Sharp Goss orientation and large magnetostriction in the rolled columnar-grained Fe-Ga alloys

In this work, the (1 0 0; directional solidified feedstock slabs were used to produce the rolled Fe-Ga sheets, and sharp Goss orientation was developed in the 0.3 mm sheets after annealing processes. The area fraction of Goss grains in the annealed binary Fe-Ga sheets approached to 62.4% without abnormal grain growth, accompanied with a maximum magnetostriction (lambda(parallel to) - lambda(perpendicular to)) of 199 ppm. The addition of only 0.1 at% NbC notably promoted the abnormal Goss grain growth without sulfur annealing, and large single-crystal-like grains, up to several centimeters, were obtained with few island-like grains after sulfur annealing and final Ar/H-2 annealing processes. High magnetostriction (lambda(parallel to) - lambda) of 245 ppm with little deviation was achieved in the (Fe83Ga17)(99.9)(NbC)(0.1) sheets, and a large magnetostrictive strain (lambda(parallel to)) up to 243 ppm under no pre-stress was observed with an applied magnetic field along the rolling direction, K. (C) 2014 Elsevier B.V. All rights reserved.