Au-Cu-Ag-based alloys

From the many further alloying elements that are added to Au-Cu-Ag-based alloys, zinc is of particular importance. It is added in large amounts of 4 wt% and significantly above especially to 14kt and lOkt jewelry alloys for color adjustment, but also because it narrows the volume of the immiscibility gap present in the ternary system. This leads to softer and more workable alloys in both the age-hardened and air-cooled states [32]. The addition of 6 wt% Zn to a 14kt alloy or 9 wt% Zn to a lOkt alloy leads to single-phased alloys that are not age hardenable. 

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