Crystallization behavior, soft magnetic properties and good bending ductility of high Fe content FeSiBCuPC alloys induced by composition design

Effects of the minor addition of similar ferromagnetic elements (Fe, Co, Ni, and Gd), metal element with strong non-metallic properties (Al), and transition metal elements with large atomic radius (V, Hf, Ti, and Cr) on crystallization behavior, magnetic properties and bending ductility of Fe85Si0·5B9P4Cu0·5C0.1M0.9 alloys were systematically investigated. The addition of Al, Ni, and Co improves the thermal stability and inhibits the growth of the α-Fe grains. Besides, Gd addition causes a large temperature interval, which suppresses the precipitation of secondary phase. Through the optimum heat treatments, the nanocrystalline alloys exhibit excellent soft magnetic properties, such as higher Ms of 191.7–208.7 emu/g and lower Hc of 6.7–12.1 A/m. Due to the nature of brittleness, the shear morphology induced by elemental microalloying is critical for understanding microscopic mechanism of plastic deformation and achieving high toughness amorphous alloys. We demonstrate that the formation of shear bands are related to the degree of amorphization, shear transformation zones and Poisson’s ratio.