Gold-cadmium-copper alloy

Figure 8. Gold-cadmium-copper alloy obtained by dissolution of CdS in molten Au-Cu alloy. The black earthy deposit is easily separated from the...

Solders and brazes for jewelry gold alloys are usually gold—silver—copper alloys that can be modified to yield a desired melting range by adjusting the silver-to-copper ratio. Additions of zinc, cadmium, tin, or nickel compensate for the changes in color introduced by compositional modification (87). 

Features of the method Most metals can be deposited by this technique, usually on to steel or copper alloys as substrates. The most commonly deposited metals are nickel, chromium, tin, copper, zinc, cadmium, gold and silver. 

Other alloys Other copper alloys can be plated, including copper-tin-zinc (Alballoy) , copper-nickel , copper-cadmium , copper-gold and copper-lead . 

Thallium alloys readily with many metals, especially sodium, potassium, mercury, magnesium, calcium, gold, silver, cadmium, copper, and zinc. 

Copper, copper alloys Bare, tinplate or tin lead (solder) plate preferred Cadmium or gold plate... 

Rubidium metal alloys with the other alkaU metals, the alkaline-earth metals, antimony, bismuth, gold, and mercury. Rubidium forms double haUde salts with antimony, bismuth, cadmium, cobalt, copper, iron, lead, manganese, mercury, nickel, thorium, and 2iac. These complexes are generally water iasoluble and not hygroscopic. The soluble mbidium compounds are acetate, bromide, carbonate, chloride, chromate, fluoride, formate, hydroxide, iodide. 

Electroplated Metals and Alloys. The metals electroplated on a commercial scale from specially formulated aqueous solutions iaclude cadmium, chromium, cobalt, copper, gold, iadium, iron, lead, nickel, platinum-group metals, silver, tin, and ziac. Although it is possible to electroplate some metals, such as aluminum, from nonaqueous solutions as well as some from molten salt baths, these processes appear to have achieved Httie commercial significance. 

The development of new alloys as a means of modifying existing electrodeposits for example the production of hard gold by alloy codeposition of copper, cadmium etc. to yield 23 or 18 carat alloys, or the use of zinc alloys for improved electrogalvanised coatings. 

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