L.V. Sitnikov, N.P. Kulik, N.I. Markelova, N.K. Tkachev,
A.A. Pankratov, N.I. Moskalenko, B.D. Antonov.
ABSTRACT
The formation of microporous metallic structures during the electrochemical dealloing of a single-phase Ag0.58Au0.37Pd0.05 alloy in a salt melt medium: in the LiCl0.57CsCl0.26KCl0.17 eutectic at a temperature of 306°C, in CsCl0.455KCl0.245NaCl0.30 + 3 mol % AgСl – at 510, 600, 700 and 815°С. Based on potentiodynamic curves, potentials for electrolysis were selected. Because of selective anodic dissolution in the potentiostatic mode, typical mutually continuous structures with pore and ligament sizes from 0.5 to 10 μm were obtained. The appearance of pores can be traced up to 815°C, but their specific density on the surface drops significantly.
An increase in the temperature of the process causes coarsening or recrystallization of the porous structure, the pore sizes increase, and the selectivity of silver dissolution decreases. It’s almost complete removal from the alloy was achieved at the lowest temperature of 306°C as a result of anodic dissolution at a potential of 0.6 V relative to the silver chloride reference electrode (Ag / LiCl0.57CsCl0.26KCl0.17 + 3 mol % AgCl).
KEYWORDS
selective anodic dissolution, gold alloys, molten salts, porous structure
DOI: 10.31857/S0235010621060098