Mechanism of Void Nucleation and Growth in bcc Fe: Atomistic Simulations Experimental Time Scales

Evolution of small-vacancy clusters in bcc Fe is simulated using a multiscale approach coupling an atomistic activation-relaxation method for sampling transition-state pathways with environment-dependent reaction coordinate calculations and a kinetic Monte Carlo simulation to reach time scales on th...

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Bibliographic Details
Main Authors: Fan, Yue, Kushima, Akihiro, Yip, Sidney, Yildiz, Bilge
Other Authors: Massachusetts Institute of Technology. Department of Nuclear Science and Engineering
Format: Article
Language:en_US
Published: American Physical Society 2011
Online Access:http://hdl.handle.net/1721.1/65864
https://orcid.org/0000-0002-2688-5666
https://orcid.org/0000-0002-2727-0137
Description
Summary:Evolution of small-vacancy clusters in bcc Fe is simulated using a multiscale approach coupling an atomistic activation-relaxation method for sampling transition-state pathways with environment-dependent reaction coordinate calculations and a kinetic Monte Carlo simulation to reach time scales on the order of ~10[superscript 4]  s. Under vacancy-supersaturated condition, di- and trivacancy clusters form and grow by coalescence (Ostwald ripening). For cluster size greater than four we find a transition temperature of 150 °C for accelerated cluster growth, as observed in positron annihilation spectroscopy experiments. Implications for the mechanism of stage-IV radiation-damage-recovery kinetics are discussed.