Glass forming ability and microstructure of Zr-Ti-Ni-Cu-Al and Zr-Ti-Ni-Cu-Ag melt spun ribbons

Melt spun ribbons prepared from the alloys (in at.%) Zr-Ti (25-22)-Ni(24-19)-Cu(14-10) with additions of 8 and 10%Al and 10, 11 and 13% of Ag were investigated. By the addition of 10 at.% Al was allowed to completely form a ribbon in the amorphous state. Modification of composition of quaternary alloy Zr-Ti25-Ni21-Cu14.5 with different Al content resulted in an increase of the glass transition, onset of crystallization and liquidus temperatures. The temperature ratio T-g/T-l decreased. Modification of the quaternary alloy composition with addition of 10-13at.% Ag and a decrease of Zr content resulted in an increased tendency for nanocrystallization. HREM observations and EDS analysis allowed us to identify nanoprecipitates as a Ag-based solid solution. This type of precipitates were observed in all Ag-containing ribbons. In comparison with the base ZrTiNiCu alloy, Ag-containing alloys possessed higher T-g and T-x temperatures and relatively high T-g/T-l value. (C) 2003 Elsevier B.V All rights reserved.