| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an R-T-B permanent magnet that can also be applied to the formation of an electroplated protective film and can sufficiently secure corrosion resistance which is the intrinsic purpose of the formation of the protective film without practically lowering the productive efficiency. <P>SOLUTION: The R-T-B permanent magnet 1 is provided with an elemental magnet body 2 composed of a sintered compact containing at least main-phase crystal grains composed of the R<SB>2</SB>T<SB>14</SB>B compound (wherein, R denotes one kind or two or more kinds of rare-earth elements including Y and T denotes one kind or two or more kinds of transition metal elements containing Fe and Co as essential elements) and a grain-boundary phase containing more R than the main-phase crystal grains do and a protective film 4 formed to cover the surface of the element magnet body 2. In the permanent magnet 1, a hydrogen-enriched layer 3 which contains hydrogen at a concentration higher than that of the hydrogen contained in the central part of the elemental magnet body 2 and in which the hydrogen concentration decreases in steps toward the inside of the element magnet body 2 from the surface of the body 2 exists in the surface layer section of the body 2. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
