Microstructure and crystallization in Cu50Zr45Al5 metallic glass

Microstructure and crystallization of a Cu50Zr45Al5 metallic glass have been investigated by differential scanning calorimetry, X-ray diffraction and extended X-ray absorption fine structure (EXAFS) using synchrotron radiation. The width of the supercooled region is ΔTx = Tx − Tg = 67 K, where Tx and Tg are the crystallization and the glass transition temperature, respectively; the reduced glass transition temperature is Trg = Tg/Tl = 0.65, where Tl is the liquid temperature; and γ = Tx/(Tg + Tl) = 0.41. After crystallization of the as-prepared Cu50Zr45Al5 metallic glass, crystalline phases are identified as tetragonal CuZr2 and orthorhombic Cu10Zr7. The local atomic structures deduced from EXAFS reveal that Zr atoms in the as-prepared Cu50Zr45Al5 metallic glass are surrounded by about 5 Cu atoms at a distance of 2.70 Å and about 5 Zr atoms at 3.14 Å.