33 巻 (2009) 5 号 p. 421-424
Giant magnetostrictive material (GMM) is fabricated by electromechanical transformation with large magnetostriction and an electro-mechanical coupling factor. Therefore, GMM can be use to make a giant magnetostrictive actuator. However, because the thermal expansion (linear expansion) coefficient of GMM is 12 ppm/°C, expansion and contraction due to temperature change influences the stroke. This paper describes the consideration of thermal expansion compensation for the GMA, and presents: (1) the features of GMM and the principles of operation of GMA, (2) the results of thermal expansion measurements of GMA, and (3) thermal expansion compensation for the tandem structure.