2008 NSTI Nanotechnology Conference and Trade Show - Nanotech 2008 - 11th Annual

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Clean Technology 2008

The Research of the Influence of Point Defects on Structural Reconstruction near Grain Boundaries of Tilt in Ni3Al Alloy

M.D. Starostenkov, G.M. Poletaev, R.Yu. Rakitin
Altay State Technical University, RU

Keywords:
defect, grain boundary, intermetallide

Abstract:
The influence of point defects – vacancies and interstitial atoms on structural reconstruction near grain boundaries of tilt in Ni3Al intermetallide was studied by the method of molecular dynamics. The grain boundaries were considered in the dependence on the concentration of point defects. The calculated block of the bicrystal contained 24x10^3 atoms. Periodical boundary conditions were applied outside the block. The bicrystal was heated impulsively at the temperature 1200 during 200 ps. The concentration of point defects was chosen on the condition of preservation of composition stoichiometry of Ni3Al alloy. It was not noticed any considerable effect of point defects interaction with grain boundaries in all cases at different concentration of vacancies. At the same time, both types of point defects influenced on the mechanisms of grain boundary reconstruction, displacingthem to the area of low temperature. The effects of aggregatization of point defects into complexes were observed in the limits of volume parts of the bicrystal. The complexes were formed from interstitial atom as tetrahedrons or crowdion accumulations. All types and mechanisms of migration caused the break of short order as in the volume of the bicrystal so near grain boundaries.


Nanotech 2008 Conference Program Abstract