J. Mater. Sci. Technol. ›› 2020, Vol. 43: 119-125.DOI: 10.1016/j.jmst.2019.10.034

• Research Article • Previous Articles     Next Articles

Enhancing strength and plasticity by pre-introduced indent-notches in Zr36Cu64 metallic glass: A molecular dynamics simulation study

Shidong Fengab*(), n Lic, K.C. Chanb*(), Lei Zhaob, Limin Wanga, Riping Liua   

  1. a State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao, 066004, China
    b Advanced Manufacturing Technology Research Centre, Department of Industrial and Systems Engineering, The Hong Kong Polytechnic University, 999077, Hong Kong, China
    c Department of Metallurgical and Materials Engineering, The University of Alabama, Tuscaloosa, AL, 35487, USA
  • Received:2019-08-06 Revised:2019-09-20 Accepted:2019-10-17 Published:2020-04-15 Online:2020-04-26
  • Contact: Feng Shidong,Chan K.C.

Abstract:

The deformation behavior in Zr36Cu64 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 densely-packed 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.

Key words: Metallic glass, Notch, Shear band, Microstructure, Molecular dynamics simulation