Enhanced magnetostrictive and magnetic properties in (Fe81Ga19)99.8Tb0.1(NbC)0.1 rolled sheets via Tb supersaturation within A2 matrix and a sharp Goss texture achieved by secondary recrystallization

Magnetostrictive Fe–Ga alloy sheets have significant application prospects in fields such as drives and sensors due to their ability to greatly reduce eddy current losses during high-frequency applications and enhance magneto-mechanical conversion efficiency. However, enhancing the magnetostriction of Fe–Ga alloy sheets still poses challenges. In this work, the (Fe81Ga19)99.8Tb0.1(NbC)0.1 alloy sheets were prepared by conventional rolling processes. The magnetostriction strain (λ//) as large as 320 ppm along rolling direction in stress-free condition was achieved. The evolution of texture during rolling deformation and continuous annealing processes was systematically studied, and the effects of Tb-rich precipitates and NbC on texture evolution and secondary recrystallization were analyzed. The pinning effect of precipitates on the primary recrystallized grains induced the abnormal growth of Goss grains and promoted the secondary recrystallization. The high-temperature annealing at 1200 °C followed by salt-water quenching promoted the solid solution of Tb atoms in the A2 matrix. The 3D-APT results shown that the solid solution of Tb atoms as high as 0.102 at. % was achieved in the A2 matrix vicinity of the Tb-rich precipitates, which increased the L60 nanoheterogeneities in the Goss textured sheets. The Goss texture and more nano-heterogeneous structures lead to the improvement in magnetostriction. The Goss textured sheets also exhibited excellent soft magnetic properties with Ms ∼200.5 emu/g and Hc ∼0.42 kA/m. This study demonstrates that a well-designed alloy composition and preparation processes could achieve the desired texture and Tb supersaturation in the Fe–Ga rolled sheets, which leads to the improved magnetostrictive and magnetic properties.