Thermal, mechanical, and electroelastic behavior of composite materials

Thesis/Dissertation · Wed Jan 01 04:00:00 EST 1992

OSTI ID:6837902

Dunn, M L

A unified analytical approach is developed to predict the effective behavior of composite materials for electronic applications. The target applications are materials for electronic packaging and electromechanical transducers where the material properties of interest are the effective thermal expansion coefficients, thermal conductivity, dielectric constant, and the couples electroelastic behavior. The analytical approach that is forwarded is based on the equivalent inclusion method of Eshelby (1957) extended to finite reinforcement concentrations through the Mori-Tanaka (1973) mean field approach. In addition to the effects of the material properties of the constituents, the effects of the volume fraction, shape, and orientation distribution of the reinforcing phase are considered. Through this approach, internal stresses generated due to the mismatch in thermal expansion coefficients of the constituents of a composite material are studied. Thermal expansion coefficients and time dependent creep deformations under a constant applied stress are analyzed. Analytical predictions of the proposed model are seen to be in good agreement with measured results of a multiphase Al2O3/Si3N4/Kerimid composite. The Mori-Tanaka mean field approach is also utilized to study the effective physical properties, modeled by Laplace's equation, of composite materials. Particular attention is devoted to microdamaged composites containing porosity or microcracks in the matrix and composites with coated reinforcement. Analytical predictions are shown to be in good agreement with measured results of the effective thermal conductivity for a multiphase Al2O3/Si3N4/Kerimid composite. Finally, the rigorous analytical solution for the couples electroelastic behavior of piezoelectric inclusions (Deeg, 1980) is utilized to derive the constraint tensors for an ellipsoidal piezoelectric inclusion in a infinite matrix.

• Research Organization: Washington Univ., Seattle, WA (United States)
• OSTI ID: 6837902
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360603 -- Materials-- Properties
360606* -- Other Materials-- Physical Properties-- (1992-)
ALUMINIUM COMPOUNDS
BEHAVIOR
COATINGS
COMPOSITE MATERIALS
CREEP
DEFORMATION
DIELECTRIC PROPERTIES
DISTRIBUTION
ELECTRICAL PROPERTIES
ELECTROMECHANICS
EXPANSION
FIBERS
INCLUSIONS
MATERIALS
MECHANICAL PROPERTIES
MECHANICS
NITRIDES
NITROGEN COMPOUNDS
ORIENTATION
PERMITTIVITY
PHYSICAL PROPERTIES
PNICTIDES
POROSITY
REINFORCED MATERIALS
SILICON COMPOUNDS
SILICON NITRIDES
STRESSES
TEMPERATURE EFFECTS
TENSORS
THERMAL CONDUCTIVITY
THERMAL EXPANSION
THERMODYNAMIC PROPERTIES
TRANSDUCERS