Quasi-static and dynamic compressive deformation behaviors in Zr-based amorphous alloys containing ductile dendrites

Abstract

Quasi-static and dynamic compressive properties of four Zr-based amorphous alloys containing ductile dendrites, whose sizes were varied with cooling rates, were investigated. Deformation mechanisms related with property improvement were investigated by focusing on how the size of ductile dendrites affected the initiation and propagation of deformation bands. These alloys contained 47-49 vol% of dendrites whose effective sizes were ranged from 15 pm to 43 pm, and showed excellent quasi-static compressive properties of maximum strength over 1.3 GPa and total strain up to 34%. Under the dynamic compressive loading, the compressive strength increased up to 2.1 GPa, whereas the total strain decreased to 9-10%. According to the observation of dynamic compressive deformation behavior, dendrites played an important role in improving the ductility by interrupting the radical propagation of shear cracks initiated at the amorphous matrix and by taking over a considerable compressive load. Particularly in the alloy containing sufficiently coarse dendrites for developing deformation bands, the deformation took place relatively homogeneously as the applied stress could be effectively dispersed even under the dynamic loading. (C) 2013 Elsevier B.V. All rights reserved.