论文部分内容阅读
在磷酸盐体系电解液中,对20%(体积分数)硅酸铝短纤维(Al2O3-SiO2)增强AZ91D镁基复合材料进行微弧氧化表面处理获得陶瓷层。利用扫描电子显微镜(SEM)和X射线衍射(XRD)仪分析陶瓷层的表面形貌、截面组织和相组成,采用动电位极化和电化学阻抗谱(EIS)测试评价微弧氧化陶瓷层的电化学腐蚀性能。结果表明,该陶瓷层主要由MgO和MgAl2O4相组成。陶瓷层的腐蚀电流密度比镁基复合材料基体低3个数量级,电化学阻抗大幅升高,耐腐蚀性能明显高于复合材料基体。
In the phosphate electrolyte system, ceramic layer was obtained by micro-arc oxidation surface treatment of 20% (volume fraction) Al2O3-SiO2 reinforced AZ91D magnesium matrix composite. The surface morphology, cross-section structure and phase composition of the ceramic layer were analyzed by scanning electron microscopy (SEM) and X-ray diffraction (XRD). Potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) Electrochemical corrosion properties. The results show that the ceramic layer is mainly composed of MgO and MgAl2O4 phases. The corrosion current density of the ceramic layer is 3 orders of magnitude lower than that of the magnesium-based composite substrate, and the electrochemical impedance increases sharply. The corrosion resistance of the ceramic layer is obviously higher than that of the composite substrate.