Ti6321合金焊接接头的微观组织及动态力学响应
Microstructure and Dynamic Mechanical Response of Ti6321 Alloy Welded Joint
张宇轩 1宋雨宸 1王琳 2范丽静 1江宇阳 1卢晓阳3
作者信息
- 1. 北京理工大学 材料学院,北京 100081
- 2. 北京理工大学 材料学院,北京 100081;北京理工大学 冲击环境材料技术国家级重点实验室,北京 100081
- 3. 洛阳船舶材料研究所,河南 洛阳 471023
- 折叠
摘要
对Ti6321 合金钨极氩弧焊焊接接头开展动态压缩载荷作用下的力学响应研究,结合光学显微镜、扫描电子显微镜、电子背散射衍射、透射电子显微镜等表征方法,研究了焊接接头的微观组织,以及 2000～2800 s-1 高应变率条件下的动态力学响应.结果表明:Ti6321 合金焊接接头处晶粒尺寸从母材区向焊缝区逐渐增大,组织由母材区双态组织向焊缝区魏氏组织过渡,热影响区等轴α相尺寸逐渐减小,焊缝区出现粗化的大块α相.在动态压缩载荷作用下,热影响区和母材区具有较高的屈服强度,而焊缝区的流变应力较低,屈服强度较小.在应变率为 2400 s-1 的条件下,各区域应变率敏感因子随着应变增大整体呈现下降趋势,应变为 0.05 时,应变率强化效应由焊缝中心向母材方向逐渐增 强.动态压缩加载后焊接接头各区域组织均发生一定的流变和晶粒破碎,热影响区晶粒变形较多,焊缝区晶粒变形较少.动态压缩后位错密度增大,孪晶含量增加.
Abstract
The mechanical response of Ti6321 alloy TIG welded joint under dynamic compressive load was studied.The microstructure and dynamic mechanical response of welded joint under high strain rate of 2000～2800 s-1 were studied,combined with optical microscopy,scanning electron microscopy,electron backscatter diffraction and transmission electron microscopy.The results show that the grain size of Ti6321 alloy welded joint gradually increases from base metal(BM)to weld metal(WM),and the microstructure transits from bimodal of BM to widmanstatten structure of WZ.The equiaxed α phase in the heat affected zone(HAZ)gradually shrinks,and coarse α phase appears in WM.Under dynamic compressive loading,HAZ and BM have higher yield strength,while the flow stress and yield strength of WM are lower.Under the strain rate of 2400 s-1,the strain rate sensitivity factors of each region show a downward trend with the increase of strain.When the strain is 0.05,the strain rate strengthening effect gradually increases from WM to BM.After dynamic compressive loading,the microstructure of each region of welded joint undergoes certain flowing deformation and grain breakage.The grain deformation in HAZ is more,and the grain deformation in WM is less.After dynamic compression,the dislocation density and twin content both increase.
关键词
Ti6321合金/焊接接头/微观组织/力学性能/动态响应行为Key words
Ti6321 alloy/welded joint/microstructure/mechanical properties/dynamic response behavior引用本文复制引用
出版年
2024
NETL
NSTL
万方数据