Magnetostriction of Fe-Cr-Co alloys

The room temperature linear saturation magnetostriction (λs) and saturation magnetization per gram (σs) were measured on polycrystalline samples of alloys containing from 30 wt% to 50 wt% chromium and up to 25 wt% cobalt. The data show that all the λsare positive and that both λsand σsdecrease with increasing chromium concentration. However, as the cobalt concentration is increased λsdisplays an anomalous behavior at around 15 wt% cobalt. The room temperature λsand σswere also measured on a spinodally decomposed sample of the alloy with the composition 28 wt% Cr-10.5 wt% Co-Bal.Fe. In a spinodally decomposed material λsand σswill be the average λsand σsof the two phases present in the material. A fair agreement was found between the measured and the calculated λsand σsfor the spinodally decomposed alloy indicating that the proposed compositions for the two phases are consistent with the magnetic measurements.