Multi-layered electroless Ni–P coatings on powder-sintered Nd–Fe–B permanent magnet
This paper has shown a successful protective coating scheme for powder-sintered Nd–Fe–B permanent magnet using multi-layered electroless nickel (EN) deposition. A low-phosphorus nickel layer is plated with an alkaline EN solution first, followed by a high-phosphorus nickel layer plated with an acidi...
| Glavni autori: | , , , |
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| Format: | Journal Article |
| Jezik: | English |
| Izdano: |
2012
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| Online pristup: | https://hdl.handle.net/10356/94650 http://hdl.handle.net/10220/8156 |
| _version_ | 1826111159917346816 |
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| author | Chen, Zhong Ng, Alice Yi, Jianzhang Chen, Xingfu |
| author2 | School of Materials Science & Engineering |
| author_facet | School of Materials Science & Engineering Chen, Zhong Ng, Alice Yi, Jianzhang Chen, Xingfu |
| author_sort | Chen, Zhong |
| collection | NTU |
| description | This paper has shown a successful protective coating scheme for powder-sintered Nd–Fe–B permanent magnet using multi-layered electroless nickel (EN) deposition. A low-phosphorus nickel layer is plated with an alkaline EN solution first, followed by a high-phosphorus nickel layer plated with an acidic solution. An additional topcoat by medium-phosphorus nickel on the high-phosphorus coating is also explored. It is shown that the high-phosphorus nickel layer coated in acidic solution provides the best corrosion protection because of its dense amorphous structure. The medium phosphorus topcoat is also dense and is able to provide reasonable corrosion resistance. The low-phosphorus layer itself does not have enough corrosion resistance; its main role is to provide an intermediate coating on the powder-sintered magnet. X-ray diffraction measurement shows that the low-phosphorus coating consists of nano-crystallines, and the high- and the medium-phosphorus coatings are dominated by amorphous structure. Microscopic observation and scratch test on these composite coatings demonstrate good adhesion between the magnet and the coatings. Remanence and coercivity of the plated magnet decrease with the applied coatings, but measured values are still very attractive for practical applications among known hard magnets. |
| first_indexed | 2024-10-01T02:46:06Z |
| format | Journal Article |
| id | ntu-10356/94650 |
| institution | Nanyang Technological University |
| language | English |
| last_indexed | 2024-10-01T02:46:06Z |
| publishDate | 2012 |
| record_format | dspace |
| spelling | ntu-10356/946502023-07-14T15:45:09Z Multi-layered electroless Ni–P coatings on powder-sintered Nd–Fe–B permanent magnet Chen, Zhong Ng, Alice Yi, Jianzhang Chen, Xingfu School of Materials Science & Engineering DRNTU::Engineering::Materials This paper has shown a successful protective coating scheme for powder-sintered Nd–Fe–B permanent magnet using multi-layered electroless nickel (EN) deposition. A low-phosphorus nickel layer is plated with an alkaline EN solution first, followed by a high-phosphorus nickel layer plated with an acidic solution. An additional topcoat by medium-phosphorus nickel on the high-phosphorus coating is also explored. It is shown that the high-phosphorus nickel layer coated in acidic solution provides the best corrosion protection because of its dense amorphous structure. The medium phosphorus topcoat is also dense and is able to provide reasonable corrosion resistance. The low-phosphorus layer itself does not have enough corrosion resistance; its main role is to provide an intermediate coating on the powder-sintered magnet. X-ray diffraction measurement shows that the low-phosphorus coating consists of nano-crystallines, and the high- and the medium-phosphorus coatings are dominated by amorphous structure. Microscopic observation and scratch test on these composite coatings demonstrate good adhesion between the magnet and the coatings. Remanence and coercivity of the plated magnet decrease with the applied coatings, but measured values are still very attractive for practical applications among known hard magnets. Accepted version 2012-05-28T08:12:40Z 2019-12-06T18:59:38Z 2012-05-28T08:12:40Z 2019-12-06T18:59:38Z 2005 2005 Journal Article Chen, Z., Ng, A., Yi, J., & Chen, X. (2006). Multi-layered Electroless Ni-P Coatings on Powder-Sintered Nd-Fe-B Permanent Magnet. Journal of Magnetism and Magnetic Materials, 302(1), 216-222. https://hdl.handle.net/10356/94650 http://hdl.handle.net/10220/8156 10.1016/j.jmmm.2005.09.008 en Journal of magnetism and magnetic materials © 2005 Elsevier. This is the author created version of a work that has been peer reviewed and accepted for publication by Journal of Magnetism and Magnetic Materials, Elsevier. It incorporates referee’s comments but changes resulting from the publishing process, such as copyediting, structural formatting, may not be reflected in this document. The published version is available at: [http://dx.doi.org/10.1016/j.jmmm.2005.09.008]. application/pdf |
| spellingShingle | DRNTU::Engineering::Materials Chen, Zhong Ng, Alice Yi, Jianzhang Chen, Xingfu Multi-layered electroless Ni–P coatings on powder-sintered Nd–Fe–B permanent magnet |
| title | Multi-layered electroless Ni–P coatings on powder-sintered Nd–Fe–B permanent magnet |
| title_full | Multi-layered electroless Ni–P coatings on powder-sintered Nd–Fe–B permanent magnet |
| title_fullStr | Multi-layered electroless Ni–P coatings on powder-sintered Nd–Fe–B permanent magnet |
| title_full_unstemmed | Multi-layered electroless Ni–P coatings on powder-sintered Nd–Fe–B permanent magnet |
| title_short | Multi-layered electroless Ni–P coatings on powder-sintered Nd–Fe–B permanent magnet |
| title_sort | multi layered electroless ni p coatings on powder sintered nd fe b permanent magnet |
| topic | DRNTU::Engineering::Materials |
| url | https://hdl.handle.net/10356/94650 http://hdl.handle.net/10220/8156 |
| work_keys_str_mv | AT chenzhong multilayeredelectrolessnipcoatingsonpowdersinteredndfebpermanentmagnet AT ngalice multilayeredelectrolessnipcoatingsonpowdersinteredndfebpermanentmagnet AT yijianzhang multilayeredelectrolessnipcoatingsonpowdersinteredndfebpermanentmagnet AT chenxingfu multilayeredelectrolessnipcoatingsonpowdersinteredndfebpermanentmagnet |