Alloys of tin

Alloys of tin are very important. Soft solder, type metal, fusible metal, pewter, bronze, bell metal. Babbitt metal. White metal, die casting alloy, and phosphor bronze are some of the... 

Tin [7440-31 -5] is one of the world s most ancient metals. When and where it was discovered is uncertain, but evidence points to tin being used in 3200—3500 BC. Ancient bron2e weapons and tools found in Ur contained 10—15 wt % tin. In 79 ad, Pliny described an alloy of tin and lead now commonly called solder (see Solders and brazing alloys). The Romans used tinned copper vessels, but tinned iron vessels did not appear until the fourteenth century in Bohemia. Tinned sheet for metal containers and tole (painted) ware made its appearance in England and Saxony about the middle of the seventeenth century. Although tinplate was not manufactured in the United States until the early nineteenth century, production increased rapidly and soon outstripped that in all other countries (1). 

The other place where the constitution is not fully defined is where there is a horizontal line on the phase diagram. The lead-tin diagram has one line like this - it runs across the diagram at 183°C and connects (Sn) of 2.5 wt% lead, L of 38.1% lead and (Pb) of 81% lead. Just above 183°C an alloy of tin -i- 38.1% lead is single-phase liquid (Fig. 3.5). Just below 183°C it is two-phase, (Sn) -i- (Pb). At 183°C we have a three-phase mixture of L -I- (Sn) -I- (Pb) but we can t of course say from the phase diagram what the relative weights of the three phases are. 

Solder (alloy of tin and lead) used for joining metals, e.g. in eleetrieal eireuits. 

The main alloys of tin together with an indication of the percentage of total Sn production for these alloys in the USA (1991) are ... 

The melting points of mixtures and solutions depend on the nature and the relative amount of each component of the solution. They are, however, lower than those of the separate components. Solder, for example, an alloy of tin and lead, melts at 183°C, a much lower temperature than either of its components tin melts at 231 °C and lead, at 328°C. 

Polyatomic anions of tin can be prepared in solution, using alloys of tin with alkali metals which are remarkably soluble in liquid ammonia. The obtained colored solutions contain the cluster anion [Sng]4, 68a106. Upon treatment with a crown ether in ethylenediamine, crystalline compounds [Na(crypt)+]4[Sn9]4 could be prepared where crypt = N(CH2CH20CH2CH20CH2CH2)3N ... 

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. 

The alloys of tin and arsenic are very hard and readily crystallise.11 When the arsenic is not present in excess they are white, sonorous and brittle, and attacked by hydrochloric acid with liberation of arsine. When heated strongly, arsenic volatilises. The electrical conductivity of thin rods, of composition Sn Asg, SnAs and Sn3As2, has been measured12 between -81° and 400° C. In each case it passes through a maximum, at 25°, 0° and - 25° C. respectively. 

Terne Plate. This is a sheet-steel product that is coated with an alloy of tin and lead. The coatings range from 50-50 mixtures of lead and tin to as low as 12% dn and 88% lead. Plate used for roofing normally is about 25% tin and 75% lead. In addition to roofing, terne plate is used in the manufacture of gasoline tanks for automotive vehicles, oil cans, and containers for solvents, resins, etc. 

Compounds of antimony are used as fire retardants in plastics and paper, and for veterinary purposes. The metal is found in specialised alloys such as white metal bearings and pewter, which is an alloy of tin, antimony (up to 7.5%) and copper. Concentrations in food are low, generally in the range <0.01 to 0.08 mg/kg, but have been found to be higher in samples of aspic jelly and cream of tartar.40 The... 

Tin (Sn) Tin is a silvery white metal. Solder is an alloy of tin and lead and is used in electrical connections. Stannous fluoride (SnF2) was once a common ingredient in toothpaste, but has largely been replaced by sodium monofluo-rophosphate. 

Tin—lead coatings (10—60 wt % tin) can be applied by hot-dipping or electrode position to steel and copper fabricated articles and sheet. A special product is teme plate used for roofing and flashings, automobile fuel tanks and fittings, air filters, mufflers, and general uses such as covers, lids, drawers, cabinets, consoles for instruments, and for radio and television equipment. Teme plate is low carbon steel, coated by a hot-dip process with an alloy of tin and lead, commonly about 7—25 wt % tin, remainder lead. Electroplating is another possibility. 

Special Alloys. Alloys of tin with the rarer metals, such as niobium, titanium, and zirconium, have been developed. The single-phase alloy Nb3Sn [12035-04-0] has the highest transition temperature of any known superconductor (18 K) and appears to keep its superconductivity in magnetic... 

Pewter is a term applied to a wide range of alloys in which tin is the dominant metal, mixed with lead and sometimes copper, antimony, and/or zinc. Some pewter contains no lead at all, and is mostly tin and copper. Bronze is also an alloy of tin and copper, but it is predominantly copper. 

When phosphorus and tin are melted together in a sealed tube, two liquid layers are formed, and the maximum amount of phosphorus taken up by the tin is 8 per cent.,4 while by heating tin and phosphorus in a sealed tube at 620° C. for 10 hours grey crystals were obtained which contained 40 per cent, of phosphorus and which after purification by hydrochloric acid, alkali and nitric acid had the composition SnP3.6 The density was 4-1 at 0° C. Alloys of tin with about 13 per cent, of phosphorus contained Sn4P3,5-6 which had a density of 5-18 and was attacked by aqueous acids. 

A recent in situ Mossbauer study (124) of a mixed tin-platinum oxide catalyst supported on zinc aluminate at 500°-600°C indicated the presence of tin(IV), tin(II), and an alloy of tin and platinum in the active catalyst. Changes in the nature of the tin species with time and temperature were correlated with the catalytic activity of the material. 

The principal alloys of tin are bronze (tin and copper), soft solder (50% tin and 50% lead), pewter (75% tin and 25% lead), and britan-nia metal (tin with small amounts of antimony and copper). 

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