Magnetostriction of Fe-Cr and Fe-Cr-B Alloys

The room temperature magnetostriction of polycrystalline Fe 100-x Cr x alloys annealed at 800 °C was investigated as a function of Cr content varying from 10 to 30 at.% Cr. All alloys exhibited a single bcc α-Fe-Cr phase with a disordered A2 structure. With increasing Cr concentration, the grain shape became very elongated. The greatest total magnetostriction value of 70 × 10 -6 was obtained in the direction of the elongated grains for 30% of Cr. We also investigated the effect of B addition on the magnetostriction and structural properties of the alloy Fe 80 Cr 20 . Although the addition of B was expected to form the Fe 2 B phase, the B-added Fe-Cr alloy forms a ternary phase (Fe z Cr 1-z ) 2 B (0