| 摘要 |
PROBLEM TO BE SOLVED: To obtain an Sm-Fe-N series magnetic material without using mechani cal stress such as pulverization by making the average grain size and coefficient of the acicular degree of alloy powder in specified ranges. SOLUTION: In this Sm-Fe-N series alloy powder, the average grain size is 0.5 to 10 μm and the coefficient of the acicular degree defined by following formula is >=75%, where the coefficient of the acicular degree (%)=(b/a)×100%, (a) = the longest size of the grain images and (b) = the maximum size vertical to (a). In the Sm2Fe17N3 alloy spherical grains, as the most preferable ranges, the average grain size is made to 0.7 to 4 μm and the coefficient of the acicular degree is made to >=90% by which its coercive force can be made to >=17 kOe and the residual magnetization can be made to >=130 emu/g. The alloy powder can be obtained by the following procedures. Sm as a rare earth element and Fe as a transition metal are dissolved in acid and Sm, Fe ions and a substance to form insoluble salt are allowed to react and are precipitated. The precipitates are fired to make them into metallic oxide which is reduced. |
