Effect of ordering energy and stoichiometry in {Sigma} = 5 boundaries in B2 compounds

Journal Article · Sun Nov 01 04:00:00 EST 1998 · Metallurgical and Materials Transactions. A, Physical Metallurgy and Materials Science

DOI:https://doi.org/10.1007/s11661-998-0306-8· OSTI ID:290264

Mutasa, B; Farkas, D ^[1]

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1. Virginia Polytechnic Inst. and State Univ., Blacksburg, VA (United States). Dept. of Materials Science and Engineering

The relaxed atomistic grain boundary structures in B2 aluminides were investigated using molecular statics and embedded atom potentials in order to explore general trends for a series of B2 compounds. The authors studied free surface energies and grain boundary structures in three compounds: FeAl, NiAl and CoAl. These alloys represent a series of materials with increasing antiphase boundary energies. The misorientations chosen for detailed study correspond to the {Sigma}5(31) and {Sigma}5(210) symmetrical tilt grain boundaries. The effects of both boundary stoichiometry and bulk simulation block stoichiometry on grain boundary energetics were investigated in detail. The structures obtained for the three alloys are very similar. Defect energies were calculated for boundaries contained in both stoichiometric and off-stoichiometric bulks. The surface energies for these B2 aluminides were also calculated so that trends concerning the cohesive energy of the boundaries could be studied. The implications of the increasing ordering energy, stoichiometry, and multiplicity of possible structures for grain boundary brittleness are discussed.

• Sponsoring Organization: USDOE
• OSTI ID: 290264
• Journal Information: Metallurgical and Materials Transactions. A, Physical Metallurgy and Materials Science, Journal Name: Metallurgical and Materials Transactions. A, Physical Metallurgy and Materials Science Journal Issue: 11 Vol. 29; ISSN 1073-5623; ISSN MMTAEB
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM ALLOYS
COBALT ALLOYS
GRAIN BOUNDARIES
GRAIN ORIENTATION
INTERMETALLIC COMPOUNDS
IRON ALLOYS
NICKEL ALLOYS
SIMULATION
STOICHIOMETRY
SURFACE ENERGY