Magnetic Annealing of “Ticonal” G Magnet Steel

Abstract

A study was made of magnetic anisotropy and interparticle distance in “Ticonal” G (a dispersion-hardening permanent-magnet alloy) when subjected to heat treatment in a magnetic field. The experimental results agree with a theoretical model in which the precipitate particles are idealized to prolate spheriods which decrease their interfacial free energy by coarsening and their magnetostatic free energy by elongation. It is concluded that the response to thermomagnetic treatment increases with the ratio between the magnetostatic free energy and the interfacial free energy. The interface tension of “Ticonal” G is found to be extremely low, of the order of 1 erg cm−2at the annealing temperature.