著者

Yoshihito Kawamura Michiaki Yamasaki

出版者

The Japan Institute of Metals and Materials

雑誌

MATERIALS TRANSACTIONS (ISSN:13459678)

巻号頁・発行日

vol.48, no.11, pp.2986-2992, 2007-11-01 (Released:2007-10-25)

参考文献数

13

被引用文献数

230 452

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We investigated the formation and mechanical properties of Mg97Zn1RE2 alloys with long-period stacking ordered (LPSO) structures by examining RE = Y, La, Ce, Pr, Sm, Nd, Gd, Dy, Ho, Er, Tb, Tm and Yb. The LPSO phase developed for RE = Y, Dy, Ho, Er, Gd, Tb and Tm. LPSO Mg-Zn-RE alloys are either type I, in which the LPSO phase forms during solidification: Mg-Zn-Y, Mg-Zn-Dy, Mg-Zn-Ho, Mg-Zn-Er and Mg-Zn-Tm, or type II, in which the LPSO phase is nonexistent in as-cast ingots but precipitates with soaking at 773 K: Mg-Zn-Gd and Mg-Zn-Tb. The criteria for REs that form an LPSO phase in Mg-Zn-RE alloys are discussed. Mg-Zn-RE alloys with an LPSO phase, which were worked by hot extrusion, include high strength both at ambient and elevated temperatures, and good ductility. Their tensile yield strength, ultimate strength and elongation were 342–377 MPa, 372–410 MPa and 3–9%, respectively at ambient temperature, and 292–310 MPa, 322–345 MPa and 4–13% at 473 K. The LPSO Mg-Zn-RE alloys are promising candidates for lightweight structural materials.