Chin. Phys. B ›› 2012, Vol. 21 ›› Issue (12): 126802-126802.doi: 10.1088/1674-1056/21/12/126802

• CONDENSED MATTER: STRUCTURAL, MECHANICAL, AND THERMAL PROPERTIES • 上一篇    下一篇

Molecular dynamics study of mechanical characteristics of Ni/Cu bilayer using nanoindentation

Muhammad Imrana, Fayyaz Hussaina b, Muhammad Rashida, S. A. Ahmada   

  1. a Department of Physics, Simulation Laboratory, The Islamia University of Bahawalpur, 63100, Pakistan;
    b Department of Physics, National University of Singapore, 2 Science Drive 3, 117542 Singapore
  • 收稿日期:2012-06-15 修回日期:2012-07-11 出版日期:2012-11-01 发布日期:2012-11-01

Molecular dynamics study of mechanical characteristics of Ni/Cu bilayer using nanoindentation

Muhammad Imrana, Fayyaz Hussaina b, Muhammad Rashida, S. A. Ahmada   

  1. a Department of Physics, Simulation Laboratory, The Islamia University of Bahawalpur, 63100, Pakistan;
    b Department of Physics, National University of Singapore, 2 Science Drive 3, 117542 Singapore
  • Received:2012-06-15 Revised:2012-07-11 Online:2012-11-01 Published:2012-11-01
  • Contact: Fayyaz Hussain E-mail:fiazz_hussain@yahoo.com

摘要: In the present work, a three-dimensional molecular dynamics simulation is carried out to perform the nanoindentation experiment on Ni single crystal. The substrate indenter system is modeled using hybrid interatomic potentials including many-body potential embedded atom method (EAM), and two-body morse potential. To simulate the indentation process, spherical indenter (diameter=80 Å, 1 Å=0.1 nm) is chosen. The results show that mechanical behaviour of a monolithic Ni is not affected by crystalline orientation. To elucidate the effect of heterogeneous interface, three bilayer interface systems are constructed, namely Ni(100)/Cu(111), Ni(110)/Cu(111), and Ni(111)/Cu(111). The simulations along these systems clearly describe that mechanical behaviour directly depends on the lattice mismatch. The interface with smaller mismatch between the specified crystal planes is proved to be harder and vice versa. To describe the relationship between film thickness and interface effect, we choose various values of film thickness ranging from 20 Å to 50 Å to perform nanoindentation experiment. It is observed that the interface is significant only for the relatively small thickness of film and the separation between interface and the indenter tip. It is shown that with the increase in film thickness, the mechanical behaviour of film shifts more toward that of monolithic material.

关键词: nanoindentation, bilayer, molecular dynamics, thin film

Abstract: In the present work, a three-dimensional molecular dynamics simulation is carried out to perform the nanoindentation experiment on Ni single crystal. The substrate indenter system is modeled using hybrid interatomic potentials including many-body potential embedded atom method (EAM), and two-body morse potential. To simulate the indentation process, spherical indenter (diameter=80 Å, 1 Å=0.1 nm) is chosen. The results show that mechanical behaviour of a monolithic Ni is not affected by crystalline orientation. To elucidate the effect of heterogeneous interface, three bilayer interface systems are constructed, namely Ni(100)/Cu(111), Ni(110)/Cu(111), and Ni(111)/Cu(111). The simulations along these systems clearly describe that mechanical behaviour directly depends on the lattice mismatch. The interface with smaller mismatch between the specified crystal planes is proved to be harder and vice versa. To describe the relationship between film thickness and interface effect, we choose various values of film thickness ranging from 20 Å to 50 Å to perform nanoindentation experiment. It is observed that the interface is significant only for the relatively small thickness of film and the separation between interface and the indenter tip. It is shown that with the increase in film thickness, the mechanical behaviour of film shifts more toward that of monolithic material.

Key words: nanoindentation, bilayer, molecular dynamics, thin film

中图分类号:  (Interface structure and roughness)

  • 68.35.Ct
68.35.Ja (Surface and interface dynamics and vibrations)