Magnetomechanical Behavior of Terfenol-D Particulate Composites

A structural composite is defined as a material consisting of two or more phases on a macroscopic scale. The properties of the composite material are improved from the properties of the constituent phases acting alone. Typically, a structural composite consists of a reinforcement phase, a matrix phase, and an interphase or interface. The reinforcement phase is usually stiffer and stronger and takes the form of particulates or fibers. The matrix could be a ceramic, a metal, or a polymer. One of the first documented uses of structural composites is straw reinforced clay bricks in ancient Egypt 6. This thesis investigates the magnetomechanical behavior of Terfenol-D particulate composites. Terfenol-D is a magnetostrictive material. By grinding the material into small particles, the powder is easily mixed into a polymer resin during manufacture of the composite. Once the resin is cured, the composite material has self-assessing capabilities since the magnetostrictive particles respond to changes in the stress state.