Uniaxial magnetic anisotropy of Elinvar alloy

The uniaxial magnetic anisotropies (U.M.A.) of cold-rolled and aged strips of the iron based 42NiCrNb Elinvar alloy have been investigated by the magnetic torque method. It has been found that the U.M.A. does not exsit in the cold-rolled strips. However, the U.M.A. have been clearly observed in the aged strips tempered at temperatures higher than 200°C. The anisotropy reached a maximum of erg/cc when the sample was tempered at 750°c. It has been shown that the easy axis of the magnetization is normal to the roll direction. The origin of the aging U.M.A. is discussed in terms of the form of the dispersion hardening phase, and the experimental results of the electric resistance and the magnetic properties.