Work-hardenable TiZr-based multilayered bulk metallic glass composites through the solid solution strengthening in ex-situ Ti layers

摘要

To circumvent the trade-off with plasticity and strength, a series of TiZr-based controllable multilayered bulk metallic glass composites (ML-BMGCs), with ex-situ Ti layers and glassy matrix containing precipitated dendrites distribution in an alternate, was fabricated by the hybrid strategy with in-situ and ex-situ. ML-BMGCs exhibit not only enhanced plasticity from 1 +/- 0.2% to 8.4 +/- 0.2% but also improved the fracture strength from 1643 +/- 15 MPa to 1956 +/- 20 MPa under compression. The improved strength is attributed to that the solid solution strengthen of Zr in the ex-situ Ti layers by Zr element diffusion from glassy matrix to them is increasing with Zr addition. Ti layers and the in-situ dendrites create a strong barrier for the shear band propagation and generate multiplies of the shear band after solid solution strengthening, thereby which together with the pronouncedly plastic deformation of Ti layers, greatly improves the plastic deformation capacity.