摘要
通过剥落腐蚀浸泡实验和极化曲线测试,研究了Zn含量对Al-Zn-Mg-Cu合金挤压棒材耐剥落腐蚀性能的影响,结合金相显微镜、扫描电镜、扫描透射电镜等微观组织表征方法对影响机理进行了分析和讨论。结果表明:Zn含量(质量分数)由7.93%增至9.85%时,棒材剥落腐蚀抗力下降,剥落腐蚀等级由EA变成EC,最大腐蚀深度由334 μm增至579 μm。Zn含量增加,合金中粗大第二相数量增加,时效后晶界η相尺寸和间距变小、Zn和Mg含量增加,是耐剥落腐蚀性能下降的主要原因。
The effect of Zn content on exfoliation corrosion resistance of extruded rods of Al-Zn-Mg-Cu alloy was investigated by standard exfoliation corrosion (EXCO) immersion test, and polarization curve measurement, optical microscopy (OM), scanning electron microscopy (SEM) and scanning transmission electron microscopy (STEM). The results show that exfoliation corrosion resistance of the rods decreases with the increase of Zn content (mass fraction,%) from 7.93% to 9.85%, and the exfoliation corrosion rating changes from EA to EC with the maximum corrosion depth increasing from 334 μm to 579 μm. The lower EXCO resistance caused by higher Zn content is mainly attributed to the increased number of coarse second phase in alloys, the decreased size and spacing, as well as the higher Zn and Mg content of η-phase at grain boundaries after aging.
作者
杨臻珅
刘胜胆
唐建国
叶凌英
Zhenshen YANG;Shengdan LIU;Jianguo TANG;Lingying YE(School of Materials Science and Engineering,Central South University,Changsha 410083,China;Key Laboratory of Nonferrous Metal Materials Science and Engineering,Ministry of Education,Central South University,Changsha 410083,China;Nonferrous Metal Oriented Advanced Structural Materials and Manufacturing Cooperative Innovation Center,Central South University,Changsha 410083,China)
出处
《材料研究学报》
EI
CAS
CSCD
北大核心
2019年第8期579-587,共9页
Chinese Journal of Materials Research
基金
国家重点研发计划(2016YFB0300901)
中南大学升华育英计划(20130603)~~
