Modified embedded atom method calculations for reconstructed (110) surfaces of face-centered cubic metals

The voids in pure Aluminum always exit in the manufacturing process. The Modified Embedded Atom Method (MEAM) potential is employed in the molecular dynamics (MD) simulation at atomic scale to investigate the interaction between voids under the impact loading for pure Aluminum. The distance between the voids distributed along the loading orientation affects the failure mechanism seriously. The results show that there are 3 kinds of mechanisms with the change of the distance between voids: 1) coalescence takes place within a critical distance between voids under extra loading, 2) when the distance between voids reaches a certain value, each void cracks at 4 locations along with the slide direction <110> of face-centered cubic (fcc), respectively, 3) a stress shield zone appears when the ligament between the voids is at the size between the cases mentioned above, which brings out the phenomena that each of the voids cracks only at 2 locations, and no crack appeared at the stress shield zone.

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Simulation of Void Growth at High Strain-Rate

MRS Proceedings ◽

10.1557/proc-539-257 ◽

1998 ◽

Vol 539 ◽

Cited By ~ 6

Author(s):

J. Belak ◽

R. Minich

Keyword(s):

Molecular Dynamics ◽

Perfect Crystal ◽

Dislocation Nucleation ◽

Growth Exponent ◽

Face Centered Cubic ◽

Dynamics Modeling ◽

Cubic Metals ◽

Embedded Atom ◽

Molecular Dynamics Modeling ◽

Face Centered

AbstractThe dynamic fracture (spallation) of ductile metals is known to initiate through the nucleation and growth of microscopic voids. Here, we apply atomistic molecular dynamics modeling to the early growth of nanoscale (2nm radius) voids in face centered cubic metals using embedded atom potential models. The voids grow through anisotropic dislocation nucleation and emission into a cuboidal shape in agreement with experiment. The mechanism of this nucleation process is presented. The resulting viscous growth exponent at late times is about three times larger than expected from experiment for microscale voids, suggesting either a length scale dependence or a inadequacy of the molecular dynamics model such as the perfect crystal surrounding the void.

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Mechanical stability and strength of a single Au crystal

Canadian Journal of Physics ◽

10.1139/p08-025 ◽

2008 ◽

Vol 86 (7) ◽

pp. 935-941 ◽

Cited By ~ 6

Author(s):

J -M Zhang ◽

Y Yang ◽

K -W Xu ◽

V Ji

Keyword(s):

Mechanical Stability ◽

Energy Difference ◽

Theoretical Strength ◽

Stable Region ◽

Embedded Atom Method ◽

Face Centered Cubic ◽

Embedded Atom ◽

Free Body ◽

Face Centered ◽

Bcc Phase

The structural stability and theoretical strength of a Au face-centered cubic (FCC) crystal under uniaxial loading is investigated by combining the modified analytical embedded atom method (MAEAM) with Born stability criteria. The results show that under sufficient compression, there exists a stress-free body-centered cubic (BCC) phase, which is unstable and slips spontaneously to a stress-free metastable body-centered tetragonal phase by consuming internal energy. The structural energy difference between the BCC and FCC phases is in good agreement with the experimental value. The stable region ranged from –2.21 GPa to 6.31 GPa in the theoretical strength or from –9.83% to 7.87% in the strain correspondingly.PACS Nos.: 62.20.–x, 61.50.Ks, 81.05.Bx

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INFLUENCE OF PRESSURE AND ATOMIC CONCENTRATION ON STRUCTURE AND MECHANICAL PROPERTIES OF CuNi ALLOY BY MOLECULAR DYNAMICS SIMULATION

Journal of Science Natural Science ◽

10.18173/2354-1059.2020-0029 ◽

2020 ◽

Vol 65 (6) ◽

pp. 54-60

Author(s):

Thao Nguyen Thi ◽

Hang Trinh Thi Thu

Keyword(s):

Mechanical Properties ◽

Dynamics Simulation ◽

Embedded Atom Method ◽

Face Centered Cubic ◽

Atomic Concentration ◽

Common Neighbor ◽

Hexagonal Close Packed ◽

Embedded Atom ◽

The Common ◽

Face Centered

The structure and mechanical properties of Cu80Ni20 and Cu50Ni50 alloys with the size of 4000 atoms have been investigated using molecular dynamic (MD) simulation. The interactions between atoms of the system were calculated by the Sutton-Chen type of embedded atom method. Using a cooling rate of 0.01 K\ps, we find that both Ni and Cu atoms are crystallized into face centered cubic (fcc) and the hexagonal close packed (hcp) phases when the sample was cooled down to 300 K. The atomic concentration of CuNi alloy samples have a different effect on this crystallization. The transformation to the crystalline phase is analyzed through the Common Neighbor Analysis (CNA) methods. Furthermore, we focus on the dependence of the mechanical properties of CuNi alloy on pressure and atomic concentration

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Analytic embedded atom method potentials for face-centered cubic metals

Journal of Materials Research ◽

10.1557/jmr.1998.0271 ◽

1998 ◽

Vol 13 (7) ◽

pp. 1919-1927 ◽

Cited By ~ 13

Author(s):

S. S. Pohlong ◽

P. N. Ram

Keyword(s):

Reasonable Agreement ◽

Mean Square Displacement ◽

Pair Potential ◽

Embedded Atom Method ◽

Face Centered Cubic ◽

Embedded Atom ◽

Phonon Spectra ◽

Morse Form ◽

Face Centered ◽

Experimental Values

The universal form of embedding function suggested by Banerjea and Smith together with a pair-potential of the Morse form are used to obtain embedded atom method (EAM) potentials for fcc metals: Cu, Ag, Au, Ni, Pd, and Pt. The potential parameters are determined by fitting to the Cauchy pressure (C12 − C44)/2, shear constant GV = (C11 − C12 + 3C44)/5, and C44, the cohesive energy and the vacancy formation energy. The obtained parameters are utilized to calculate the unrelaxed divacancy binding energy and the unrelaxed surface energies of three low-index planes. The calculated quantities are in reasonable agreement with the experimental values except perhaps the divacancy energy in a few cases. In a further application, lattice dynamics of these metals are discussed using the present EAM potentials. On comparison with experimental phonons, the agreement is good for Cu, Ag, and Ni, while in the other three metals, Au, Pd, and Pt, the agreement is not so good. The phonon spectra are in reasonable agreement with the earlier calculations. The frequency spectrum and the mean square displacement of an atom in Cu are in agreement with the experiment and other calculated results.

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Voids in Irradiated Tungsten and Molybdenum

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100062865 ◽

1969 ◽

Vol 27 ◽

pp. 190-191

Author(s):

Robert C. Rau ◽

Robert L. Ladd

Keyword(s):

Melting Point ◽

Fast Neutron ◽

Neutron Irradiation ◽

Elevated Temperatures ◽

Irradiation Temperature ◽

The Body ◽

Face Centered Cubic ◽

Body Centered Cubic ◽

Cubic Metals ◽

Face Centered

Recent studies have shown the presence of voids in several face-centered cubic metals after neutron irradiation at elevated temperatures. These voids were found when the irradiation temperature was above 0.3 Tm where Tm is the absolute melting point, and were ascribed to the agglomeration of lattice vacancies resulting from fast neutron generated displacement cascades. The present paper reports the existence of similar voids in the body-centered cubic metals tungsten and molybdenum.

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