Dislocation punching from interfaces in functionally-graded materials

Journal Article · Sun Jun 01 04:00:00 EDT 1997 · Acta Materialia

DOI:https://doi.org/10.1016/S1359-6454(96)00344-8· OSTI ID:514656

Taya, M; Lee, J K ^[1]; Mori, T ^[2]

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1. Univ. of Washington, Seattle, WA (United States). Dept. of Mechanical Engineering
2. Ryobi Ltd., Tokyo (Japan). Research and Development Div.

A new dislocation punching model for a functionally graded material (FGM) subjected to a temperature change is proposed, using Eshelby`s model. FGM, consisting of several layers, is deposited on a ceramic substrate. Two types of microstructures are examined for a layer: one consists of a metal matrix and ceramic particles and the other of a ceramic matrix and metal particles. An elastic energy is evaluated when plastic strain, in addition to thermal mismatch strain, is introduced in the metal phase. The work dissipated by the plastic deformation is also calculated. From the condition that the reduction in the elastic energy is larger than the work dissipated, a critical thermal mismatch strain to induce stress relaxation is determined. The magnitude of the plastic strain is also determined, when the relaxation occurs. The theory is applied to a model FGM consisting of mixtures of Pd and Al{sub 2}O{sub 3} on an Al{sub 2}O{sub 3} substrate.

• Sponsoring Organization: Department of the Air Force, Washington, DC (United States)
• OSTI ID: 514656
• Journal Information: Acta Materialia, Journal Name: Acta Materialia Journal Issue: 6 Vol. 45; ISSN 1359-6454; ISSN ACMAFD
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM OXIDES
CERAMICS
COMPOSITE MATERIALS
DISLOCATIONS
LAYERS
MATHEMATICAL MODELS
METALS
MICROSTRUCTURE
PALLADIUM
STRAINS
SUBSTRATES
THERMAL STRESSES