Abnormal (110) Grain Growth and Magnetostriction in Recrystallized Galfenol With Dispersed Niobium Carbide

The influence of high temperature annealing processes on abnormal grain growth in Galfenol (Fe 81 Ga 19 alloy plus 1 mol% NbC) sheet is examined in this paper. Results are presented on magnetostriction and grain orientation after rolling and annealing processes. Abnormal (110) grains grew to several millimeters after annealing at 1200degC. The grain orientation changed from a gamma -fiber texture and {100}lang011rang orientation in as-rolled sheet to close to a Goss texture {110}lang001rang in a sample annealed at 1200degC. This was accompanied by an increase in magnetostriction. The lang001rang easy axis (-20deg-off of the rolling direction) and a maximum magnetostriction of 183 ppm was observed in samples annealed at 1250degC. Annealing at a temperature of 1300 deg C produced a change in grain orientation to {111} < uvw > , Ga loss of as much as 2.8%, and a degradation in magnetostriction.