Accession Number:

ADP012213

Title:

Nanoscale Compositional Changes Along Fast Ion Tracks in Equilibrium Solid Solutions: A Computer Simulation of Ultra-Fast Solidification and Thermomigration

Descriptive Note:

Corporate Author:

CENTRO ATOMICO BARILOCHE (ARGENTINA) INST BALSEIRO

Report Date:

2001-11-01

Pagination or Media Count:

6.0

Abstract:

Starting from two equilibrium solid solutions in the Au-Ni system, we analyze the change in composition due to a 400 eVA fast ion track simulated by molecular dynamics in the Embedded Atom approximation. We aim at determining the influence of the thermodynamic forces derived from the large thermal gradients and the rapid solidification across the solidus and liquidus on the motion of solute atoms. One dimensional gradients as well as analytic models are used to quantitatively determine the domains of influence of these forces. Evidence shows that the liquidus and solidus equilibrium solidification predicted by the phase diagram is not reached during the track. The solute concentration is mainly determined by the combined diffusion and thermomigration mechanisms in the liquid stage.

Subject Categories:

  • Physical Chemistry
  • Computer Programming and Software
  • Thermodynamics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE