Twin-solute, twin-dislocation and twin-twin interactions in magnesium

Magnesium alloys have received considerable research interest due to their lightweight, high specific strength and excellent castability. However, their plastic deformation is more complicated compared to cubic materials, primarily because their low-symmetry hexagonal close-packed (hcp) crystal structure. Deformation twinning is a crucial plastic deformation mechanism in magnesium, and twins can affect the evolution of microstructure by interacting with other lattice defects, thereby affecting the mechanical properties. This paper provides a review of the interactions between deformation twins and lattice defects, such as solute atoms, dislocations and twins, in magnesium and its alloys. This review starts with interactions between twin boundaries and substitutional solutes like yttrium, zinc, silver, as well as interstitial solutes like hydrogen and oxygen. This is followed by twin-dislocation interactions, which mainly involve those between {101¯2} tension or {101¯1} compression twins and 〈 a 〉, 〈 c 〉 or 〈 c + a 〉 type dislocations. The following section examines twin-twin interactions, which occur either among the six variants of the same {101¯2} or {101¯1} twin, or between different types of twins. The resulting structures, including twin-twin junctions or boundaries, tension-tension double twin, and compression-tension double twin, are discussed in detail. Lastly, this review highlights the remaining research issues concerning the interactions between twins and lattice defects in magnesium, and provides suggestions for future work in this area.