Competitive twinning behavior in magnesium and its impact on recrystallization and texture formation

MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING

卷:707

Article

Basu, I.^1,2  Al-Samman, T.¹ 

[1] Rhein Westfal TH Aachen, Inst Metallkunde & Metallphys, D-52056 Aachen, Germany

[2] Univ Groningen, Zernike Inst Adv Mat, Dept Appl Phys, NL-9747 AG Groningen, Netherlands

关键词: Texture;    Dynamic recovery;    Recrystallization;    Magnesium;    Rare-earths;   

DOI  :  10.1016/j.msea.2017.09.053

来源: Elsevier

【 摘 要 】

Rolled pure Mg and Mg-1 wt% Gd alloy were subjected to room temperature in-plane compression along the rolling direction, followed by isochronal annealing treatments for 1 h. The results of deformation texture and microstructure showed substantial differences due to rare earth alloying. In spite of imposed c-axis extension during deformation, the Mg-1Gd alloy retained the initial texture with the majority of basal poles concentrated near the longitudinal direction of the used channel-die tool. Electron back scatter diffraction analysis of the deformation microstructure revealed a predominance of {10 (1) over bar1} compression and {10 (1) over bar1}-{10 (1) over bar2} double twins relative to coexisting {10 (1) over bar2} tension twins. This behavior was significantly contrasting in comparison with that of pure Mg, wherein first and second generation {1012} tension twins were observed in profuse quantities. Continuous dynamic recrystallization took place inside compression and double twins by means of slip assisted subgrain rotation about the [0001] axis giving rise to a sharp prismatic fiber of recrystallized orientations. This fiber was transformed into a randomized texture pattern during subsequent static recrystallization and grain growth due to a different discontinuous recrystallization mechanism. This resulted in a significant annealing texture weakening and an increase of the overall Schmid factor for basal slip.

【 授权许可】

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