腐蚀环境下典型“钛-铝”复合耳片腐蚀防护性能研究

Corrosion Protection Performance of Typical“Titanium-Aluminum”Composite Lugs in Corrosive Environment

目的研究腐蚀环境下典型“钛–铝”复合耳片的腐蚀防护性能。方法开展典型“钛–铝”双耳两层结构的加速腐蚀环境试验,共10个周期。采用扫描电镜(SEM)和能谱(EDS)分析结构的腐蚀形貌、腐蚀产物,研究“钛–铝”复合耳片结构的腐蚀防护性能。结果在腐蚀环境下,“钛–铝”复合耳片结构中衬套周围异种金属连接部位的电偶腐蚀敏感性高,其他部位防护体系的耐蚀性较好。经过10个周期的加速试验,衬套周围铝合金结构发生较为严重的点蚀,各蚀坑扩展相连,形成较大蚀坑。在第10周期,典型“钛–铝”复合耳片铜衬套周围铝合金蚀坑处出现裂纹扩展,并发生腐蚀疲劳破坏。结论增强典型“钛–铝”复合耳片结构的腐蚀防护措施,加强典型“钛–铝”复合耳片异种金属接触部位的日常维护,能有效提高结构的腐蚀防护能力。

The purpose of this paper is to study the corrosion protection performance of the typical“titanium-aluminum”composite lugs in the corrosive environment.The accelerated corrosion environment test of the typical“titanium-aluminum”composite lugs is carried out.The accelerated corrosion environment test has a total of 10 cycles.The scanning electron micro-scope(SEM)and energy dispersive spectroscopy(EDS)are used to analyze the corrosion morphology and corrosion products of the structure and to study the corrosion protection performance of the typical“titanium-aluminum”composite lugs.The results show that the joints of dissimilar metals around the bushing in the typical“titanium-aluminum”composite lugs is highly sensi-tive to galvanic corrosion.The protection system of other parts has better corrosion resistance.After 10 cycles of accelerated test,the aluminum alloy structure around the bushing is seriously pitted,and the etch pits are expanded and connected to form large etch pits.At the 10th cycle,crack propagation occurred at the etch pit of aluminum alloy around copper bushing,and cor-rosion fatigue failure occurred.To reinforce the corrosion protection measures of the typical“titanium-aluminum”composite lugs,and strengthen the daily maintenance of the contact parts of the typical“titanium-aluminum”compound lugs with dissimi-lar metals,can effectively improve the corrosion protection capability of the structure.