Abstract
This experiment was carried out to investigate the effect of Y addition on magnetic properties of Sm-Fe-Co-Mn-Ti system nitride with TbCu7-type structure. Sm10(Fe0.9Co0.1)89−xMn0.5Ti0.5Yx (x=0∼2.0) alloy ribbons were prepared by the single roller rapid-quenching method. And the effect of alloy composition, and conditions of heat-treatment and nitrogenation on the magnetic properties were examined. The typical preparation conditions of the compound with high coercivity are as follows. Composition: {Sm10(Fe0.9Co0.1)87.7Mn0.5Ti0.5Y1.3}85.3N14.7, roller velocity: 50 m/s, heat treatment condition: 660°C×60 min in high-purity Ar gas, and nitrogenation condition: 420°C×15 h in high-purity N2 gas. Typical magnetic properties of the obtained powder are Jr=0.77 T, HcJ=1649.6 kA/m, (BH)max=104.1 kJ/m3, and TC=532°C. The average crystal particle size of heat treated ribbon was 13 nm. The value of (BH)max for the isotropic compression molding bonded magnet prepared from the {Sm10(Fe0.9Co0.1)87.7Mn0.5Ti0.5Y1.3}85.3N14.7 powder is 57.50 kJ/m3, when the density of bonded magnet is 6.00 Mg/m3. And the relative temperature coefficient of Jr is α(Jr)=−0.044 %/°C, the temperature coefficient of HcJ in the range from 25°C to 125°C obtained by a linear interpolation is α(HcJ)=−0.488 %/°C. And we examined the temperature dependence of the flux loss rate on Sm-Fe-Co-Mn-Ti-Y-N and MQP-A bonded magnet. When the temperature is 150°C, the flux loss rate of MQP-A bonded magnet is −3.09%, that of Sm-Fe-Co-Mn-Ti-Y-N bonded magnet is −2.36%.
