How does the structural inhomogeneity influence the shear band behaviours of metallic glasses |
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Authors: | G N Yang C T Liu |
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Institution: | 1. School of Electromechanical Engineering, Guangdong University of Technology, Guangdong, People’s Republic of China;2. School of Material Science and Engineering, Tsinghua University, Beijing, People’s Republic of China;3. Key Laboratory for Advanced Materials Processing Technology, Ministry of Education, Beijing, People’s Republic of China;4. Centre for Advanced Structural Materials, Department of Mechanical and Biomechanical Engineering, City University of Hong Kong, Hong Kong, People’s Republic of China;5. Centre for Advanced Structural Materials, Department of Mechanical and Biomechanical Engineering, City University of Hong Kong, Hong Kong, People’s Republic of China |
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Abstract: | ABSTRACTHere we propose a model to understand the influence of structural inhomogeneity on the shear band behaviours of metallic glasses. By considering the inhomogeneous structure and stress concentration, the model predicts that the strain for shear band nucleation in metallic glasses can be variable and far below the theoretical elastic limit. During sliding, the shear band will approach a dynamic equilibrium state of balanced free volume generation and annihilation. By considering the accumulation of irreversible structure change, the shear band will finally develop into fracture. Under fluctuating load, the shear band shows an ‘activate-arrest’ behaviour, which results from a delayed response to the external load change. These results reasonably explain and correlate the physics behind the elastic limit, stick-slip shear band behaviour, implicit shear events, and shear band fracture in metallic glasses. The study can provide another perspective and platform to understand the correlations between structural inhomogeneity and shear band behaviours in metallic glasses, and further explore other shear band related phenomena not only in metallic glasses but also in the class of shear-softened materials. |
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Keywords: | Metallic glasses shear bands free volume plastic deformation structural inhomogeneity |
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