Network structure composite in phase separating Gd30Zr25Al25(Co/Cu)20 metallic glassy alloys

In the present study, 3-dimensionally interconnected microstructure resulted by spinodal decomposition in liquid state have been investigated in melt spun Gd30Zr25Al25(Co/Cu)(20) alloys. In Gd30Zr25Al25Co20 melt spun ribbon, a positive heat of mixing between Gd and Zr leads the melt to solidify into two different amorphous phases due to their good glass forming abilities (GFA). Rapid quenching keeps an early stage decomposed microstructure with a fine wavelength (similar to 5 nm) frozen in the melt spun ribbon. Replacement of Co by Cu decreases the GFA of Gd-rich phase, thus it solidifies into crystalline phase resulting in a network structure composite consisted of one amorphous phase and one crystalline phase. This result suggests a new method to fabricate metallic glass matrix composite with network structure using phase separation. (C) 2010 Elsevier Ltd. All rights reserved.