The Effects of the Uncertainty of Thermodynamic and Kinetic Properties on Nucleation and Evolution Kinetics of Cr-Rich Phase in Fe-Cr Alloys
Technical Report,01 Aug 2009,30 Sep 2012
US Army Research Laboratory Aberdeen Proving Ground United States
Pagination or Media Count:
The objective of this research is to develop a framework capable of exploring uncertainty quantification due to atomic-level simulations in iron-chromium Fe-Cr systems, particularly associated with defect segregation in grain boundaries GBs. We have applied this approach to the interaction between point defects vacancies and self-interstitial atoms SIAs and elements with GBs in body-centered cubic BCC Fe, as an example, and then extended to Fe-helium He and Fe-Cr systems. The present results provide detailed information about the interaction energies of point defects and elements with symmetric tilt grain boundaries STGBs in Fe and the length scales involved with point defect absorption and element segregation toby GBs. In one example, both low and high angle GBs were found to be effective sinks for point defects, with a few low- GBs e.g., the 3112 twin boundary that have properties different from the rest. Additionally, the effect of GB energy, disorientation angle, and -designation on metrics proposed to evaluate the boundary sink strength was explored the strongest correlation occurred between the GB energy and the mean point defect formation energies. The significance of this research is in its applicability to quantifying, with some confidence, grain boundary interactions with defects and elements at the nanoscale.
- Metallurgy and Metallography