应变速率对TB6钛合金绝热剪切敏感性的影响  

Effects of Strain Rate on Susceptibility of TB6 Titanium Alloy to Adiabatic Shear

作　　者：刘小刚 郭正华[1] 郦逸凡 姜丽红[1] 冯琛文 LIU Xiaogang;GUO Zhenghua;LI Yifan;JIANG Lihong;FENG Chenwen(School of Aeronautical Manufacturing Engineering,Nanchang Hangkong University,Nanchang 330063,Jiangxi,China)

机构地区：[1]南昌航空大学航空制造工程学院,江西南昌330063

出　　处：《矿冶工程》2024年第1期157-160,共4页Mining and Metallurgical Engineering

基　　金：江西省重大科技研发专项项目(20194ABC28001);南昌航空大学研究生创新专项资金项目(YC2022-029)。

摘　　要：在室温下采用分离式霍普金森压杆对TB6钛合金帽型试样进行动态加载,研究了应变速率对TB6钛合金绝热剪切敏感性的影响。结果表明,应变速率1950~2510 s^(-1)时,4组试样均表现出明显的应变硬化效应;在绝热温升作用下,4组试样均发生热塑失稳形成绝热剪切带;受冲击载荷和材料晶粒尺寸影响,基体和绝热剪切带之间的过渡区域变形梯度不明显;热剪切带内100 nm等轴晶的形成是旋转动态再结晶机制作用的结果。通过观察金相、表征绝热剪切敏感性及计算扩展能发现,TB6钛合金绝热剪切敏感性随应变速率增加而增加。The effect of strain rate on susceptibility of TB6 titanium alloy to adiabatic shear was investigated through dynamic loading of hat-shaped specimen of TB6 titanium alloy by using a split-Hopkinson compression bar at room temperature.The following results are obtained:all four groups of specimens exhibit obvious strain hardening effects at a strain rate of 1950-2510 s^(-1);with the rising of adiabatic temperature,adiabatic shear bands(ASBs)form in all four groups of specimens due to thermoplastic instability;there is no obvious deformation gradient in the transition zone between the matrix and the adiabatic shear band due to the influence of impact load and material grain size;the equiaxed grains with size of 100 nm are formed in the hot shear band due to rotational dynamic recrystallization.By observing the metallographic structure,characterizing the adiabatic shear sensitivity,and calculating the expansion energy,it can be inferred that the susceptibility of TB6 titanium alloy to adiabatic shear increases with the increase of strain rate.

关 键 词：绝热剪切敏感性 绝热剪切带 应变速率 旋转动态再结晶 TB6钛合金 分离式霍普金森压杆 

分 类 号：TG115[金属学及工艺—物理冶金]