.org/portal/site/

http://www/AsmStore/ProductDetails/?vgnextoid=0ba0fdca43dce110VgnVCM100000701e010aRCRD#details

 

[RoarkS]

Well... go figure ASM would have it LOL! Thanks. Got it.


Still no idea about the T63 heat treat.

That document listed T21,T61,T77,T571.

Still need to determine an appropriate replacement... going thru Mil-HDBK-5 to see what I can find.

 

[WKTaylor]

Be careful... From what I can tell this aluminum alloy has a high service temperature.

AMS4222D 142-T77 Sand Casting makes the following statement.

Application : Primarily for air cooled cylinder heads

Other statements made RE this allloy indicate it is used for high temperature engine applications [pistons, cylinders, etc].


Regards, Wil Taylor

Trust - But Verify!

We believe to be true what we prefer to be true.

For those who believe, no proof is required; for those who cannot believe, no proof is possible.

 

[RoarkS]

Right on the money there wktaylor...It's the head. Max design cyl head temp is 575°F.

I have been going thru MIL-HDBK-5 trying to sort out heat properties of normal aluminum alloys... The A201.0-T7 series offers temps up to 350°... and that's it.

What I have found is that just about every version of this alloy has been cancelled. What replaced it?

The big aircraft air cooled engine companies must make their heads out of something... hopefully they are not so big that their alloy is proprietary. What about Air cooled motorcycle heads? what are they made from?

 

[TVP]

High temperature alloys like 242, 336, and 391 (Mercosil from Mercury Castings) are used for industrial applications. They contain Ni for improved properties above 150 C. NASA has developed alloy 398 that may have some licensees as well. Here are a few links for more information:

http://www.rotaryeng.net/aluminum-alloy-rotors2.pdf

http://www.mid-atlanticcasting.com/alum-casting-alloys_FEB05.pdf

http://www.ncccoat.com/PDF/MercuryNCCSAEtechnicalpapers.pdf

 

[RoarkS]

TVP THANK YOU!

I'm still in the initial assessment of this project, and was worried when I dead ended on the material. Thank you for the reassurance there are alloys out there... that will put my mind at rest for now and give me some background when I get to the point of talking with the foundries. ...WOW 750°F NICE. WAY better than what the original stuff was.