Soft gold

The hardness of such coatings may reach a maximum of about 400 Hy as compared with approximately 50 Hy for a soft gold deposit. A series of corrosion studies in industrial and marine atmospheres by Baker" has indicated that the protective value of hard gold coatings is comparable with that of the pure metal, and that a thickness of only 0-002 5 mm gives good protection to copper base alloys during exposure for six months. 

Industry, however, favours electrodeposited palladium-nickel alloy since it is cheaper than palladium, harder and less prone to cracking, fingerprinting and formation of polymer films Its wear resistance is poor, so it is usually given a thin topcoat of hard (sometimes, soft) gold. ... 

Resuspend the soft gold pellet in 1.5 mL PBS with 0.04% PEG. The hard gold pellet is uncoated gold. 

Gold possesses a unique combination of physical and optical properties. Its malleability, ductility and flexibility make it useful in industry as well as in ornamentation. As it is so soft, gold must be combined with other elements, usually silver, nickel, copper or palladium, before it can be used in coins or jewelry. Ancient gold objects may have a very high gold content because the metal was used just as it came out of the ground. 

Two representative examples of this behavior are reflected in two distinct different chemical systems, namely (a) copper deposition from an acid sulfate electrolyte containing the co-inhibitors PEG-C1 and a bi-functional catalytic species SPS-C1 [12, 136, 243, 264] and (b) silver deposition from a cyanide electrolyte where inhibition is provided by adsorption of silver cyanide species and catalysis is achieved through adsorption of selenocyanate, SeCN [72-75]. Similar behavior is evident in some electrolytes used for the deposition of bright soft gold films [121, 180, 255-261, 267]. 

The soft gold metal center displays a higher affinity for the carbenic center than the nitrogen center so that a translocation of the Mo and Au metal centers was observed. 

The thickness of the soft gold plating on the nickel base is specified carefully based on the trials. 

Lesch, A. Momotenko, D. Cortes-Salazar, F Wirth, L Tefashe, U. M. Meiners, F Vaske, B. Girault, H. H. Wittstock, G. 2012. Fabrication of soft gold microelectrode arrays as probes for scanning electrochemical microscopy. J. Electroanal. Chem., 666, 52-61. 

Acid Neutral Alkaline Hard gold Soft gold Color gilding (flash deposition) Gold alloy Electroformed gold... 

Cyanide neutral baths are largely employed for the electrodeposition of soft gold layers serving as a bonding surface. 

Basic Formulations of Neutral and Acid Baths for the Electrodeposition of Soft Gold and Additive-Free Hard Gold (AFHG) (Concentration in g L )... 

Mixed Sulfite-Thiosulfate Bath for Soft Gold Electrodeposition (Concentration in mol h unless Otherwise Noted)... 

---