Fundamentals of Interfacial Strength in Composite Materials

Abstract : Research in the third program year has examined fatigue and toughness behavior of composites with 6061 and 7090 or 7191 alloy matrix material, with the goal being better understanding of relationships between microstructure and mechanical properties of these matrices with particulate SiC reinforcement. Tensile and Fatigue testing results, in air and in corrosive environments, of the various microstructures (i.e. aging conditions) chosen are presented, along with toughness results and finite-element studies to interpret the observed toughness levels. The strong microstructural dependence of mechanical properties is emphasized, along with possible avenues for improvement of these properties. (js)