邓超,熊梓旭,洪睿,冉春华

• 1:重庆大学材料科学与工程学院

摘要(Abstract)：

Mg-Li双相合金作为最轻的金属结构材料，其应用潜力备受关注。然而，其中β-Li相因化学活性强且对表面损伤高度敏感，长期无法获得可解析的电子背散射衍射(EBSD)菊池花样。这一技术瓶颈已困扰学界近30年，严重制约了该合金微观组织及变形机制的深入研究。针对此问题，提出一种基于低温氩离子束抛光(cryo-argon ion beam polishing)的样品制备新方法。该方法采用2步抛光策略:先以大电压(3～6 kV)、大电流(20～80μA)和小角度(0.5°～1°)快速去除表面损伤层;再以小电压(0.5～2 kV)、小电流(5～20μA)和更小角度(0°～0.5°)进行精细修整。同时，借助液氮冷却(-80～0℃)有效抑制离子束引发的热效应及结构相变，成功实现了β-Li相的高质量EBSD表征。实验结果表明，在优化工艺条件下，Mg-Li双相合金样品的β-Li相可获得到完整解析，其菊池花样清晰、标定准确，且未发生α-Mg相的误标。与常温抛光相比，该方法显著减轻了离子束级联损伤引入的表面应力与应变。该技术为Mg-Li合金及其他软/硬双相难加工材料的EBSD样品制备提供了一种可靠且可重复的解决方案。

关键词(KeyWords)： Mg-Li双相合金;电子背散射衍射;氩离子束抛光;级联损伤;β-Li相

Abstract:

Keywords:

基金项目(Foundation): 重庆市研究生教育教学改革研究一般项目(YJG250032);; 重庆市高等教育教学改革项目(252016)

作者(Author): 邓超,熊梓旭,洪睿,冉春华

DOI: 10.19927/j.cnki.syyt.2026.10.002

参考文献(References)：

• [1]Doddapaneni S,Kumar S,Sharma S,et al. Advancements in EBSD techniques:a comprehensive review on characterization of composites and metals,sample preparation,and operational parameters[J].Journal of Composites Science,2025,9(3):132.
• [2]Peng X,Liu W C,Wu G H. Strengthening-toughening methods and mechanisms of Mg-Li alloy:a review[J]. Rare Metals,2022,41(4):1176-1188.
• [3]Peng X,Liu W C,Wu G H,et al. Plastic deformation and heat treatment of Mg-Li alloys:a review[J]. Journal of Materials Science&Technology,2022,99:193-206.
• [4]Yang Y,Xiong X M,Peng X D,et al. The development and prospect of ultra-light Mg-Li alloys[J]. Journal of Magnesium and Alloys,2026,18:102084.
• [5]Sun Y,Zhang F, Ren J, et al. Effect of Li content on the microstructure and mechanical properties of as-homogenized Mg-LiAl-Zn-Zr alloys[J]. Alloys,2023,2(2):89-99.
• [6]Xu M N,Xiao L R,Gao B,et al. Strengthening mechanisms induced by sequential grain refinement and solid solution strengthening in dual-phase heterostructured Mg-Li alloys with low Al content[J]. Journal of Alloys and Compounds, 2025, 1021:179527.
• [7]Mineta T. Surface treatment and electron backscatter diffraction(EBSD)analysis of the body-centered cubic phase in Mg-Li based alloys processed by severe plastic deformation[J]. Micron,2020,137:102914.
• [8]Qian X Y,Wang C L,Li Y X,et al. First-principles investigation of vacancy defect-mediated irradiation effects on grain/phase boundaries stability and crack resistance in Mg-Li alloy[J]. Materials Letters,2026,413:140403.
• [9]Li H L,Guo A H,Kong C,et al. Microstructure evolution and mechanical properties of Al/Mg-Li/Al laminate metallic composites via hot roll bonding and subsequent cryorolling[J]. Materials Science and Engineering a-Structural Materials Properties Microstructure and Processing,2024,891:146007.
• [10]Huang Y C,Qi F Z,Sun J W,et al. Strengthening dual-phase MgLi alloy through precipitation control[J]. Materials Research Letters,2025,13(1):17-23.
• [11]Wu R,Yan Y,Wang G,et al. Recent progress in magnesiumlithium alloys[J]. International Materials Reviews,2015,60(2):65-100.
• [12]Tang S,Xin T Z,Xu W Q,et al. Precipitation strengthening in an ultralight magnesium alloy[J]. Nature Communications,2019,10:1003.
• [13]Guo F,Jiang L Y,Ma Y L,et al. Strengthening a dual-phase Mg-Li alloy by strain-induced phase transformation at room temperature[J].Scripta Materialia,2020,179:16-19.
• [14]詹美燕，李春明．电子背散射衍射的制样方法和影响花样质量的因素[J]．物理测试，2021,39(1):31-36.
• [15]邓超，王淞，丁玉萍，等．一种Mg-Li双相合金EBSD样品的制备方法:中国，CN116879329A[P]. 2023-10-13.
• [16]Wu J Y,Yuan L X,Li Z,et al. Air-stable means more:designing air-defendable lithium metals for safe and stable batteries[J].Materials Horizons,2020,7(10):2619-2634.
• [17]Brown W L. Collision cascades, ionization, spikes and energy transfer[J]. MRS Online Proceedings Library,1985,51(1):53-70.
• [18]Thompson M W. Atomic collision cascades in solids[J]. Vacuum,2002,66(2):99-114.
• [19]Zhang X,Yang K,Bai W W,et al. Crystallographic orientation and variant selection of trimodal microstructure in dual-phase Mg-Li alloy after solid solution treatment[J]. Scripta Materialia, 2026,271:117004.