Fracture Toughness of Nd_2Fe_<14>B Magnets
Nd<SUB>2</SUB>Fe<SUB>14</SUB>B is currendy the best (highest energy product) hard magnet available. Like mostmagnetic 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 Nd<SUB>2</SUB>Fe<SUB>14</SUB>B magnets ranged from 2.5 to 5.5 MPa√m. In comparison, SmCo<SUB>5</SUB> 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.
- Materials transactions, JIM
Materials transactions, JIM 37(4), 860-863, 1996-04