Gold alloy phase diagrams

Hello to all. I hope someone can help or point me in the right
direction to solve a problem I’ve encountered. I am working on an
enameling project in 18K green gold (75%Au, 25%Ag) and I need a
solder that will flow easily, not melt or flow under 1500 degrees
Farenheit, be close to the 18K green color and karat (optional) , and
be able to be depletion gilded in Sparex (hopefully - or another acid
you might recommend) so that the gold comes up to a oxide free “skin”
after soldering. I have searched the internet for ternary or
quadrary (?) type phase diagrams so that I could see percentages of
each metal (I’m thinking of gold, silver, copper & zinc) but can’t
come up with anything. Does anyone have the name of an obtainable
reference source or is anyone willing to check in their own book of
tables for me? I sure would appreciate any help in getting a
workable formula. Thanks in advance to all!

Diane Almeyda
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