Surface enrichment of low gold alloys

Characteristic dissolution kinetics, obtained from a nuclear tracer technique (gammaspectrometry) and surface analysis (ESCA) measurements, of some metals and alloys immersed in chloride-containing water are presented. The tarnishing of low gold alloys in simulated saliva solutions is shown to be less severe when silver is excluded as an alloying element in these alloys. Experimental data on interdiffusion at room temperature of a gold-copper-zinc alloy are presented, and it is seen that these diffusion data predict the lowest possible dissolution rate of the alloy exposed to an aqueous solution.