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Numerical Analysis of Nanograin Collision by Classical Molecular Dyanmics.

DE2007917893

Publication Date	2007
Personal Author	Ohnishi, N.; Bringa, E. M.; Remington, B. A.; Gilmer, G.; Minich, R.
Page Count	6
Abstract	We have carried out atomistic simulations of grain-grain collisions for spherical grains of 1.4 and 4 nm radii, with relative velocities of 3.66.1 km/s and a number of impact parameters. Since the initial grains are crystallites without any pre-existing defects, grain shattering due to nucleation of cracks was not observed in our simulations. We find grain fusion in some events, but generally melting occurs, leading to nucleation, growth and linkage of voids in the melt, which then leads to production of small clusters. The size distribution does not obey a simple power law and can be considered as having four different regimes, where each regime can be fitted as a power law.
Keywords	Molecular dynamics Grain boundaries Collisions Velocity Crystal structure Nucleation Cracks Defects Numerical analysis Voids Production Clusters
Source Agency	Technical Information Center Oak Ridge Tennessee
Corporate Authors	Lawrence Livermore National Lab., CA.; Tohoku Univ., Sendai (Japan).; Osaka City Univ. (Japan).; Department of Energy, Washington, DC.; National Aeronautics and Space Administration, Moffett Field, CA. Ames
Supplemental Notes	Prepared in cooperation with Tohoku Univ., Sendai (Japan)., Osaka City Univ. (Japan). and National Aeronautics and Space Administration, Moffett Field, CA. Ames Research Center. Sponsored by Department of Energy, Washington, DC.
Document Type	Technical Report
NTIS Issue Number	200806

Numerical Analysis of Nanograin Collision by Classical Molecular Dyanmics.

Numerical Analysis of Nanograin Collision by Classical Molecular Dyanmics.
DE2007917893

Publication Date	2007
Personal Author	Ohnishi, N.; Bringa, E. M.; Remington, B. A.; Gilmer, G.; Minich, R.
Page Count	6
Abstract	We have carried out atomistic simulations of grain-grain collisions for spherical grains of 1.4 and 4 nm radii, with relative velocities of 3.66.1 km/s and a number of impact parameters. Since the initial grains are crystallites without any pre-existing defects, grain shattering due to nucleation of cracks was not observed in our simulations. We find grain fusion in some events, but generally melting occurs, leading to nucleation, growth and linkage of voids in the melt, which then leads to production of small clusters. The size distribution does not obey a simple power law and can be considered as having four different regimes, where each regime can be fitted as a power law.
Keywords	Molecular dynamics Grain boundaries Collisions Velocity Crystal structure Nucleation Cracks Defects Numerical analysis Voids Production Clusters
Source Agency	Technical Information Center Oak Ridge Tennessee
Corporate Authors	Lawrence Livermore National Lab., CA.; Tohoku Univ., Sendai (Japan).; Osaka City Univ. (Japan).; Department of Energy, Washington, DC.; National Aeronautics and Space Administration, Moffett Field, CA. Ames
Supplemental Notes	Prepared in cooperation with Tohoku Univ., Sendai (Japan)., Osaka City Univ. (Japan). and National Aeronautics and Space Administration, Moffett Field, CA. Ames Research Center. Sponsored by Department of Energy, Washington, DC.
Document Type	Technical Report
NTIS Issue Number	200806