The reduction diffusion method was performed for the sludge scrap of Nd-Fe-B sintered magnets with adding Ca metal to recover the oxidized Nd-Fe-B phase. After washing the resultant powders to remove Ca metal componen...The reduction diffusion method was performed for the sludge scrap of Nd-Fe-B sintered magnets with adding Ca metal to recover the oxidized Nd-Fe-B phase. After washing the resultant powders to remove Ca metal component, the powders obtained were recycled as an isotropic magnetic powder by the melt spinning method. The magnetic properties of powders as recycled were inferior, especially for the coercivity value, due to the deletion of rare earth metals during the washing process. The adjustment of metal composition, i.e., the addition of Nd metal, at the melt spinning process improved the magnetic properties to be B r=～0.75 T, H cj=～0.93 mA·m -1, and (BH) max=～91 kJ·m -3. The magnetic properties of the bonded magnets prepared from the composition-adjusted powders were B r=～0.66 T, H cj=～0.92 mA·m -1, and (BH) max=～70 kJ·m -3, which are approximately comparable to the commercially available MQPB boned one (B r=～0.73 T, H cj=～0.79 mA·m -1, and (BH) max=～86 kJ·m -3).展开更多
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文摘The reduction diffusion method was performed for the sludge scrap of Nd-Fe-B sintered magnets with adding Ca metal to recover the oxidized Nd-Fe-B phase. After washing the resultant powders to remove Ca metal component, the powders obtained were recycled as an isotropic magnetic powder by the melt spinning method. The magnetic properties of powders as recycled were inferior, especially for the coercivity value, due to the deletion of rare earth metals during the washing process. The adjustment of metal composition, i.e., the addition of Nd metal, at the melt spinning process improved the magnetic properties to be B r=～0.75 T, H cj=～0.93 mA·m -1, and (BH) max=～91 kJ·m -3. The magnetic properties of the bonded magnets prepared from the composition-adjusted powders were B r=～0.66 T, H cj=～0.92 mA·m -1, and (BH) max=～70 kJ·m -3, which are approximately comparable to the commercially available MQPB boned one (B r=～0.73 T, H cj=～0.79 mA·m -1, and (BH) max=～86 kJ·m -3).
