Abstract
Magnetotsrictive materias are potential in micro electro - mechanical system (MEMS) because of the transfer of electromagnetic energy to mechanical energy. Increasing magnetostriction (λ) at low magnetic field is the main objective of this study. Tb0.3Dy0.7Fe2 (Terfenol - D) being well - known for its giant saturation magnetostriction (λs), therefor was chosen as the base alloy. Different amount of berylium, copper and niobium was added into Terfenol - D to substitute for iron as Tb0.3 Dy0.7 (Fe1-xBex)2、Tb0.3Dy0.7 (Fe1-xCux)2、Tb0.3Dy0.7 (Fe1-xNbx)2 (x = 0.1 ~ 0.5). The effect of substitution elements on magnetic properties of Terfenol - D alloy was studied. The experimental results show that a small amount of be substitution can improve greatly the λ value at low field. When the Be addition is 6.66 at.%, the λ increases from 13.3 ppm to 73.8 ppm at the field of 0.05T, and the σ increases from 1031 ppm to 1235 ppm at the field of 2T. Saturation magnetization (σs) and Curie temperature (Tc) decrease with increasing Be, s decreases from 82.95 emu / g to 70.4 emu / g (13.66 at.% Be); Tc decreases from 379℃ to 372℃. While the remanent magnetization σr and the coercivity Hc increase with Be. The addition of Cu and Nb are harmful for magnetic and mechanical properties. The λ and σs continuously decrease with increasing addition.