Promotion of texture weakening in magnesium by alloying and thermomechanical processing: (I) alloying

• Published in: Journal of materials science Vol. 49; no. 3; pp. 1408 - 1425
• Main Authors: Sanjari, M., Farzadfar, A., Kabir, A. S. H., Utsunomiya, H., Jung, In-Ho, Petrov, R., Kestens, L., Yue, S.
• Format: Journal Article
• Language: English
• Published: Boston Springer US 01.02.2014; Springer; Springer Nature B.V
• Subjects: Activated; Alloying; Alloys; Annealing; Characterization and Evaluation of Materials; Chemistry and Materials Science; Classical Mechanics; Crystallography and Scattering Methods; Deformation mechanisms; Dislocations; Dynamic recrystallization; Electron backscatter diffraction; Finish rolling; Grain boundaries; Hardness; Magnesium; Materials Science; Mechanical properties; Microstructure; Misalignment; Nucleation; Polymer Sciences; Solid Mechanics; Solid solutions; Texture; Thermomechanical treatment; Twinning; Warm rolling; Warm working; Zinc; Zinc compounds; Slip Mode; Boundary Mobility; Prismatic Slip; Misorientation Angle; Texture Weaken
• ISSN: 0022-2461; 1573-4803
• DOI: 10.1007/s10853-013-7826-3

The recrystallization and texture evolution of four Mg–Zn–Ce sheets with a warm-rolled microstructure obtained through two stages that can be characterised as rough rolling and finish rolling were investigated at different stages of post-rolling annealing. On annealing, the same regions of the microstructure, located by hardness indentations, were examined and tracked by electron backscatter diffraction (EBSD). Furthermore, intragranular misorientation axes (IGMA) analysis was used to investigate the associated deformation mechanisms in the as-deformed material. By combining these two methods, the development of the recrystallization microstructure was investigated and important aspects, such as preferential nucleation sites, correlation between activated deformation mechanism and initial orientation of the recrystallized grains, were studied. The results showed that the Mg–1Zn–1Ce alloy, which had the highest Ce/Zn ratio, showed the weakest as-rolled texture and the most homogenous distribution of shear banding/twinning. The IGMA analysis also showed that in Mg–1Zn–1Ce, other types of dislocations rather than basal 〈a〉 were activated; in particular, prismatic 〈a〉 type was activated during deformation. Therefore, the weakening of recrystallization texture during rolling resulting from the addition of RE elements was linked with a change in dynamic recrystallization (DRX) behaviour. Since the Mg–1Zn–1Ce alloy corresponds to the highest level of Ce in solid solution, the observed texture weakening was possibly due to decreasing grain boundary mobility as a result of solute partitioning of RE elements to dislocations and grain boundaries.