The effect of quenching rate on structure and soft magnetic properties of high Bs Fe-based nanocrystalline alloys

摘要

Recently some nanocrystalline soft magnetic materials containing nano-sized α-Fe grains have been obtained by crystallization of amorphous melt-spun ribbons. These structures are nanocomposites in which nano-sized grains are distributed within an amorphous matrix. The soft magnetic ribbons composed of Fe_(80)B_(10)Si_8Nb_1Cu_1 alloy were prepared by melt spinning method with different quenching rates (wheel speed of 10, 20 and 40 m/s). The XRD results exhibit an increase in the copper wheel speed (quenching rate) causes the fraction of crystallinity and grain size to decrease. The grain size varies in the range of 20 to 200 nm that is in good agreement with TEM results. The VSM results show that these nanostructured samples exhibit coercivity in the range of 10 to 30 A/m and magnetic saturation in the range of 1.5 to 1.7 T.