Synthesis and characterization of copper fiber reinforced Zr41.2Ti13.8Cu12.5Ni10.0Be22.5 bulk metallic glass

Highly conductive Cu fibers were introduced into Zr41.2Ti13.8Cu12.5Ni10Be22.5 (Vitreloy1) Bulk Metallic Glass (BMG) of poor conductivity to produce a composite with a thermal anisotropy. The composites with circular and square cross-sections with the volume fraction ranging from 7 to 60% were processed successfully by pressure-gravity infiltration. Differential Scanning Calorimetry (DSC) showed that the BMG matrix remained predominantly amorphous after adding up to 60 vol.% of Cu fibers. The limited crystallization at the Cu/Vitreloy1 interface was observed under optical microscope. This crystallization is attributed to heterogeneous nucleation starting from the Cu/Vitreloy1 interface followed by the growth in the region with higher Cu concentration around the copper fibers. A combination of two-dimensional triangular and square ordering of the fibers was observed in the composite samples. X-ray diffraction patterns of the composites showed the peaks from the reinforced fibers and crystals around the Cu/Vitreloy1 interface superimposed on the broad diffuse maxima from the amorphous phase. Best processing parameters in terms of processing time and temperature were determined for the composite reinforced with 60 vol.% fibers.