The Effects of the Uncertainty of Thermodynamic and Kinetic Properties on Nucleation and Evolution Kinetics of Cr-Rich Phase in Fe-Cr Alloys
Abstract
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 to/by 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 3{112 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.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 2012
- Accession Number
- AD1043117
Entities
People
- Fei Gao
- Mark Tschopp
- Xin Sun
Organizations
- United States Army Research Laboratory