| Titre : | Development of novel grain morphology during hot extrusion of magnesium AZ21 alloy (2011) |
| Auteurs : | M. A. Azeem, Auteur ; A. Tewari, Auteur ; S. Mishra, Auteur |
| Type de document : | Article : texte imprimé |
| Dans : | Acta materialia (Vol. 58 N° 5, Mars 2010) |
| Article en page(s) : | pp. 1495–1502 |
| Note générale : | Métallurgie |
| Langues : | Anglais |
| Tags : | Magnesium alloy Extrusion Dynamic recrystallization Annealing Electron backscattering diffraction (EBSD) |
| Résumé : | Microstructure and microtexture evolution during static annealing of a hot-extruded AZ21 magnesium alloy was studied. Apart from fine recrystallized equiaxed grains and large elongated deformed grains, a new third kind of abnormal grains that are stacked one after the other in a row parallel to the extrusion direction were observed. The crystallographic misorientation inside these grains was similar to that of the fine recrystallized grains. The large elongated grains exhibited significant in-grain misorientation. A self-consistent mechanistic model was developed to describe the formation of these grain morphologies during dynamic recrystallization (DRX). The texture of pre-extruded material, although lost in DRX, leaves a unique signature which manifests itself in the form of these grain morphologies. The origin of abnormal stacked grains was associated with slow nucleation in pre-extruded grains of a certain orientation. Further annealing resulted in large secondary recrystallized grains with occasional extension twins. |
| DEWEY : | 669 |
| ISSN : | 1359-6454 |
| En ligne : | http://www.sciencedirect.com/science/article/pii/S1359645409007599 |
