Dependence of the magnetic properties of Zn bonded Sm/sub 2/Fe/sub 17/N/sub x/ magnets on the particle size distribution

摘要

By adjusting the particle size distribution of the Sm/sub 2/Fe/sub 17/ alloy-powder the density of cold isostatically pressed (p=200 MPa) magnets as well as of die-pressed (p=600 MPa) magnets could be improved up to 72% of the theoretical density. A remanent polarization and a coercivity of 0.77 T and 10.8 kA/cm could be achieved for Zn-bonded magnets containing 5 wt.% Zn. The temperature coefficients of Zn-bonded Sm/sub 2/Fe/sub 17/N/sub 3/ magnets are superior compared to polymer-bonded Nd-Fe-B magnets and amount to /spl alpha/(J/sub r/)=-6.06%/K and /spl alpha/(H/sub cJ/)=-0.36%/K.