Abnormally high residual dislocation density in pure aluminum after Al/Ti/Al laminate annealing for seven days

We report an abnormally high residual dislocation density in aluminium in an Al/Ti/Al laminate annealed at 873 K for seven days. The residual dislocation density reaches 7.5 x 1014 m−2, higher than that in aluminum after severe plastic deformation processes such as accumulative roll bonding and high-pressure torsion. It is proposed that the high residual dislocation density may result from obstruction of the movement of TiAl3 nanoparticles by the grain boundary and Ti atoms conglomerating at vacancies distributed in the aluminium matrix at a high temperature for a sufficient time to allow a relatively stable crystal.