This study's purpose is development of Fe-Ga Al (Galfenol) system alloy with large magnetostriction and high strength by precipitation hardening effect of the dispersed carbides for torque sensor system. Three kinds of composition bulk samples which added elements of Carbon, Zirconium, Niobium and Molybdenum to Fe-Ga Al alloy, (Fe-Ga_<0.15>-Al_<0.05>)_<99.0>-X_<0.5>-C_<0.5>(X=Zr, Nb, Mo) [at%], were prepared Those bulk samples were given heat treatment after the arc melting. Then, metallurgical characterization, the magnetic characteristic and strength property were studied. As a result (Fe-Ga_<0.15>-Al_<0.05>)_<99.0>-Zr_<0.5>-C_<0.5> [at%] arc melted and annealed sample showed a maximum magnetostriction of λ_<max>=90ppm and tensile stress σB=800MPa level, (Fe-Ga_<0.15>-Al_<0.05>)_<99.0>-Nb_<0.5>-C_<0.5> sample showed λ_<max>60ppm, σ_B=730MPa class, and (Fe-Ga_<0.15>-Al_<0.05>)_<99.0>-Mo_<0.5>-C_<0.5> sample showed λ_<max>=90ppm and tensile stress σ_B=780MPa level. As magnetostrictive alloy with high tensile strength like an 800MPa was not reported up to the present Those materials developed here have a potential of industrial applications such as torque sensor under severe environment.
