Fracture toughness of commercial magnets

Author

Horton, J.A. ; Wright, J.L. ; Herchenroeder, J.W.

Author_Institution

Div. of Metals & Ceramics, Oak Ridge Nat. Lab., TN, USA

Volume

32

Issue

5

fYear

1996

fDate

9/1/1996 12:00:00 AM

Firstpage

4374

Lastpage

4376

Abstract

Nd₂Fe₁₄B is currently the best (highest energy product) hard magnet available. Like most permanent magnetic materials, it is rather brittle. The fracture toughness of specimens of commercially available hard magnets were measured using a chevron notch, three-point bend test. Values for Nd₂Fe₁₄B magnets ranged from 2.5 to 5.5 MPa√m. In comparison, SmCo₅ was measured to have a fracture toughness of 1.9 MPa√m. It appears that this testing technique will allow differences in fracture toughness to be measured between alloys with different compositions and fabricated by different production methods and should be able to track the fracture toughness as improvements are made to a particular alloy

Keywords

boron alloys; brittleness; cobalt alloys; ferromagnetic materials; fracture toughness; iron alloys; neodymium alloys; permanent magnets; samarium alloys; Nd₂Fe₁₄B; SmCo₅; brittle; chevron notch three-point bend test; commercial magnets; fracture toughness; hard magnet; highest energy product; Area measurement; Building materials; Displacement measurement; Energy measurement; Geometry; Magnetic materials; Magnets; Steel; Surface cracks; Testing;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/20.538873

Filename

538873