Composition, Structure, And Property Regulation Of 2:17 SmCo Magnet

Due to the high Curie temperature,good temperature stability and corrosion resistance,the 2:17-type SmCo rare-earth permanent magnetic material has been attracted in high temperature fields,such as the microwave communication,aviation,military military.Based on the theory of composition design of high energy 2:17 type SmCo permanent magnet,the composition of the magnet and the sintering process were optimized by means of mixing powder.By means of scanning electron microscopy,energy dispersive spectroscopy,electron probe,X ray diffraction and magnetic light Kerr microscopy,the phase morphology,element distribution and content,magnetic domain state of the magnet were studied.In addition,the magnetic properties of the magnet at room temperature and high temperature were measured by using the NIM-500C ultra high temperature permanent magnet measuring instrument.This paper studies the Sm(Co_0.65Fe_0.28Cu_0.05Zr_0.02)_z magnet with z=6.2-7.4 value.For the optimal magnet composition of Sm(Co_0.65Fe_0.28Cu_0.05Zr_0.02)_6.8,the sintering temperature and the temperature of solution are explored.In addition,the high temperature magnetic properties of the magnet with the sintering temperature of1200?,the solid solution temperature of 1150?,1155?,1160?and 1165?are tested.At the same time,the magnetic properties of the magnets with solid solution temperature of 1155?are B_r=11.92k Gs,H_cj=8.89kOe and?BH?_max=22.19MGOe.Under the condition of 300?,the magnetic properties of the magnet are B_r=10.41kGs,H_cj=3.54kOe and?BH?_max=14.22MGOe.The temperature coefficient of the remanence?_18?-300?is-0.0449%/?and the temperature coefficient of coercive force?_18?-300?is-0.2134%.By improving the process parameters,the magnetic properties of the magnet were optimized.The optimal sintering temperature was 1215?,and the solid solution temperature was 1150?.The magnetic properties were B_r=12.03k Gs,H_cj=7.97kOe and?BH?_max=26.90MGOe.In addition,in order to further improve the coercivity,Cu micron particles with mass fraction of 0.25 wt.%,0.5 wt.%,0.75 wt.%and 1.0 wt.%were added.For the magnet doped with 1.0 wt.%Cu microparticles,the magnetic properties are B_r=11.64kGs,H_cj=15.92kOe and?BH?_max=27.66MGOe;when tested at300?,the magnetic properties are B_r=10.30kGs,H_cj=6.17kOe and?BH?_max=19.66MGOe.The samples with copper content of 1.0 wt.%have better high temperature magnetic properties than that of the samples without copper addition.The remanence temperature coefficient of the magnets with different copper content was about-0.04%/?,and the temperature coefficient of coercivity of the magnets with0.25 wt.%content was-0.1719%/?.Through the analysis of magnetic domain,it was found that the magnetic domain of samples with copper doped turnedover more slowly.By means of electron probe analysis,it was found that copper diffused into the grain interior and the magnetic properties of the magnets were improved by doping copper.