中国有色金属学报(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 21 No. 2 February 2011 |
（1. School of Materials Science and Engineering, Beijing Institute of Technology, Beijing 100081, China;
2. Laboratory of Advanced Materials Behavior Characteristics, Beijing Institute of Technology and
Institute of Space Medico-Engineering, Beijing 100081, China）
Abstract:The dynamic fracture behaviors of Ti-6Al-4V alloy at high strain rate loading were investigated systemically through Taylor impact test, over the range of impact velocities from 145 m/s to 306 m/s. The critical impact velocity of fracture ranges from 217 m/s to 236 m/s. Smooth surfaces and ductile dimple areas were observed on the fracture surfaces. As the impact velocity reached 260 m/s, the serious melting regions were also observed on the fracture surfaces. Self-organization of cracks emerges when the impact velocity reaches 260 m/s, while some special cracks whose “tips” are not sharp but arc and smooth, and without any evidence of deformation or adiabatic shear band were also observed on the impact end surfaces. Examination of the sections of these special cracks reveals that the cracks expand along the two maximum shear stress directions respectively, and finally intersect as a tridimensional “stagger ridge” structure.
Key words: Ti-6Al-4V alloy; dynamic fracture behavior; adiabatic shear band; Taylor impact test
