电磁铆接初始温度对TB2铆钉绝热剪切变形的影响  

Adiabatic Shear Deformation of TB2 Rivet with Different ElectromagneticRiveting Initial Temperature

作　　者：姚钰杰 邓将华[1] 范治松 卢圳彬 Yao Yujie;Deng Jianghua;Fan Zhisong;Lu Zhenbin(School of Mechanical Engineering and Automation,Fuzhou University,Fuzhou 350116,China)

机构地区：[1]福州大学机械工程及自动化学院,福建福州350116

出　　处：《稀有金属》2024年第7期976-988,共13页Chinese Journal of Rare Metals

基　　金：国家自然科学基金项目(51774097)资助。

摘　　要：为提高电磁铆接接头质量,在210 V放电电压下分别对20℃和加热到100, 200和300℃的TB2铆钉进行电磁铆接工艺试验,并对铆钉镦头微观组织进行观察,分析绝热剪切带内微观组织演变及剪切带的形成机制。结果表明,随着初始温度的升高、铆钉的变形量增加,当温度达到300℃时,TB2铆钉最大变形量接近58%,相比于20℃时提高了20%。观察到绝热剪切变形过程中剪切带经历萌生、扩展到断裂3个阶段,初始温度的升高会延缓剪切带的出现,剪切带的宽度受温度和变形量两个因素的影响。从过渡区域到剪切带中心方向上的位错密度逐渐降低,拉长的大晶粒内存在位错胞,随着变形量的增加,大晶粒逐渐破碎成等轴纳米级晶粒,符合旋转动态再结晶晶粒形成的特征。In order to improve the quality of electromagnetic riveting joints,TB2 rivets at 20℃and heated to 100,200 and 300℃were tested for electromagnetic riveting technology under 210 V discharge voltage.The rivet heads were observed by optical microscope(OM),scanning electron microscope(SEM)and scanning transmission electron microscope(STEM),the effects of different initial temperatures on riveting effects were discussed,and the microstructure evolution in adiabatic shear band(ASB)and the formation mechanism of the shear band were analyzed.The results showed that with the increase of initial temperature,the material was softened by heating,the maximum deformation of TB2 gradually increased,and the plasticity becomes better,which was helpful for rivet forming.At 20℃,the maximum deformation was 38%,when the deformation reached 40%,the specimen shears along 45°direction.When the temperature reached 200℃,the maximum deformation of TB2 samples was 52%,which increased by 8%.When the temperature reached 300℃,the maximum deformation of TB2 sample was close to 58%,and the maximum deformation was increased by 20%.Through SEM observation on TB2 rivet upsets with different deformation,it was found that ASB would initially appear around the rivet upsets,and the width of ASB would decrease with the increase of deformation within a certain amount of deformation.During the whole adiabatic shear deformation process,ASB had experienced three stages of initiation and extension to fracture,which was a shear band from the formation of the main shear band to the formation of both the primary and secondary shear bands,and then to the final fracture.With the increase of the initial temperature,ASB would be delayed.ASB width ranged from 20 to 50μm at different temperatures and deformations.With the increase of deformation,the width of ASB at 20,100 and 200℃showed a downward trend.The adiabatic shear band would be roughly formed at 30%of the deformation,but when the temperature rose to 300℃,30%of the deformation was not enough to

关 键 词：TB2钛合金 电磁铆接 绝热剪切带 旋转动态再结晶 

分 类 号：TG391[金属学及工艺—金属压力加工]