Several 14 ct red gold alloys for investment casting with different composition have been studied and compared. A 585Au-80Ag-335Cu alloy that is particularly used in Russia has been taken as a reference. Starting from this composition, several different alloys have been formulated, with the addition of different amounts and combinations of different alloying elements, like zinc, gallium, indium, silicon and iridium.
The different additions have been balanced, in such a way to keep a colour similar to the reference alloy. Different characteristics of the studied alloys have been evaluated, that are relevant to investment casting, i.e. shrinkage and gas porosity, grain size, mould filling ability, melting temperature and range and resistance to oxidation.