粗糙度和金属间化合物粒子对A6111铝合金表面腐蚀的影响
Effect of Roughness and Intermetallic Particles on Surface Corrosion of A6111 Alloy
康明龙 1邓运来 2雷金琴3
作者信息
- 1. 中南大学轻合金研究院,湖南长沙 410083
- 2. 中南大学轻合金研究院,湖南长沙 410083;中南大学有色金属材料科学与工程教育部重点实验室,湖南长沙 410083
- 3. 东北轻合金有限责任公司,黑龙江哈尔滨 150060
- 折叠
摘要
钎焊铝蜂窝夹层结构板常用于高速列车的地板和船舶的甲板.其中四层铝复合板(4343/3003/6111/3003)作为该蜂窝结构的面板常暴露于腐蚀性环境中.经过成分优化的6111铝合金作为四层铝复合板的主要支撑层材料,其组织结构和表面状态对腐蚀性能有很大影响.采用不同粒度的砂纸磨削6111铝合金,研究了不同程度磨削后6111铝合金的微观组织和表面腐蚀行为.结果表明:6111合金中的AlFeSi(Mn,Cu)相的电位高于基体电位,这种相作为阴极与相邻基体形成多级体系,加剧了表面腐蚀.同时,较光滑的表面具有更好的耐腐蚀性.当表面粗糙度从18.03 μm降至0.92 µm时,表面几何体积由0.629 mm3减少至0.029 mm3,金属间化合物AlFeSi(Mn,Cu)粒子的平均数量由1631 mm2减少至917 mm-2,其面积分数由3.93％降至0.92％.相应地,平均腐蚀深度由237 μm降至95μm.
Abstract
Four-layer aluminum brazing sheets(4343/3003/6111/3003)with honeycomb sandwich structure are used as candidates for floor of high-speed train and ship deck,which are often exposed to corrosive environments.Microstructure and surface conditions of optimized 6111 aluminum alloy,which serves as the main support layer of this four-layer brazing sheet,have a great effect on the corrosion properties,which were investigated by a set of 6111 aluminum alloy ground with sandpaper of different grits.The results show that the AlFeSi(Mn,Cu)phase acts as cathode,due to its higher potential than that of the matrix,and forms a multi-stage system with adjacent matrix,which aggravates the surface corrosion.A smoother surface exhibits better corrosion resistance.Specifically,when lowering surface roughness from 18.03 μm to 0.92 μm,the surface volume decreases from 0.629 mm3 to 0.029 mm3,and the average number of intermetallic particles AlFeSi(Mn,Cu)is reduced from 1631 mm-2 to 917 mm-2,with area fraction decreasing from 3.93％to 0.92％.As a consequence,the average corrosion depth decreases from 237 μm to 95 μm.
关键词
6111铝合金/表面粗糙度/金属间化合物颗粒/耐腐蚀性/电化学测试Key words
A6111 alloy/surface roughness/intermetallic particles/corrosion resistance/electrochemical test引用本文复制引用
基金项目
国家自然科学基金(51705539)
Major State Research Program of China(2016YFB0300901)
出版年
2024
NETL
NSTL
万方数据