Microstructure and mechanical evolution of Ti-based bulk metallic glass induced by deformation and isothermal annealing in supercooled liquid region

•Thermally-deformed specimens have a denser structure and higher characteristic temperature than the annealed specimens.•Thermally-deformed and annealed specimens precipitated some nanocrystals with the size of approximately 10 nm at 648 K.•The yield and fracture strengths of the thermally-deformed specimen are higher than that of the annealed specimen.•Both the 648 K-deformed and 648 K-annealed specimens exhibited brittle fracture characteristics. The effects of deformation and isothermal annealing in supercooled liquid region on the microstructure and room-temperature mechanical properties of the Ti33Zr30Cu9Ni5.5Be22.5 bulk metallic glass were systematically investigated. The results indicated that the thermally-deformed specimens exhibited denser structures and higher characteristic temperatures (Tg and Tx) than the annealed specimens at the corresponding temperature; however, this difference gradually decreased as the experimental temperature increased. Further, the thermally-deformed specimens exhibited higher yield and fracture strengths than the annealed specimens, whereas they exhibited similar plasticity. The deformed and annealed specimens precipitated some nanocrystals with a size of approximately 10 nm when the experimental temperature increased to 648 K, causing the rapid deterioration of their plasticity.