Highly oriented NdFeB nanocrystalline magnets from partially recombined compacts with ultrafine grain size by reactive deformation under low pressure  

作　　者：余云萍 李军 刘颖 王仁全 郑青 连利仙 

机构地区：[1]College of Materials Science and Engineering, Sichuan University

出　　处：《Journal of Rare Earths》2015年第12期1298-1302,共5页稀土学报（英文版）

基　　金：supported by the National Natural Science Foundation of China(51171122);the Sichuan Province Science and Technology Support Program(2013GZX0164;2013GZ0056)

摘　　要：The partially recombined compacts with ultrafine grain size were taken advantage of preparing anisotropic nanocrystalline magnets with full density and homogenous microstructure and texture by reactive deformation under low pressure. Because of the ul- trafine grain size of the precursors, the partially recombined phases could quickly achieve recombination. The results suggested that the newly recombined Nd2Fe14B grains with fme grain size could undergo deformation immediately during the desorp- tion-recombination reaction, and then an obvious anisotropy and uniform alignment would be obtained. The magnetic properties, （BH）max=214 kJ/m3, Br= 1.26 T, Hcj=463 kA/m, were obtained after being treated for 5 min at 820 ℃ in high vacuum under low pres- sure less than 26 MPa. Microstructures of the magnets were analyzed using X-ray diffraction （XRD）, scanning electron microscopy （SEM） and transmission electron microscopy （TEM） respectively. Magnetic measurements were carried out using a vibrating sample magnetometer （VSM） with the maximum field of 2.88 T. Accurate phase contents were measured by a Mossbauer spectrometer.The partially recombined compacts with ultrafine grain size were taken advantage of preparing anisotropic nanocrystalline magnets with full density and homogenous microstructure and texture by reactive deformation under low pressure. Because of the ul- trafine grain size of the precursors, the partially recombined phases could quickly achieve recombination. The results suggested that the newly recombined Nd2Fe14B grains with fme grain size could undergo deformation immediately during the desorp- tion-recombination reaction, and then an obvious anisotropy and uniform alignment would be obtained. The magnetic properties, （BH）max=214 kJ/m3, Br= 1.26 T, Hcj=463 kA/m, were obtained after being treated for 5 min at 820 ℃ in high vacuum under low pres- sure less than 26 MPa. Microstructures of the magnets were analyzed using X-ray diffraction （XRD）, scanning electron microscopy （SEM） and transmission electron microscopy （TEM） respectively. Magnetic measurements were carried out using a vibrating sample magnetometer （VSM） with the maximum field of 2.88 T. Accurate phase contents were measured by a Mossbauer spectrometer.

关 键 词：NdzFe14B NANOCRYSTALLINE HDDR deformation anisotropy rare earths 

分 类 号：TB383.1[一般工业技术—材料科学与工程]