Mechanical and Magnetic Properties of New (Fe,Co,Ni)–B–Si–Ta Bulk Glassy Alloys

Abstract

The alloying effects of the like-atom substitution of Ni and Co for Fe on the various properties of Fe70B16.7Si8.3Ta5 metallic glass are investigated in this present work. New Fe-based bulk glassy alloys, namely Fe60–x Co x Ni10B16.7Si8.3Ta5 (at.%; x = 10, 20 and 30) with critical diameters up to 1.5 mm, were made by means of copper mold casting. A new glass-forming ability indicator, viz., the enthalpy of supercooled liquid, has been introduced for assessment of the glass-forming abilities (GFAs) of these Fe-based multi-component alloys. Nano-indentation results indicate that the calculated elastic modulus and hardness of the bulk glassy alloys are lower than those of the Fe70B16.7Si8.3Ta5 alloy. Among these bulk glassy alloys, Fe70B16.7Si8.3Ta5 exhibits the large elastic modulus and hardness with values of 178 ± 1 GPa and 12.9 ± 0.1 GPa, respectively. All the bulk glassy alloys exhibit good soft magnetic properties with high saturation magnetization B s ~ 0.75–1.04 T but low coercive force H c ~ 0.2–5.2 A/m.