Melt Spinning Process and Its Effect on the Magnetic Properties and Structure of Sm (Co, Fe, Cu, Zr)z Melt-Spun Ribbons

The Sm(Co_0.93-x-yFe_xCu_0.07Zr_y)_7.8 (x = 0.245-0.27, y = 0.02, 0.025) ribbons are prepared by melt spinning at the wheel speed of 10-60 m/s. It is found that the thickness of the ribbons is inversely proportional to the wheel surface speed ranging from 10 to 60 m/s. The X-ray diffraction and transmission electron microscopy results show that the ribbons melt-spun at 25-50 m/s are composed of 1:7H phase. Magnetic measurements show that the saturation magnetization Ms locates in the range of ~80 to ~110 emu/g, and remanence Mr from ~50 to ~80 emu/g, and intrinsic coercivity H_cj from~1200 to ~5000 Oe with the increase in v from 25 to 50 m/s. The optimal magnetic properties of the ribbons are M_s: ~100 emu/g, M_r: ~70 emu/g, H_cj: ~5000 Oe for Sm(Co_0.66Fe_0.245Cu_0.07Zr_0.025)_7.8 ribbons at v = 40-50 m/s.