Other Lead Alloys

Alloys of Pb—Li are attractive in some nuclear shielding apphcations due to their ability to thermalize neutrons. Lead containing more than 0.5 wt% In wets glass, and Pb—In alloys with up to 5 wt% In can be used for soldering glass over a narrow temperature range. Additions over 25 wt% of In are made to Pb—Sn solders to increase their alkali resistance. An addition of 1 - 2 wt% In in Pb—Ag solders increases their strength. Indium is also used in multi-component fusible aUoy systems. 

Alloy name Nominal composition (wt%) Fatigue strength (MPa) at 10 cycles 37-50 Hz Applications 

Alloy B Pb-0.8-0.95Sb 9.6 Solid type cables and telecommunication cables subjected to severe vibrations 

Alloy C Pb-0.35-0.45 Sn-0.12-0.18Cd 5.4 Power cables in ships. Acceptable for most types of cables 

Alloy me Pb-0.18-0.22% Sb-0.06-0.09 Cd 4.2 0.07% Oil-filled and submarine powa- cables. Power cables subjected to severe vibrations in service. Acceptable for most types of reinforced cables 

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Wrought lead—calcium—tin anodes have replaced many cast lead—calcium anodes (14). Superior mechanical properties, uniform grain stmcture, low corrosion rates, and lack of casting defects result in increased life for wrought lead—calcium—tin anodes compared to other lead alloy anodes. 

Copper-containing lead alloys undergo less corrosion in sulfuric acid or sulfate solutions than pure lead or other lead alloys. The uniformly dispersed copper particles give rise to local cells in which lead forms the anode and copper forms the cathode. Through this anodic corrosion of the lead, an insoluble film of lead sulfate forms on the surface of the lead, passivating it and preventing further corrosion. The film, if damaged, rapidly reforms. 

Table 1. ISO/DIS 9453 Specification for Tin—Lead and Other Lead—Alloy Solders ...

Other lead alloys are used to make bearings for gasoline and diesel engines, type metal for printing, corrosion-resistant cable coverings, and ammunition. 

Copper and Copper Alloys 296 3.1.11.9 3.1.11.10 Lead Cable Sheathing Alloys Other Lead Alloys A21 A21... 

A distinction is sometimes made in lead scrap between battery scrap, old soft lead (from lead cables and pipes) and antimonial lead (print metal, bearing metal and other lead alloys), as well as mixed lead batches. Muller-Ohlsen op at... 

A typical automobile battery weighs 16.4 kg and consists of 3.5 kg metallic lead, 2.6 kg lead oxides, 4.0 kg lead sulfate, 1.3 kg polypropylene, 1.1 kg PVC, mbber and other separators, and 3.9 kg electrolyte. Including acid and water, the lead-beating parts represent 61 wt %, ie, 21 wt % of lead alloy (2% Sb) and 40 wt % lead oxides and sulfate. Nonlead-beating parts constitute the remaining 39% the case (hard mbber or polypropylene) and separators (PVC) at 15 wt % and the electrolyte at 24 wt %. 

Metallurgy. Lithium forms alloys with numerous metals. Early uses of lithium alloys were made in Germany with the production of the lead alloy, BahnmetaH (0.04% Li), which was used for bearings for railroad cars, and the aluminum alloy, Scleron. In the United States, the aluminum alloy X-2020 (4.5% Cu, 1.1% Li, 0.5% Mn, 0.2% Cd, balance Al) was introduced in 1957 for stmctural components of naval aircraft. The lower density and stmctural strength enhancement of aluminum lithium alloys compared to normal aluminum alloys make it attractive for uses in airframes. A distinct lithium—aluminum phase (Al Li) forms in the alloy which bonds tightly to the host aluminum matrix to yield about a 10% increase in the modules of elasticity of the aluminum lithium alloys produced by the main aluminum producers. The density of the alloys is about 10% less than that of other stmctural aluminum alloys. 

Sodium—lead alloys that contain other metals, eg, the alkaline-earth metals, are hard even at high temperatures, and are thus suitable as beating metals. Tempered lead, for example, is a beating alloy that contains 1.3 wt % sodium, 0.12 wt % antimony, 0.08 wt % tin, and the remainder lead. The German BahnmetaH, which was used ia axle beatings on railroad engines and cars, contains 0.6 wt % sodium, 0.04 wt % lithium, 0.6 wt % calcium, and the remainder lead, and has a Brinell hardness of 34 (see Bearing MATERIALS). 

Other alloying ingredients in lead, eg, arsenic (0.5—0.7%) and silver [7440-22-4] (0.1—0.15%), inhibit grid growth on overcharge and reduce positive grid corrosion. Tin added to a lead alloy produces well-defined castings that are readily adapted to mass production techniques (84). 

Calcium metal is produced in the United States by Pfizer Inc., Canaan, Coimecticut, and in Canada by Timminco Metals, Toronto, Ontario. In France it is produced by Pechiney ElectrometaHurgie. It is also produced in the Commonwealth of Independent States (CIS) and the People s RepubHc of China. Both Pfizer and Timminco supply the various grades in a variety of sizes and forms. In addition, Pfizer suppHes an 80% Ca—20% Mg alloy and a steel-clad calcium wire for use in deoxidation of steel and other metals. Timminco and Pfizer both supply ca 75% Ca—25% Al alloy for use in lead alloying. Timminco also suppHes a 70% Mg—30% Ca alloy for use in lead debismuthizing (18), and calcium particulate products, which are purchased by several companies for the manufacture of cored wire for use in the steel industry. 

The secondary production of lead begins with the recovery of old scrap from worn-out, damaged, or obsolete products and with new scrap. The chief source of old scrap is lead-acid batteries other sources include cable coverings, pipe, sheet, and other lead-bearing metals. Solder, a tin-based alloy, may be recovered from the processing of circuit boards for use as lead charge. 

Of the elements commonly found in lead alloys, zinc and bismuth aggravate corrosion in most circumstances, while additions of copper, tellurium, antimony, nickel, silver, tin, arsenic and calcium may reduce corrosion resistance only slightly, or even improve it depending on the service conditions. Alloying elements that are of increasing importance are calcium especially in maintenance-free battery alloys and selenium, or sulphur combined with copper as nucleants in low antimony battery alloys. Other elements of interest are indium in anodesaluminium in batteries and selenium in chemical lead as a grain refiner ". 

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

Lead alloy solder is critical to the transistors, relays, and other components in the printed circuit boards used in all computers and advanced electronic equipment. 

All the other metallic alloys (iron, zinc, lead, etc.) that do not form protective and/or aesthetic patina, are usually covered with paint as protection layer. Anyway, many world treasures have been moved indoors after restoration, as in the case of Marco Aurelio and the Venice Horses. 

Low force/low voltage separable connectors used in computers, and other electronic devices, are typically plated with gold or palladium over a barrier layer of nickel. The tail ends of these connectors, which are usually joined to the device by soldering, are plated with a tin-lead alloy, or pure tin. 

The bimolecular reduction of aromatic nitro compounds, depending on reaction conditions, may produce azoxy compounds, azo compounds, hydrazo compounds (1,2-diarylhydrazines), benzidines, or amines. Whereas the reduction with zinc and sodium hydroxide leads to azo compounds, zinc and acetic acid/acetic anhydride produces azoxy compounds. Other reducing agents suggested are stannous chloride, magnesium with anhydrous methanol, a sodium-lead alloy in ethanol, thallium in ethanol, and sodium arsenite. 

The electrolysis Of fused alkali salts.—Many attempts have been made to prepare sodium directly by the electrolysis of the fused chloride, since that salt is by far the most abundant and the cheapest source of the metal. The high fusion temp. the strongly corrosive action of the molten chloride and the difficulty of separating the anodic and cathodic products, are the main difficulties which have been encountered in the production of sodium by the electrolysis of fused sodium chloride. Attention has been previously directed to C. E. Acker s process for the preparation of sodium, or rather a sodium-lead alloy, by the electrolysis of fused sodium chloride whereby sodium is produced at one electrode, and chlorine at the other but the process does not appear to have been commercially successful. In E. A. Ashcroft s abandoned process the fused chloride is electrolyzed in a double cell with a carbon anode, and a molten lead cathode. The molten lead-sodium alloy was transported to a second chamber, where it was made the anode in a bath of molten sodium hydroxide whereby sodium was deposited at the cathode. A. Matthiessen 12 electrolyzed a mixture of sodium chloride with half its weight of calcium chloride the addition of the chloride of the alkaline earth, said L. Grabau, hinders the formation of a subchloride. J. Stoerck recommended the addition of... 

The term stannum, as used by Pliny, does not mean tin, but alloys of tin and lead, or silver and lead, alloys which were used instead of tin, probably in covering copper utensils, or for other purposes, as solder. 

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