镁合金微弧氧化层Al_2O_3溶胶后续处理的研究

Al_2O_3 Sol Follow-up Processing for Micro-arc Oxidation Coating on Magnesium Alloy

通过溶胶-凝胶(Sol-gel)技术以异丙醇铝(AIP)为前躯体在微弧氧化处理的AZ91D镁合金基体表面制备了Al2O3溶胶封孔涂层。采用热重-差示扫描量热(TG-DSC)、X-射线衍射(XRD)、能谱(EDX)和扫描电镜(SEM)对凝胶热性能和涂层的成分以及微观形貌结构进行了分析,并对封孔处理前后试样的耐蚀性用动电位极化曲线进行测试。结果表明:封孔处理后的样品Icorr降低了2个数量级;Rp提高了2个数量级,样品表现出了良好的抗蚀性。

Al2O3 sol hole sealing coatings were prepared with tetraethyl ortho-silicate（TEOS） as precursor on substrate surface of micro-arc oxided AZ91D magnesium alloy by Sol-gel technology.The thermal properties of xerogel,the composition and morphology of films were analyzed by thermo-gravimetric（TG）,X-ray diffraction（XRD）energy dispersive X-ray（EDX） and scanning electron microscopy（SEM）.The anticorrosion behavior of the sol-gel coated and uncoated samples were measurd by potentiodynamic polarization tests.The results showed that the coated sample Icorr two orders of magnitude lower,Rp two orders of magnitude higher,good corrosion resiatance was exhibited.