HDDR NdFeB磁粉两步法伴温磁场取向制备高性能柔性各向异性NdFeB黏结磁体

High performance anisotropic NdFeB flexible bonded magnets prepared by magnetic alignment with temperature utilizing HDDR NdFeB powder

利用高性能吸氢-歧化-脱氢-再复合(HDDR)NdFeB各向异性磁粉,通过两步法伴温磁场取向工艺制备高性能柔性各向异性NdFeB黏结磁体,重点研究了两步法伴温磁场取向工艺制备出不同成分配比磁体的磁性能和力学性能.结果发现:制备出磁体的取向度有大幅度提高,当成分配比(质量分数)为96.5%磁粉+1%偶联剂+2.5%黏结体系的磁体在120℃加热保温30 min磁场取向后,磁能积达到97 kJ.m-3,而磁体的矫顽力最大降幅只有1.3%,论证了两步法伴温磁场取向工艺制备柔性各向异性NdFeB黏结磁体在实际生产的可行性.环氧树脂润滑剂的加入使得制备出磁体的延伸率和柔性均大幅度下降,并且加入量越多,下降幅度越大,因此环氧树脂润滑剂最大加入量不应超过1%(质量分数).

High performance anisotropic NdFeB flexible bonded magnets were prepared by a two-step method which includes cal- endering and magnetic alignment steps utilizing hydrogenation-disproportionation-desorption-recombination （HDDR） NdFeB powder, and their magnetic and mechanical properties were investigated. It is found that the degree of alignment （DOA） of the flexible bonded magnets goes up sharply. The maximum energy product （BH）m^x is 97 kJ. m-3 for the composition of 96.5% magnetic powder, 1% coupling agent, and 2. 5% bonded rubber after heated at 120 ~C for 30 min during magnetic alignment, while the coercivity of the flexi- ble bonded magnets only decreases by 1.3% , which further proves the feasibility of the two-step method in industrial production. Because the mechanical properties of the flexible bonded magnets will deteriorate with the amount of epoxy resin lubricant increasing, the mass fraction of epoxy resin lubricant should be less than 1%.