INVESTIGATION OF METAL AND CERAMIC-MATRIX COMPOSITES MODULI - EXPERIMENT AND THEORY

The elastic behavior of metal and ceramic-matrix composites were chara cterized by ultrasonic techniques. While an immersion ultrasonic techn ique was used to measure the stiffness moduli of silicon carbide (SiC) particulate reinforced aluminium metal-matrix composites, a dry-coupl ing method was used to determine the elastic constants of woven Nicalo n(TM) fiber reinforced SiC ceramic-matrix composites. A unified microm echanics model was developed to predict the elastic moduli of these co mposites from the knowledge of their constituent elastic constants. Th e model quantitatively predicted the effects of microstructural charac teristics, such as the reinforcement content and porosity in the mater ial, on the elastic moduli of the composite systems studied. The predi cted moduli were in good agreement with the experimental results for b oth the particulate reinforced metal-matrix composites and woven fiber reinforced ceramic-matrix composites.