Processing, microstructure and properties of bulk metallic glass composites

초록

A Zr-Nb-Cu-Ni-Al bulk metallic glass was reinforced with up to 80 volume-percent (% V-f) continuous fibers, short fibers or particles. Characterization based on X-ray diffraction, differential scanning calorimetry, electron microprobe and scanning electron microscopy is presented. The metallic glass matrix remains amorphous after adding reinforcements. Reactions at the matrix/reinforcement interfaces were examined using transmission electron microscopy. A narrow band of crystalline particles typically forms adjacent to the reinforcement. The composites were tested in compression. Compressive strain-to-failure increased by up to a factor of 12 compared to the unreinforced bulk metallic glass. The increase in compressive strain-to-failure is due to the particles restricting shear band propagation, promoting the generation of multiple shear bands and additional fracture surface area.