For T4 22024 alloy,many rod-likeT(Al20Cu2Mn3) dispersoids
and various morphologies of dislocations,which generally formed
during water quenching of the supersaturated solid solution,
collectively constitutes the main microstructural aspects of the
alloy.Detailed introduction can be found in our previous contribu-tions [26,27]. Under uniaxial tensil eloading,crack initiates from the circular edges of the thinned region which are apt to cause stress