Figure 5

Microstructure of Cu-Zr-based BMGs flash-annealed to temperatures above T _x. (a) SEM-image of a Cu₄₆Zr₄₆Al₈ BMG flash-annealed at φ _ave = 34 K/s to T _ej = 903 K. The microstructure consists of Cu₁₀Zr₇ crystals with a dendritic shape, spherical B2 CuZr particles and a glassy matrix. (b) The corresponding EDX map proves the presence of the Cu-rich Cu₁₀Zr₇ dendrites. Their immediate surroundings are enriched in Zr. (c) SEM-image near the surface of a glassy Cu₄₄Zr₄₄Al₈Hf₂Co₂ rod, which was flash-annealed at φ _ave = 41 K/s to T _ej = 907 K. Only spherical B2 CuZr particles are embedded in the amorphous matrix and the inset depicts the crystal size distribution. (d) DSC curves of the flash-annealed Cu₄₄Zr₄₄Al₈Hf₂Co₂ specimen and the respective as-cast specimen show the glass transition (T _g) as well as crystallization (T _x).