7075 This is one of the highest strength aluminum alloys available Its strength-to weight ratio is excellent and it is ideally used for highly stressed parts. It may be formed in the annealed condition and subsequently heat treated. Spot or flash welding can be used, although arc and gas welding are not recommended. It is available in the clad ('Alclad") form to improve the corrosion resistance with the over-all high strength being only moderately affected. Applications: Used where highest strength is needed.
The letter "T' is always followed oy one or more digits. These digits indicate the meathod used to produce the stable tempers, as follows:
-T3 Solution heat treated, then cold worked.
-T351 Solution heat treated, stress-relieved stretched, then cold worked.
-T36 Solution heat treated, then cold worked (controlled).
-T4 Solution heat treated, then naturally aged.
-T451 Solution heat treated, then stress relieved stretched.
-T5 Artificially aged only,
-T6 Solution heat treated, then artificially aged.
-T61 Solution heat treated (boiling water quench), then artificially aged.
-T651 Solution heat treated, stress-relieved stretched, then artificially aged (precipitation heat treatment).
-T652 Solution heat treated, stress relieved by compression. then artificially aged.
-T7 Solution heat treated, then stabilized.
-T8 Solution heat treated, cold worked, then artificially aged.
-T81 Solution heat treated, cold worked (controlled), then artificially aged.
-T851 Solution heat treated, cold worked, stress-relieved stretched, then artificially aged.
-T9 Solution heat treated, artificially aged, then cold worked.
-TlO Artificially aged, then cold worked.
Added digits indicate modification of standard practice.
http://www.ez.org/aluminum.htm
The letter "T' is always followed oy one or more digits. These digits indicate the meathod used to produce the stable tempers, as follows:
-T3 Solution heat treated, then cold worked.
-T351 Solution heat treated, stress-relieved stretched, then cold worked.
-T36 Solution heat treated, then cold worked (controlled).
-T4 Solution heat treated, then naturally aged.
-T451 Solution heat treated, then stress relieved stretched.
-T5 Artificially aged only,
-T6 Solution heat treated, then artificially aged.
-T61 Solution heat treated (boiling water quench), then artificially aged.
-T651 Solution heat treated, stress-relieved stretched, then artificially aged (precipitation heat treatment).
-T652 Solution heat treated, stress relieved by compression. then artificially aged.
-T7 Solution heat treated, then stabilized.
-T8 Solution heat treated, cold worked, then artificially aged.
-T81 Solution heat treated, cold worked (controlled), then artificially aged.
-T851 Solution heat treated, cold worked, stress-relieved stretched, then artificially aged.
-T9 Solution heat treated, artificially aged, then cold worked.
-TlO Artificially aged, then cold worked.
Added digits indicate modification of standard practice.
http://www.ez.org/aluminum.htm
