Corrosion losses in sintered (Nd, Dy)-Fe-B magnets for different geometries

Elisa Isotahdon; Elina Huttunen-Saarivirta; Veli-Tapani Kuokkala; Martti Paju

doi:10.1109/LMAG.2015.2501404

Corrosion losses in sintered (Nd, Dy)-Fe-B magnets for different geometries

Elisa Isotahdon, Elina Huttunen-Saarivirta, Veli-Tapani Kuokkala, Martti Paju

Research output: Contribution to journal › Article › Scientific › peer-review

3 Citations (Scopus)

Abstract

Sintered neodymium-iron-boron (Nd-Fe-B) magnets with cube and flat geometries were exposed to pressurized heat-humidity corrosion tests for 96 and 240 h. Measurements of weight and flux losses were performed after the corrosion tests. The corroded specimens were further characterized using scanning electron microscopy and optical profilometry. The microcrystalline anisotropy of sintered magnets gave rise to heterogeneous corrosion, where the pole faces degraded preferentially to the side faces. The magnetic field from the magnet itself thus contributed to the amount and location of detached ferromagnetic grains. The magnets with cube geometry suffered greater losses than the flat magnets, even though the flat magnets had a higher relative pole-face area. The higher total flux (due to the larger volume) of the cube-shaped magnets led to the higher overall losses. In the flat magnets, the corrosion concentrated heavily on areas near the corners.

Original language	English
Article number	5500504
Journal	IEEE Magnetics Letters
Volume	7
DOIs	https://doi.org/10.1109/LMAG.2015.2501404
Publication status	Published - 2016
MoE publication type	A1 Journal article-refereed

Keywords

corrosion
hard magnetic materials
Nd-Fe-B magnets

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10.1109/LMAG.2015.2501404

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title = "Corrosion losses in sintered (Nd, Dy)-Fe-B magnets for different geometries",

abstract = "Sintered neodymium-iron-boron (Nd-Fe-B) magnets with cube and flat geometries were exposed to pressurized heat-humidity corrosion tests for 96 and 240 h. Measurements of weight and flux losses were performed after the corrosion tests. The corroded specimens were further characterized using scanning electron microscopy and optical profilometry. The microcrystalline anisotropy of sintered magnets gave rise to heterogeneous corrosion, where the pole faces degraded preferentially to the side faces. The magnetic field from the magnet itself thus contributed to the amount and location of detached ferromagnetic grains. The magnets with cube geometry suffered greater losses than the flat magnets, even though the flat magnets had a higher relative pole-face area. The higher total flux (due to the larger volume) of the cube-shaped magnets led to the higher overall losses. In the flat magnets, the corrosion concentrated heavily on areas near the corners.",

keywords = "corrosion, hard magnetic materials, Nd-Fe-B magnets",

author = "Elisa Isotahdon and Elina Huttunen-Saarivirta and Veli-Tapani Kuokkala and Martti Paju",

year = "2016",

doi = "10.1109/LMAG.2015.2501404",

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journal = "IEEE Magnetics Letters",

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TY - JOUR

T1 - Corrosion losses in sintered (Nd, Dy)-Fe-B magnets for different geometries

AU - Isotahdon, Elisa

AU - Huttunen-Saarivirta, Elina

AU - Kuokkala, Veli-Tapani

AU - Paju, Martti

PY - 2016

Y1 - 2016

N2 - Sintered neodymium-iron-boron (Nd-Fe-B) magnets with cube and flat geometries were exposed to pressurized heat-humidity corrosion tests for 96 and 240 h. Measurements of weight and flux losses were performed after the corrosion tests. The corroded specimens were further characterized using scanning electron microscopy and optical profilometry. The microcrystalline anisotropy of sintered magnets gave rise to heterogeneous corrosion, where the pole faces degraded preferentially to the side faces. The magnetic field from the magnet itself thus contributed to the amount and location of detached ferromagnetic grains. The magnets with cube geometry suffered greater losses than the flat magnets, even though the flat magnets had a higher relative pole-face area. The higher total flux (due to the larger volume) of the cube-shaped magnets led to the higher overall losses. In the flat magnets, the corrosion concentrated heavily on areas near the corners.

AB - Sintered neodymium-iron-boron (Nd-Fe-B) magnets with cube and flat geometries were exposed to pressurized heat-humidity corrosion tests for 96 and 240 h. Measurements of weight and flux losses were performed after the corrosion tests. The corroded specimens were further characterized using scanning electron microscopy and optical profilometry. The microcrystalline anisotropy of sintered magnets gave rise to heterogeneous corrosion, where the pole faces degraded preferentially to the side faces. The magnetic field from the magnet itself thus contributed to the amount and location of detached ferromagnetic grains. The magnets with cube geometry suffered greater losses than the flat magnets, even though the flat magnets had a higher relative pole-face area. The higher total flux (due to the larger volume) of the cube-shaped magnets led to the higher overall losses. In the flat magnets, the corrosion concentrated heavily on areas near the corners.

KW - corrosion

KW - hard magnetic materials

KW - Nd-Fe-B magnets

U2 - 10.1109/LMAG.2015.2501404

DO - 10.1109/LMAG.2015.2501404

M3 - Article

SN - 1949-307X

VL - 7

JO - IEEE Magnetics Letters

JF - IEEE Magnetics Letters

M1 - 5500504

ER -

Corrosion losses in sintered (Nd, Dy)-Fe-B magnets for different geometries

Abstract

Keywords

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