镁合金表面Mg-MOF-74/硅烷复合涂层的制备及耐蚀性  

Preparation and corrosion resistance of Mg-MOF-74/silane composite coating on magnesium alloy surface

作　　者：李耀辉 廖宏儿 耿铁[1] 尚龙 李海平[1] 刘伟[1] LI Yaohui;LIAO Honger;GENG Tie;SHANG Long;LI Haiping;LIU Wei(School of Mechanical&Electrical Engineering,Henan University of Technology,Zhengzhou 450001,China)

机构地区：[1]河南工业大学机电工程学院,河南郑州450001

出　　处：《电镀与涂饰》2022年第4期245-250,共6页Electroplating & Finishing

基　　金：国家自然科学基金(U1504504)。

摘　　要：通过水热合成法制备了微米级的金属有机骨架材料Mg-MOF-74粉体,采用浸渍提拉法在AZ31B镁合金表面制备了掺杂一定量Mg-MOF-74粉体的硅烷涂层。使用扫描电镜和红外光谱仪研究了Mg-MOF-74掺杂对硅烷涂层表面形貌和组织结构的影响。结果表明:相比于单纯的硅烷涂层,Mg-MOF-74/硅烷复合涂层更加平整致密;Mg-MOF-74中的羟基与水解后的硅烷脱水缩合生成了交联密度较高的网状结构,能够有效阻挡腐蚀介质向镁基底渗透。通过极化曲线测量、电化学阻抗谱测试、浸泡试验等方法研究了Mg-MOF-74/硅烷复合涂层的耐蚀性。与纯硅烷涂层相比,Mg-MOF-74/硅烷复合涂层的腐蚀电位正移了0.121 V,腐蚀电流密度下降了一个数量级,容抗弧半径明显增大,在模拟体液中浸泡13 d后的析氢量也下降了一半,表明Mg-MOF-74/硅烷复合涂层有效提高了镁合金基底的耐蚀性。Micron-sized Mg-MOF-74 powder,a metal-organic framework material,was prepared by hydrothermal synthesis.Silane coatings doped with Mg-MOF-74 powder were prepared on AZ31B magnesium alloy by dip coating method.The effect of Mg-MOF-74 doping on the surface morphology and microstructure of silane coating were studied by scanning electron microscopy and infrared spectroscopy.The results showed that the Mg-MOF-74/silane composite coating was smoother and more compact than the undoped silane coating.The hydroxyl groups in Mg-MOF-74 were dehydrated and condensed with the hydrolyzed silane,forming a highly crosslinked network structure,effectively preventing the corrosive media from penetrating into the magnesium alloy substrate.The corrosion resistance of Mg-MOF-74/silane composite coating was examined by polarization curve measurement,electrochemical impedance spectroscopy,and immersion corrosion test.As compared with the pure silane coating,the Mg-MOF-74/silane composite coating had a positively shifted corrosion potential,one order of magnitude lower corrosion current density,larger radius of capacitance impedance arc,and only half of hydrogen evolution amount in the simulated body fluid after 13 days of immersion,indicating that Mg-MOF-74/silane composite coating could effectively improve the corrosion resistance of magnesium alloy substrate.

关 键 词：镁合金 金属有机骨架材料 硅烷 复合涂层 耐蚀性 模拟体液 电化学 

分 类 号：TG174.45[金属学及工艺—金属表面处理] TG174.462[金属学及工艺—金属学]