Ductile Co-Nb-B bulk metallic glass with ultrahigh strength

A ternary Co61Nb8B31 bulk metallic glass with plasticity of 5% and yield strength of 5200 MPa was fabricated. It is shown that the primary crystallization product of the Co61Nb8B31 glass is the vertex- and edge-sharing Co2Nb type phase. The enhanced plastic strain is consistent with the observed multiple shear bands that can redistribute the internal shear stress. The appreciable plastic strain favors the formation of metallic bonding network-like structure and holds high Poisson's ratio. (c) 2013 Elsevier B.V. All rights reserved.