烧结温度对NdFeB磁体组织与性能的影响

Effect of Sintering Temperature on Microstructure and Properties of NdFeB Magnet

采用速凝薄带加氢破碎法制备了烧结NdFeB永磁体,通过光学显微镜、扫描电镜以及AMT—4磁学特性测量仪表征了磁体的组织和性能,考察了烧结温度对磁体组织和性能的影响规律。结果表明:随着烧结温度的升高,磁体的致密度升高,剩磁、矫顽力、最大磁能积先增大后减小,其原因是随着烧结温度的升高,主晶相晶粒长大,富钕相分布更加均匀;当烧结温度超过某一值时,磁体的组织不均匀,富钕相发生团聚。

NdFeB permanent magnet was prepared by rapid solidification strip casting and hydrogenation crushing,and its microstructure and properties were characterized by optical microscopy,scanning electron microscopy and AMT—4magnetic property tester.Investigation was made of the effect of sintering temperature on the microstructure and properties of the magnet.The results show that with sintering temperature increasing,the density of the sintered magnet increases,and its remanence,coercivity and maximum magnetic energy product increase at first and then decrease.The reason is that the major crystalline phase grains grow up and the neodymium-rich phase distribution is more homogeneous with sintering temperature increasing.However,when the sintering temperature reaches a certain value,the magnet microstructure is inhomogeneous and the neodymium-rich phase agglomerates.