Application-oriented characterization of Sm/sub 2/(Co,Fe,Cu,Zr)/sub 17/ permanent magnets

Liu, S.; Hoffman, Eugene P.

doi:10.1109/20.539500

Cited by 18 publications

(11 citation statements)

References 1 publication

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“…On the other hand, the density of lamella phase increases, first quickly and then slightly, from 0.024 to 0.062 nm-1 [15,16]. When the Zr content is further increased to over 0.08, a 2:7 phase is formed leading to a decrease in coercivity [ 17]. As mentioned before in Zr-free magnets with higher Cu content, a fine cellular microstructure is observed which becomes highly non-unifonn with aging.…”

Section: Effect Of Zrmentioning

confidence: 65%

“…As mentioned before in Zr-free magnets with higher Cu content, a fine cellular microstructure is observed which becomes highly non-unifonn with aging. After the addition of Zr and Cu in the magnets, a normal microstructure consisting of rhombohedral Sm 2 (Co,Fe) 17 cells surrounded by a Cu-rich hexagonal Sm(Co,Cu) 5 cell boundary phase is always formed. These results indicate that the lamellar phase formed by adding Zr stabilizes a uniform cellular microstructure with the right microchemistry for high coercivity [9].…”

Section: Effect Of Zrmentioning

confidence: 99%

“…Some studies [17,18] suggested that the high temperature performance of SmCo 2:17 magnets can be improved by decreasing the Fe content. Our results show that for some compositions the addition of a certain amount of Fe is necessary to develop a uniform cellular microstructure with a larger cell size and thus a high coercivity.…”

Section: Effect Of Fementioning

confidence: 99%

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Effect of Composition and Processing on the Microstructure and Magnetic Properties of 2:17 High Temperature Magnets

Tang

Zhang

Goll³

et al. 2001

MRS Proc.

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A comprehensive and systematic study has been made on Sm(CobalFevCuyZrx)zmagnets to completely understand the effects of composition and processing on their magnetic properties. The homogenized Sm(Co,Fe,Cu,Zr)z magnets have a featureless microstructure. A cellular/lamellar microstructure develops after 2-3 hours of aging at 800-850°C, but the coercivity increases only after a subsequent slow cooling to 400°C. During cooling, diffusion takes place and Cu is concentrated in the 1:5 cell boundaries and Fe in the 2:17R cells. This dilutes the magnetic properties of the 1:5 phase and causes domain wall pinning/nucleation at the cell boundaries. Higher ratio z leads to larger cells as expected due to the larger amount of the 2:17 phase. For a fixed Cu content, this translates to a larger amount of Cu in the 1:5 cell boundaries, and therefore, to a higher coercivity. Magnets without Cu but with Zr have a lamellar and a cellular like microstructure. In Zr free samples, however, a larger amount of Cu is needed to form the cellular microstructure. This cellular microstructure is unstable with prolonged isothermal aging. A uniform and stable cellular/lamellar microstructure is only observed in alloys containing both Cu and Zr. A higher aging temperature Tag leads to larger cells and higher coercivity as explained above. The results of all these studies clearly show that the amount of Cu in the 1:5 cell boundaries controls both the coercivity and its temperature dependence leading to positive and negative temperature coefficients of coercivity in low and high Cu content alloys, respectively.

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Section: Effect Of Zrmentioning

confidence: 65%

Section: Effect Of Zrmentioning

confidence: 99%

See 1 more Smart Citation

Effect of Composition and Processing on the Microstructure and Magnetic Properties of 2:17 High Temperature Magnets

Tang

Zhang

Goll³

et al. 2001

MRS Proc.

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show abstract

“…Iron has a significant effect on the high-temperature magnetic properties of Sm(Co,Fe,Cu,Zr) z [3,4,11,12]. The lower the Fe content is, the higher the intrinsic coercivity at high temperature is.…”

Section: Article In Pressmentioning

confidence: 98%

“…Serious efforts to improve high-temperature performance of 2:17-type Sm-Co magnets began in 1995 [3][4][5].…”

Section: Introductionmentioning

confidence: 99%

Sm(Co, Fe, Cu, Zr)z sintered magnets with a maximum operating temperature of 500°C

Guo

Pan

2006

Journal of Magnetism and Magnetic Materials

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Recent Developments in High-Temperature Permanent Magnet Materials

Liu

Handbook of Advanced Magnetic Materials

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Application-oriented characterization of Sm/sub 2/(Co,Fe,Cu,Zr)/sub 17/ permanent magnets

Cited by 18 publications

References 1 publication

Effect of Composition and Processing on the Microstructure and Magnetic Properties of 2:17 High Temperature Magnets

Effect of Composition and Processing on the Microstructure and Magnetic Properties of 2:17 High Temperature Magnets

Sm(Co, Fe, Cu, Zr)z sintered magnets with a maximum operating temperature of 500°C

Recent Developments in High-Temperature Permanent Magnet Materials

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