microstructure; magnetic force microscope

作者:吕友胜;陈翌庆;苏勇;成问好;熊永飞;依晓飞;周庆涛;
关键词:NdFeB; microstructure; magnetic force microscope; domain structure; rare earths
单位:School of Materials Science magnetic materials
http://www.999magnet.com and Engineering  Hefei University of Technology,School of Materials Science and Engineering Hefei University of Technology,School of Materials Science and Engineering Hefei University of Technology,Earth Wind Advance Magnetic Material Co. Ltd.,Earth Wind Advance Magnetic Material Co. Ltd.,Earth Wind Advance Magnetic Material Co. Ltd.,School of Materials Science and Engineering Hefei University of Technology,,Hefei 230009 China,Hefei 230009 China,Hefei 230009 China,Lujiang,Anhui,China,Lujiang,Anhui,China,Lujiang,Anhui,China,Hefei 230009 China
摘要:A new alloy of Nd33.5Dy0.99Febal.Al0.52Cu0.1B1.15 (%, mass fraction) was fabricated by powder metallurgy. The effects of Dy, Al and Cu additions on the microstructure and magnetic properties of sintered NdFeB magnet were investigated. The additions of Dy, Al and Cu are effective to refine grains and improve coercivity. Moreover, suitable amounts of Dy, Al and Cu lead to a demagnetization curve with good rectangularity. It is found that the sintered NdFeB magnet has relatively high magnetic performance of Br=12.17 kGs, jHc=13.52 kOe and (BH)max=34.71 MGOe. The sintered NdFeB sample was examined by magnetic force microscope which revealed the domain structures at the surface. It is revealed that the mean Nd2Fe14B grain size is significantly larger than the average scale of the magnetic contrast. An explanation about this is that most Nd2Fe14B grains in sintered NdFeB alloy are dominated with the multidomain structures when the magnet is in thermally demagnetization state.