2005 Fiscal Year Final Research Report Summary
Development of Rare-Earth・Iron・Boron system exchange coupling type bonded magnet materials with high quality heat-resistant.
| Project/Area Number |
16360159
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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 | 一般 |
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| Research Field |
Electronic materials/Electric materials
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| Research Institution | Meiji University |
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Principal Investigator |
YAMAMOTO Hiroshi Meiji Univ., School of Science and Technology, Professor, 理工学部, 教授 (30061972)
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| Co-Investigator(Kenkyū-buntansha) |
OOMURA Masashi Meiji Univ., School of Science and Technology, assistant (now : Nissan Jidousha Co, Ltd), 理工学部(平成17年3月退職), 専任助手 (50360194)
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| Project Period (FY) |
2004 – 2005
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| Keywords | Rare-Earth system alloy / melt-spun ribbon / bonded magnet / magnetic properties / high coercivity / heat-resistant |
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| Research Abstract |
The melt-spun ribbons of Didymium-Fe-B and Pr-Fe-B system alloys were prepared by single roller rapid-quenching method. The effects of composition, wheel velocity and heat-treatment on the magnetic properties were investigated. And some properties of bonded magnets prepared by using these ribbons were examined. The sunmnaly of the experimental results is following.
In Didymium-Fe-B alloy system, the melt-spun ribbons of Didymium_<12.5>Fe_<68>Co_<10>Nb_1V_1Tb_<0.5>B_7 prepared at a wheel velocity of 17.5 m/s were crystallized by heat treatment. The optimum heat treatment condition was found to be at 600℃ for 5 min. The values of (BH)_<max> and H_<cJ> amount to 103.6 kJ/m^3, 1628.0 kA/m, respectively. The temperature coefficients of J_r and H_<cJ> for the crystallized ribbons were α (J_r)_<ave>=-0.03 %/℃(reversible) and α (H_<cJ>)=-0.37 %/℃(irreversible) for the temperature range 25 to 125℃. The compression molded Didymium_<12.5>Fe_<68> Co_<10>Nb_1V_1Tb_<0.5>B_7 isotropic bonded magnet, p
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repared by using the ribbons annealed at 600℃ for 5 min, achieve the (BH)_<max> of 66.2 kJ/m^3. The density amount to 6.32 Mg/m^3. At 150℃ irreversible losses of -2.50 % result.
In Pr-Fe-B system alloys, melt-spun ribbons of Pr_xFe_<91.5-x-y-z>Co_yTi_<1.5>B_zSi_<0.5> (x = 10.0〜13.0, y = 8.0〜12.0, z=7.0〜14.0) alloys were prepared by the single roller liquid rapid-quenching method, and the effects of composition, wheel velocity and annealing condition on the magnetic properties were studied. The optimum preparation conditions and some of the properties were as follows : composition : Pr_<11>Fe_<68.5>Co_8Ti_<1.5>B_<10.5>Si_<0.5> ; wheel velocity : 10.0 m/s and annealing condition : 650℃ for 0 min in Ar atmosphere ; magnetic properties J_r=0.8 T (, H_<cJ>=1570 kA/m, H_<cB> = 550 kA/m, (BH)_<max> = 111.2 kJ/m^3, H_k/H_<cJ>×100 = 24.9%, α(J_r) =-0.04%/℃, α (H_<cJ>)=-0.37%/℃ and T_c = 403℃. From a TEM observation, the average particle size of this ribbon was found to be about 23 nm. The compression molding isotropic bonded magnets were prepared by using Pr_<11>Fe_<68.5>Co_8Ti_<1.5>B_<10.5>Si_<0.5> ribbons annealed at 600℃ for 5 min. The magnetic properties of this bonded magnet were J_r = 0.60 T (6.0 kG), H_<cJ> = 1530 kA/m, H_<cB> = 420 kA/m and (BH)_<max>=66.8 kJ/m^3. The irreversible losses of Pr_<11>Fe_<66.5>Co_<10>Ti_<1.5>B_<10.5>Si_<0.5> and Pr_<11>Fe_<64.5>Co_<12>Ti_<1.5>B_<10.5>Si_<0.5> bonded magnets were smaller than that of MQP-O one at 150℃. Less
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Research Products
(14 results)
