Scanning transmission electron microscopy and atom probe tomography analysis of non-stoichiometry long-period-stacking-ordered structures in Mg-Ni-Y/Sm alloys  

作　　者：Yimeng Chen Manuel Legrée Jean-Louis Bobet Alexander Kvit 

机构地区：[1]CAMECA Instruments Inc,Madison,WI 53711,USA [2]ICMCB,Universitéde Bordeaux,Pessac,CEDEX 33608,France [3]NIAC&Materials Science Department,University of Wisconsin,Madison,WI 53706,USA

出　　处：《Journal of Magnesium and Alloys》2024年第3期954-965,共12页镁合金学报（英文）

基　　金：the financial support provided by ANR(Project ANR-22-PEHY-0007);DGA(French Direction Générale des Armées,2018600045);Région Nouvelle Aquitaine(agreement 2018–1R10126).

摘　　要：The long-period-stacking-ordered(LPSO)structure affects the mechanical,corrosion and hydrolysis properties of Mg alloys.The current work employs high angle annular dark field-scanning transmission electron microscopy(HAADF-STEM)and atom probe tomography(APT)to investigate the structural and local chemical information of LPSO phases formed in Mg-Ni-Y/Sm ternary alloys after extended isothermal annealing.Depending on the alloying elements and their concentrations,Mg-Ni-Y/Sm develops a two-phase LPSO+α-Mg structure in which the LPSO phase contains defects,hybrid LPSO structure,and Mg insertions.HAADF-STEM and APT indicate non-stoichiometric LPSO with incomplete Ni_(6)(Y/Sm)_(8) clusters.In addition,the APT quantitatively determines the local composition of LPSO and confirms the presence of Ni within the Mg bonding layers.These results provide insight into a better understanding of the structure and hydrolysis properties of LPSO-Mg alloys.

关 键 词：Magnesium alloys Long-range ordering Atom probe tomography(APT) STEM HAADF Hydrolysis properties. 

分 类 号：TG146.22[一般工业技术—材料科学与工程]