【作者】 李静；

【导师】 高玉周； 严立；

【作者基本信息】 大连海事大学 ， 载运工具运用工程， 2006， 硕士

【摘要】 采用微弧氧化技术,在铝、钛表面制备陶瓷层。利用扫描电镜（SEM）、能谱仪（EDS）、X射线衍射（XRD）研究了陶瓷层的成分、表面形貌、相结构、厚度、横截面,用摩擦磨损试验机研究了陶瓷层的摩擦学行为。揭示了微弧氧化技术的反应机理、陶瓷层的形成过程,并着重探讨了电导率、氧化时间、Na₂WO₄添加剂对铝微弧氧化陶瓷层成分、相结构和表面形貌的影响,电解液酸碱性、Na₂Mo₇O₂₄添加剂对钛微弧氧化的影响。 铝微弧氧化研究表明:氧化膜主要有α-Al₂O₃和γ-Al₂O₃相构成;硅酸钠、碳酸钠电解液中制备的微弧氧化膜表面光滑、高硬度、与基体结合紧密,随着氧化时间的延长陶瓷膜增厚,粗糙度增大,α-Al₂O₃相增多;pH值为8.6的硼砂、磷酸氢二钠的缓冲溶液中加入硅酸钠、碳酸钠的复合体系中制备的陶瓷层表面粗糙度最小,随着电导率的增加,a-Al₂O₃相减少;硅酸钠、碳酸钠体系随着电导率的增大,成膜质量变好,a-Al₂O₃相增加显著;随Na₂WO₄浓度的升高,陶瓷层中a-Al₂O₃的含量减少。 钛微弧氧化研究表明:在酸性电解液中生成的氧化膜主要为锐钛矿型TiO₂,且随着pH值的减小,锐钛矿型TiO₂的含量增加,膜层表面结构不均匀,疏松多孔;在近中性电解质溶液中,生成的氧化膜为锐钛矿型TiO₂和金红石型TiO₂混合相结构;在弱碱性电解质溶液中,生成的氧化膜为锐钛矿型TiO₂和金红石型TiO₂混合相结构,主要是金红石型TiO₂,随着pH值的增加,金红石型TiO₂的含量增加,氧化膜光滑致密,与基体结合紧密;以Na₂Mo₇O₂₄为添加剂时,随着Na₂Mo₇O₂₄浓度的增加,金红石型TiO₂的成分增加。更多还原

【Abstract】 Ceramic coating is prepared on the surface of aluminum and titanium by the method of Micro-arc Oxidation （MAO）. Coating composition, surface appearance and microstructure are determined by Scanning Electron Microscope （SEM）, Energy Dispersive Spectroscopy （EDS）, and X-ray Diffraction （XRD）. The ceramic coating tribological behavior is investigated by abrasion test machine. Mechanism of micro-arc oxidation and growth progress of ceramic coating is opened up. The effect of conductance, oxidation time, the addition of Na₂WO₄ on the microstructure and surface appearance of Al₂O₃ ceramic coating, the effect of the electrolyte, the time and the additive of Na₂Mo₇O₂₄ on the TiO₂ ceramic coating are mainly discussed.The research on the aluminous micro-arc oxidation indicates that the ceramic coating mainly consists of α-Al₂O₃ and Y-Al₂O₃, the coating created in the electrolyte of Na₂SiO₃ and Na₂CO₃ possesses smooth surface, high micro-hardness, and good adhesion with the aluminum substrate. Thickness and surface roughness of the ceramic coating increases with the time of micro-arc oxidation. The surface roughness of the ceramic coating created in the electrolyte of Na₂B₄O₇、NaH₂PO₄、Na₂CO₃、Na₂SiO₃ is the smallest. The property of the ceramic coating becomes better with the conductance increase. The content of α-Al₂O₃ decreases with increase of the concent of Na₂WO₄.The research on titanic micro-arc oxidation indicates that the ceramic coating in acid electrolyte is mainly composed of anatase TiO₂. The content of anatase TiO₂ increases with decrease of pH of the electrolyte. There are lots of micro-holes on the ceramic coating surface. The ceramic coating created in approximate neutral electrolyte is composed of anatase TiO₂ and rutile TiO₂. The ceramic coating is mainly composed of rutile TiO₂ and a small quantity of anatase TiO₂ in the alkalescency electrolyte. The content of rutile TiO₂ increases as pH of the electrolyte increases. The ceramic coating becomes smooth and has a better cohesion with the substrate. The content of rutile TiO₂ increases while the Na₂Mo₇O₂₄ additive concentration increases.更多还原