A new Sm-Co-type hard magnetic alloy with an amorphous based nanocrystalline microstructure

摘要

Sm-Co-Al amorphous alloys with high Sm content have very low coercivity at room temperature (RT). In this paper, Sm_(11.6)Co_(60.7)Fe_(15.7)Zr_7Cu_1B_4 alloys with low level of Sm and mixed addition of several elements were prepared via arc melting, copper mold casting and rapid quenching technique, respectively. The ribbons melt-spun at 40 m/s present a novel microstructure with Sm(Co,M)_7 and other minor nanocrystalline phases embedded in the amorphous matrix, which makes the average coercivity reach up to 18.2 ± 1.6 kOe at RT. The temperature dependence of magnetization curves of the ribbons suggest a high content of amorphous phase which is stable and behaves ferromagnetism below 500 °C.