锻压技术

等径角挤压道次对7075铝合金组织和腐蚀性能的影响

英文标题：Influence of equal-channel angular pressing pass on microstructure and corrosion properties for 7075 aluminum alloy

作者：丁文文李涛吴何畏

单位：湖北文理学院理工学院

关键词：7075铝合金等径角挤压挤压道次耐蚀性晶粒细化

分类号：TG311

出版年,卷(期):页码：2019,44(9):146-150

摘要：

对7075铝合金进行等径角挤压(ECAP)以及热处理，并通过实验测试方法观察ECAP道次对其组织和腐蚀性能的影响。研究结果表明：经过4道次ECAP处理后，晶粒发生显著细化，第2相出现了长大现象；固溶时效后，晶粒尺寸发生了长大；ECAP道次增加会提高腐蚀电位，降低腐蚀电流密度，有效提高材料耐蚀性，提高钝化膜耐蚀性能；当变形道次提高后，将会使腐蚀凹坑的数量及尺寸都减小，形成结构完整的氧化膜，显著增强其耐蚀性；经过ECAP处理后，减小了第2相晶界的偏析程度，使晶界部位的棒状第2相尺寸与数理都发生明显降低，阻碍晶界的腐蚀过程。

7075 aluminum alloy was treated by equal-channel angular pressing (ECAP) and heat treatment, and the influences of ECAP pass on its microstructure and corrosion properties were observed by experimental method. The results show that after four passes of ECAP treatment, the grains are significantly refined and the second phase grows up. After solution aging, the grain size grows. The increase of ECAP pass increases the corrosion potential, reduces the corrosion current density, effectively improves the corrosion resistance of material, and improves the corrosion resistance of passivation film. When the deformation pass increases, the number and size of corrosion pits decrease, and a structurally complete oxidation film is formed to significantly enhance its corrosion resistance. After ECAP treatment, the degree of segregation at the grain boundary of the second phase reduces, and the size and mathematical properties of the rod-shaped second phase at the grain boundary significantly reduce to hinder the corrosion process of the grain boundary.

基金项目：

“机电汽车”湖北省优势特色学科群2018年开放基金项目（XKQ2018063）

丁文文（1986-）,女，硕士，讲师 E-mail：330966532@qq.com

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