Brittleness of Zr-based bulk metallic glass matrix composites containing ductile dendritic phase

Zr63Al10Ni10Cu14Nb3 monolithic bulk metallic glass (BMG) and Zr55Al8.5Ni8.5Cu13Nb15 BMG matrix composite containing densely distributed bcc dendritic phase were prepared by copper mould casting. The ductility of the dendritic phase was verified by nanoindentation tests. However, the composite samples exhibit relatively lower yield strength and no plastic strain under room temperature compression test. Microstructural characterization and fractography studies reveal that the simultaneous formation of quasicrystalline phase on the outermost region of the composite results in the brittleness of the composites.