Observation of Dislocation Multiple Cutting of the Semicoherent Precipitate in Al-Cu-Mg-Ag Alloy

The interaction between dislocations and semicoherent precipitates (the Omega phase) is discussed. The investigation shows that the semicoherent precipitate is cut by dislocations during deformation. Conventional TEM and HRTEM observations demonstrate that shearing of precipitates by dislocations has occurred. The multiple cutting of the precipitate was observed. A cutting model was proposed to interpret the multiple cutting phenomena. The general theory is not only applicable to the precipitate in Al-Cu-Mg-Ag alloys, but also to semicoherent precipitates in other alloys. (Author)