Microstructures and tensile properties of CuZrAlNb metallic glass composites under different cooling rates

Cu_48-xZr₄₈Al₄Nb_x (x = 1 or 5 at.%) metallic glass composite rods with diameters of 4 mm, 3 mm and 2 mm were prepared by using copper mold drop-casting. Their microstructures and tensile properties under different cooling rates were investigated. The microstructure and tensile properties of samples were affected by the crystalline phase content. With the increase in Nb content or the decrease of cooling rates, the microstructures of samples crystallized more significantly and the tensile fracture strength reduced. The fracture mode changed from shear fracture to brittle fracture, shear bands on the side surface decreased and vein stripes on the fracture surface were transformed into plastic pit structures as Nb content increased from 1 to 5%. The results may be helpful for the investigation of metallic glass composite mechanical behavior.