Characterization of multiple crystallization steps in Zr41.2Ti13.8Cu12.5Ni10Be22.5 bulk metallic glass

The effects of crystallization on the thermal and mechanical properties of Zr41.2Ti13.8Cu12.5Ni10Be22.5 (number indicate at.%) bulk metallic glass (BMG) have been systematically studied by varying annealing times at 400 °C. An icosahedral quasicrystalline phase was identified in the specimen annealed for 30 min at 400 °C by using differential scanning calorimetry, X-ray diffraction, and (high-resolution) transmission electron microscopy. Embrittlement behavior due to nanocrystallization has also been examined by carrying out hardness and compression tests for specimens annealed for various times. The fracture strength at room temperature was found to decrease as the annealing time increased. The hardness was, on the other hand, observed to increase due to the increase in nanocrystalline volume fraction with the progress of annealing treatment.