Stability maps to predict anomalous ductility in B2 materials
Name
Sun-2013-Stability maps to predict.pdf
Size
535.53 KB
Format
Adobe PDF
Checksum (MD5)
b65134487f8646769c8b7db7a18f11bb
Author(s)
Sun, Ruoshi
Johnson, D.
Date Issued
March 2013
Journal
Physical Review B
Publisher
American Physical Society
Citation
Sun, Ruoshi, and D. Johnson. “Stability Maps to Predict Anomalous Ductility in B2 Materials.” Phys. Rev. B 87, no. 10 (March 2013). © 2013 American Physical Society
Version
Final published version
Abstract
While most B2 materials are brittle, a new class of B2 (rare-earth) intermetallic compounds is observed to have large ductility. We analytically derive a necessary condition for ductility (dislocation motion) involving ⟨111⟩ versus ⟨001⟩ slip and the relative stability of various planar defects that must form. We present a sufficient condition for antiphase boundary bistability on {1[bar over 1]0} and {11[bar over 2]} planes that allows multiple slip systems. From these energy-based criteria, we construct two stability maps for B2 ductility that use only dimensionless ratios of elastic constants and defect energies, calculated via density functional theory. These two conditions fully explain and predict enhanced ductility (or lack thereof) for B2 systems. In the 23 systems studied, the ductility of YAg, ScAg, ScAu, and ScPd, ductile-to-brittle crossover for other rare-earth B2 compounds, and brittleness of all classic B2 alloys and ionic compounds are correctly predicted.
MIT Department
Massachusetts Institute of Technology. Department of Materials Science and Engineering
Terms of Use
Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use.
Persistent DSpace Link
DOI of Published Version
https://doi.org/10.1103/PhysRevB.87.104107
