| Magnetostrictive Materials | |
| Overview | |
| Magnetostrictive materials are broadly defined as materials that undergo a change in shape due to change in the magnetization state of the material. Nearly all ferromagnetic materials exhibit a change in shape resulting from magnetization change. In most common materials, nickel, iron, and cobalt, the change in length is on the order of 10 parts per million (see figure at right). In addition, the change in volume is very small. Terfenol-D has become the preeminent magnetostrictive material, although research continues into new materials constantly. (...more) | |
| Current Research Projects | ||
| Damping Capacity of Terfenol-D Particulate Composites | ||
| Catherine Kerrigan | ||
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Particle orientation has a significant impact on composite properties due to anisotropy of magnetostriction in Terfenol-D. The importance of crystal orientation in Terfenol-D arises due to the large increase of magnetostriction along [111] directions as compared to [100] directions. For Terfenol-D, the constant that describes the magnitude of magnetostriction along the [111] direction, 111, is an order of magnitude larger than the constant that describes magnetostriction along [100] directions. Due to this effect, Terfenol-D is made commercially in a two-step process. First a polycrystalline block of material is prepared followed by a directional solidification step which textures the material along the [112] growth axis. Material produced in this way possesses improved magnetostriction over polycrystalline materials. The Goal of this research is to use this orientation effect to obtain improved magnetostriction performance from particulate composites. |
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| Magnetostrictive Particulate Composites | ||
| Nersesse Nersessian | ||
| The research involves manufacturing and characterizing magnetostrictive Terfenol-D and nickel particulate composites. Particles used are both commercially bought and spark eroded. Terfenol-D and nickel particles are spark eroded into spherical particles, and subsequently characterized using VSM, XRD, SEM and EDAX. Spherical particles are used to obtain preferential alignment in magnetostrictive composites, making single crystal behavior possible. | ![]() |
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| Previous Research Projects | |
| :: Meso-scale Actuator Device (MAD) | |
| :: Micro-Interlocking Strength Testing | |
| :: Magnetostrictive Composites | |
| :: Oriented Particulate Magnetostrictive Composites by Geoff McKnight | |