Preparation And Performance Study Of Bonded Ndfeb Magnet

In recent years, with the development of science and technology, the study of bonded NdFeB permanent magnet gets more and more. The performance and the application scope of NdFeB permanent material developed rapidly. In order to give full play to Chinese rare earth resources and promoting the development of permanent NdFeB magnetic industry, this paper systematically studied the system-related problems during the process of high-performance molding bonded NdFeB magnet.This paper described the preparation of bonded NdFeB magnets, including the milling process, bonding process and molding process, and introduced factors affecting the magnetic properties during the process. Then we analyzed functional properties and the corresponding application theory of bonded NdFeB permanent magnet materials. This paper also analyzed parameters and the factors that affect the performance of bonded NdFeB permanent magnets by given experimental works.This paper studied the effects of pressure force, dwell time, thermosetting temperature, thermosetting time, amount of adhesion, wet and dry mixture, amount of solvent, warm-pressing temperature and warm-pressing pressure on magnetic properties through experiments. The best parameters of the preparation of bonded NdFeB magnets are given in following: amount of adhesion 2%, pressure force in 1200MPa, dwell in 100s, thermosetting temperature on 120℃, thermosetting in 150min, warm-pressing on 130℃and warm-pressing with 200MPa. On the basement of amount of experiments, we obtained the best bonded NdFeB permanent magnet with the following parameters Br=0.705T, Hcj=751kA/m, Hcb=461.6kA/m, (BH)max= 81.8kJ/m~3 .Experiments show that in the bonded NdFeB magnet prepared by pressing process, the molding pressure and holding pressure time, curing temperature and curing time, binder, solvent, warm-pressing temperature and warm-pressing pressure are important factors to the affect of the magnetic properties.