高应变速率下TC11钛合金动态剪切行为与性能

Dynamic Shearing Behavior and Mechanical Property of TC11 Alloys at High Strain Rates

采用分离式霍普金森压杆(Hopkinson Bar)装置系统,对TC11钛合金进行室温高应变速率(700～2 100s-1)动态剪切试验,通过光学显微镜、显微硬度分析仪、扫描电镜研究了TC11钛合金动态剪切行为、绝热剪切带微观组织与性能。结果表明:TC11钛合金随应变速率的提高绝热剪切敏感性增加;绝热剪切带由过渡区域的变形拉长组织和中间部位的细小晶粒组织组成,具有清晰的剪切变形流线,宽度约为10μm;绝热剪切带内的显微硬度值高于基体组织,是由应变速率强化和应变强化与热软化相互作用的结果。

Dynamic shear experiment of TCll at high strain rates （700-2 100 s^-1） was carried out by torsional split Hopkinson bar. The behavior of dynamic shear, microstructure and properties of TCll alloy were investigated by optical microscope, microhardness instrument, stereoscan electron microscope and transmission electron microscope. The results show that the sensitivity of adiabatic shear increases with increase of strain rate. Adiabatic shear band consists of elongated microstructures located in transition areas and equiaxed grains with fine grain size of intermediate position. Adiabatic shear band is about 10 μm and characterized by shearing deformation streamline. The microhardness value of shear bands is higher than that of matrix body. This can be attributed to strain rate strengthening and interacting between strain strengthening and thermal softening.