Quantitative microscopic measurement of void distribution in shear bands in Zr(66.7)Cu(33.3) metallic glass

We employ an electron phase retrieval technique in the transmission electron microscope to reconstruct the projected thickness maps of metallic glass specimens and measure the void distribution at a microscopic level. We examine an as-spun melt-spun Zr66.7Cu33.3 glass and the shear bands formed in this glass from inhomogeneous deformation in tension and compression. Both as-spun and deformed glasses show no variation in projected thickness indicative of voids down to the limit of this medium-resolution technique (0.32nm). This demonstrates that the free volume generated in deformation does not condense into stable voids larger than 0.32nm in radius, but is distributed diffusely in shear bands.