纯镁表面Zn-TiO_2涂层的制备及其耐蚀性

Preparation of Zn-TiO_2 film on magnesium and its corrosion behavior

以四氯化钛为前驱体,去离子水为溶剂,ZnCl2为掺杂剂,采用溶胶-凝胶方法制得TiO2溶胶,采用旋涂法在纯镁基体上制得Zn-TiO2薄膜。采用XRD、DSC/TG、SEM,表征不同实验条件下试样的组成和结构,发现Zn2+在一定程度上抑制了晶粒的长大和晶型转变;以电化学阻抗值作为评价标准,通过正交实验研究了热处理温度、涂层次数、Zn2+掺杂浓度对试样耐腐蚀性的影响。结果表明,Zn2+掺杂浓度为0.5%,涂层次数为3,热处理温度为300℃下得到的TiO2薄膜具有最好的耐蚀性。

Zn-TiO2 sol,prepared by sol-gel technique using titanium tetrachloride as precursor,deionized water as solvent and ZnCl2 as dopant,was coated on pure magnesium（Mg） by the method of spin-coating to improve the matrix corrosion resistance.The phases and microstructure of the coated-TiO2 magnesium at different experimental conditions were characterized using XRD,TG/DSC,SEM.It was found that Zn2＋ inhibited the growth of grains and crystal transformation.The effects of the heat-treatment temperature,coating times and Zn2＋ doping concentration on the corrosion resistance of the samples were investigated by the orthogonalizing analysis,where electrochemical impedance value was chosen as evaluation criteria.According to the results,the optimal synthesis route was 0.5% Zn2＋ doping concentration,3 coating times,and 300℃ heat-treatment temperature where TiO2-coated Mg had the best corrosion resistance.