Structurally-induced elastic anomalies in a superlattice of (001) twist grain boundaries

Journal Article · Wed Nov 01 00:00:00 EST 1989 · Journal of Materials Research; (USA)

DOI:https://doi.org/10.1557/JMR.1989.1427· OSTI ID:5153071

Wolf, D; Lutsko, J F ^[1]

---

1. Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439 (US)

It is suggested that the supermodulus effect'' observed for composition-modulated strained-layer superlattices may arise from the presence of the structurally disordered solid interfaces and not necessarily from electronic structure effects. The latter are excluded by investigating the elastic properties of a so-called grain-boundary superlattice in which chemically identical materials are joined to form a three-dimensional superlattice. Both an embedded-atom-method and Lennard-Jones potential are employed in our zero-temperature atomistic calculations of the elastic constants and moduli of such a superlattice. They yield qualitatively similar results which, for large modulation wave lengths, can be represented by a mean-field model in which the interfacial regions are characterized by a set of effective elastic constants which are different from those of the bulk regions. The appearance of a maximum in the biaxial modulus and a minimum in the shear modulus is shown to arise from the interaction between interfaces. It is also shown that such extreme anomalies appear only in the moduli but not in the elastic constants of the grain-boundary superlattice.

• DOE Contract Number: W-31-109-ENG-38
• OSTI ID: 5153071
• Journal Information: Journal of Materials Research; (USA), Vol. 4:6; ISSN 0884-2914
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
SUPERLATTICES
ELASTICITY
CHEMICAL COMPOSITION
COMPOSITE MATERIALS
GRAIN BOUNDARIES
INTERFACES
LAYERS
MODULATION
ORDER-DISORDER TRANSFORMATIONS
STRAINS
CRYSTAL STRUCTURE
MATERIALS
MECHANICAL PROPERTIES
MICROSTRUCTURE
PHASE TRANSFORMATIONS
TENSILE PROPERTIES
360103* - Metals & Alloys- Mechanical Properties
360102 - Metals & Alloys- Structure & Phase Studies