| 摘要 |
In a preferred method, a magnetically hard composition is prepared by intermingling rare earth (RE) metal, transition metal (TM) and boron (B) alloy powders of the general formula RE-(Fe(1-x)Cox)-B. The value of x ranges from 0 to 1 and is different for each of the powders, thus providing a blend of alloy powders with diverse Curie temperature (Tc) and a less abrupt rate of change of thermal expansion and/or specific heat with temperature, as compared to a single alloy powder. The magnetically hard compositions with improved thermomechanical properties are formed from two or more alloy powders. Preferably, two alloy powders are used and the value of x for the first alloy is less than about 0.1. The value of x for the second alloy is in a range of about 0.1 to about 0.6, and preferably 0.3 to 0.5. When the intermingled alloy powders of the invention are hot pressed with or without subsequent hot working, a magnetically hard body is formed and it is characterized by a lesser rate of change of specific heat and/or thermal expansion with temperature as compared to any one of the single alloy powders similarly hot pressed or hot worked.
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