Developing new Mg alloy as potential bone repair material via constructing weak anode nano-lamellar structure  

作　　者：Jinshu Xie Lele Wang Jinghuai Zhang Liwei Lu Zhi Zhang Yuying He Ruizhi Wu 

机构地区：[1]Key Laboratory of Superlight Material and Surface Technology,Ministry of Education,College of Materials Science and Chemical Engineering,Harbin Engineering University,Harbin,150001,China [2]School of Materials Science and Engineering,Hunan University of Science and Technology,Xiangtan,411201,China

出　　处：《Journal of Magnesium and Alloys》2023年第1期154-175,共22页镁合金学报（英文）

基　　金：the support of the National Natural Science Foundation of China(51871069,52071093);the Zhejiang Province Key Research and Development Plan,China(2021C01086);Student Research and Innovation Fund of the Fundamental Research Funds for the Central Universities(3072022GIP1004)。

摘　　要：The mechanics-corrosion and strength-ductility tradeoffs of magnesium(Mg)alloys have limited their applications in fields such as orthopedic implants.Herein,a fine-grain structure consisting of weak anodic nano-lamellar solute-enriched stacking faults(SESFs)with the average thickness of 8 nm and spacing of 16 nm is constructed in an as-extruded Mg96.9Y1.2Ho1.2Zn0.6Zr0.1(at.%)alloy,obtaining a high yield strength(YS)of 370 MPa,an excellent elongation(EL)of 17%,and a low corrosion rate of 0.30 mm y−1(close to that of high-pure Mg)in a uniform corrosion mode.Through scanning Kelvin probe force microscopy(SKPFM),one-dimensional nanostructured SESFs are identified as the weak anode(∼24 mV)for the first time.The excellent corrosion resistance is mainly related to the weak anodic nature of SESFs and their nano-lamellar structure,leading to the more uniform potential distribution to weaken galvanic corrosion and the release of abundant Y^(3+)/Ho^(3+)from SESFs to form a more protective film with an outer Ca_(10)(PO_(4))_(6)(OH)_(2)/Y_(2)O_(3)/Ho_(2)O_(3) layer(thickness percentage of this layer:72.45%).For comparison,the as-cast alloy containing block 18R long period stacking ordered(LPSO)phase and the heat-treated alloy with fine lamellar 18R-LPSO phase(thickness:80 nm,spacing:120 nm)are also studied,and the characteristics of SESFs and 18R-LPSO phase,such as the weak anode nature of the former and the cathode nature of the latter(37-90 mV),are distinguished under the same alloy composition.Ultimately,we put forward the idea of designing Mg alloys with high mechanical and anti-corrosion properties by constructing"homogeneous potential strengthening microstructure",such as the weak anode nano-lamellar SESFs structure.

关 键 词：Mg alloys Corrosion Solute-enriched stacking faults LPSO structure SKPFM HYDROXYAPATITE 

分 类 号：TG146[一般工业技术—材料科学与工程]