Quantification of internal dislocation density using scanning transmission electron microscopy in ultrafine grained pure aluminium fabricated by severe plastic deformation

Dislocation density within ultrafine grains in severely deformed aluminium was evaluated by the scanning transmission electron microscopy. The values were around 1014 m−2 in commercial pure aluminium samples with equivalent strain up to 10. The obtained dislocation densities values correspond to strength between 55 MPa and 70 MPa according to the Bailey–Hirsch relationship.