Abstract Scope |
Precipitation constitutes a microstructural design tool that has been utilized successfully to strengthen metals such as, for example, aluminum alloys and nickel superalloys. However, particle hardening has proven significantly less effective in magnesium, thus severely limiting the possibilities for structural alloy design.
Exploiting the hardening potential of precipitates in magnesium alloys requires a profound understanding of the interaction between dislocations and precipitates. Basal dislocations are usually the main strain carriers, although non-basal slip systems may also become active and play a key role. The relative contribution of each mechanism depends on testing conditions, composition, microstructure and texture.
This lecture will review recent research on dislocation-particle interactions in magnesium alloys using a combined approach including micromechanical testing, slip trace analysis, and high resolution transmission electron microscopy. The interaction of basal and non basal dislocations with particles of different sizes and orientations with respect to the matrix will be discussed. |