Tensile Elastic Behavior of a Zr–Cu–Ag–Al Bulk Metallic Glass

Tensile elastic behavior of bulk Zr 46 (Cu 4.5/5.5 Ag 1/5.5 ) 46 Al 8 metallic glass was experimentally investigated. It exhibited linear and non-linear time-independent elastic deformation with a demarcative stress of approximately 500 MPa within the timescale in the present work, and repeated loading–unloading before yielding did not alter stress–strain relationship. The pure linear elastic strain limit is 0.6%, significantly lower than 2% as generally reported, but still much higher than 0.1% observed for typical crystalline alloys. Deviation from linear elastic behavior at stresses higher than 500 MPa is explained here as a macroscopic manifestation of local fluctuations in elastic strain, which becomes pronounced at stresses higher than the critical value. The occurrence of non-linear elasticity is possibly also related to the sinusoidal relationship between shear stress and atomic displacement.