【摘要】 为研究脉冲频率对微弧氧化膜层组织结构及耐蚀性能的影响，采用不同脉冲频率在硅酸盐电解液中对MB8镁合金进行微弧氧化处理。采用扫描电镜（SEM）、能谱仪（EDS）、X射线衍射仪（XRD）、膜层测厚仪、表面粗糙度仪和电化学工作站等对膜层组织结构与性能进行研究。结果表明：不同脉冲频率制备的MB8镁合金微弧氧化膜层的物相主要由Mg、MgO和Mg₂SiO₄组成；随着脉冲频率的增大，膜层的厚度减小，表面粗糙度增加，孔隙率和最大孔径呈现先减小后增大的趋势；与MB8镁合金基体相比，微弧氧化膜层的自腐蚀电位升高，腐蚀电流密度降低；当脉冲频率为1200 Hz时，微弧氧化膜层的孔隙率最小，表面质量较好，耐腐蚀性能最佳，腐蚀电流密度为1.338×10^-6 A·cm^-2,腐蚀电阻为3.356×10⁴Ω·cm²。更多还原

【Abstract】 To investigate the effect of pulse frequency on microstructure and corrosion resistance of micro-arc oxidation（MAO） coating, MB8 magnesium alloy was subjected to micro-arc oxidation treatment in silicate electrolyte with different pulse frequencies. The microstructure and properties of the MAO coatings were studied using scanning electron microscopy（SEM）, energy dispersive spectrometer（EDS）, X-ray diffractometer（XRD）, thickness tester, surface roughness analyzer, and electrochemical workstation. The results show that the phases of the MAO coatings on the MB8 magnesium alloy surface prepared at different pulse frequencies are mainly composed of Mg, MgO, and Mg₂SiO₄. As the pulse frequency increases, the thickness of the MAO coatings decreases, the surface roughness increases, and the porosity and maximum pore size show a trend of first decreasing and then increasing. Compared with the MB8 magnesium alloy substrate, the self-corrosion potential of the MAO coatings increases and the corrosion current density decreases. When the pulse frequency is 1200 Hz, the porosity of the MAO coating is the smallest, the surface quality is good, and the corrosion resistance is the best, with a corrosion current density of 1.338×10^-6 A·cm^-2 and a corrosion resistance of 3.356×10⁴ Ω·cm².更多还原