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

Abstract

Starting from two equilibrium solid solutions in the Au-Ni system, we analyze the change in composition due to a 400 eV/A 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.

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Document Details

Document Type
Technical Report
Publication Date
Nov 01, 2001
Accession Number
ADP012213

Entities

People

  • Alfredo Caro
  • Edmundo M. Lopasso
  • Eduardo Ogando Arregui
  • Magdalena Caro

Tags

DTIC Thesaurus Topics

  • Alloys
  • Cells
  • Cold Regions
  • Computer Simulations
  • Diagrams
  • Equations
  • Liquid Phases
  • Molecular Dynamics
  • Nanocomposites
  • Phase
  • Phase Diagrams
  • Regions
  • Simulations
  • Solid Phases
  • Solid Solutions
  • Temperature Gradients
  • Three Dimensional

Fields of Study

  • Materials science

Readers

  • Computational Modeling and Simulation
  • Materials Science and Engineering.