The Optimazation And Mechanism Reaserch On Bonded Ndfeb Magnets

In this paper,the influence of coupling agent,solidification process,formation process and the size of NdFeB powder on NdFeB bonded magnet has been systematically studied by a lot of experiments and the mechanism analysis has been discussed.The results show that the effect of titanate coupling agent coated is better than silane coupling agent coated on the magnetic property of the bonded NdFeB magnets.From the analysis of the relationship between different particle size and the magnetic properties,the proportion of the particle size with<100mesh,100-200mesh,>200mesh is 1:2:3,can get the better result.Epoxy resin with the midsplit epoxy value is better than low epoxy resin to the magnetic performance and the content is 2.5wt%will do good to improve the magnetic properties of the bonded NdFeB magnet.The combination with higher magnetic and mechanic properties of the bonded magnet is presented on the basis of proper solidification process.It is 120℃×120min and proper mold pressure is 600MPa, keeping Press time is 30-40 seconds.Using orthogonal test optimize the fabrication process,it has shown that the affecting order of the processing factors is:forming pressure >size ratio>binder >coupling agent.The optimum process parameters are:<100mesh:100 - 200 mesh: >200mesh as follow:1:2:3.coupling agents:1.0wt%,binder:2.5wt%,forming press: 600Mpa.The better performance of bonded NdFeB magnets,the properties are B_r=0.724T,H_ic=873kA·m^-1,(BH)max=76kJ·m^-3,σ= 126Mpa。...