【作者】 郭兴龙；

【导师】 于先进；

【作者基本信息】 山东师范大学 ， 微电子学与固体电子学， 2004， 硕士

【摘要】 论文对铝用惰性阳极的研究和发展进行了回顾和展望，对已经有的各种阳极材料进行了评述。指出惰性阳极面临的主要问题是阳极的耐铝和电解质的腐蚀性差。 选择了ZnO、Fe₂O₃烧结合成ZnFe₂O₃的适宜条件为：1210℃，20h：通过选择合适的添加剂，改善了阳极试样的导电性和耐腐蚀性，研制的几种阳极材料都具有高于或接近炭素电极的导电能力，耐铝电解质腐蚀性和高温氧化性气氛下的化学稳定性良好，满足铝电解惰性阳极的要求，制作的惰性阳极在Na₃AlF₆熔盐中电化学性质是稳定的。 阳极材料在铝电解条件下的腐蚀机理复杂，铁锌阳极在Na₃AlF₆-Al₂O₃熔液中总会有一定的腐蚀，其原因有：高温电解质熔液对它的侵蚀；液态铝对它的还原作用；阳极气体的冲刷和电解质流动造成的腐蚀。 经过对锌铁尖晶石在阳极进行的电化学测试，可得以下结论：惰性电极的静态开路长时间内电势波动很小；多次重复测试结果都有较好的重复性；用静态开路电势来评价金属氧化物电极的稳定性是可行的。 对于阳极材料在铝电解质中的耐腐蚀进行了研究得出：电解质中Al₂O₃不饱和时，提高Al₂O₃浓度、降低分子比，并保持高的阳极电流，可减少电解质中的阳极损失：电解质中Al₂O₃饱和时，在电流低时，增大电流可以减少阳极的腐蚀；有铝存在的条件下腐蚀速度明显增大。 首次利用磁控溅射进行了薄膜电极的试制和试验，实验在导电基体上（Ni）溅射ZoO，用X-射线衍射（XRD）分析、电子显微（SEM）扫描分析，对实验前后的薄膜成分、形貌进行了定性分析和观察，实验结果表明：在基体上形成了致密的ZnO纳米薄膜。薄膜微小颗粒紧密排布，颗粒粒径可以达到20纳米左右，在960℃冰晶石熔盐电解质中试样电极具有良好的耐腐蚀性能，腐蚀速度约为3.2×10^-4g／h·cm²。用此方法制造的电极与煅烧、冷压制作方法相比较来说表面摘要细致、并且有比较耐腐蚀的特性。得出一些可以借鉴的宝贵的经验，对以后此类电极的研究和探讨具有参考作用。更多还原

【Abstract】 The literature survey was made. Several kinds of inert anode were tested and the most serious difficulty for inert anode encountered was the problem of corrosion.ZnFe204 was chose as inert anode materials for the special microstructure.ZnFeA powder was synthesized with ZnO, Fe20:, at 1210 for 20 hours. Theinert anode samples were prepared by cold-pressing and sintering method.Selected additives were used to improve the sintering behavior, electricconductivity and corrosion resistance of the anodes. Several anodesamples got very good conductivity, even high than carbon anode at thesame temperature of aluminum electrolysis. Under the condition of moltensalt electrolysis, the anode was with high electrochemical stability.Under the condition of aluminum electrolysis, the principle of corrosionof anode materials is sophisticated, including the corrosion of the anodein high temperature electrolyte, the reduction of liquid aluminum, thecorrosion of the scour of anode gaseous fluid and the flow of theelectrolyte.Electrochemical tests proved that the anode is static in long term open-circuit working. The potential fluctuates little and several repetitions of testing are doing well. Static open-circuit potential is practicable for metallic oxide anode stability.The corrosion behavior of the anode used in aluminum electrolysis were examined, the conclusion is as follow: when Al20:i-content in the electrolyte was not saturated, the corrosion rate of the anode would be reduced by increasing the A1203 content in the bath, increasing the anodiccurrent density and decreasing in the bath ratio; when the electrolyte was saturated with A120.). the corrosion rate of the anode will be reduced by increasing the anode current. The corrosion rate of anode would be increased obviously, if the electrolyte containing aluminum.The NiO membranes firstly were prepared on the Ni-plate by the magnetron sputtering technique. The samples mentioned above were used as inert anodes in aluminum electrolysis experiments. The composition and structures of the membranes (before and after the experiment) were analyzed by X~ray diffraction and SEM. The results show that the minute particles of the membrane distribute tightly and the testing anodes are well corrosion-resistant in melt salt electrolyte at 960癈.The corrosion rate of anode is 3. 2X10Hg/h ?cm2. Compared with the ZnFe204-based anode, it has a smooth surface and corrosion-resistant. From this, we can obtain valuable experience and use for reference. There are reference price for scientific research and investigation of this sort of anode.更多还原