初生α相含量对TC4 ELI钛合金动态应力应变行为的影响  

Effect of primary α phase content on dynamic stress strain behavior of TC4 ELI titanium alloy

作　　者：刘清华[1] 惠松骁[1] 叶文君[1] 王国[1] 胡光山[1] 

机构地区：[1]北京有色金属研究总院、有色金属材料制备加工国家重点实验室,北京100088

出　　处：《中国有色金属学报》2012年第10期2749-2755,共7页The Chinese Journal of Nonferrous Metals

基　　金：国家"十一五"科技支撑计划资助项目(2008BAE62B03);中国博士后科学基金资助项目(20100470260)

摘　　要：利用分离式霍普金森压杆(SHPB)装置,对低间隙Ti-6Al-4V(TC4 ELI)钛合金中4种初生α相含量不同的等轴组织在不同应变速率(2 000、3 000和4 000 s 1)下进行动态压缩试验,通过动态压缩试验得到材料的动态真应力—应变(σ—ε)曲线,并利用金相显微镜(OM)等对试验后发生剪切失效破坏试样的端面进行观察分析。结果表明:随着初生α相含量的增加,TC4 ELI的平均动态流变应力、均匀动态塑性应变和冲击吸收功(E)的变化规律不明显,在4 000 s 1应变速率加载条件下,4组试样均发生剪切失效破坏,在失效试样的端面观察到几乎呈同心的圆弧形白亮绝热剪切带(ASB),部分剪切带发生分叉,裂纹在剪切带内形核、长大和聚合,最终导致试样断裂。The dynamic mechanical properties of four equiaxed microstructures with different contents of primary a phase in Ti-6A1-4V extra low interstitial （TC4 ELI） were studied with split Hopkinson pressure bar device. The dynamic stress--strain curves under different conditions were obtained, and the end surfaces of samples lapsed by shear force were examined under a optical microscope. The results show that there exists no regularity on the variation of dynamic strength, dynamic strain and absorbed energy of TC4 ELI alloy with the increasing content of primary a phase. The shear failure damage occurs at the strain rate of 4 000 s-1, the white light adiabatic shear bands （ASBs） of almost concentric are-shaped are observed on the specimen face of four samples. The bifurcation of some adiabatic shear bands occurs. The cracks nucleate, grow and converge in the ASBs, eventually leading to specimen fracture.

关 键 词：TC4ELI钛合金 初生Α相 分离式霍普金森压杆 绝热剪切带 

分 类 号：TG146.2[一般工业技术—材料科学与工程]