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

参考文献：

［1］Wang X H, Wang J H, Fu C W . Characterization of pitting corrosion of 7A60 aluminum alloy by EN and EIS techniques
［J］. Transactions of Nonferrous Metals Society of China, 2014, 24(12):3907-3916.

［2］贺俊光, 文九巴, 周旭东. 第二相对AlZnSnGaMg 合金腐蚀行为的影响
［J］. 中国有色金属学报, 2013, 23(3):628-634.

He J G, Wen J B, Zhou X D. Influence of second phase on corrosion behavior of Al-Zn-Sn-Ga-Mg alloy
［J］. The Chinese Journal of Nonferrous Metals, 2013, 23(3):628-634.

［3］刘文辉，邱群，陈宇强，等. 预热温度对等径角轧制6016铝合金织构及力学性能的影响
［J］. 稀有金属,2018, 42(6):586-593.

Liu W H, Qiu Q, Cheng Y Q, et al. Texture evolution and mechanical properties of 6016 aluminum alloys as equal channel angular rolling at different preheat temperatures
［J］. Chinese Journal of Rare Metals,2018, 42(6):586-593.

［4］刘贵立, 方戈亮. Al-Zn-Mg-Cu超高强铝合金晶界偏聚与腐蚀机制研究
［J］. 稀有金属材料与工程, 2009, 38(9):1598-1601.

Liu G L, Fang G L. Grain-boundary segregation and corrosion mechanism of Al-Zn-Mg-Cu ultra high strength aluminum alloys
［J］. Rare Metal Materials and Engineering, 2009, 38(9):1598-1601.

［5］王素梅, 孙康宁, 刘睿, 等. 第二相粒子对ECAP挤压的2A12 铝合金晶粒细化的影响
［J］. 材料科学与工艺,2007, 15(1): 115-117.

Wang S M, Sun K N, Liu R, et al. Effect of the second phase on grain refinement of 2A12 aluminum alloy by ECA pressing
［J］. Materials Science and Technology,2007, 15(1): 115-117.

［6］杨西荣，井菲菲，刘晓燕，等. 模具角度对CP-Zr室温ECAP变形组织与性能的影响
［J］. 稀有金属,2018, 42(4):367-372.

Yang X R, Jing F F, Liu X Y, et al. Microstructure and properties of CP-Zr by ECAP at room temperature with different die angles
［J］. Chinese Journal of Rare Metals,2018, 42(4):367-372.

［7］Wang X, Nie M, Wang C T, et al. Microhardness and corrosion properties of hypoeutectic Al-7Si alloy processed by high-pressure torsion
［J］. Materials & Design, 2015, 83:193-202.

［8］Su L H, Lu C, He L Z, et al. Study of vacancy-type defects by positron annihilation in ultrafine-grained aluminum severely deformed at room and cryogenic temperatures
［J］. Acta Materialia,2012, 60(10):4218-4228.

［9］Chen Y, Gao N, Sha G, et al. Strengthening of an Al-Cu-Mg alloy processed by high-pressure torsion due to clusters, defects and defect-cluster complexes
［J］. Materials Science and Engineering: A, 2015, 627:10-20.

［10］Pang J J, Liu F C, Liu J, et al. Friction stir processing of aluminium alloy AA7075: Microstructure, surface chemistry and corrosion resistance
［J］. Corrosion Science, 2016, 106: 217-228.

［11］Ralston K D, Fabijanic D, Birbilis N . Effect of grain size on corrosion of high purity aluminium
［J］. Electrochimica Acta, 2011, 56(4):1729-1736.

［12］Chen Y, Gao N, Sha G, et al. Microstructural evolution, strengthening and thermal stability of an ultrafine-grained Al-Cu-Mg alloy
［J］. Acta Materialia, 2016, 109: 202-212.

服务与反馈：

【本网站尚未开通全文下载服务】【加入收藏】