Deformation-induced anisotropic Cr-Co-Fe permanent magnet alloys

A series of new anisotropic magnet alloys has been developed in low-cobalt (5 - 11.5wt%) ternary Cr-Co-Fe system using a new "deformation-aging" technique that induces a strong magnetic anisotropy (Br/Bs ∼ 0.99) without magnetic field heat treatment. The prerequisite condition for the deformation-aging is a micro-structure consisting of essentially spherical particles which are then physically elongated by deformation. The new technique eliminates the compositional requirements in magnetic field aging that the Curie temperature be close to, but above, the spinodal temperature for effective particle alignment. Excellent magnet properties of (BH)max = 2 - 6 MG.Oe are obtained. Potential applications of these ductile, low-cobalt magnets include a substitution of high cobalt Alnico and Vicalloy magnets.