Method of increasing the coercive force of pulverized rare earth-cobalt alloys
AssigneeTh. Goldschmidt AG
InventorsEkkehard Greinacher, Klaus Reinhardt, Karl Strnat
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Abstract
The coercive force of pulverized selected rare earth-cobalt alloys is increased or maintained at least at its initial value by depositing tin on the surface of the alloy particles and subjecting the particles to a heat treatment so as to cause diffusion of the tin into the particle structure. Permanent magnets formed from tin enriched rare earth-cobalt alloy particles are also disclosed.
Claims11
A method of maintaining the coercive force of particulate rare earth-cobalt alloys at least at its initial value, which comprises enveloping substantially each alloy particle with a layer of solid tin and then heating the enveloped particles to a temperature sufficiently high so as to cause diffusion of tin into the particle structure.
A method of maintaining the coercive force of particulate rare earth-cobalt alloys at least at its initial value, said rare earth-cobalt alloy consisting essentially of a first rare earth component being composed of one or several of Y, Sc, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu and a second component consisting essentially of cobalt alone or cobalt in mixture with at least one of Mn, Fe, Ni or Cu, the ratio of rare earth component to the second component being about 10-25 atomic percent to 75-90 atomic percent, which comprises depositing tin on the surface of the alloy particles to envelope substantially each particle with a substantially continuous layer of tin and then heating the enveloped alloy particles to a temperature sufficiently high so as to cause diffusion of tin into the particle structure.
Dependencies are inferred from the claim text.