Integrated MD simulation of scratching and shearing of 3D nanostructure

An integrated MD simulation of scratching and shearing with one specimen is conducted to analyze the nanomachining mechanism and mechanics properties of nanostructures. Simulation results indicate that during scratching the onset and propagation of dislocations depend on the scratch depths; during shearing, the yielding stress of a small-size nanostructure is more sensitive to nanomachining imperfection and residual defects. Dislocations nucleate first near the burr in a scratched specimen. In an ideal nanostructure or a nanostructure with shallow scratched groove, the distribution of stress is generally lower and flatter. As the depth of groove increases, high stresses transit from the corner to either end of groove, especially near the burr or around the location of tool withdraw. During the deformation of nanostructures, shear stress plays a leading role in the elastic stage, and both normal stress gradients and shear stress determine the onset and evolvement of defects in the plastic stage. When the ratio of the depth of groove to the height of specimen is up to one third, the scratched groove determines the breakpoint of a nanostructure. The fluctuation of shear stress during the plastic deformation of specimen is caused by the competition between atoms which form new atomic planes and slip on different slip planes.

[1]  Mark F. Horstemeyer,et al.  A multiscale analysis of fixed-end simple shear using molecular dynamics, crystal plasticity, and a macroscopic internal state variable theory , 2003 .

[2]  Sidney Yip,et al.  Ideal shear strain of metals and ceramics , 2004 .

[3]  Cheng-I Weng,et al.  Three-dimensional molecular dynamics analysis of processing using a pin tool on the atomic scale , 2000 .

[4]  Mark F. Horstemeyer,et al.  A deformation gradient tensor and strain tensors for atomistic simulations , 2007 .

[5]  Hoover,et al.  Canonical dynamics: Equilibrium phase-space distributions. , 1985, Physical review. A, General physics.

[6]  Johnson,et al.  Analytic nearest-neighbor model for fcc metals. , 1988, Physical review. B, Condensed matter.

[7]  I. Inasaki,et al.  Investigation of Surface Integrity by Molecular Dynamics Simulation , 1995 .

[8]  K. Maekawa,et al.  Friction and tool wear in nano-scale machining—a molecular dynamics approach , 1995 .

[9]  Jun Shimizu,et al.  Molecular dynamics simulation of friction on the atomic scale , 1998 .

[10]  D. Roundy,et al.  Ideal Shear Strengths of fcc Aluminum and Copper , 1999 .

[11]  Hiroaki Tanaka,et al.  Towards a deeper understanding of wear and friction on the atomic scale—a molecular dynamics analysis , 1997 .

[12]  C. Weng,et al.  Nanoindentation and nanomachining characteristics of gold and platinum thin films , 2006 .

[13]  A. Benzerga,et al.  Scale dependence of mechanical properties of single crystals under uniform deformation , 2006 .

[14]  Steven J. Plimpton,et al.  Computational nanoscale plasticity simulations using embedded atom potentials , 2001 .

[15]  Ranga Komanduri,et al.  Molecular dynamics simulation of atomic-scale friction , 2000 .

[17]  Fengzhou Fang,et al.  Nanometric cutting of copper: A molecular dynamics study , 2006 .

[18]  S. Nosé.  A unified formulation of the constant temperature molecular dynamics methods , 1984 .

[19]  M. Baskes,et al.  Atomistic simulations of Bauschinger effects of metals with high angle and low angle grain boundaries , 2004 .

[20]  Jian-Sheng Wang,et al.  Atomistic and continuum simulation on extension behaviour of single crystal with nano-holes , 2004 .

[21]  M. Baskes,et al.  Embedded-atom method: Derivation and application to impurities, surfaces, and other defects in metals , 1984 .

[22]  Shengyuan Deng,et al.  Where, and how, does a nanowire break? , 2007, Nano letters.

[23]  A. Pasturel,et al.  Phase stability of δ-Pu alloys: a key role of chemical short range order , 2004 .

[24]  Xichun Luo,et al.  Modeling and simulation of the tool wear in nanometric cutting , 2003 .

[25]  N. Chandrasekaran,et al.  Molecular dynamics (MD) simulation of uniaxial tension of some single-crystal cubic metals at nanolevel , 2001 .

[26]  Steven J. Plimpton,et al.  LENGTH SCALE AND TIME SCALE EFFECTS ON THE PLASTIC FLOW OF FCC METALS , 2001 .

[27]  Shoichi Shimada.  Molecular Dynamics Analysis of Nanometric Cutting Process , 1995 .

[28]  Shoichi Shimada,et al.  Molecular dynamics analysis on microstructure of diamond-turned surfaces , 1995, Other Conferences.

[29]  J. R. Morris,et al.  Molecular dynamics simulation of nanoscale machining of copper , 2003 .

[30]  Jun Shimizu,et al.  Simulation and experimental analysis of super high-speed grinding of ductile material , 2002 .

[31]  K. Kaski,et al.  MOLECULAR-DYNAMICS STUDY OF COPPER WITH DEFECTS UNDER STRAIN , 1998 .

[32]  M. Doyama,et al.  Plastic deformation of copper thin foils , 2003 .

[33]  Ting Zhu,et al.  Atomistic mechanisms governing elastic limit and incipient plasticity in crystals , 2002, Nature.

[34]  Wen-Jay Lee,et al.  A molecular dynamics study of the tensile behaviour of ultrathin gold nanowires , 2004 .

[35]  Ranga Komanduri,et al.  MD simulation of indentation and scratching of single crystal aluminum , 2000 .

[36]  H. P. Lee,et al.  Molecular dynamics simulation of a solid platinum nanowire under uniaxial tensile strain: Temperature and strain-rate effects , 2005 .

[37]  Ju Li,et al.  Analysis of shear deformations in Al and Cu: empirical potentials versus density functional theory , 2004 .

[38]  Huajian Gao,et al.  Simulating materials failure by using up to one billion atoms and the world's fastest computer: Work-hardening , 2002, Proceedings of the National Academy of Sciences of the United States of America.

[39]  M. Baskes,et al.  Semiempirical, Quantum Mechanical Calculation of Hydrogen Embrittlement in Metals , 1983 .

[40]  K. Cheng,et al.  An investigation on the mechanics of nanometric cutting and the development of its test-bed , 2003 .

[41]  N. Chandrasekaran,et al.  Molecular dynamic simulations of uniaxial tension at nanoscale of semiconductor materials for micro-electro-mechanical systems (MEMS) applications , 2003 .

[42]  Structure and conductance histogram of atomic-sized Au contacts , 2004, cond-mat/0406281.

[43]  Tu,et al.  Diffusivity and solubility of Ni (63Ni) in monocrystalline Si. , 1989, Physical review. B, Condensed matter.

[44]  Yoshitada Isono,et al.  Three-Dimensional Molecular Dynamics Simulation of Atomic Scale Precision Processing Using a Pin Tool. , 1997 .

[45]  Jee-Gong Chang,et al.  Molecular dynamics simulation of nano-lithography process using atomic force microscopy , 2002 .

[46]  Zhen Chen,et al.  An investigation of the combined size and rate effects on the mechanical responses of FCC metals , 2007 .

[47]  David L. McDowell,et al.  Design of experiments for constitutive model selection: application to polycrystal elastoviscoplasticity , 1999 .

[48]  Ranga Komanduri,et al.  The significance of normal rake in oblique machining , 2004 .

[49]  Mark F. Horstemeyer,et al.  A large deformation atomistic study examining crystal orientation effects on the stress–strain relationship , 2002 .

[50]  Martin L. Dunn,et al.  Atomistic simulations of the yielding of gold nanowires , 2004 .

[51]  J. C. Hamilton,et al.  Surface step effects on nanoindentation. , 2001, Physical review letters.