硼硫酸阳极氧化6061铝合金在不同大气环境中的初期腐蚀行为研究

发布时间：2019-04-03 14:15

【摘要】：通过在青岛和北京进行6061铝合金户外大气暴露实验,利用形貌观察、失重分析、力学性能分析和断面分析等方法,研究了经硼硫酸阳极氧化处理的6061铝合金在工业-海洋大气环境和北方半乡村大气环境中的初期腐蚀规律和机理。结果表明,表面阳极氧化的试样与裸材相比,在工业-海洋大气环境和北方半乡村大气环境一年暴露试验的平均腐蚀速率分别下降43.4%和10.1%,即阳极氧化处理降低材料腐蚀速率,且在恶劣腐蚀环境下的效果更明显;但相对于裸材在工业-海洋大气环境一年暴露试验后的延伸率比初始值下降35%,阳极氧化试样的延伸率下降幅度仍达23%,即硼硫酸阳极氧化对工业-海洋大气环境下合金的力学性能保护不够,塑性降低幅度大,对应的断裂机理发生改变,点蚀导致合金表层从韧性断裂转变为解理脆性断裂。
[Abstract]:The outdoor air exposure experiments of 6061 aluminum alloy were carried out in Qingdao and Beijing. The methods of morphology observation, weight loss analysis, mechanical properties analysis and cross-section analysis were used. The initial corrosion rule and mechanism of 6061 aluminum alloy treated by boron sulfate anodization in the industrial-marine atmosphere and the northern semi-rural atmosphere were studied. The results show that the average corrosion rates of the surface anodized samples are decreased by 43.4% and 10.1% respectively in one year exposure test in the industrial-marine atmospheric environment and the northern semi-rural atmospheric environment compared with the bare materials. The anodic oxidation treatment can reduce the corrosion rate of the material, and the effect is more obvious in the harsh corrosion environment. However, the elongation of the specimen decreased by 35% compared with the initial value after one year exposure test in the industrial-marine atmosphere environment, and the elongation of the anodized sample still decreased by 23%, compared with that of the bare material after one-year exposure test in the industrial-marine atmospheric environment. That is to say, boron sulfate anodizing is not enough to protect the mechanical properties of the alloy in the industrial-marine atmosphere environment, the plasticity decreases greatly, the corresponding fracture mechanism changes, pitting corrosion causes the surface layer of the alloy to change from ductile fracture to cleavage brittle fracture.
【作者单位】：北京科技大学腐蚀与防护中心;腐蚀与防护教育部重点实验室;
【基金】：国家重点基础研究发展计划(2014CB643300) 国家自然科学基金(51471033) 国家材料环境腐蚀平台~~
【分类号】：TG178

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