摘要
Mg(OH)2/Mg-Al-layered double hydroxide (LDH) coatings were modified with methyltrimethoxysilane (MTMS) on magnesium alloys. Effect of hydrolysis degree of silane solution on coating formation was investigated. Chemical compositions and surface morphologies of the coatings were examined using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and field-emission scanning electronic microscopy (FESEM). Results indicated that the composite coatings consisted of polymethyltrimethoxysilane (PMTMS), LDH and Mg(OH)2. Electrochemical and hydrogen evolution measurements revealed that the composite coatings possessed good corrosion resistance, especially the ones prepared in a high hydrolysis degree of silane. The optimum corrosion resistance of the composite coati ng was LDH/PMTMS-3 coating, which had the lowest value of corrosion current density (5.537×10^-9 A·cm^-2) and a dense surface.Plausible mechanism for coating formation and corrosion process of MTMS-modified Mg(OH)2/Mg-Al-LDH coatings were discussed.
Mg（OH）2/Mg-Al-layered double hydroxide（LDH）coatings were modified with methyltrimethoxysilane（MTMS）on magnesium alloys.Effect of hydrolysis degree of silane solution on coating formation was investigated.Chemical compositions and surface morphologies of the coatings were examined using X-ray diffraction（XRD）,Fourier transform infrared spectroscopy（FTIR）,X-ray photoelectron spectroscopy（XPS）and field-emission scanning electronic microscopy（FESEM）.Results indicated that the composite coatings consisted of polymethyltrimethoxysilane（PMTMS）,LDH and Mg（OH）2.Electrochemical and hydrogen evolution measurements revealed that the composite coatings possessed good corrosion resistance,especially the ones prepared in a high hydrolysis degree of silane.The optimum corrosion resistance of the composite coating was LDH/PMTMS-3 coating,which had the lowest value of corrosion current density(5.537 × 10-9 A·cm-2)and a dense surface.Plausible mechanism for coating formation and corrosion process of MTMS-modified Mg（OH）2/Mg-Al-LDH coatings were discussed.
基金
financially supported by the National Natural Science Foundation of China (Nos.51601108 and 51571134)
the Natural Science Foundation of Shandong Province (No. 2016ZRB01A62)
the Shandong University of Science and Technology Research Fund (No. 2014TDJH104)
the Opening Fund of Ministry-Province Jointly Constructed Cultivation Base for State Key Laboratory of Processing for Non-ferrous Metal and Featured Materials
作者简介
Fen Zhang,e-mail:zhangfen2011@hotmail.com;Rong-Chang,e-mail:rczeng@foxmail.com.
