Crack-tip plasticity in bulk metallic glasses

The fracture and plastic deformation mechanisms of a Zr-Ti-Ni-Cu-Be bulk metallic glass are reviewed. In particular. the effects of stress state and local heating on the development of shear bands are discussed. The temperature increase at the crack tip during fracture was measured and was found to be consistent with predictions of the dissipation of plastic work as heat. In order to examine the effect of stress state on failure. tensile bars with notches of varying severity were used to superimpose a tensile mean stress. A constant mean stress was found to provide an accurate correlation with the onset of strain localization and failure. (C) 2001 Elsevier Science B.V. All rights reserved.