CORRELATION BETWEEN ELASTIC-CONSTANTS AND FLOW BEHAVIOR IN METALLIC GLASSES

The addition of glass formers, B and P, raises not only the shear stiffness but also the tensile yield strain (εy) of Fe- and Co-based glasses. εy increases by a factor of 2 from 1.23×10 -2 for Pt-Ni-P glasses to 2.45×10-2 for Fe-B glasses as the Poisson's ratio decreases from 0.42 to 0.32. The Vickers hardness of a Fe75B25 glass attains 1300 kg/mm2 which is the highest value reported for metallic glasses. The directionality of interatomic forces either due to atomic ordering or s-d hybrid bonding in transition metals is proposed to be responsible for this behavior.