The influence of Ag addition on the microstructure of rapidly quenched (Cu0.5Zr0.5)100-xAg 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 Cu40Zr40Ag 20. 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 Cu40Zr40Al 10Ag10 alloy a homogeneous element distribution is observed in accordance with the microstructure of ternary (Cu 0.5Zr0.5)100-xAg x glasses (x = 10, 20 at.%).
Bibliographical noteFunding Information:
The authors thank B. Bartusch and B. Opitz for technical assistance. Valuable discussions with O. Fabrichnaya and D. Louzguine are gratefully acknowledged. This work was supported by the Global Research Laboratory (GRL) Program of the Korea Ministry of Education, Science and Technology. Financial support of Tohoku University Sendai is acknowledged for research stay at the Institute for Materials Research (N.M.).
All Science Journal Classification (ASJC) codes
- Mechanics of Materials
- Mechanical Engineering
- Metals and Alloys
- Materials Chemistry