Quaternary Fe-based bulk metallic glasses with a diameter of 5 mm

Bulk metallic glasses with a diameter of 5 mm were obtained by drop casting in the quaternary Fe–B–Y–Nb and Fe–B–Y–Mo systems. Starting from the best glass former Fe71.2B24Y4.8 in the ternary Fe–B–Y system, the search quickly led to the discovery of the quaternary good glass formers (Fe71.2B24Y4.8)96Nb4, (Fe73.2B22Y4.8)95Mo5 and (Fe70.7B24Y5.3)95Mo5 after trying only around a dozen of alloys. No obvious glass transition event was observed for these quaternary alloys. No Nb and Mo containing crystalline phases were detected in the alloys studied. The potential beneficial effects of Nb and Mo in enhancing the glass forming ability (GFA) of the Fe–B–Y alloy system are discussed.