The Nd-Fe-B magnets are pre-sintered and then processed with hot-pressing,and the resulting magnets are called the hot-pressed pretreated(HPP)magnets.The coercivity of the HPP magnets increases as the annealed tempera...The Nd-Fe-B magnets are pre-sintered and then processed with hot-pressing,and the resulting magnets are called the hot-pressed pretreated(HPP)magnets.The coercivity of the HPP magnets increases as the annealed temperature increases.When the annealing temperature is 900℃,the coercivity of the magnet is only 17.6 kOe(1 Oe=79.5775 A·m^-1),but when the annealing temperature rises up to 1060℃,the coercivity of the magnet reaches 23.53 kOe,which is remarkably increased by 33.7%.The microstructure analysis indicates that the grain surface of the HPP magnet becomes smoother as the annealed temperature increases.The microstructure factorαis changed according to the intrinsic coercivity model formula.Theαof the magnet at 900℃is only 0.578,but it is 0.825 at 1060℃.Microstructural optimization is due mainly to the increase of coercivity of the HPP magnet.展开更多
基金Project supported by the Major Project of“Science and Technology Innovation 2025”in Ningbo City,China(Grant Nos.2018B10086 and 2018B10017).
文摘The Nd-Fe-B magnets are pre-sintered and then processed with hot-pressing,and the resulting magnets are called the hot-pressed pretreated(HPP)magnets.The coercivity of the HPP magnets increases as the annealed temperature increases.When the annealing temperature is 900℃,the coercivity of the magnet is only 17.6 kOe(1 Oe=79.5775 A·m^-1),but when the annealing temperature rises up to 1060℃,the coercivity of the magnet reaches 23.53 kOe,which is remarkably increased by 33.7%.The microstructure analysis indicates that the grain surface of the HPP magnet becomes smoother as the annealed temperature increases.The microstructure factorαis changed according to the intrinsic coercivity model formula.Theαof the magnet at 900℃is only 0.578,but it is 0.825 at 1060℃.Microstructural optimization is due mainly to the increase of coercivity of the HPP magnet.
