Title of article :
Computational study of the impurity induced reduction of grain boundary energies in nano- and bi-crystalline Al–Pb alloys
Author/Authors :
Purohit، نويسنده , , Y. and Sun، نويسنده , , L. and Irving، نويسنده , , D.L. and Scattergood، نويسنده , , R.O. and Brenner، نويسنده , , D.W.، نويسنده ,
Issue Information :
روزنامه با شماره پیاپی سال 2010
Pages :
7
From page :
1769
To page :
1775
Abstract :
Segregation of impurities with limited solubilities to grain boundaries can slow or even eliminate grain growth in nanocrystalline materials. Due to a very limited miscibility Pb is a potential candidate for thermodynamically stabilizing nanocrystalline Al. To investigate this we have used atomic modeling to characterize the structure and energy of substitutional Pb defects in bulk Al, in Al bi-crystals and in an Al nanocrystal. Monte Carlo simulations using a modified embedded-atom method (MEAM) potential fit to the results of density functional theory (DFT) calculations predict the formation of Pb clusters, in agreement with prior experiments. In addition, the simulations show strong segregation of Pb atoms to grain boundaries, a result that supports prior suggestions that Pb is distributed along grain boundaries in nanocrystals created by ball milling. Analysis of the enthalpies for Pb defects using MEAM and DFT calculations suggests that Pb impurities can help stabilize nanocrystalline Al against grain growth.
Keywords :
Nanostructure , AL , pb , Segregation , Grain boundary , Grain stabilization , Bi-crystal
Journal title :
MATERIALS SCIENCE & ENGINEERING: A
Serial Year :
2010
Journal title :
MATERIALS SCIENCE & ENGINEERING: A
Record number :
2161875
Link To Document :
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