Enhanced Glass Forming Ability of Fe–Co–Zr–Mo–W–B Alloys with Ni Addition

A new bulk metallic glass (BMG) with superior glass forming ability has been successfully developed based on the Fe–Co–Zr–Mo–W–B system, by addition of a certain amount of Ni. The as-cast, bulk amorphous Fe[[inf]]58[[/inf]]Co[[inf]]6[[/inf]]Ni[[inf]]4[[/inf]]Zr[[inf]]10[[/inf]]Mo[[inf]]5[[/inf]]W[[inf]]2[[/inf]]B[[inf]]15[[/inf]] alloy of 3 mm diameter had a high thermal stability with a glass transition temperature above 880 K, a supercooled liquid region up to 70 K and a high hardness up to 1283 kg f mm[[sup]]−2[[/sup]]. It was found that a minor addition of Ni had an important influence on the glass forming ability in this bulk amorphous alloy system. Compression testing at room temperature showed that the bulk amorphous sample, with compression fracture strength of 1823 MPa, was a rather brittle material.