【摘要】 为了提高AZ91D镁合金的耐蚀性能，利用单极性脉冲电源制备具有不同ZrO₂纳米颗粒含量的微弧氧化膜层，研究纳米ZrO₂颗粒对AZ91D镁合金微弧氧化膜层耐蚀性的影响。采用扫描电子显微镜观察复合膜层的表面及截面形貌；同时利用X射线衍射仪分析不同ZrO₂纳米颗粒含量的膜层中的相组成；测试样品的电化学腐蚀性能。结果表明：当电解液中加入1 g/L ZrO₂颗粒时，纳米ZrO₂颗粒能够渗入微弧氧化膜层之中，封闭膜中原有的微孔和微裂纹等缺陷，膜层表面质量较好；随着电解液中ZrO₂颗粒含量由2 g/L增加到3 g/L时，膜层的裂纹明显增多，导致腐蚀介质容易进入膜层发生腐蚀，耐蚀性能下降；在电解液中添加纳米ZrO₂颗粒时，1～3 g/L范围内添加1 g/L ZrO₂纳米颗粒的微弧氧化膜层的耐蚀性能最好。更多还原

【Abstract】 In order to improve the corrosion resistance of AZ91D magnesium alloy, micro-arc oxidation coatings with different ZrO₂ nanoparticle contents were prepared by unipolar pulse power supply, and the effect of nano ZrO₂ particles on the corrosion resistance of AZ91D magnesium alloy micro-arc oxidation coatings was studied. Scanning electron microscope was used to observe the surface and cross-sectional morphology of the composite films, meanwhile, X-ray diffractometer was used to analyze the phase composition of films with different contents of ZrO₂ nanoparticles. The prepared samples were then tested for electrochemical corrosion performance. The results show that when the content of 1 g/L ZrO₂ particles is added to the electrolyte, the nano ZrO₂particles can penetrate into the micro-arc oxidation film layer to close the original defects such as micropores and microcracks, and the surface quality of the film layer is good. When the content of ZrO₂ particles in the coating layer is increased from 2 g/L to 3 g/L,the crack formation of the coating layer is obviously enhanced, which makes it easier for the corrosive medium to enter the coating layer, so that corrosion is more likely to occur, and the corrosion resistance performance decreases. Therefore, when the content of nano-ZrO₂ particles added to the electrolyte is in the range of 1-3 g/L, the corrosion resistance of the micro-arc oxidation film layer with 1 g/L ZrO₂ nanoparticles is the best.更多还原