Accession Number:

ADA127545

Title:

Computer-Simulation Studies of Grain Boundary Systems and Molecular Solids.

Descriptive Note:

Final rept. 1 Jan 78-31 Jan 83,

Corporate Author:

MASSACHUSETTS INST OF TECH CAMBRIDGE

Personal Author(s):

Report Date:

1983-04-20

Pagination or Media Count:

11.0

Abstract:

Structural, thermodynamic and mechanical properties of bicrystals have been studied using molecular dynamics and Monte Carlo simulation. A grain boundary melting transition in a two-dimensional system has been observed. Atomic diffusion along grain boundaries was investigated by following in detail the migration of a vacancy initially introduced into the bicrystal. The activation energy for vacancy migration in iron has been determined, and thermal activation of Frenkel pairs in the grain boundary core was observed. Structural phase transformation in stressed solids has been studied using an extended Monte Carlo method. Stress-strain relations obtained for iron showed the existence of bcc - fcc transition under tension or compression. Dynamical properties of a one-dimensional nonlinear lattice the U4-lattice have been analyzed in terms of kink propagation and damping and kink diffusion. Both perturbation theory and molecular dynamic calculations were carried out. Author

Subject Categories:

  • Numerical Mathematics
  • Crystallography
  • Nuclear Physics and Elementary Particle Physics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE