Alnico 5磁石の時効過程における磁気特性の変化

抄録

It has been found recently that Alnico 5 under goes a reversible change in magnetic properties during aging processes. The analysis of this phenomenon is our purpose. The results of our magnetic measurement are summarized as follows: (1) The changes in magnetic proprety due to aging in the temperature range from 590° to 640°C are almost reversible. By aging above about 650°C, the reversibility is gradually lost with the rise of the aging temperature. (2) Changes in the coercive force as well as the maximum energy product as a function of aging temperature show an inclination similar to each other for specimens heat-treated with and without magnetic field, but changes in residual induction for these treatments are different in the two specimens. (3) The ratio of residual to saturation induction shows also different temperature dependence for specimens heat-treated with and without magnetic field. These phenomena should be noted, because they may have some relation with the mechanisms of the single domain magnetization.