High-temperature dislocation-precipitate interactions in Al alloys: An in situ transmission electron microscopy deformation study

The fundamental processes controlling the high-temperature interaction of dislocations with precipitates in Al-alloys were investigated in real time by deforming specimens in situ in the transmission electron microscope at elevated temperature. The observations support a bypass mechanism involving the interaction of lattice dislocations with the precipitate-matrix interface dislocations, where the rate-limiting step in the interaction is the release of the dislocation from the particle. These observations are discussed in relation to high-temperature deformation processes and models.