1999 Fiscal Year Final Research Report Summary
DEVELOPMENT OF HIGH-PERFORMANCE RARE EARTH BONDED MAGNETS
| Project/Area Number |
10555218
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 展開研究 |
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| Research Field |
Inorganic materials/Physical properties
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| Research Institution | Osaka University |
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Principal Investigator |
MACHIDA Ken-ichi Materials Chemistry, Osaka University Associate Professor, 大学院・工学研究科, 助教授 (00157223)
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| Co-Investigator(Kenkyū-buntansha) |
ADACHI Gin-ya Materials Chemistry, Osaka University Professor, 大学院・工学研究科, 教授 (60029080)
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| Project Period (FY) |
1998 – 1999
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| Keywords | Rare earth compounds / Interstitial metal nitrides / Permanet magnets / Bonded magnets / Coercivity / Remanence / Surface coating / Maximum energy product |
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| Research Abstract |
In the present work, the purpose was to prepare fine magnetic powders of SmィイD22ィエD2FeィイD217ィエD2NィイD2xィエD2-related compounds with good oxidation-resistance as well as excellent magnetic properties and to evaluate the possibility of their practical uses as the raw materials for high-performance anisotropic bonded magnets.
First, it was found that SmィイD22ィエD2 (Fe, Co)ィイD217ィエD2NィイD2xィエD2 possesses more excellent intrinsic magnetic property and oxidation-resistance than those of SmィイD22ィエD2FeィイD217ィエD2NィイD2xィエD2. As a result of these properties, high energy product values of (BH)ィイD2maxィエD2>340 kJ/mィイD13ィエD1 were observed on Zn/SmィイD22ィエD2 (Fe, Co)ィイD217ィエD2NィイD2xィエD2 powders as prepared surface-coating with the zinc metal produced via the photo-decomposition of diethyl zinc. Furthermore, the bonded magnets molded from those powders also provided high (BH)ィイD2maxィエD2 values up to 186 kJ/mィイD13ィエD1, and their thermal stability was better than that of the cobalt-free SmィイD22ィエD2FeィイD217ィエD2NィイD2xィエD2-related compounds, together with the oxidation-resistance.
On the other hand, metal-bonded magnets were prepared from the SmィイD22ィエD2FeィイD217ィエD2NィイD2xィエD2-related compound powders using In metal or Sn-Zn eutectic alloy as a binder under warm pressing condition. The (BH)ィイD2maxィエD2 values recorded were around 150 kJ/mィイD13ィエD1, which were the highest ones among the figures reported on the similar rare earth metal-bonded magnets. Since the metal binders produced the inter-grain structure between the magnetic powder particles and protected them from water and oxygen in atmosphere, the metal-bonded magnets of SmィイD22ィエD2FeィイD217ィエD2NィイD2xィエD2-related compounds provided excellent oxidation and thermal stability.
In addition, new surface-coating method was employed in this work to develop the magnetic ptoperty of the SmィイD22ィエD2FeィイD217ィエD2NィイD2xィエD2-related bonded magnets. This sorption method allowed us to mass-produce the surface-coated magnetic powders.
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Research Products
(14 results)
