03-05-2012 дата публикации
Номер: US20120105184A1
An anisotropic rare earth sintered magnet has a tetragonal RFeB compound as a major magnetic phase, wherein R is Nd or a mixture of Nd with at least one rare earth element. Grains of the compound phase have two crystallographic axes, c and a-axes aligned. The biaxially aligned magnet exhibits a coercivity Hc of at least 1.6 MA/m. 1. An anisotropic rare earth sintered magnet comprising a tetragonal RFeB compound as a major magnetic phase , wherein R is at least one rare earth element essentially including Nd , compound phase grains having two crystallographic axes , c and a-axes aligned.2. The magnet of claim 1 , having a composition consisting essentially of R-R′-T-M-B and incidental impurities wherein R is a rare earth element which is Nd or a combination of Nd with at least one member selected from the group consisting of Y claim 1 , La claim 1 , Ce claim 1 , Pr claim 1 , Sm claim 1 , Eu claim 1 , Gd claim 1 , Ho claim 1 , Er claim 1 , Tm claim 1 , Yb claim 1 , and Lu claim 1 , R′ is Dy and/or Tb claim 1 , T is Fe or Fe and Co claim 1 , M is at least one element selected from the group consisting of Ti claim 1 , Nb claim 1 , Al claim 1 , V claim 1 , Mn claim 1 , Sn claim 1 , Ca claim 1 , Mg claim 1 , Pb claim 1 , Sb claim 1 , Zn claim 1 , Si claim 1 , Zr claim 1 , Cr claim 1 , Ni claim 1 , Cu claim 1 , Ga claim 1 , Mo claim 1 , W claim 1 , and Ta claim 1 , and the contents of these elements are 10 at %≦R≦20 at % claim 1 , 0 at %≦R′≦5 at % claim 1 , 0 at %≦M≦15 at % claim 1 , 3 at %≦B≦15 at % claim 1 , with the balance of T.3. The magnet of wherein the composition contains a rare earth element R which is Nd or a combination of Nd with at least one member selected from the group consisting of Y claim 2 , La claim 2 , Ce claim 2 , Pr claim 2 , Sm claim 2 , Eu claim 2 , Gd claim 2 , Ho claim 2 , Er claim 2 , Tm claim 2 , Yb claim 2 , and Lu claim 2 , and is free of Dy and Tb claim 2 , and the magnet has a coercivity Hcj of at least 1.6 MA/m.4. A method for preparing ...
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