The investigation of the electrolytic etching parameters for a gold alloy

Goldsmith has been practiced since as early as 4000 BC but the microstructure examination of precious metals is still an enigma to many metallographers. The precious metal industry, historically secretive, was slow to share technology. In this study, the effects of the electrolytic etching reagents and etching parameters on microstructure for a gold alloy with composition of 91.60 Au - 7.44 Cu - 0.63 Ag - 0.21 Zn - 0.12 Ni (in wt.%) has been investigated. The determination of the optimum etching conditions has been performed using an etching reagent of 32% HCl.