【摘要】 采用传统烧结技术和放电等离子体烧结技术(SPS)制备相同成分的烧结NdFeB永磁合金。研究了所制备合金的力学性能和断裂行为。利用扫描电子显微镜观察了合金的显微组织和断口形貌;测量了合金的抗弯强度并对磁体的力学性能进行评价。结果表明:SPS NdFeB磁体的抗弯强度较传统烧结体有显著的提高,前者σbb=402·25MPa,后者σbb=278·97MPa;SPS NdFeB磁体显微组织主相晶粒细小均匀、富稀土相细小弥散且彼此隔断,断口观察发现了较明显的撕裂棱及一些解理断裂;而传统烧结磁体主相晶粒粗大、富稀土相粗大且彼此连接,沿晶断裂特征明显。更多还原

【Abstract】 Conventional sintering technique and spark plasma sintering technique(SPS)have been used to prepare sintered NdFeB magnetic alloys of same composition. Mechanical properties and fracture behavior of the alloys were investigated.Micostructure and fracture morphology were observed by scanning electronic microscopy (SEM). Bending strength of alloys were tested and applied to evaluate the mechanical properties of alloys. The results show that the microstructure of SPS NdFeB is composed of fine and even matrix phase grains with average size of 5～8μm, as well as fine and separated Nd-rich phase, and its fracture morphology shows obvious tearing ridge and some cleavage face, whereas the microstructure of conventional sintered NdFeB is composed of coarse grains with size range from 10 to 20μm, its fracture morphology shows a typical inter-granular mode. The bending strength of SPS NdFeB and conventional sintered NdFeB are 402.25 and 278.97 MPa, respectively.更多还原