METHOD OF TREATMENT OF CASTINGS MADE FROM GOLD-BASED ALLOYS Russian patent published in 2006 - IPC C25F3/16 

FIELD: electrochemical treatment of surfaces: electrochemical polishing of intricate profiles of gold-based alloy castings.

SUBSTANCE: proposed method includes preparatory mechanical treatment of surfaces with hand tools, preliminary electrochemical polishing of surface in electrolyte of the following composition: thiocarbamide, 90 g/l; concentrated sulfuric acid, 70 g/l at the following parameters of technological current pulses: duration, (0.5-2)·10^-3 s; period-to-width ratio, 1.5-3; amplitude current density, 5-10 A/dm², stamping and final polishing of surface in electrolyte of the same composition at the following parameters of technological current pulses: duration, (2-3)·10^-3; period-to-width ratio, 1.25-1.5; amplitude current density, 3-5 A/dm²; average micro-roughness of surface after mechanical treatment with hand tools is kept at level of R_z= (2.0-1.6)·10^-6 m; preliminary polishing of surface is continued till average micro-roughness is at level R_z= (0.4-0.2)·10^-6 m; final polishing of surface is performed till average micro-roughness of surface is at level R_z= (0.05-0.02)·10^-6.

EFFECT: improved quality of finishing of gold-based alloy castings.

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