Enhancing strength and plasticity by pre-introduced indent-notches in Zr₃₆Cu₆₄metallic glass: A molecular dynamics simulation study

Shidong Feng^1,2，Lin Li³，K.C.Chan²，Lei Zhao²，Limin Wang¹，Riping Liu¹

1. State Key Laboratory of Metastable Materials Science and Technology, Yanshan University2. Advanced Manufacturing Technology Research Centre, Department of Industrial and Systems Engineering, The Hong Kong Polytechnic University3. Department of Metallurgical and Materials Engineering, The University of Alabama

摘 要：The deformation behavior in Zr36 Cu64 metallic glasses with pre-introduced indent-notches has been studied by molecular dynamics simulation at the atomic scale. The indent-notches can trigger the formation of densely-packed clusters composed of solid-like atoms in the indent-notch affected zone. These denselypacked clusters are highly resistant to the nucleation of shear bands. Hence, there is more tendency for the shear bands to nucleate outside the indent-notch affected zone, which enlarges the deformation region and enhances both the strengthening effect and the plastic deformation ability. For indent-notched MGs, when determining the initial yielding level, there is a competition process occurring between the densely-packed clusters leading to the shear band formation outside the indent-notch affected zone and the stress-concentration localizing deformation around the notch roots. When the indent-notch depth is small, the stress-concentration around the notch root plays a dominant role, leading to the shear bands initiating from the notch root, reminiscence of the cut-notches. As the indent-notch depth increases,there are many densely-packed clusters with high resistance to deformation in the indent-notch affected zone, leading to the shear band formation from the interface between the indent-notch affected zone and the matrix. Current research findings provide a feasible means for improving the strength and the plasticity of metallic glasses at room temperature.

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