2018 年 26 巻 1 号 p. 250-255
Co-rich Fe-Co alloy with Co content of 66~75at% is known to have the potential of large saturation magnetostriction, high Curie temperature, high strength and good mechanical workability, however, its properties of thin plate and fine fiber below 1mm thickness remain unknown. Therefore, microstructure, magnetization and magnetostriction of the rolled Fe30Co70 alloy thin plate of 0.05mm in thickness were investigated. Crystalline microstructure becomes very fine and complicated due to the heavily deformation by the rolling process repeated many times at room temperature. Those morphology changes were investigated by the profile figures of XRD and SEM-EBSD/OIM analyses. The increases of magnetostriction value and its sensitivity were confirmed especially in the cold-rolled and subsequently annealed alloy plates. On the other hand, the coercive force decreased by decreasing the internal defects such as residual stress, dislocation density. These results will become useful for small magnetostrictive stress sensor and vibration energy harvesting device in considering of magnetostrictive composite materials for infra-structure health monitoring (SHM).
