Effect of rapid quenching speeds on phase structure and magnetic properties of melt-spun Sm(Co,Fe,Cu,Zr)7.5 ribbons

Abstract Sm(Co 0.68 Cu 0.07 Fe 0.22 Zr 0.03 ) 7.5 nanocrystalline melt-spun ribbons are prepared at different speeds. The results show that the ribbons consist of Sm(Co,M) 7 (M = Cu, Fe, Zr) main phase and a little α-Fe phase. And the ribbons are composed of three areas: equiaxed area, columnar area, and dendritic crystal area. Preferred orientation exists in both the columnar area and the dendritic crystal area. Following the increase of the melt-spun speed, the orientation degree of melt-spun ribbons increases first, then descends, and reaches the maximum ratio I (0 0 2) / I (1 1 1) of 3.81 when the speed is 20 m/s. Preferred orientation in the ribbons helps to improve the magnetic properties of ribbons. The best comprehensive magnetic properties of the ribbons melt-spun at 20 m/s are M r = 39.27 emu/g, M s = 75.79 emu/g, H ci = 1301.9 Oe, and M r / M s = 0.52.