Phase Separation and Crystallization in Cu-Zr Metallic Glasses

Abstract

The structural behavior of rapidly quenched Cu-Zr amorphous alloys was analyzed. High energy X-ray diffraction patterns and atomic pair correlation functions exhibit monotonic changes with composition. The experimental results can be well described by a solid solution-like replacement of Cu and Zr atoms in the whole composition range. No indications are observed that would support the existence of phase separation in the supercooled liquid state of the binary Cu-Zr alloys. For Cu₆₀Zr₃₀Ti₁₀ and Cu₆₀Zr₂₀Ti₂₀ bulk metallic glasses the formation of ultrafine nanostructures are proven upon heating. The transformation starts below the glass transition temperature. Phase separation in Cu-Zr-Ti bulk metallic glasses is related to primary crystallization.