金属玻璃的剪切带变形与断裂机制研究进展

屈瑞涛, 王晓地, 吴少杰, 张哲峰

Research Progress in Shear Banding Deformation and Fracture Mechanisms of Metallic Glasses

QU Ruitao, WANG Xiaodi, WU Shaojie, ZHANG Zhefeng

图3 压缩下剪切带形成及渐进扩展时的表观硬化机理示意图^[36]
(a1) compressed sample with a stress concentration, where a shear band will be nucleated(a2) local shearing of shear transformation zones (STZs) near the stress concentration
(a3) stress distribution along the shear direction of Ox
(b1) compressed sample after the first shear with a short shear band (OA)
(b2) contraction and traction of local atoms/clusters around the origin of shear banding
(b3-b5) distributions of contraction and traction stresses, shear stress, and local shear offset along the shear direction of Ox, respectively
(c1) successive shearing of the compressed sample, creating the grown shear band with length of OB

Fig.3 Illustration showing the formation of a shear band under compression and the mechanism of apparent work-hardening during progressive propagation (σ_contraction and σ_traction denote the contraction and traction stresses on the initial shear band, respectively; σ_iSB and σ_y are critical stresses for shear band initaiton and propagation, respectively; τ is shear stress; σ and λ are local stress and shear offsets along the distance (x) from point O, respectively; σ_max is the maximum stress at the point O, while λ_max1 and λ_max2 are the maximum shear offsets at the point O, respectively)^[36]