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Zusammenfassung:
The influence of Ag addition on the microstructure of rapidly quenched
(Cu0.5Zr0.5)(100-x)Ag-x melts was investigated (x = 0-40 at.%). Fully
glassy alloys were obtained for 0 <= x <= 20 at.% Ag, which are
characterized by a homogeneous microstructure without any indication of
phase separation. For 30 <= x <= 40 at.% Ag a composite structure is
formed consisting of fcc-Ag nano-crystallites 5 nm in size and an
amorphous matrix phase Cu40Zr40Ag20. With higher Ag-content the volume
fraction of the fcc-Ag phase becomes increased mainly due to crytal
growth during quenching. The primary formation of fcc-Ag for 30 <= x <=
40 at.% Ag is confirmed by the analysis of the microstructure of mold
cast bulk samples which were fully crystalline. From the experimental
results we conclude that the miscibility gap of the liquid phase of the
ternary Ag-Cu-Zr system may occur only for x > 40 at.% Ag. For the bulk
glass forming quaternary Cu40Zr40Al10Ag10 alloy a homogeneous element
distribution is observed in accordance with the microstructure of
ternary (Cu0.5Zr0.5)(100-x)Ag-x glasses (x = 10, 20 at.%). (C) 2014
Elsevier B.V. All rights reserved.
