Aluminum for Low Temperature
Aluminum for Low Temperature
(OP)
I am trying to decide which Al alloy to use.
I have a cylinder approx 38mm long with very thin walls (<1mm along most of it). Aluminum with black anodize is really the only option due to weight and other factors so I need to determine if I should use 6061-T6 or 7075-T6. These are the only alloys that are allowed by the customer so I can't stray from those.
The temperature range is +71C down to -41C. At low temperature there is very little radial stress but the axial stress is fairly high (given the wall thickness) and I want to make sure that it will not break. I am worried about the brittleness of 7075-T6 when compared with 6061-T6.
Any suggestions?
Thanks,
Dan
I have a cylinder approx 38mm long with very thin walls (<1mm along most of it). Aluminum with black anodize is really the only option due to weight and other factors so I need to determine if I should use 6061-T6 or 7075-T6. These are the only alloys that are allowed by the customer so I can't stray from those.
The temperature range is +71C down to -41C. At low temperature there is very little radial stress but the axial stress is fairly high (given the wall thickness) and I want to make sure that it will not break. I am worried about the brittleness of 7075-T6 when compared with 6061-T6.
Any suggestions?
Thanks,
Dan





RE: Aluminum for Low Temperature
Regards,
Cory
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.
RE: Aluminum for Low Temperature
Thanks for that. I did that and they both look OK. I guess what I am really worried about is how the fracture toughness changes (if at all) when you get down to -41C.
I can't find any reference with anything but, I am assuming, at 20C and no mention of if that changes with temperature.
Dan
RE: Aluminum for Low Temperature
Alloy KIc @ 24 °C KIc @ -196 °C
--------- ----------- ------------
6061-T651 29.1 MPa m0.5 41.6 MPa m0.5
7075-T651 22.5 MPa m0.5 27.6 MPa m0.5
Regards,
Cory
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.
RE: Aluminum for Low Temperature
Thats exactly what I needed, thanks.
Dan