7075 T6 vs. T6511

[Mitz14]

I understand that T6511 is stress-relieved by stretching and artificially aged, whereas T6 is simply artificially aged, but theoretically they have the same mechanical (tensile) properties. What is the difference between these materials in terms of design? If a part usually manufactured in T6511 was instead made in T6, what differences in performance would be expected? Would the T6 part be more prone to cracks or stress corrosion due to the fact it is not stress-relieved?

 

[metman]

Stress corrosion maybe since you would have residual stress -- but wait until you have some more responses from others more expert than me. Also if the part is to be machined, you might experience some distortion when layers of residual stress are unequally removed from surfaces during machining.

 

[swall]

What product form are you asking about? That makes a difference, as certain products, would not be available in both tempers. I suspect that has to do with how much stretching is typically needed to straighten a product, such as bar.

 

[CoryPad]

What is the difference between these materials in terms of design?

Nothing.

Regards,

Cory

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[swertel]

I use them interchangeably in designs. My material will be called out as 7075-T6/T651. For the most part T6511 is implied if I call out T651.

Like swall states, some raw stock comes only as T6, some only as T651. In the end, it doesn't matter but allowing for either means your purchasing group can pick the less expensive of the two, or the one that can be delivered quicker.

--Scott

http://wertel.eng.pro

 

[MadMango]

My only experience has been with a DoD program, components had to be T6511 for the reasons that metman pointed out. We had trouble finding a supplier due to our OD was 5.00", and normally T6511 is only up to 3.50", so everyone is correct that stock sizes should be taken under consideration as well.

"Art without engineering is dreaming; Engineering without art is calculating."

Have you read faq731-376 to make the best use of Eng-Tips Forums?

 

[Mitz14]

The part usually comes to us manufactured in the T6511 temper. We want to make the part ourselves from an extrusion in the T6511 temper, work it in the W temper then heat treat back to T62 (since it will be a user temper.) I am not worried about mechanical properties since I know those will be the same, it more a matter of fatigue and damage tolerance. Will the part have the same characteristics over time as the T6511.

By the way, I just joined here and I really appreciate the advice. Thanks.

 

[lgearhart]

The difference in the -T6 and the -T651 or -T6510 or -T6511 tempers only shows when machining them: the stress relieved tempers might be more stable when machining. I say "might" since it is SO DEPENDENT on your machining process- how fast you machine, how sharp your tools are, etc.

You should also realize that while it isn't explicitly stated in ANSI H35.1, the stress relieved tempers such as -T6511 are a subset of the -T6 temper. That's why I push our drawings to call out -T6, because then if our vendor gives us -T6511, it's per print.