碳对烧结Nd-Fe-B永磁体性能的影响  

The Effects of C Contents on The Magnetic Properties of Sintered Nd-Fe-B Permanent Magnets

作　　者：谈萍[1] 罗建军[1] 李增峰[1] 

机构地区：[1]西北有色金属研究院,西安710016

出　　处：《金属功能材料》2007年第1期1-4,共4页Metallic Functional Materials

摘　　要：本文采用两种不同碳含量的原料铁棒，按相同的传统烧结Nd—Fe-B永磁体的工艺，制得NdDyAlCuBFe块状永磁体，研究了碳对烧结Nd—Fe-B永磁体性能的影响。结果显示，原料铁棒中C含量增高，磁体的磁性能如剩磁、矫顽力、磁能积以及方形度都下降。SEM和金相显微观察表明：高C含量中的Nd2Fe14B主相的晶粒大小不均匀，小的为10μm，而大的达到100μm，且富Nd相分布也不均匀；而低C含量中的Nd2Fe14B主相的晶粒细小均匀，约为10～20μm，而且富Nd相分布均匀。造成上述差别的原因是：C是一种杂质元素，呈负电性，易与Nd发生反应，在晶界形成富C、富Nd的第二相杂质，破坏Nd2Fe14B主相，从而使磁体的各项磁性能指标都下降。The influence of C content on the magnetic properties oF sintered Nd-Fe-B permanent magnets was studied. The NdDyAlCuBFe permanent magnets were produced by the conventional sintering process, using two kinds of raw material with different C content. The results show that the magnetic properties, such as Be, Hej, （BH） and squareness of the demagnetization curve, were all reduced with increasing of C content. The micro- structure of the samples showed that for the Nd-Fe-B with high C content, the grain size of the hard magnetic phase was very inhomogeneous （from 10 to 100tLm） and the neodymium-rich boundary was also distributed inhomogeneously. But in the case of lower C content, the grain size of the hard magnetic phase was finer and homogeneous（about 10～20μm）, and the neodymium-rich boundary was distributed homogeneously. It was supposed that it is easy to combine with Nd for C with electronegativity, which forms second-phase impurities（such as carbon-rich or neodymium-rich） along boundary resulting in destroying the hard magnetic phase, as a result, the magnetic properties were reduced.

关 键 词：磁性能 碳 烧结Nd—Fe-B永磁体 

分 类 号：TF125[冶金工程—粉末冶金]