| 摘要 |
PURPOSE:To achieve an improved corrosion resistance by forming a strong and stable non-oxidizable plating layer or a non-oxidizable formation film and a non-oxidizable resin layer on a surface of an Nd-Fe-B permanent magnet with a specific composition and by allowing a Co concentration of an R rich phase to be within a specific range. CONSTITUTION:The title item has a composition which consists of R (R is at least one of Y and rare-earth elements) 28-36wt.% B 0.8-1.3wt.%, Co 2-15wt.% M (at least one of Al, Ga, Cu, and Ni) 0.1-3.0wt.%, and the balance of Fe and in which the Co concentration of an R rich phase is 5-12wt.%. Also, after an alloy with the above composition is dissolved and is casted for forming an ingot, the ingot is subjected to homogenizing heat treatment within a temperature range of 500-1100 deg.C for 5 minute - 20 hours, thus producing a rare-earth element magnet with improved corrosion resistance. Then, for example, a non- oxidizable plating layer is applied to a surface of the above magnet body or a salt chromate film is formed on a surface of the above magnet body, and then a non-oxidizable resin layer is formed on it. |
