Ti-5Al-5Mo-5V-1Cr-1Fe合金高应变速率变形中的微观结构演变

Microstructural Evolution in High-Strain-Rate Deformation of Ti-5Al-5Mo-5V-1Cr-1Fe Alloy.

作者信息

Ran Chun, Chen Pengwan, Sheng Zemin, Li Jingbo, Zhang Wangfeng

机构信息

State Key Laboratory of Explosion Science and Technology, Beijing Institute of Technology, Beijing 100081, China.

School of Materials Science and Engineering, Beijing Institute of Technology, Beijing 100081, China.

出版信息

Materials (Basel). 2018 May 18;11(5):839. doi: 10.3390/ma11050839.

DOI:10.3390/ma11050839

PMID:29783693

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC5978216/

Abstract

To study the microstructural evolution in high-strain-rate shear deformation of Ti-5Al-5Mo-5V-1Cr-1Fe (Ti-55511) alloy, a series of forced shear tests of hat-shaped specimens have been conducted using a split Hopkinson pressure bar combined with the "strain-frozen" technique. A localized shear band is induced in Ti-55511 alloy in these tests. The experimental results demonstrate that the flow stress in hat-shaped specimens remains constant (about 600 MPa) and is independent of punching depth. The width of the adiabatic shear band increases with increasing punching depth and tends to saturate at 30 μm, and the estimation of the adiabatic shear band (ASB) width in hat-shaped (HS) specimens has been modified. Relying on the experimental results, thermal softening has a minor effect on the onset of the adiabatic shear band and dynamic recrystallization formation, and the nucleation mechanism for dynamic recrystallization is strain-induced boundary migration and subgrain rotation and coalescence. In addition, we suggest the concept of adhesive fracture as the dynamic failure mechanism for Ti-55511 alloy.

摘要

为研究Ti-5Al-5Mo-5V-1Cr-1Fe（Ti-55511）合金在高应变速率剪切变形中的微观结构演变，采用分离式霍普金森压杆结合“应变冻结”技术对帽形试样进行了一系列强制剪切试验。在这些试验中，Ti-55511合金中诱发了局部剪切带。实验结果表明，帽形试样中的流动应力保持恒定（约600MPa），且与冲压深度无关。绝热剪切带的宽度随冲压深度的增加而增大，并在30μm时趋于饱和，同时修正了帽形（HS）试样中绝热剪切带（ASB）宽度的估算方法。基于实验结果，热软化对绝热剪切带的起始和动态再结晶形成的影响较小，动态再结晶的形核机制为应变诱导边界迁移以及亚晶粒旋转和合并。此外，我们提出了粘着断裂的概念，作为Ti-55511合金的动态失效机制。