FeNi-based bulk glassy alloys with superhigh mechanical strength and excellent soft-magnetic properties

FeNi-based bulk glassy alloys (BGAs) with diameters up to 4mm were formed in [(Fe1−xNix)0.75B0.2Si0.05]96Nb4 system. The increase of Ni to Fe concentration ratio is effective in improving the glass-forming ability. The BGAs exhibit a superhigh fracture strength of 4150–4300MPa, Young’s modulus of 203–215GPa, elastic strain of 0.02, plastic strain of 0.0015, and a well developed vein pattern in the fracture surface. The glassy alloys also exhibit excellent soft-magnetic properties, i.e., rather high saturation magnetization of 0.8–1.1T, low coercive force of 1.2–2.3A∕m, and high permeability of 16 000–24 000 at 1kHz under a field of 1A∕m.