Transition of plasticity and fracture mode of Zr-Al-Ni-Cu bulk metallic glasses with network structures
(1. College of Mechanical Engineering, Hunan Institute of Science and Technology, Yueyang 414000, China;
2. State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China;
3. Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China;
4. School of Physics and Electronics, Central South University, Changsha 410083, China)
2. State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China;
3. Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China;
4. School of Physics and Electronics, Central South University, Changsha 410083, China)
Abstract: Effect of network structure on plasticity and fracture mode of Zr-Al-Ni-Cu bulk metallic glasses (BMGs) was investigated. The microstructures of transversal and longitudinal sections were exposed by chemical etching and observed by scanning electron microscopy (SEM). The mechanical properties were examined by room-temperature uniaxial compression test. The results show that both plasticity and fracture mode are significantly affected by the network structure and the alteration occurs when the size of the network structure reaches up to a critical value. When the cell size (dc) of the network structure is ~3 μm, Zr-based BMGs characterize in plasticity that decreases with increasing dc. The fracture mode gradually transforms from single 45° shear fracture to double 45° shear fracture and then cleavage fracture with increasing dc. In addition, the mechanisms of the transition of the plasticity and the fracture mode for these Zr-based BMGs are also discussed.
Key words: bulk metallic glass; plasticity; fracture mode; network structure