材料期刊网

用电弧熔炼法制备 Sm2(Fex Co1－x )17(x＝0,0．3和0．7)母合金锭,均匀化退火后采用球磨方法制备纳米晶合金粉末.研究了 Fe 掺杂及球磨处理对Sm2(Fex Co1－x )17合金结构、居里温度及永磁性能的影响.实验结果表明,随着Fe含量增多,合金中1∶5相逐渐减少,当x＝0．7时,形成单相2∶17型化合物,同时居里温度从938℃(x＝0)下降到590℃(x＝0．7).球磨处理过程有利于形成单相2∶17纳米合金粉,饱和磁化强度随着球磨时间的增加逐渐增大,同时内禀矫顽力和磁能积与球磨时间的关系呈两头下降的趋势.球磨时间在0．5~1 h 时,纳米合金粉末的永磁磁性能达到最佳,Sm2 Co17的最佳磁性能为4πMs ＝0．65 T,iHc＝246．8 kA/m,(BH)max＝25．5 kJ/m3.

A series of Sm2(FexCo1-x)17(x=0,0.3,0.7)alloy ingots were made by arc-melting method,and then annealed for homogenization.The nanocrystalline Sm2 (Fex Co1-x )17 powders were prepared by ball milling the annealed sample.Effect of Fe-doping and ball milling on the phase structure,the Curie temperature and mag-netic properties of the alloys has been systematically investigated.The experimental results show that upon in-creasing the Fe content,1∶5 phase in the alloy gradually reduces,and for x=0.7 sample,1∶5 phase disap-pears,forming a single-phase 2∶17 type compound.Curie temperature decreases from 938 ℃ for the x=0 sample to 590 ℃ for x=0.7.Meanwhile ball milling process was beneficial for the formation of 2∶17 phase and after ball milling for 0.5 h,1∶5 phase in the alloy disappears,forming single-phase nanopowders.With an in-crease of milling periods of time,saturation magnetization gradually increases,while the intrinsic coercive force and magnetic energy product show a tendency of increase at first and then decrease.Samples milled for 0.5-1 h exhibit optimal magnetic properties with (BH)max=25.5 kJ/m3,iHc=246.8 kA/m and 4πMs=0.65 T for Sm2 Co17 nanopowder.