Studies Of High-performance M-Type Strontium Ferrites By Wet Compacting

M-type Strontium ferrites has wide applications in the automotive, computer, power tools, home appliances, office equipment and electroacoustic field and other industries as a traditional permanent magnetic material, which will have a huge space for development with automation trends in the global, so how to ensure the premise of the price advantage, improve their magnetic properties has been the focus of social research.High-performance anisotropic Strontium ferrites were prepared by traditional ceramic technique when Magnetic Materials Research Center of Anhui Province will to research and development high-performance anisotropic Strontium ferrites in associate with Benxi Iron and Steel HUANYU Magnetic Materials Co. Ltd. The influences of different ratio of the second additives, milling time and milling process had been study. The best ratio of the second additives, appropriate time and milling process had been found after the experiments. The sample were studied by X-ray diffraction(XRD), field emission scanning electron microscopy(SEM) and permanent magnet material measuring instrument and other equipment. The results were as follows:1,The good shape, impure phase less Y30H-2 pre-sintered grains had been found by scanning electron microscopy(SEM) and energy dispersive spectrometer scattered radiation(EDS).2,The effects of second additives CaCO3,Cr2O3,H3BO3 and Sorbitol on the performance of the sample were studied by the wet-pressing experiment, and found the best ranges of additives:CaCO3=0.7-0.9wt%, Cr2O3=0.3-0.5wt%, H3BO3=0.2-0.4wt%, SiO2=0.3-0.4wt%, Sorbitol=0.7-0.8wt%.3,The effects of different milling time and milling process on the performance of the sample were studied. The results showed that best magnetic properties of the sample was obtained when the milling time was 5h; the Br of sample milling by ball mill made by Benxi Iron and Steel HUANYU Magnetic Materials Co. Ltd increased 10-20mT to the planetary ball made by Nanjing University Instrument Factory, The Hcj-increased 15-20kA·m-1. 4, The effects of sintering temperature on the structure and performance of M-type strontium ferrite were studied. The results showed that the magnetic performance of sample was best when the sintering temperature was 1235℃.5, The optimal additive formulation with 0.8wt%CaCO3,0.3wt%Cr2O3, 0.2wt%H3BO3,0.4wt%SiO2,0.7wt% Sorbitol have been established though the orthogonal experiment. The magnetic properties Br=410.2mT, Hcj=316.0kA·m-1, (BH)max=31.8kJ·m-3,which has been reached the requirements FB5H of TDK Corporation of Japan.6, The sample, which reached FB5H requirements, were studied by X-ray diffraction (XRD), field emission scanning electron microscopy (SEM). The results showed that sample 5 was a single-phase strontium ferrite, hexagonal crystal, and the magnetization arranged along the direction of C axis.