Saturation and Engineering Magnetostriction of an Iron-Base Amorphous Alloy for Power Applications

• Published in: Journal of applied physics Vol. 55; no. 6-IIA; pp. 1784 - 1786
• Main Authors: Datta, A, Nathasingh, D M, Martis, R J, Flanders, P J, Graham, C D
• Format: Journal Article
• Language: English
• Published: 08.11.1983
• ISSN: 0021-8979

The saturation magnetostriction ( lambda sub s ) of a ferromagnetic material is measured by determining the strain that occurs when the saturation magnetization vector is rotated through 90 deg C. However, the magnetostrictive strain responsible for transformer noise is the net strain measured parallel to the applied field when the material is magnetized from the demagnetized state. Because of its engineering significance, it is proposed that this net strain measured parallel to the applied field be called the engineering magnetostriction ( lambda sub e ). The value of lambda sub e depends on the domain structure both in the demagnetized and magnetized states whereas lambda sub s is an intrinsic property of the material. The lambda sub e for an Fe-base amorphous alloy, Metglas 2605S2, is measured as a function of the direction of the field-induced anisotropy using a piezoelectric transducer. Although Metglas 2605S2 has a high value of lambda sub s ( approx 27 x 10 exp --6 ), the value of lambda sub e in the longitudinal field annealed condition is found to be nearly zero. The magnitude of lambda sub e measured on a prototype transformer core is also discussed. 10 ref.--AA