5A90铝锂合金显微组织及海洋大气环境腐蚀行为  

Marine Atmospheric Corrosion Behavior of 5A90 Al-Li Alloy

作　　者：苏艳[1] 张伦武[1] 钟勇[1] 

机构地区：[1]中国兵器工业第五九研究所,重庆400039

出　　处：《中国腐蚀与防护学报》2016年第3期260-266,共7页Journal of Chinese Society For Corrosion and Protection

基　　金：技术基础科研计划项目(JSHS2015209C002)资助

摘　　要：采用海洋大气环境暴露实验以及XRD,OM和SEM等分析手段,对比研究了5A90铝锂合金和2D12铝合金的显微组织、腐蚀行为和力学性能,探讨了腐蚀机制。结果表明,5A90铝锂合金的主要强化相为δ′(Al3Li)和T(Al2Mg Li),细密析出呈弥散分布,其微观腐蚀形貌与2D12铝合金存在明显区别,即晶界和晶粒内部同时发生腐蚀,晶间腐蚀特征不明显。用腐蚀失重表征铝合金腐蚀损伤程度,5A90合金腐蚀过程不符合幂函数规律,腐蚀造成的力学损伤明显大于2D12合金的。5A90合金的原始断裂方式以撕裂和韧窝为主,环境腐蚀作用促进合金由韧性断裂向沿晶脆性断裂的转变,严重降低材料塑性。The microstructure, corrosion behavior and the influence of corrosion on mechanical performance of 5A90 Al-Li alloy and 2D12 alloy were studied comparatively by means of X-ray diffraction, metallurgical analysis, scanning electron microscopy and marine atmospheric exposure test, while the relevant corrosion mechanism was also discussed. The results showed that the strengthening phases δ ′-Al_3 Li and T-Al_2MgLi of 5A90 Al-Li alloy are fine and dispersed quite uniformly. 5A90 Al-Li alloy showed corrosion characteristics in micro-scale apparently different from2D12 alloy, i.e. the corrosion of the former occurred simultaneously at grain boundaries and in grains. The corrosion process of 5A90 Al-Li alloy did not follow the power function in terms of corrosion mass loss. The mechanical performance degradation of 5A90 Al-Li alloy due to corrosion is apparently faster than that of 2D12 alloy. The fracture manner of 5A90 Al-Li alloy is mainly dimple fracture, while the environmental corrosion promotes the transition from ductile fracture to intergranular brittle fracture.

关 键 词：铝锂合金 显微组织 腐蚀行为 自然环境实验 

分 类 号：TG178[金属学及工艺—金属表面处理]