The Impact Regulation Of The Additives On The Strontium Permagnetferrite And Its Mechanism

In order to develop the permagnetferrite industry and satisfy the instant need of the market ,this paper systematically study the impact of the additives on the strontium permagnetferrite and discuss its mechanism from the microstructure. The results show:(1)The basis to obtain the high-powered permagnetferrite includes raw sintered ferrite material with equal diameter, special milling technique, strictly controlling the parameter of molding with magnetic fields and accelerating the rate in sinter process.(2)The additives such as PVA, La2O3 can obviously improve the magnetic when the amount of PVA is 0.4wt%,La2O3 is 0.6wt%. The additives such as CaCO3, TiO2 can obviously improve the magnetic remanence when the amount of CaCO3 is 0.6wt% and TiO22 is 0.6wt%. The additives such as SiO2, HBO3, A12O3, Cr2O3 etc can obviously improve the coercive force when the amount of SiO2 is 0.8wt%, HBO3 is 0.8wt%, A12O3 is 0.6wt%, Cr2O3 is 0.6wt%. (3)Both remanence and coercive force of strontium permagnetferrite can be improved using two add ways of CaCO3-SiO2 and CaCO3-HBO3. when the add amount of CaCO3 is 0.6wt%, SiO2 is 0.4wt%, the best magnetic is Br=417mT, (BH)max=33.2kJ/m3, Hcb=251.2kA/m, Hcj=258.4kA/m. and when the amount of CaCO3 is 0.6 wt%, HBO3 is 0.4wt% ,the best magnetic is Br=420 mT, (BH)max=33.5kJ/m3, Hcb=265.6kA/m, Hcj=276.8kA/m. both of the two ways can reach FB5B standard of TDK company. The coercive force of strontium permagnetferrite can be improved when A12O3 or Cr2O3 was added to CaCO3-SiO2 or CaCO3-HBO3 multi-additives.(4)Comparing with normal CaCO3 and SiO2,the nano CaCO3 and SiO2 improve the magnetic . for thenano CaCO3 and SiO2 have high chemical activations and excellent distribution , the density of permagnetferrite can be improved and the sinter temperature of it can be reduced.