The Microstructure And Mechanical Properties Of High Performance Permanent Magnetic Strontium Ferrite Is Studied

Firstly, the traditional Strontium Ferrite production process was improved, and on the basis of a variety of additives on magnetic properties of strontium ferrite, microstructure and the squareness of demagnetization curve, reached the following Conclusion:1.Forming green body formed with the orientation degree increased with the increase magnetic field strength, but when forming the magnetic field increases to a certain value, the orientation degree of body shape tends to a constant value. The average particle size0.7um for the slurry forming the magnetic field strength to reach for the870kA/m. The average particle size0.4um for the slurry is achieved even if the magnetic field forming870kA/m could not get a satisfactory degree of orientation. Ferrite powder in the crushing process, dry grinding can effectively reduce the magnetic reunion. In wet processing, dispersant can effectively increase the degree of magnetic orientation.2.CaCO3can promote grain flat, but when adding more than1.2%will lead to grain coarsening, add CaCO3and SrCO3densification on with the promotion of the role of the magnet, CaCO3and SiO2composite added to inhibit the coarse grain behavior, by adjusting the CaCO3/SiO2ratio can have different magnetic properties. H3BO3and SiO2can generate low melting point compounds, inhibit the excessive grain growth.3.Al2O3and Cr2O3can be permanent ferrite materials were replaced by Fe3+, both in the pre-sintering between the grains in the ferrite grain growth inhibition. Co2+at high temperatures will partially replace Fe3+, Br and to improve the magnet plays a significant role HcJ. La Department of rare earth metal ions can be greatly increased to replace the coercivity, but difficult to maintain a high remanence.4.La2O3-ZnO composite can be added over435mT high remanence Br material, La2O3-Co2O3compound added to the2.5%increase while Br HcJ increased by35%, adding the number of the best atomic ratio of La:Co=1.5:1.Add Fe2O3can add LaCoSr type magnets Fe3+, Fe2O3the addition of4wt%～6wt%better when obtained magnetic properties:Br:428mT, HcJ>400kA/ m, Fe2O3addition is always less than6wt%access to square degree (Hk/HcJ) greater than0.9magnet. La2O3-Co2O3compound added, lanthanum oxide addition level3.2×10-2mol/kg, atomic number ratio of La:Co=1:3～1:2in the case, can be obtained by adding SrCO3with Br>405mT, HcJ>390kA/m, or Br>410mT, HcJ>370kA/m excellent magnetic properties of magnets, magnet at this time the squareness (Hk/HcJ) greater than0.9.