Ternary bulk metallic glasses formed by minor alloying of Cu_8Zr_5 icosahedron

摘要

Icosahedron Cu_8Zr_5, derived from the Cu_8Zr_3 phase structure, corresponds to the deepest eutectic Cu_(0.618)Zr_(0.382). Near this composition is the best glass-forming Cu-Zr composition, Cu_(0.64)Zr_(0.36). (Cu_(0.64)Zr_(0.36))_(1-x)M_x and (Cu_(0.61)Zr_(0.382))_(1-x)M_x were examined for glass formation, where M represents Nb, Sn, Mo, Si, V, Ag, or Ta. A series of Cu-Zr based bulk metallic glasses are discovered with minor Nb, Sn, Mo, Ag, and Ta additions (lower than 3 at. %). The minor alloying mechanism was discussed in the light of atomic size and electron concentration factors.