Effects of aging on mechanical properties of severe cold plastic deformation 2 024 aluminum alloy have been examined by mechanical tensile test

TEM observation. The results show that aging response rate of severe cold plastic deformed Al alloy is improved

which approaches to the ultimate tensile strength with aging time of 20 min

decreased by 6 min than that of T6 treatment. Aging curves of the alloy exhibits two peak

in which the maximum strength

such as tensile strength of 580 MPa

elongation of 9.2%

can be observed at the first peak that occurs in aging time about 40 min

and the second peak can be generated at aging time about 120 min. In addition

the σ

0.2 /σ

b

at the second peak is significantly higher than that of at the first peak. Elongation of the alloy shows a multi-stage change

where elongation is more than 8% when aging time is below 40 min

while elongation is less than 6% when aging time is more than 60 min. Furthermore

the elongation of the alloy retains a constant with increasing in aging time

which indicates the existence of critical aging time for the sever cold plastic deformed 2 024 alloy.