title: Natural ageing responses of duplex structured Mg-Li based alloys.
abstract: Natural ageing responses of duplex structured Mg-6%Li and Mg-6%Li-6%Zn-1.2%Y alloys have been investigated. Microstructural analyses revealed that the precipitation and coarsening process of α-Mg particles could occur in β-Li phases of both two alloys during ageing process. Since a certain amount of Mg atoms in β-Li phases were consumed for the precipitation of abundant tiny MgLiZn particles, the size of α-Mg precipitates in Mg-6%Li-6%Zn-1.2%Y alloy was relatively smaller than that in Mg-6%Li alloy. Micro hardness measurements demonstrated that with the ageing time increasing, the α-Mg phases in Mg-6%Li alloy could have a constant hardness value of 41 HV, but the contained β-Li phases exhibited a slight age-softening response. Compared with the Mg-6%Li alloy, the age-softening response of β-Li phases in Mg-6%Li-6%Zn-1.2%Y alloy was much more profound. Meanwhile, a normal age-hardening response of α-Mg phases was maintained. Tensile results indicated that obvious ageing-softening phenomenon in terms of macro tensile strength occurred in both two alloys. Failure analysis demonstrated that for the Mg-6%Li alloy, cracks were preferentially initiated at α-Mg/β-Li interfaces. For the Mg-6%Li-6%Zn-1.2%Y alloy, cracks occurred at both α-Mg/β-Li interfaces and slip bands in α-Mg and β-Li phases.
authors.affiliation: CAS Key Laboratory of Nuclear Materials and Safety Assessment, Institute of Metal Research, Chinese Acadamy of Sciences, 62 Wencui Road, Shenyang 110016, China.|Key Laboratory for Anisotropy and Texture of Materials (Ministry of Education), Northeastern University, Shenyang 110819, China.
authors.forename: C Q
authors.initials: CQ
authors.lastname: Li
authors.affiliation: CAS Key Laboratory of Nuclear Materials and Safety Assessment, Institute of Metal Research, Chinese Acadamy of Sciences, 62 Wencui Road, Shenyang 110016, China.
authors.forename: D K
authors.initials: DK
authors.lastname: Xu
authors.affiliation: CAS Key Laboratory of Nuclear Materials and Safety Assessment, Institute of Metal Research, Chinese Acadamy of Sciences, 62 Wencui Road, Shenyang 110016, China.
authors.forename: B J
authors.initials: BJ
authors.lastname: Wang
authors.affiliation: Peking University, Shenzhen Institute, Shenzhen Key Lab Human Tissue Regenerate &Repair, Shenzhen 518057, China.
authors.forename: L Y
authors.initials: LY
authors.lastname: Sheng
authors.affiliation: Jiangsu University of Science &Technology, Zhenjiang 212003, China.
authors.forename: Y X
authors.initials: YX
authors.lastname: Qiao
authors.affiliation: CAS Key Laboratory of Nuclear Materials and Safety Assessment, Institute of Metal Research, Chinese Acadamy of Sciences, 62 Wencui Road, Shenyang 110016, China.
authors.forename: E H
authors.initials: EH
authors.lastname: Han