Deformation behavior of a Zr-based bulk metallic glass under a complex stress state

In this work, the deformation behavior of a Zr-based bulk metallic glass specimen under a tailored complex stress state was investigated. When the specially designed specimen was subjected to a uniaxial tensile loading, the in-plane stress distribution along the symmetrical plane was hyperbolic, with the presence of both compressive and tensile stresses. The evolution of deformation in the specimen was found to consist of three stages: the shear band initiation stage (stage I), the shear band multiplication stage (stage II) and the final rapid fracture stage (stage III). In a conventional tensile specimen with uniformly distributed stresses, the specimen fractures (stage III) catastrophically after stage I. However, in the specially designed specimen, the complex stress distributions result in not only more stable shearing processes in stage I, but also the evolution of stage II before stage III, which causes the formation of a large number of shear bands. The findings shed more light on the deformation mechanisms of bulk metallic glasses under complex stress states.