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Article
Stability maps to predict anomalous ductility in B2 materials
Physical Review B
  • Ruoshi Sun, University of Illinois at Urbana-Champaign
  • Duane D. Johnson, Iowa State University
Document Type
Article
Publication Version
Published Version
Publication Date
3-1-2013
DOI
10.1103/PhysRevB.87.104107
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 {11¯0} and {112¯} 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.

Comments

This article is from Phys. Rev. B 87, 104107 (2013), doi:10.1103/PhysRevB.87.104107. Posted with permission.

Copyright Owner
American Physical Society
Language
en
File Format
application/pdf
Citation Information
Ruoshi Sun and Duane D. Johnson. "Stability maps to predict anomalous ductility in B2 materials" Physical Review B Vol. 87 Iss. 10 (2013) p. 104107
Available at: http://works.bepress.com/duane_johnson/30/