Effect of crystallographic texture and twinning on the corrosion behavior of Mg alloys: A review

Magnesium and its alloys have gained significant popularity due to their light weight and their potential for use as bioresorbable materials. However, their application is limited in practice due to their relatively poor corrosion resistance. Several methods are available for improving the corrosion resistance of Mg alloys for bio-applications such as using different coatings, alloying, and modifying the microstructural parameters such as the grain size and the crystallographic texture. This review provides a comprehensive summary of the effects of crystallographic texture and twinning, as one of the most important deformation mechanisms of Mg and Mg alloys, on the corrosion behavior. Regarding the crystallographic texture, it is shown that theoretically the basal planes should exhibit a lower corrosion rate but in some cases, such as when there is a galvanic effect or when corrosion films control the overall corrosion behavior, different results may take place. Also, there are contradictory results concerning the effect of twinning on the corrosion behavior. Thus, in some cases twinning may provide preferential sites for corrosion due to the higher energies of atoms located in the twin region by comparison with normal atomic positions in the crystalline lattice whereas there are also other examples where experiments show that twins produce more protective films than in the surrounding matrix.