Characterization of localized corrosion pathways in 2195-T8 Al-Li alloys exposed to acidic solution

作     者：De-jun Liu Gan Tian Guo-feng Jin Wei Zhang You-hong Zhang De-jun Liu;Gan Tian;Guo-feng Jin;Wei Zhang;You-hong Zhang

作者机构：Rocket Force University of EngineeringCollege of Missile EngineeringChina 

出 版 物：《Defence Technology（防务技术）》 (Defence Technology)

年 卷 期：2023年第25卷第7期

页      面：152-165页

核心收录：

学科分类：080703[工学-动力机械及工程] 08[工学] 0806[工学-冶金工程] 082501[工学-飞行器设计] 0807[工学-动力工程及工程热物理] 0804[工学-仪器科学与技术] 0805[工学-材料科学与工程（可授工学、理学学位）] 0825[工学-航空宇航科学与技术] 

基　　金：National Natural Science Foundation of China (Grant No.52075541) Shaanxi Province Natural Science Foundation (Grant No. 2022JM-243) to provide fund for conducting experiments。 

主　　题：Al-Li alloy Corrosion behavior Corrosion features Immersion test Intermetallic particles 

摘      要：The corrosion properties of aluminum-lithium(Al-Li) alloys, which are potential materials used to construct for tanks of liquid rockets or missiles, are essential for safe propellant storage and transport. In order to manifest the corrosion resistance of the 2195 Al-Li alloy in practical propellant tanks filled with N2O4, the alloy was soaked in 30% nitric acid solution, an accelerating corrosion environment, to test its corrosion behavior. Scanning electron microscopy(SEM) and transmission electron microscopy(TEM)were used to characterize microstructure and corrosion morphology of the alloy. Focused ion beam(FIB),combined with SEM, was used to demonstrate localized corrosion features and the propagation of corrosion pathways beneath the alloy surface. It was found that the corrosion network was formed with most intergranular corrosion and sparse intragranular corrosion. Additionally, the distribution and number of intermetallic particles influenced the localized corrosion degree and the direction of corrosion pathways. Aggregated particles made corrosion pathways continuously and caused more severe corrosion. The results from this work were valid and useful to corrosion prevention and protection for storage safety on propellant tanks in N_(2)O_(4).