Corrosion Resistance of Superhydrophobic Mg(OH)_(2)/Calcium Myristate Composite Coating on Magnesium Alloy AZ31  

作　　者：Zheng-Zheng Yin Wei Zhao Jing Xu Rong-Chang Zeng Feng-Qin Wang Zhen-Lin Wang 

机构地区：[1]Corrosion Laboratory for Light Metals,College of Materials Science and Engineering,Shandong University of Science and Technology,Qingdao 266590,China [2]School of Materials Science and Engineering,Zhengzhou University,Zhengzhou 450001,China [3]Hubei Key Laboratory of Advanced Technology for Automotive Components,Wuhan 430070,China [4]College of Materials Science and Engineering,Chongqing University of Technology,Chongqing 400065,China

出　　处：《Acta Metallurgica Sinica(English Letters)》2021年第12期1618-1634,共17页金属学报（英文版）

基　　金：This work was supported by the National Natural Science Foundation of China(No.52071191);the Open Foundation of Hubei Key Laboratory of Advanced Technology for Automotive Components(No.XDQCKF2021006).

摘　　要：Hydrophobic Mg(OH)_(2)/calcium myristate(Ca[CH3(CH2)12COO]_(2),CaMS)and Mg(OH)_(2)/magnesium myristate(Mg[CH3(CH2)12COO]2,MgMS)composite coatings were prepared on the alkali-treated AZ31 substrates via both electrodeposition and dipping methods.The morphologies,compositions,and constitutes of the coatings were investigated by using field-emission scanning electron microscopy(SEM),X-ray photoelectron spectroscopy(XPS),and Fourier transform infrared spectrometry(FTIR)together with X-ray diffractometer(XRD).Furthermore,electrochemical(polarization and impedance spectroscopy)and hydrogen evolution tests were applied to evaluate the corrosion resistance.The wettability and adhesive strength of the composite coatings were characterized through water static contact angle(CA),sliding angle(SA),and nano-scratch tests.Results indicated that the better super-hydrophobicity,corrosion resistance,and adhesion were achieved via an electrodeposited process.The corrosion current density(icorr)and hydrogen evolution rate(HER)of the electrodeposited coating were three and one orders of magnitude smaller than the substrate,implying a significantly improved corrosion resistance.This scenario was ascribed to the super-hydrophobicity of electrodeposited composite coating with a contact angle(CA)and slide angle(SA)of 159.2°±0.8°and 5.2°±0.8°,respectively.However,the dipped composite coating was adverse to the improvement of corrosion resistance and adhesion due to the dissolution of the underlying Mg(OH)_(2)layer and smooth surface with less organic fatty acid salt(MgMS)

关 键 词：Magnesium alloy Electrodeposition and dipping SUPER-HYDROPHOBICITY Corrosion resistance 

分 类 号：TG174.4[金属学及工艺—金属表面处理]