Structural and magnetic properties of backward extruded Nd–Fe–B ring magnets made by different punch chamfer radius  

作　　者：Ren-Quan Wang Biao Chen Jun Li Ying Liu Qing Zheng 

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

出　　处：《Rare Metals》2014年第3期304-308,共5页稀有金属（英文版）

基　　金：financially supported by the National High Technology Research and Development Program of China (No. 2011AA03A403);the National Natural Science Foundation of China (No. 51171122);the Sichuan Provence Science and Technology Support Program (Nos. 2011GZ0117 and 2013GZ0056)

摘　　要：Radially oriented Nd-Fe-B ring magnets were prepared by backward extrusion of MQ-C powder. The punch chamfer radius has a great impact on the microstructure and magnetic properties of the ring magnet. With the chamfer radius changing from 2, 5 to 8 mm, the cracks in the inner wall decrease obviously while the crystallographic alignment drops. Furthermore, the mechanism of caxis growth was suggested to be a combination of shear deformation in the corner and solution-precipitation under the stress parallel to radial direction. The alignment drops on the top of ring because the grains grow freely and some textured grains grow through nucleation and recrystallization. In the present work, the optimal punch chamfer radius is found to be 2 mm, and in this case, the remanence,coercivity, and maximum energy product of the ring magnet achieve 1.4 T, 670 kJám, and 342 kJám,respectively.Radially oriented Nd-Fe-B ring magnets were prepared by backward extrusion of MQ-C powder. The punch chamfer radius has a great impact on the microstructure and magnetic properties of the ring magnet. With the chamfer radius changing from 2, 5 to 8 mm, the cracks in the inner wall decrease obviously while the crystallographic alignment drops. Furthermore, the mechanism of caxis growth was suggested to be a combination of shear deformation in the corner and solution-precipitation under the stress parallel to radial direction. The alignment drops on the top of ring because the grains grow freely and some textured grains grow through nucleation and recrystallization. In the present work, the optimal punch chamfer radius is found to be 2 mm, and in this case, the remanence,coercivity, and maximum energy product of the ring magnet achieve 1.4 T, 670 kJám, and 342 kJám,respectively.

关 键 词：Backward extrusion Nd-Fe-B ring magnet Microstructure Alignment 

分 类 号：TM27[一般工业技术—材料科学与工程]