| 摘要 |
A RARE EARTH PERMANENT MAGNET IS IN THE FORM OF A SINTERED MAGNET BODY HAVING A COMPOSITION R1AR2BTCADFEOFMG WHEREIN F AND R2 ARE DISTRIBUTED SUCH THAT THEIR CONCENTRATION INCREASES ON THE AVERAGE FROM THE CENTER TOWARD THE SURFACE OF THE MAGNET BODY, THE CONCENTRATION OF R2 / ( R1+R2 ) CONTAINED IN GRAIN BOUNDARIES SURROUNDING PRIMARY PHASE GRAINS OF ( R1 , R2 ) 2 T14A TETRAGONAL SYSTEM WITHIN THE SINTERED MAGNET BODY IS ON THE AVERAGE HIGHER THAN THE CONCENTRATION OF R2 / ( R1+R2 ) CONTAINED IN THE PRIMARY PHASE GRAINS, AND THE OXYFLUORIDE OF ( R1 ,R2 ) IS PRESENT AT GRAIN BOUNDARIES IN A GRAIN BOUNDARY REGION THAT EXTENDS FROM THE MAGNET BODY SURFACE TO A DEPTH OF AT LEAST 20 M. THE INVENTION PROVIDES R-FE-B SINTERED MAGNETS WHICH EXHIBIT HIGH MAGNET PERFORMANCE DESPITE MINIMAL AMOUNTS OF TB AND DY USED.
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