Abstract
Magnetostriction in isotropic Alnico magnet was studied by the of strain-gauge method. The results obtained were as follows: An increase in Co generally causes an increase in magnetostriction, except in some cases of heat-treatment. In the measurement of magnetostriction dependent upon Ni content for a basic material, an unusual change which was not correspondent to the change of magnetic properties was detected. The change of magnetostriction due to aging-treatment is not simple. However it is supposed from these results that there is in all probability another mechanism which was comfirmed for anisotropic magnet, Alnico 5, by the authors in the precipitation in isotropic Alnico magnet, too.
