×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Annealing Aly 2024T3

Annealing Aly 2024T3

Annealing Aly 2024T3

(OP)
It anneals at  higher temps  than the other alys
But at what temp
Thanks in advance

RE: Annealing Aly 2024T3

For full anneal (to T-0 temper): 2-3 hours at a metal temperature of 775oF (413 C), followed by slow cooling at 50oF/hr to 500oF.  Faster cooling thereafter is permissible.  

RE: Annealing Aly 2024T3

(OP)
Thanks Ken
Yes I used 2011 for model eng heads and its apparently not the done thing
 ,,,,, so 2024 is the go
I think its the manganese and chrome which gives the 2024 the  heat resistance over the others like 2011 and suchlike
Great
These air cooled engines run at approx 400F so I didnt think 2011 would  be a prob
But apparently it is

RE: Annealing Aly 2024T3

(OP)
Ken
I guess I should have asked at what temp does say,,,,,, aly 2011 start to lose its mechanical  strength
That would be considerably lower than the annealing temp I guess
And thanks heaps
You guys are very impressive on my first post
Well done

By the by, con- rods in model engines are 2024 too
 

RE: Annealing Aly 2024T3

MIL-HDBK-5J  METALLIC MATERIALS AND ELEMENTS FOR AEROSPACE VEHICLE STRUCTURES, a free (& huge) download at http://assist2.daps.dla.mil/quicksearch/, has data on the effect of temperature on the physical properties of Al 2024 but not 2011.  For 1000 hours exposure, the yield strength of Al 2024 is down to ~87% at 300oF and 80% at 400oF.

For a comparison of the 2 alloys, the precipitation hardening temperature (to produce the T6 temper from solutionized alloy) is 320-340oF for 2011 vs. 375oF for 2024.  Longer periods than the ~12 hour aging period (or higher temperatures) will cause overaging and loss of strength. Al 2024 has a significant advantage during long-term operation in the 300'soF, consistent with your observations.

RE: Annealing Aly 2024T3

(OP)
Ken

You said for 1000 hours exposure the yield of 2024 aly is down to 80% at 400C

Does that mean its down to 80% yield immediatly the temp is 400C ????????
 
Thanks in advance

RE: Annealing Aly 2024T3

Not quite, yield stress = f(Temperature and time @ Temperature).
From MIL-HDBK-5J,
Figure 3.2.3.1.1(b). Effect of temperature on the tensile yield strength(Fty) of 2024-T3, T351, and 2024-T4 aluminum alloy (all products except extrusions).
[Curves are shown for 1/2, 10, 100, 1000 & 10,000 hours.]

At 400oF, yield strength as % of room T value:
1/2 hr   78%
10        76
100       70
1000     60
10,000  46
Note: these values are more accurate than in previous post where I read off monitor; these are from a printout.

RE: Annealing Aly 2024T3

(OP)
Gee Thanks Ken

Well explained

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources