烧结NdFeB永磁材料的力学性能及断裂行为的各向异性

Anisotropy of Mechanical Properties and Fracture Behaviour in Sintered NdFeB Permanent Magnetic Materials

对从同一磁体上切取取向不同的3组烧结NdFeB试样进行抗弯强度测定,对其抗弯断口进行宏观观察和SEM观察。对烧结NdFeB永磁材料的力学性能和断裂行为的各向异性进行了研究。研究结果表明:烧结NdFeB永磁材料的抗弯强度和断裂行为具有明显的各向异性。不同取向方向试样断裂的微观机制都主要为沿晶断裂。当取向方向沿抗弯试样的长度方向时,在断口上发现了明显的穿晶解理断裂,且该组试样的抗弯强度值明显低于沿其它两个方向取向的试样。

The bending strength of three groups of samples variously oriented with respect to the length direction of the parent bulk have been measured. The bending macrofractography was carefully observed using SEM. Both the mechanical properties and the fracture behavior of sintered NdFeB permanent magnetic materials were investigated and found to be strongly anisotropic. Intergranular fracture was the primary fracture micromechanism. Cleavage fracture has been clearly observed in the microfractography of the group of bending samples whose orientation was parallel to the length direction, and the bending strength of the corresponding samples was far lower than those of the transverse oriented samples.