I'll ask you if this is an accidental mis-statement? If so, edit the posting and I'll edit this one.Aluminum, BTW, does not have a fatigue limit. Even a very low stress, if repeated enough cycles, will eventually lead to cracking and fatigue failure. That’s why springs are not made of aluminum.
If not, please try to explain.
And with that, I’ve probably “beat” this topic to “death.”