| 摘要: |
| 采用高速微粒轰击技术对7A52铝合金进行表面纳米化处理，利用OM、XRD和TEM研究了表面纳米晶层的微观结构特征，利用CHI660A型电化学工作站测试了样品表面纳米化处理前后电化学腐蚀性能，利用SEM和EDS分析了表面纳米样品电化学腐蚀机制。结果表明：纳米晶最表层晶粒尺寸约为8～20 nm，平均晶粒尺寸约为16 nm，表面纳米晶层的厚度为20 μm左右；表面纳米晶层自腐蚀电流密度icorr由 4.07E-7 A·cm-2变为 9.476E-7 A·cm-2，明显降低且晶层无龟裂，表现出优异的耐腐蚀性能。表面纳米晶层耐腐蚀性能明显提高的主要原因是表面纳米化增加了样品表面活性，生成了质量优异的钝化膜。 |
| 关键词: 7A52铝合金 表面纳米化 电化学腐蚀 |
| DOI： |
| 分类号: |
| 基金项目:装备维修科研资助项目(代号略) |
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| Electrochemical Corrosion of the Nancrystalline Layer on the Surface of 7A52 Aluminum Alloy |
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MA Shi–ning，WANG Xiang，WANG Xiao–ming
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Department of Remanufacture Engineering, Academy of Armored Force Engineering，Beijing 100072
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| Abstract: |
| 7A52 aluminum alloy was nanocrystallized with supersonic fine particles bombarding(SFPB)．The microstructure of nanocrystalline layer was studied by OM，XRD and TEM，the electrochemical corrosion property of the sample before and after surface nanocrystallization was examined by CHI660A tester and electrochemical corrosion mechanism of nanocrystalline sample was analyzed by SEM and EDS．The results show that the average grain size is about 8～20 nm in the top surface layer with 16 nm in average，and the thickness of deformation surface layer is about 20 μm．The corrosion current density of nanocrystalline layer decreases from 4.07E-7 A·cm-2 to 9.476E-7 A·cm-2，and there are no crack and pitting corrosion on the surface which show good corrosion performace．The corrosion resistance of nanocrystalline layer is obviously enhanced due to the high activity of the surface and the formation of oxide film of high quality on the surface after surface nanocrystallization． |
| Key words: 7A52 aluminum alloy surface nanocrystallization electrochemical corrosion |
