| 摘要 |
PURPOSE:To obtain the titled alloy powder of magnetic characteristics of very large maximum energy product with which the industrial value of the alloy powder is greatly enhanced by a method wherein the R-B-Fe alloy powder of the specially designated mesh or less is jet-milled into the specific average grain size using Ar gas or N2 gas or the mixture of said two types of gas. CONSTITUTION:The component range of R-B-Fe permanent magnet alloy powder is composed of Fe of 40-90atom%, B of 2-28% and R (rare-earth metal containing Y) of 8-30% as essential ingredients, for example, one or more kinds of specific element of the prescribed percentage or less is contained, and the average grain size of the powder is set at 1-10mum. It is difficult to pulverize the alloy powder into the average grain size of 1mum or less by performing jet milling and its magnetic coercive force is reduced when the average grain size exceeds 10mum. Also, the grain of the jet-milled alloy powder is set at 28 meshes or less. The alloy powder exceeding 28 meshes can not be formed by the jet milling. Ar gas, N2 gas or the mixture of them is used as the gas for the jet milling. |
