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在K2ZrF6-Y(NO3)3-NaAlO2电解液中采用微弧氧化技术在AZ91D镁合金表面制备了Y2O3-ZrO2-MgO复合膜层(Al-Zr-Y膜).运用电子显微镜(SEM)、能谱分析仪(EDS)、X射线衍射仪(XRD)和电化学分析与高温氧化等方法研究了Al-Zr-Y膜的组成与结构、耐腐蚀性及热稳定性.结果表明:Al-Zr-Y膜主要由Y2O3,ZrO2,MgO和Al2O3等物相组成,与Na2SiO3-(NaPO3)6电解液中的膜层(Si-P膜)相比,Al-Zr-Y膜的厚度较小,但膜层的致密性较好、表面粗糙度小;腐蚀电流密度较小、开路电位较正、极化阻抗较高;在5%NaCl溶液中的腐蚀速率低于Si-P膜,约为AZ91D镁合金的1%.Al-Zr-Y膜层比普通Si-P膜层具有更好的抗高温氧化性能和耐热冲击性能.
In the K2ZrF6-Y (NO3) 3-NaAlO2 electrolyte, the Y2O3-ZrO2-MgO composite film (Al-Zr-Y film) was prepared on the surface of AZ91D magnesium alloy by using micro-arc oxidation technique.Using electron microscope (SEM) The composition and structure, corrosion resistance and thermal stability of Al-Zr-Y films were investigated by EDS, XRD, electrochemical analysis and high temperature oxidation. The results show that Al-Zr The Y-film mainly consists of Y2O3, ZrO2, MgO and Al2O3. The thickness of the Al-Zr-Y film is smaller than that of the Si-P film in the Na2SiO3- (NaPO3) But the compactness of the film is better, the surface roughness is smaller; the corrosion current density is smaller, the open circuit potential is more positive and the polarization resistance is higher; the corrosion rate in 5% NaCl solution is lower than that of Si-P film, which is about AZ91D Magnesium alloy 1% .Al-Zr-Y film than ordinary Si-P film has better high temperature oxidation resistance and thermal shock resistance.