Effects of Au and Ge Additions on the Microstructures and Properties of Ag-1.5Cu-0.1Y Alloys.

Desheng Zhang,Sida Li,Hongying Yang,Qin Zhang

doi:10.3390/ma12010123

Abstract

The application of silver is seriously affected by its tendency to oxidize and corrode. Therefore, the addition of proper alloying elements to silver-based alloys to achieve better properties has become a hot topic at present. In this current study, the effects of the addition of the two elements Au and Ge on the microstructures and properties of Ag-1.5Cu-0.1Y alloys were investigated. The results showed that the microstructures were refined and the second dendrite was shortened in the Ag-1.5Cu-0.1Y alloys with the addition of Au and Ge. Adding Au enhanced the corrosion resistance of the Ag-1.5Cu-0.1Y alloys. Furthermore, the corrosion resistance of the Ag-1.5Cu-0.1Y alloys with the addition of both Ge and Au was better than that of the alloy samples with Au added alone. The best corrosion resistance of the Ag-1.5Cu-0.1Y alloys was achieved by adding 1.0 wt.% Au and 1.0 wt.% Ge. The microhardness was enhanced by the addition of Au and Ge, and was strongly correlated with the secondary dendrite arm spacing (λ2) of the Ag-1.5Cu-0.1Y alloys. In addition, the Au addition could improve the conductivity of the Ag-1.5Cu-0.1Y alloy; however, Ge had little effect on the conductivity of the alloy samples. This work provides an experimental basis for the design of better performing silver-based alloys.

Highlights

Silver (Ag), as a precious metal, has a low price and bright white color
The electrical resistivity of the Ag‐1.5Cu‐0.1Y alloys increased with the addition of Ge. It could not be significantly changed by added in the study (Au)
1.5 wt.% Au and Ge may not dissolve well in the Ag-1.5Cu-0.1Y alloy, few black aggregates would appear at the grain boundary

Summary

Introduction

Silver (Ag), as a precious metal, has a low price and bright white color. It gained high popularity in ancient China and was widely used in the production of money, tableware, ornaments, works of art, etc. Researchers often use alloying elements or surface modification to improve silver processing and weather ability [19,20]. The addition of trace Au affected the distribution of Cu atoms in the Al–Cu alloy but caused the segregation of Cu. The effect of Ge on the microstructure and properties of 925 silver has been

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Conclusion