Soft magnetic Fe–Si–B–P–C bulk metallic glasses without any glass-forming metal elements

Abstract

Fe-based bulk metallic glasses with good soft magnetic softness, high strength and relatively low material cost should have greatest potential for wide variety of applications among many kinds of bulk metallic glasses (BMGs). However, the glass-forming metal elements such as Al, Ga, Nb, Mo, Y and so forth in the Fe-based BMGs significantly decrease saturation magnetization ( J s) which is an essential property as soft magnetic materials and also increase the material cost. The development of the Fe-metalloids BMGs without any glass-forming metal elements and with high glass-forming ability (GFA) has been earnestly desired from academia to industry, however, has been left unsolved matter over many years. Here, we present a Fe 76Si 7.6B 9.5P 5C 1.9 BMG exhibiting with unusual combination of higher J s of 1.44 T than those of the other Fe-based BMGs with the glass-forming metal element and high GFA leading to a rod with a diameter of 3 mm. This alloy composed of familiar and low-priced elements also has the extremely low coercivity of 1 A/m which should enable ultra-high efficient transformers as well as the high fracture strength of 3.7 GPa, therefore, could be more viable for engineering applications.