时效热处理对2219铝合金搅拌摩擦焊焊缝组织性能的影响  

Effect of aging heat treatment on microstructure and properties of friction stir welding seam of 2219 aluminum alloy

作　　者：汤智茂 湛利华[1,2,3] 徐永谦 李国鹏[1,3] TANG Zhi-mao;ZHAN Li-hua;XU Yong-qian;LI Guo-peng(State Key Laboratory of High-Performance Complex Manufacturing,Central South University,Changsha 410083,China;Light Alloy Research Institute,Central South University,Changsha 410083,China;College of Mechanical and Electrical Engineering,Central South University,Changsha 410083,China)

机构地区：[1]中南大学高性能复杂制造国家重点实验室,湖南长沙410083 [2]中南大学轻合金研究院,湖南长沙410083 [3]中南大学机电工程学院,湖南长沙410083

出　　处：《塑性工程学报》2021年第5期134-144,共11页Journal of Plasticity Engineering

基　　金：国家重点研发计划项目(2017YFB0306300);国家自然科学基金青年基金资助项目(51905551);高性能复杂制造国家重点实验室自由探索课题(ZZYJKT2019-11)。

摘　　要：采用光学显微镜、扫描电子显微镜、万能力学试验机和显微硬度仪表征分析了焊后时效热处理对2219铝合金搅拌摩擦焊焊缝组织性能的影响规律,并讨论了其影响机制。结果表明:短时人工时效能使焊缝的热影响区硬度提高至与母材同一水平,但对热机影响区硬度影响不显著;随着时效时间增加,焊核区和母材硬度可进一步提高,焊接板材整体屈服强度和抗拉强度提升,但伸长率降低;室温拉伸断裂位置在前进侧的热机影响区,断裂方式主要为韧性断裂和局部的脆性断裂,这可能是由该区域内无时效析出且存在微孔洞等缺陷导致的。The effect law of post-weld aging heat treatment on microstructure and properties of friction stir welding seam of 2219 aluminum alloy was analyzed using optical microscope( OM),scanning electron microscope( SEM),universal testing machine and microhardness tester,and its effect mechanism was discussed. The results show that short-time artificial aging can increase the hardness of heat affected zone( HAZ) of welding seam to the same level as the base metal( BM),but has no significant effect on the hardness of thermo-mechanical affected zone( TMAZ). As the aging time increases,the hardness of the weld nugget zone( WNZ) and the BM can be further improved,and the overall yield strength and tensile strength of the welded sheet can be improved,but the elongation rate is reduced. The tensile fracture position at room temperature is in TMAZ on the advancing side,and the mainly fracture modes are ductile fracture and local brittle fracture,which may be due to the aging free precipitation and the existance of microvoids in this zone.

关 键 词：2219铝合金 搅拌摩擦焊 时效热处理 力学性能 

分 类 号：TG441.8[金属学及工艺—焊接]