Design of high strength Fe-(P, C)-based bulk metallic glasses with Nb addition

Bulk metallic glass (BMG) rods Fe71Mo5-xNbxP12C10B2 (x=1, 2, 3, 4 and 5) with diameter of 1 or 2 mm were synthesized by copper mold casting. The effects of Nb substitution for Mo on the structure, thermal and mechanical properties of Fe71Mo5-xNbxP12C10B2 alloys were studied by X-ray diffraction, differential scanning calorimetry and compressive testing. The results show that the substitution of Nb for Mo leads to a decreased glass forming ability, but with plasticity of 1.0%, the fracture strength of Fe71Mo2Nb3P12C10B2 alloy increases up to 4.0 GPa. The improvement of the fracture strength is discussed in terms of the enhancement of atomic bonding nature and the favorite formation of a network-like structure due to the substitution of Nb for Mo.