Effects of LPSO/α-Mg interfaces on dynamic recrystallization behavior of Mg96.5Gd2.5Zn1 alloy

Journal Article · Fri Dec 15 04:00:00 EST 2017 · Materials Characterization

DOI:https://doi.org/10.1016/J.MATCHAR.2017.10.028· OSTI ID:22832942

Chen, Yuanli; Jin, Li; Dong, Jie; Wang, Fenghua; Li, Yangxin ^[1]; Li, Yanjun ^[2]; Pan, Hongchen; Nie, Xi ^[1]

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1. National Engineering Research Center of Light Alloy Net Forming, State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, Shanghai 200240 (China)
2. Shanghai Institute of Measurement and Testing Technology, 1500 Zhang Heng Road, Shanghai 201203 (China)

Highlights: • The effects of LPSO/α-Mg interfaces on the dynamic recrystallization (DRX) behavior of Mg{sub 96.5}Gd{sub 2.5}Zn{sub 1} (at.%) alloy during indirect extrusion at 350 °C were investigated. • The LPSO/α-Mg interfaces in Mg{sub 96.5}Gd{sub 2.5}Zn{sub 1} alloy appeared as two groups, including the basal and non-basal LPSO/α-Mg interfaces, which have various effects on the DRX behavior of Mg{sub 96.5}Gd{sub 2.5}Zn{sub 1} alloy. • Compared with the basal LPSO/α-Mg interfaces, DRX grains are preferentially nucleated near the non-basal LPSO/α-Mg interfaces where there is higher V{sub GROD} and lower required energy E{sub s} for the DRX nucleation. - Abstract: Mg-Gd-Zn alloy, which contains a long period stacking ordered (LPSO) structure, has the potential to become a high-strength Mg alloy within the automotive and aerospace industries. Two types of LPSO/α-Mg interfaces in Mg{sub 96.5}Gd{sub 2.5}Zn{sub 1} (at.%) alloy were characterized, namely, basal and non-basal LPSO/α-Mg interfaces. The effects of LPSO/α-Mg interfaces on the dynamic recrystallization (DRX) behavior during indirect extrusion at 350 °C were investigated. The grain reference orientation deviation (GROD) value (V{sub GROD}), derived from EBSD, could qualitatively characterize the dislocation density within a grain and determine the presence of DRX grain nucleation. The results suggested that the areas around non-basal LPSO/α-Mg interfaces always have higher V{sub GROD} than do basal LPSO/α-Mg interfaces. In addition, the stored energy (E{sub s}) required for DRX nucleation on the non-basal LPSO/α-Mg interface is lower than that on the basal LPSO/α-Mg interface. This is a result of the flat, sharp basal LPSO/α-Mg interface compared to the faceted non-basal LPSO/α-Mg interface. Regardless of whether the LPSO structure/α-Mg matrix interface is coherent or not, non-basal LPSO/α-Mg interfaces are favorable nucleation sites for DRX grains due to the higher V{sub GROD} and lower required energy E{sub s}.

• OSTI ID: 22832942
• Journal Information: Materials Characterization, Journal Name: Materials Characterization Vol. 134; ISSN 1044-5803; ISSN MACHEX
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
BACKSCATTERING
COMPARATIVE EVALUATIONS
DISLOCATIONS
ELECTRON DIFFRACTION
EXTRUSION
GADOLINIUM COMPOUNDS
MAGNESIUM ALLOYS
RECRYSTALLIZATION
ZINC COMPOUNDS