Effect of B addition on the microstructure and magnetic properties of melt-spun Sm12Co60-xFe19Cu6Zr3Bx (0 ≤ x ≤ 3) ribbons

The melt-spun Sm12Co60-xFe19Cu6Zr3Bx (0 <= x <= 3) ribbons were prepared using arc-melting method at a wheel speed of 20 m/s followed by annealing at different temperatures. The structural characterization showed that Sm12Co60-xFe19Cu6Zr3Bx (0 <= x <= 3) ribbons were mainly composed of TbCu7-type phase and alpha-Fe phase. The alpha-Fe phase in melt-spun ribbons was increased and the glass-forming ability (GFA) of Sm-Co matrix alloys was improved with the addition of B. The TbCu7-type phase in the ribbons annealed over 700 degrees C for 10 min was observed to decompose into Th2Zn17, CaCu5 and alpha-Fe type phases. The addition of higher B content resulted in decomposition of TbCu7-type phase more easily. Both coercivity and remanence were significantly affected by the B addition and annealing temperature. The Curie temperatures of amorphous Sm-Co phase, Sm(Co,M)(5) and Sm-2(Co,M)(17) were found between 445 degrees C and 484 degrees C, 684 degrees C and 714 degrees C and 840 degrees C and 854 degrees C, respectively. (C) 2010 Elsevier B.V. All rights reserved.