7075厚板铝合金搅拌摩擦焊接头晶间腐蚀行为研究  

Intergranular Corrosion Behavior of Friction-stir Welding Joint for 20 mm Thick Plate of 7075 Al-alloy

作　　者：刘德强[1,2] 柯黎明[1,3] 徐卫平[1] 邢丽[1] 毛育青 LIU Deqiang KE Liming XU Weiping XING Li MAO Yuqing(School of Aeronautical Manufacturing and Engineering, Nanchang Hangkong University, Nanchang 330063, China Jiangling Holdings Co., Ltd., Nanehang 330052, China State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi＇an 710072, China)

机构地区：[1]南昌航空大学航空制造工程学院,南昌330063 [2]江铃控股有限公司,南昌330052 [3]西北工业大学凝固技术国家重点实验室,西安710072

出　　处：《中国腐蚀与防护学报》2017年第3期293-299,共7页Journal of Chinese Society For Corrosion and Protection

基　　金：国家自然科学基金(51265043和51364037);航空科学基金(20140956003)~~

摘　　要：对20 mm厚7075铝合金搅拌摩擦焊(FSW)接头沿板厚方向进行分层晶间腐蚀行为研究。借助光学显微镜及扫描电子显微镜分析了接头组织、第二相成分及分布、腐蚀深度及接头各区腐蚀形貌。结果表明:焊缝中心区腐蚀程度最轻,热机影响区(TMAZ)次之,热影响区(HAZ)腐蚀程度最严重;沿板厚向下,焊核区(NZ)腐蚀程度逐渐变大,TMAZ腐蚀程度先变大后减小,HAZ腐蚀程度逐渐减小;接头沿板厚方向晶粒大小和第二相粒子尺寸及分布存在差异,是造成沿板厚方向各区不同晶间腐蚀程度的主要原因。The intergranular corrosion behavior of friction-stir welding（FSW） joint for 20 mm thick plate of 7075 Al-alloy was investigated in solution of 57 g NaCl＋1000 mL H2O＋10 mL H2O2 corresponding to the national standard GBT7998-2005.The microstructure of welded joint,the composition and distribution of the second phase,corrosion depth and corrosion morphology of different zones of the weld joint were characterized by optical microscope and scanning electron microscope.The results show that the corrosion severity of the center zones of the weld joint is the lightest.The corrosion severity of the thermal mechanical affected zone（TMAZ） is between that of the center zones and heat affected zone（HAZ）.Downward along the thickness direction of the weld joint,the corrosion severity of the nugget zone（NZ）gradually increased,while that of the TMAZ increased first and then decreased,and that of the HAZ gradually decreased.The difference in the size and the distribution of the second phase and in the grains size of the weld joint along the thickness direction may be the main factor which caused the different corrosion severity for different zones along the thickness direction of the weld joint.

关 键 词：搅拌摩擦焊 厚板 7075铝合金 晶间腐蚀 第二相 

分 类 号：TG172.9[金属学及工艺—金属表面处理]