Corrosion behavior of 2A97 Al-Cu-Li alloys in different thermomechanical conditions by quasi-in-situ analysis

准原位分析2A97 Al-Cu-Li合金在不同热机械条件下的腐蚀行为

As a promising material in the aircraft industry,2A97 Al-Cu-Li alloy exhibits high corrosion susceptibility that may limit its application.In the present work,to illustrate the influences of precipitate and grain-stored energy on localized corrosion evolution in 2A97 Al-Cu-Li alloy,cold working and artificial aging were carried out to produce 2A97 Al-Cu-Li alloys under different thermomechanical conditions.Quasi-in-situ analysis,traditional immersion test and electrochemical measurement were then conducted to examine the corrosion behavior of 2A97 alloys.It is revealed that precipitate significantly affects Cu enrichment at corrosion fronts,which determines corrosion susceptibility of alloys,whereas grain-stored energy distribution is closely associated with localized corrosion propagation.It is also indicated that quasi-in-situ analysis exhibits a consistent corrosion evolution with traditional immersion tests,which is regarded as a proper method to explore localized corrosion mechanisms by providing local microstructural information with enhanced time and spatial resolutions.

2A97 Al-Cu-Li合金在航空工业领域具有十足的发展前景,但其表现出的高腐蚀敏感性限制其更广泛的应用。本文作者采用冷加工和时效工艺,在不同热机械条件下制备2A97 Al-Cu-Li合金,以阐明析出相和晶格储存能对其局部腐蚀演变的影响。结合准原位分析、传统浸泡试验和电化学测量,研究2A97合金的腐蚀行为。结果表明:析出相显著影响腐蚀尖端的铜富集现象,从而显著影响铝合金的腐蚀敏感性;而晶格储存能的分布则与局部腐蚀扩展密切相关。准原位分析不仅表现出与传统浸泡测试相当的腐蚀规律,还可提供具有更高时间和空间分辨率的组织结构演化信息,因而被视作一种探索局部腐蚀微观机制的有效方法。