In situ recrystallization by transmission electron microscopy of the 7050 aluminum alloy

In situ recrystallization by TEM in a termomechanically processed 7050 aluminum alloy was investigated. The nucleation of recrystallization has occured preferentially at strong deformation zones around the coarse particles (0,5 μm), which have been formed by group of smaller subgrains with similar orientation. The recrystallization nuclei have occured by a poligonization process, in which the pinning effect due to equilibrium precipitates (50 nm) had a important role. The recrystallization event only took place when these precipitates were solutioned. The equilibrium precipitates have changed the of recrystallization mechanisms at large particles, but the overal nucleation rate has not changed since that the recrystallized grain size agree with the mean planar separation of coarse particles. (author)