研究了在取向磁场下由HDDR磁粉注射成型的各向异性粘结NdFeB磁体,分析了粘结剂和添加剂对各向异性粘结NdFeB磁体的密度、磁性能以及抗压强度的影响。通过磁粉表面改性,磁粉的抗氧化性能以及磁体的磁性能都得到提高。比较了6种粘结剂对磁体性能的影响,从中得到比较理想的粘结剂,并且考察了抗氧剂以及润滑剂加入量对于磁体性能的影响。试验中,混炼温度为205-215℃,注射温度为265℃,注射压力为5~6MPa,保压时间为5s,模具加热温度为80℃。制得的磁体的性能为:Bt=0.72T,iHc=983kA/m,(BH)max=75kJ/m^3。
This study is on the anisotropic Nd-Fe-B bonded magnets fabricated from HDDR powders by injection molding process under orientation magnetic field. The effects of polymer binder, chemicals such as coupling agent for surface modification of the powders, antioxidant and lubricant on the density, magnetic and the mechanical properties of anisotropic Nd-Fe-B magnets were investigated. The corrosion resistance of the powder and magnetic properties of the magnets would improve through the surface modification of the powders. Six kinds of binder and the amount of antioxidant and lubricant were studied. The magnetic properties of the anisotropic bonded Nd-Fe-B magnets fabricated in the following conditions: mixing temperature of 205-215 ℃, injection temperature of 265 ℃, injection pressure of 5-6 MPa, press holding time of 5 s, and molding temperature of 80 ℃, were Br of 0.72 T, iHc of 983 kA/m, (BH)max of 75 kJ/m^3.