铜含量对Al-Zn-Mg-(Cu)合金晶间腐蚀和剥落腐蚀敏感性的影响  

Effect of Cu content on intergranular corrosion and exfoliation corrosion susceptibility of Al−Zn−Mg−(Cu)alloys

作　　者：张梦晗 刘胜胆[1,2,3] 蒋靖宇 韦卫昌 Meng-han ZHANG;Sheng-dan LIU;Jing-yu JIANG;Wei-chang WEI(School of Materials Science and Engineering,Central South University,Changsha 410083,China;Key Laboratory of Non-ferrous Metals Science and Engineering,Ministry of Education,Central South University,Changsha 410083,China;National Key Laboratory of Light and High Strength Structural Materials,Central South University,Changsha 410083,China;School of Metallurgy and Environment,Central South University,Changsha 410083,China)

机构地区：[1]中南大学材料科学与工程学院,长沙410083 [2]中南大学有色金属材料科学与工程教育部重点实验室,长沙410083 [3]中南大学轻质高强结构材料重点实验室,长沙410083 [4]中南大学冶金与环境学院,长沙410083

出　　处：《Transactions of Nonferrous Metals Society of China》2023年第7期1963-1976,共14页中国有色金属学报（英文版）

摘　　要：通过电化学试验和浸泡试验,使用电子背散射衍射、光学显微镜、扫描电镜和扫描透射电镜及扫描开尔文探针原子力显微镜,研究铜含量对Al-Zn-Mg-(Cu)合金晶间腐蚀和剥落腐蚀敏感性的影响。结果表明,铜含量从0增加至2.6%(质量分数),晶间腐蚀敏感性增高;而剥落腐蚀敏感性先增高后降低,铜含量为1%时的剥落腐蚀敏感性最高。随着Cu含量的增加,再结晶分数增加,再结晶晶粒的长宽比先减小后增大;晶界析出相与基体的伏打电势差提高,使晶界析出相更易被腐蚀。根据晶界析出相的形貌特征、晶粒组织和晶界析出相与基体的伏打电势差,对晶间腐蚀和剥落腐蚀的萌生和扩展进行讨论。The effect of Cu content on intergranular corrosion(IGC)and exfoliation corrosion(EXCO)susceptibility of Al-Zn-Mg-(Cu)alloys was investigated by electrochemical test,immersion test,electron backscattered diffraction,optical microscope,scanning electron microscope,scanning transmission electron microscope and scanning Kelvin probe force microscope.As Cu content increases from 0 to 2.6 wt.%,IGC susceptibility increases,while EXCO susceptibility first increases and then decreases,reaching the maximum at Cu content of 1 wt.%.With the increase of Cu content,the area fraction of recrystallized grains increases,and the aspect ratio of recrystallized grains first decreases and then increases;moreover,the Volta potential difference between grain boundary precipitates(GBPs)and the matrix increases,making GBPs more susceptible to corrosion.The initiation and propagation of IGC and EXCO are discussed mainly based on the features of GBPs,grain structure,and the Volta potential difference between GBPs and the matrix.

关 键 词：铜 晶间腐蚀 剥落腐蚀 AL-ZN-MG-CU合金 扫描开尔文探针原子力显微镜 

分 类 号：TG174.3[金属学及工艺—金属表面处理]