(湘潭大学 土木工程与力学学院，湘潭 411105)
摘 要: 通过原子力显微镜(AFM)纳米压痕实验研究传统纳米压痕实验形成的Fe基非晶合金剪切带区域及未变形区域的变形；结合压痕形貌实时原位观测，探讨块体非晶合金塑性变形局域化的原因。结果表明：最大载荷44.6 μN下，材料的剪切带、剪切带间和未变形区域的AFM纳米压痕残余面积分别为3 274.7、2 976.5和2 879.2 nm2，对应的硬度分别为13.62、14.98和15.49 GPa，剪切带区域的硬度值比未变形区域的硬度值降低了约10%，说明塑性变形过程中，过剩自由体积的产生使剪切带结构发生软化。
关键字: 块体非晶合金；剪切带；原子力纳米压痕；硬度
shear bands of bulk metallic glasses
（College of Civil Engineering and Mechanics, Xiangtan University, Xiangtan 411105, China）
Abstract:The deformation behaviors of the shear bands produced by traditional indentation test and undeformed region of a Fe-based bulk metallic glass (BMG) were investigated by atomic force microscope (AFM) nanoindentation tests. Combining with in-situ observation of the indentation morphology, the origin of the localization of plastic deformation of BMG was studied. The results show that, under the maximum load of 44.6 μN, the residual impressions areas caused by AFM indenter in the shear band, inter-band and undeformed regions are 3 274.7, 2 976.5 and 2 879.2 nm2 with the corresponding hardness of 13.62, 14.98 and 15.49 GPa, respectively. The hardness of shear band is about 10% smaller than that of undeformed region, which indicates that the plasticity in metallic glasses is associated with strain softening induced by the creation of excess free volume during deformation.
Key words: bulk metallic glass; shear band; atomic force microscope nanoindentation; hardness
