Preparation and corrosion resistance of superhydrophobic coatings on AZ31 magnesium alloy

AZ31镁合金表面超疏水涂层的制备及耐蚀性（英文）

In order to improve the corrosion resistance of the Mg alloys, the superhydrophobic coatings on AZ31 Mg alloy wereprepared by a two-step process of micro-arc oxidation treatment and superhydrophobic treatment in stearic acid ethanol solution. Theeffects of voltages, frequencies and treatment time on the contact angle of the superhydrophobic treated sample were investigated.The results showed that with increasing the voltage, frequency and treatment time, all of the contact angles of the superhydrophobictreated sample increased first, and then decreased, reaching the maximum values at 350 V, 1000 Hz and 5 min, respectively. Theoptimal superhydrophobic coating was mainly composed of MgO and Mg2SiO4 phases, with the pore diameter of ～900 nm, thethickness of ～6.86 μm and the contact angle of 156.96°. The corrosion current density of the superhydrophobic AZ31 sampledecreased by three orders of magnitude, and the amount of hydrogen evolution decreased by 94.77% compared with that of the AZ31substrate sample.

为提高镁合金的耐蚀性,通过微弧氧化和硬脂酸乙醇溶液疏水处理两步法在镁合金表面制备超疏水涂层。考察微弧氧化电压、频率和时间对疏水处理试样接触角的影响。结果表明:随着微弧氧化电压、频率和时间的增加,疏水处理试样的接触角均先增大后减小,分别在350 V、1000 Hz和5 min时获得最大值。最佳超疏水涂层主要由MgO和Mg2Si O4相组成,其表面微孔直径为～900nm,厚度为～6.86μm,接触角高达156.96°。超疏水试样的腐蚀电流密度较基体降低3个数量级,而氢气析出量较基体降低94.77%。