Devitrification behavior and glass-forming ability of Cu-Zr-Ag alloys

This paper presents an influence of Ag addition on the glass-forming ability and devitrification behavior of Cu-Zr glassy alloys on heating. The crystallization kinetics and structure changes in Cu45Zr45Ag10 and Cu35Zr45Ag20 glassy alloys on heating were studied by X-ray diffraction, transmission electron microscopy, differential scanning and isothermal calorimetry methods. Based on the results obtained one can assume that the improvement of the glass-forming ability of the Cu-Zr alloys by the addition of Ag is connected with a particular crystallization mechanism and a higher reduced glass-transition temperature of the Cu45Zr45Ag10 ternary alloy compared to the binary Cu55Zr45 counterpart. As observed in the present work crystallization of the Cu-Zr-Ag alloys is found to cause embitterment of the samples and should be avoided as these alloys are considered to be used as structural materials. The Cu35Zr45Ag20 alloy shows possible submicron-scale phase separation upon annealing. (C) 2007 Elsevier B.V. All rights reserved.