Best aluminum alloy for fatigue resistance? 3

[dtwo]

I have an application where I need an aluminum alloy with high strength as well as high fatigue resistance.

 

[swall]

If you want fatigue resistance in high strength aluminum (which ever alloy you pick) you need to shot peen and you also need to avoid hard coat anodizing.

 

[TVP]

Agree with swall. Start by looking at 7xxx alloys:

7075-T6 or -T6511
7068-T6511

 

[CoryPad]

Also aluminium-lithium alloys in the 2XXX and 8XXX series.

 

[MintJulep]

The strength and fatigue resistance of a part are determined as much by geometry as by material properties.

So you would be well served by engineering in lieu of random material selection derived from unquantified criteria on an internet forum.

 

[MikeHalloran]

MJ: Amen.


Mike Halloran
Pembroke Pines, FL, USA

 

[jagad5]

How hot does it get? 7075 looses strength above 250F. 2219 does pretty well up to 325F. The temp will influence the effectiveness of the shot peening, too. And watch out for any anodize process, particularly if your raw stock from the mill is large sections.

Doug

 

[ornerynorsk]

Aluminum does not have an inherant fatigue limit. As others have mentioned, your best investment is in engineering the front side of your project, and if possible, do not immediately discount other materials.

It is better to have enough ideas for some of them to be wrong, than to be always right by having no ideas at all.