Molecular dynamics study of crystal plasticity during nanoindentation in Ni nanowires

被引:27
作者
Dupont, V. [1 ]
Sansoz, F. [1 ]
机构
[1] Univ Vermont, Sch Engn, Burlington, VT 05405 USA
基金
美国国家科学基金会;
关键词
MECHANICAL-PROPERTIES; THIN-FILMS; DEFORMATION; GOLD; NANOSCALE; STRENGTH; NUCLEATION; ONSET;
D O I
10.1557/JMR.2009.0103
中图分类号
T [工业技术];
学科分类号
08 ;
摘要
Molecular dynamics simulations were performed to gain fundamental insight into crystal plasticity, and its size effects in nanowires deformed by spherical indentation. This work focused on < 111 >-oriented single-crystal, defect-free Ni nanowires of cylindrical shape with diameters of 12 and 30 nm. The indentation of thin films was also comparatively studied to characterize the influence of free surfaces in the emission and absorption of lattice dislocations in single-crystal Ni. All of the simulations were conducted at 300 K by using a virtual spherical indenter of 18 mm in diameter with a displacement rate of 1 m.s(-1). No significant effect of sample size was observed on the elastic response and mean contact pressure at yield point in both thin films and nanowires. In the plastic regime, a constant hardness of 21 GPa was found in thin films for penetration depths larger than 0.8 nm, irrespective of variations in film thickness. The major finding of this work is that the hardness of the nanowires decreases as the sample diameter decreases, causing important softening effects in the smaller nanowire during indentation. The interactions of prismatic loops and dislocations, which are emitted beneath the contact tip, with free boundaries are shown to be the main factor for the size dependence of hardness in single-crystal Ni nanowires during indentation.
引用
收藏
页码:948 / 956
页数:9
相关论文
共 45 条
  • [11] Size-affected single-slip behavior of pure nickel microcrystals
    Dimiduk, DM
    Uchic, MD
    Parthasarathy, TA
    [J]. ACTA MATERIALIA, 2005, 53 (15) : 4065 - 4077
  • [12] Nanolithography and nanoindentation of tantalum-oxide nanowires and nanodots using scanning probe microscopy
    Fang, TH
    Chang, WJ
    [J]. PHYSICA B-CONDENSED MATTER, 2004, 352 (1-4) : 190 - 199
  • [13] Atomistic simulations of spherical indentations in nanocrystalline gold
    Feichtinger, D
    Derlet, PM
    Van Swygenhoven, H
    [J]. PHYSICAL REVIEW B, 2003, 67 (02)
  • [14] A study of the mechanical properties of nanowires using nanoindentation
    Feng, G
    Nix, WD
    Yoon, Y
    Lee, CJ
    [J]. JOURNAL OF APPLIED PHYSICS, 2006, 99 (07)
  • [15] Greer JR, 2006, ACTA MATER, V54, P1705, DOI [10.1016/j.actamat.2005.12.004, 10.1002/art.21799]
  • [16] Nanoscale gold pillars strengthened through dislocation starvation
    Greer, Julia R.
    Nix, William D.
    [J]. PHYSICAL REVIEW B, 2006, 73 (24)
  • [17] Nanowire-based very-high-frequency electromechanical resonator
    Husain, A
    Hone, J
    Postma, HWC
    Huang, XMH
    Drake, T
    Barbic, M
    Scherer, A
    Roukes, ML
    [J]. APPLIED PHYSICS LETTERS, 2003, 83 (06) : 1240 - 1242
  • [18] An atomistic investigation of elastic and plastic properties of Au nanowires
    Hyde, B
    Espinosa, HD
    Farkas, D
    [J]. JOM, 2005, 57 (09) : 62 - 66
  • [19] Johnson K.L., 1985, Contact Mechanics, DOI [10.1017/CBO9781139171731, DOI 10.1017/CBO9781139171731]
  • [20] Observation of plastic deformation in freestanding single crystal Au nanowires
    Lee, Dongyun
    Zhao, Manhong
    Wei, Xiaoding
    Chen, Xi
    Jun, Seong C.
    Hone, James
    Herbert, Erik G.
    Oliver, Warren C.
    Kysar, Jeffrey W.
    [J]. APPLIED PHYSICS LETTERS, 2006, 89 (11)