摘要
为探究安装外部静止轴肩对搅拌摩擦焊接头成形和力学性能的影响,采用自主研制的外部静止轴肩辅助搅拌摩擦焊(Non-Rotational Shoulder Assisted Friction Stir Welding,NRSA-FSW)焊具对2219-T6铝合金4 mm厚板材进行对接焊试验,观察焊后接头表面成形情况.采用拉伸和显微硬度试验对焊缝的力学性能进行测试,并与相同焊接参数下的搅拌摩擦焊(Friction Stir Welding,FSW)进行对比分析.使用金相显微镜和场发射扫描电镜对接头焊缝组织进行分析.结果表明,由于静止轴肩的平动刮擦作用,NRSA-FSW相比FSW,接头表面更加光滑,无鱼鳞纹、飞边以及接头减薄现象.NRSA-FSW接头相比于FSW接头软化区有所增加,接头显微硬度分布更加均匀.NRSA-FSW接头平均抗拉强度323 MPa,达到母材的72%,抗拉强度同FSW相近.NRSA-FSW焊核呈"U"状,焊缝组织无缺陷.接头拉伸试验在焊核区(Nuggest-Zone,NZ)处断裂,为韧性断裂.
To investigate the effect of the external stationary shoulder on the formability and mechanical proper-ties of friction stir welding joint,the self-developed NRSA-FSW( non-rotational shoulder assisted friction stir welding) was used to weld 2219-T6 aluminum alloy with the thickness of 4 mm plate. Mechanical properties of the joint were analyzed by tensile test and microhardness test. Optical microscopy and field emission scanning electron micro-scope were used to analyze the microstructure of the joint cross section. The results showed that the surface of the joint processed by NRSA-FSW formed without fish scales,flash,and thinning,and represented smooth appearance due to the scrapping effect of the static shoulder. Compared with the joint processed by FSW(friction stir welding) under the same condition,the softening zone of the joint processed by NRAS-FSW increased,and the microhardness distribution of the joint was more uniform. The average ultimate tensile strength of joints processed by NRAS-FSW was 323 MPa,approaching 72% of the base material,which was similar to the joint processed by FSW. Defects were not observed in the joint processed by NRSA-FSW. NZ(nuggest-zone) appeared as a "U" shape and the joint fractured in the NZ during tensile tests,which was ductile fracture.
作者
贺地求
刘朋
王海军
王东曜
赖瑞林
HE Diqiu;LIU Peng;WANG Haijun;WANG Dongyao;LAI Ruilin(Light Alloy Research Institute,Central South University,Changsha 410083,China;State Key Laboratory of High Performance Complex Manufacturing,Central South University,Changsha 410083,China;State Key Laboratory of Powder Metallurgy,Central South University,Changsha 410083,China)
出处
《湖南大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2021年第8期11-18,共8页
Journal of Hunan University:Natural Sciences
基金
国家重点研发计划资助项目(2019YFA0709000)~。
