Silver-antimony alloy

Kristev I, Nikolova M (1986) Structural effects during the electrodeposition of silver-antimony alloys from ferrocyanidethiocyanate electrolytes. J Appl Electrochem 16 875-878... 

The increased mobility of silver in a silver-antimony alloy as compared with a pure silver lattice may be considered as due to the loosening of the silver lattice by distortion due to introducing antimony. Von Hevesy (40) suggested that as a... 

Figure 11.1 Rotating spiral waves during the electrodeposition of silver-antimony alloy. The characteristic wavelength (i.e., the pitch) and the rotation period of the spiral waves are 10 lm and 10 s, respectively. Reprinted with permission from Ref [11].

A qualitatively different type of precipitation patterns concerns structures formed during the electrodeposition of alloys. In 1938, Raub and Schall observed the formation of propagating wave patterns during the electrodeposition of silver-indium alloy [9, 10]. However, their observation was widely ignored, because no systematic theory was available that could classify these patterns as typical features of systems far from thermodynamic equilibrium. In 1986, the phenomenon was studied by Krastev and Nikolova in the possibly related electrodeposition of a silver-antimony alloy (Figure 11.1) [11]. Furthermore, very similar patterns were observed by Saltykova et al. during the electrodeposition of iridium-ruthenium alloy from molten salts [12]. 

Krastev, 1. and Koper, M.T.M. (1986) Pattern formation during the electrodeposition of a silver-antimony alloys. 

Silver reduces the oxygen evolution potential at the anode, which reduces the rate of corrosion and decreases lead contamination of the cathode. Lead—antimony—silver alloy anodes are used for the production of thin copper foil for use in electronics. Lead—silver (2 wt %), lead—silver (1 wt %)—tin (1 wt %), and lead—antimony (6 wt %)—silver (1—2 wt %) alloys ate used as anodes in cathodic protection of steel pipes and stmctures in fresh, brackish, or seawater. The lead dioxide layer is not only conductive, but also resists decomposition in chloride environments. Silver-free alloys rapidly become passivated and scale badly in seawater. Silver is also added to the positive grids of lead—acid batteries in small amounts (0.005—0.05 wt %) to reduce the rate of corrosion. 

The washed slime is dried and melted to produce slag and metal. The slag is usually purified by selective reduction and smelted to produce antimonial lead. The metal is treated ia the molten state by selective oxidation for the removal of arsenic, antimony, and some of the lead. It is then transferred to a cupel furnace, where the oxidation is continued until only the silver—gold alloy (dorn) remains. The bismuth-rich cupel slags are cmshed, mixed with a small amount of sulfur, and reduced with carbon to a copper matte and impure bismuth metal the latter is transferred to the bismuth refining plant. 

The corrosion rate of Pb02 - often enhanced by mechanical erosion - is relatively high and may be a problem due to the toxicity of lead. Pb02 can be stabilized by modification with, for example, silver, antimony, tin, cobalt oxides (or by alloying of the lead base metal with these metals, respectively) [29]. 

Silver-aluminium alloy, 0002 Silvered copper, 0003 Sodimn-antimony alloy, 4797 Sodimn germanide, 4418 Sodium-zinc alloy, 4798 Titanium-zirconimn alloys, 4921 See also LANTHANIDE-TRANSITION METAL ALLOY HYDRIDES... 

Solders -for dental materials [DENTAL MATERIALS] (Vol 7) -for electronic packaging [PACKAGING - ELECTRONIC MATERIALS] (Vol 17) -for gold alloys [GOLD AND GOLD COMPOUNDS] (Vol 12) -lead m [LEAD] (Vol 15) -lead-antimony alloys for [LEAD ALOYS] (Vol 15) -lead-silver alloys [LEAD ALOYS] (Vol 15) -phosphorus compounds m [PHOSPHORUS COMPOUNDS] (Vol 18) -tin compounds m [TIN COMPOUNDS] (Vol 24)... 

Lead—tin alloys, 4877 Lead—zirconium alloys, 4878 Lithium—magnesium alloy, 4676 Lithium—tin alloys, 4677 Plutonium bismuthide, 0231 Potassium antimonide, 4668 Potassium—sodium alloy, 4641 Silicon—zirconium alloys, 4904 Silver—aluminium alloy, 0002 Silvered copper, 0003 Sodium germanide, 4412 Sodium—antimony alloy, 4791 Sodium—zinc alloy, 4792 Titanium—zirconium alloys, 4915... 

In the analysis of high purity metals, trace elements were pre-concentrated by partial dissolution of the matrix. The remaining small part of the matrix retains all trace elements that are electrochemically less noble than the matrix [79,80]. In this way the trace elements were pre-concentrated from silver-, cadmium-, gallium-, indium-, zinc-, lead-, manganese-, aluminium-, and lead-antimony alloys. 

K. Sugitnoto, Y. Sawaka, The effect of some alloying elements on the corrosion resistance of lead-antimony alloys—11. Silver, Corros. Sci. 17 (1977) 415-417. 

Removal of silver using zinc must follow copper removal and softening . Copper forms intermetallic compounds with zinc, as does arsenic and tellurium. The presence of antimony and tin also affects the performance of the desilverising operation, in particular separation of the silver-zinc alloy phase. 

Crude lead contains traces of a number of metals. The desilvering of lead is considered later under silver (Chapter 14). Other metallic impurities are removed by remelting under controlled conditions when arsenic and antimony form a scum of lead(II) arsenate and antimonate on the surface while copper forms an infusible alloy which also takes up any sulphur, and also appears on the surface. The removal of bismuth, a valuable by-product, from lead is accomplished by making the crude lead the anode in an electrolytic bath consisting of a solution of lead in fluorosilicic acid. Gelatin is added so that a smooth coherent deposit of lead is obtained on the pure lead cathode when the current is passed. The impurities here (i.e. all other metals) form a sludge in the electrolytic bath and are not deposited on the cathode. 

Solders. In spite of the wide use and development of solders for millennia, as of the mid-1990s most principal solders are lead- or tin-based alloys to which a small amount of silver, zinc, antimony, bismuth, and indium or a combination thereof are added. The principal criterion for choosing a certain solder is its melting characteristics, ie, soHdus and Hquidus temperatures and the temperature spread or pasty range between them. Other criteria are mechanical properties such as strength and creep resistance, physical properties such as electrical and thermal conductivity, and corrosion resistance. 

Betts Electrolytic Process. The Betts process starts with lead bullion, which may carry tin, silver, gold, bismuth, copper, antimony, arsenic, selenium, teUurium, and other impurities, but should contain at least 90% lead (6,7). If more than 0.01% tin is present, it is usually removed from the bullion first by means of a tin-drossing operation (see Tin AND TIN ALLOYS, detinning). The lead bullion is cast as plates or anodes, and numerous anodes are set in parallel in each electrolytic ceU. Between the anodes, thin sheets of pure lead are hung from conductor bars to form the cathodes. Several ceUs are connected in series. 

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