镁合金表面有机/无机杂化涂层的性能

Properties of Organic/Inorganic Hybrid Coatings Formed on Magnesium Alloy Surface

在AZ31镁合金表面制备有机/无机杂化涂层,用扫描电子显微镜、扫描探针显微镜、电化学工作站、光学显微镜、涂层测厚仪等手段对杂化涂层的表面形貌、耐蚀性、附着力及厚度进行表征,研究了有机/无机杂化溶胶-凝胶体系的pH值对涂层性能的影响。结果表明:pH值对镁合金表面的杂化涂层的性能有显著的影响。当pH值为3~3.5时,可在镁合金表面制备出高平整度且少缺陷的涂层,厚度约为22μm;当pH值为2.2~2.8时,涂层变薄、表面起伏较大且有较多的孔洞。当pH=3时杂化涂层具有良好的附着力和最正的腐蚀电位,且腐蚀电流密度最小(约为7.34×10-5A/cm^2),相对于空白镁合金试样的缓蚀效率约为99.7%。

Organic/inorganic hybrid coatings were prepared on AZ31 magnesium alloy, which then was characterized by means of scanning electron microscope, scanning probe microscope, electrochemical analyzer, optical microscope and coatings thickness tester in terms of surface morphology, corrosion resistance, adhesion and thickness. While the influence of pH value of organic/inorganic hybrid sol-gel on the properties of organic/inorganic hybrid coating was also investigated. The results show that pH values of organic/inorganic hybrid sol-gel have important effect on the properties of the organic/inorganic hybrid coatings formed on AZ31 magnesium alloy： When pH value is in the range 3~3.5, a smooth and few defects hybrid coating of the thickness of 22 μm can be obtained; When pH value is in the range2.2~2.8, the hybrid coating became thin and coarse with some big pores; When pH value equals to 3.0,the hybrid coating has good adhesion, highest corrosion potential and minimum corrosion current density（~7.34 × 10^（-5）A/cm^2）. Corrosion inhibition efficiency of the hybrid coating prepared by sol-gel with pH 3.0could reach ~ 99.7% compared to the blank AZ31 magnesium alloy.