碱金属有机酸盐型飞机除冰液对飞机铝材腐蚀机理研究

There are serious environmental hazard and damage of traditional alcohol-based type I aircraft deicing/anti-icing fluids for high COD value (Chemical Oxygen Demand). So, under the ecological pressure, some manufacturers have tried to develop alkali metal organic acid salt aircraft deicing/anti-icing fluids with low COD value. Although, it maybe increases the risk of corrosion of aircraft by using alkali metal organic acid salt aircraft deicing/anti-icing fluids, but, because there is no systematic study, it has no sufficient evidence to ban or recommend using this kind of aircraft deicing/anti-icing fluid in the world. This project intends to establish corrosion test device and test method which can be consistent with actual use of aircraft deicing/anti-icing fluids. It will be systematically researched and revealed about the corrosion mechanism of aircraft aluminum due to alkali metal organic acid salt aircraft deicing/anti-icing fluids by using the advanced dynamics of the thin liquid film technology, micro area scanning electrochemical technology, fretting corrosion test method for the first time. These studies have important scientific value and practical significance. Then, referenced with the corrosion test data of traditional alcohol aircraft deicing/anti-icing fluids by using corrosion test device and test method established in this project, compared with field survey data and talking about the important role of corrosion inhibitor, and combined with the relevant technical standards and regulatory requirements of the aircraft deicing/anti-icing fluids, the corrosion degree and influence of alkali metal organic acid salt aircraft deicing/anti-icing fluids on aircraft aluminum will been comprehensive evaluated, and the advices will be given about weather alkali metal organic acid salt is suitable for the aircraft deicing/anti-icing fluids. These researches will provide the technical basis on improving the aircraft deicing/anti-icing fluids standards; provide the technical guidance and theoretical basis on developing environmentally friendly aircraft deicing/anti-icing fluids without alcohols to improve its environmental protection performance.

传统醇基飞机除冰液COD高，存在严重的环境隐患；已有制造商试图研制COD低的碱金属有机酸盐型飞机除冰液。虽然碱金属有机酸盐型飞机除冰液可能增加腐蚀风险，但由于尚无系统研究，国际上还没有充分证据来禁止或推荐使用这种除冰液。本项目拟建立与飞机除冰液使用情况相符的腐蚀试验装置和试验方法，首次采用先进的动态薄液膜技术、微区扫描电化学技术、微动腐蚀试验方法等，系统研究并揭示碱金属有机酸盐型飞机除冰液对飞机铝材的腐蚀机理，具有重要的科学价值和现实意义。以本项目研究方法测得的醇类除冰液对飞机铝材的腐蚀数据为参照，在对比现场调研结果和讨论缓蚀剂重要作用的基础上，结合飞机除冰液技术标准及相关适航要求，综合评判碱金属有机酸盐型飞机除冰液对飞机铝材的腐蚀程度与适航影响，给出其是否适用于飞机除冰液的建议；为完善飞机除冰液标准提供技术基础；为提高飞机除冰液环保性能，开发非醇类环保型飞机除冰液提供技术指导和理论依据。

传统醇基飞机除冰液化学耗氧量（COD）高，存在严重的环境隐患；已有制造商试图研制COD低的碱金属有机酸盐型飞机除冰液。虽然碱金属有机酸盐型飞机除冰液可能增加腐蚀风险，但由于尚无系统研究，国际上还没有充分证据来禁止或推荐使用这种除冰液。. 本研究在对飞机冬季运行过程中飞机除冰液的实际使用条件，除冰液与飞机蒙皮等铝材表面接触状态，以及飞机铝材现场腐蚀情况等进行全面调研的基础上，在实验室建立了与飞机除冰液实际使用情况相符的腐蚀试验装置和试验方法，采用先进的低温动态薄液膜腐蚀电化学技术、微区扫描电化学技术等，系统研究并揭示碱金属有机酸盐型飞机除冰液对飞机铝材的腐蚀机理。. 研究发现，在除冰液实际应用过程中经常出现的薄液膜或干湿交替条件下，飞机铝材在飞机除冰液中的腐蚀速率明显高于全浸腐蚀条件，在薄液膜一定厚度范围内，腐蚀速率较高。在除冰液实际应用过程中，随着冰雪不断融化，除冰液将被不断稀释，浓度将不断降低。在薄液膜或干湿交替条件下，被稀释的除冰液对飞机铝材的腐蚀性反而更强，飞机铝材在低浓度的除冰液中的腐蚀速率明显高于原液或高浓度除冰液。除冰液中的缓蚀剂对减缓飞机铝材接触除冰液时的腐蚀作用显著，但需对其使用浓度进行严格限制。碱金属有机酸盐型除冰液用作飞机除冰液时，必须添加高效缓蚀剂，且保证除冰液使用过程（因冰雪融化除冰液浓度降低）中缓蚀剂的浓度始终保持在最佳浓度范围内。. 研究结果很好的解释了飞机蒙皮表面的腐蚀与接触飞机除冰液的关系，揭示了碱金属有机酸盐型除冰液对飞机铝材的腐蚀行为和腐蚀机理，并对碱金属有机酸盐型除冰液用作飞机除冰提出了建议；所建立的低温动态薄液膜腐蚀和干湿交替腐蚀试验装置及试验方法，更接近除冰液实际应用条件，对于丰富相关腐蚀理论，建立与实际情况更加吻合的飞机除冰液对飞机蒙皮腐蚀的标准测试评估方法具有重要的科学意义、理论指导价值和应用前景。