Acta Metallurgica Sinica (English Letters) ›› 1993, Vol. 6 ›› Issue (11): 341-344.

• Research paper • Previous Articles     Next Articles

PREPARATION OF HIGH COERCIVE Sm-Fe-N PERMANENT MAGNET

LIU Wei WANG Qun ZHAO Xinguo ZHAO Tong ZHANG Zhidong SUN Xiaokai Institute of Metal Research,Academia Sinica,Shengyang,China research assistant,Institute of Metal Research,Academia Sinica,Shenyang 110015,China   

  • Received:1993-11-11 Revised:1993-11-11 Online:1993-11-11 Published:2009-10-10

Abstract: Using pure Sm and Fe powders as starting materials,high coercive Sm-Fe-N mag- nets have been prepared by mechanical alloying in combination with beat treatment and nitriding.The best result is:_iH_c=33.1 kA/cm(41.6 kOe)and(BH)_(max)=98.7 kJ/cm~3(12.4 MGOe).The phases formed in the specimens during mechanical alloying, crystallizing and nitriding processes were examined by X-ray diffraction technique.The magnetic properties of the specimens were measured with the pulsed magnetometer in field up to 12 T.Experimental results show that mechanical alloying is an efficient ap- proach for preparing high coercive magnets.As an important factor for obtaining a high coercivity,the grain sizes of magnets are about tens of nanometer.The presence of some soft magnetic phases in the specimens leads to a neck on the demagnetization curve.

Key words: Sm-Fe-N magnet, mechanical alloying, nitriding, annealing