Mechanical properties and corrosion behavior of (Cu0.6Hf0.25Ti0.15)90Nb10 bulk metallic glass composites

An in situ formed (Cu0.6Hf0.25Ti0.15)90Nb10 (number indicate at.%) bulk metallic glass (BMG) composite was prepared by copper mold casting. The ductile Nb-rich crystalline phase with a dendritic structure disperses homogeneously in the glassy matrix. The (Cu0.6Hf0.25Ti0.15)90Nb10 composite alloy exhibits much higher corrosion resistance in 1N HCl and 3 mass% NaCl solutions than the Nb-free alloy. The addition of Nb is favorable for the alloys to form a Hf-, Ti- and Nb-enriched highly protective surface film with higher chemical stability in HCl and NaCl solutions. Young's modulus, compressive fracture strength and compressive plastic strain of the (Cu0.6Hf0.25Ti0.15)90Nb10 BMG composite are 106 GPa, 2625 MPa and 12.5%, respectively. The increase in compressive strain-to-failure is due to the ductile dendrites restricting shear band propagation, promoting the generation of multiple shear bands.