Effect of annealing close to Tg on notch fracture toughness of Pd-based thin-film metallic glass for MEMS applications

Notch fracture toughness of Pd-based thin-film metallic glasses, prepared both as-deposited and annealed at 640 K close to the glass transition temperature (Tg = 637 K), was examined by static bending tests. The experimental results show that the notch fracture toughness of thin-film metallic glasses decreased with increasing annealing time at 640 K. The fracture behaviors, the propensity for shear banding, as well as the variation of Young’s modulus of Pd-based thin-film metallic glasses as a function of annealing time, were demonstrated to be correlated with fracture resistance.