Microstructural characterization of intermetallic phases in a solution-treated Mg–5.0Sm–0.6Zn–0.5Zr (wt%) alloy

Journal Article · Thu Nov 15 04:00:00 EST 2018 · Materials Characterization

DOI:https://doi.org/10.1016/J.MATCHAR.2018.08.059· OSTI ID:22805865

Guan, Kai; Li, Baishun ^[1]; Yang, Qiang; Zhang, Dongdong ^[1]; Zhang, Xuhu; Zhang, Jingqi; Zhao, Lei ^[2]; Liu, Xiaojuan; Meng, Jian ^[1]

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1. State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China)
2. Aerospace Research Institute of Materials & Processing Technology, Beijing, 100076 (China)

Highlights: • Intermetallic phases in a solution-treated Mg–Sm−Zn−Zr alloy were studied using TEM. • Four types of the Zn-/Zr-containing particles were revealed. • New orientation relationships between Zn{sub 2}Zr{sub 3} and Mg matrix were found and discussed. • Intermetallic particles formed during solution can influence alloy's precipitation. - Abstract: Although Zn–Zr intermetallic phases have been frequently reported in solution-treated Mg–RE–Zn–Zr systems (RE presents rare earth), the types, crystal structures and influence on precipitation remain to be systematically investigated. In this work, the intermetallic phases formed during solution treatment in a Mg–Sm–Zn–Zr alloy were studied using transmission electron microscopy. Four types, namely the plate phase, the spindle-like phase, the nano-scale granuliform phase and the rod-like phase were revealed. Except the first one, the other three ones are Zn–Zr phase. In addition, the granuliform phase presents quadrate-shaped or lath-shaped and was identified as Zn{sub 2}Zr{sub 3}. However, these two Zn{sub 2}Zr{sub 3} phases with different shapes follow quite different orientation relationships with Mg matrix. Furthermore, three kinds of rod-like phases were observed: one across the grain boundary but only coherent with one grain, one covered by jagged Mg{sub 3}Sm precipitates and one with no surficial phase. The former twos are Zn{sub 2}Zr{sub 3} while the later one is Zn{sub 2}Zr. Finally, this work indicates that only the plate MgZn{sub 2} phase and the rod-like Zn{sub 2}Zr{sub 3} phase in the grain interior will act as heterogeneous nucleation sites for the Mg{sub 3}Sm precipitates, thus influencing the precipitation.

• OSTI ID: 22805865
• Journal Information: Materials Characterization, Journal Name: Materials Characterization Vol. 145; ISSN 1044-5803; ISSN MACHEX
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CRYSTAL STRUCTURE
GRAIN BOUNDARIES
INTERMETALLIC COMPOUNDS
MAGNESIUM ALLOYS
NUCLEATION
PRECIPITATION
SAMARIUM COMPOUNDS
TRANSMISSION ELECTRON MICROSCOPY
ZINC COMPOUNDS
ZIRCONIUM COMPOUNDS