镁合金表面TiO_(2)二维薄膜的制备及其耐腐蚀性能研究

Preparation and Corrosion Resistance of TiO_(2)Two-dimensional Thin Films on Magnesium Alloy Surface

由于镁是一种较为活泼的金属,容易被氧化,且生成的氧化膜不具备保护性,这会进一步加快镁的腐蚀速率。通过在镁合金表面制备一层保护膜来阻断其与腐蚀物质的接触,从而增强镁合金的耐腐蚀性。首先根据已有文献制备TiO_(2)胶体,然后利用电泳沉积法,以镁合金基样为阳极,在其表面制备TiO_(2)薄膜,电泳液为上述TiO_(2)胶体,并探究了制备过程中的各项实验参数(不同电泳时间和不同沉积时间)对样品的影响。采取XRD、SEM等测试方法对制备的TiO_(2)薄膜进行分析,并进一步测试样品的极化曲线并做出分析。通过一系列参数优化可知,最优参数为电泳电压20 V,沉积时间90 s,此时制备的TiO_(2)薄膜的腐蚀电位最正,为-1.26 V,同时腐蚀电流密度也最低,为4.21×10^(-6)A/cm^(2)。

As magnesium is a relatively reactive metal,it is easy to be oxidized,and the generated oxide film is not protective,which further leads to a higher corrosion rate of magnesium easily.By preparing a protective film on the surface of magnesium alloy to hinder contact with corrosive media,the contact with corrosive substances can be blocked,thus the corrosion resistance of magnesium alloy can be enhanced.Firstly,TiO_(2)colloid was prepared according to the existing literature,and then TiO_(2)thin film was prepared on the surface of magnesium alloy base sample using electrophoretic deposition method with the above mentioned TiO_(2)colloid as the anode,and the effect of each experimental parameter(different electrophoretic time and different deposition time)on the sample in the preparation step was investigated.The prepared TiO_(2)films were analyzed by XRD,SEM and other testing methods,and the polarization curves of the samples were further tested and analyzed.Through a series of parameter optimization,it is found that the optimal parameters are electrophoresis voltage of 20 V and deposition time of 90 s.In this case,the TiO_(2)film prepared has the most positive corrosion potential,which is-1.26 V,and the lowest corrosion current density is 4.21×10^(-6)A/cm^(2).