High lead-low tin solder

Soldering materials are alloys that are composed primarily of tin and lead (qv), and have low melting temperatures relative to the conductor metals which are being soldered (see Lead alloys Tin and tin alloys). Welding requires sufficientiy high temperatures for the fusion of metals. 

Lead and copper ions in water pose health risks and contribnte to the corrosion of pipes and fittings, as does water that is at a high or low pH. Lead solder was banned from pipes in 1986, but much old plumbing still contains a mixture of 50 percent lead and 50 percent tin solder in joints. In plumbing systems having pipes and fittings of two different metals, corrosion may lead to the failnre of joints. 

The case of mechanical vibration is less well defined in terms of the predominance of creep versus time-independent (plastic) deformation. Although the applied stresses are often quite low, the strain rates can be sufficiently high, so that a mixture of creep and plastic deformation modes define the fatigue response of the material. This sensitivity of fatigue behavior to cyclic loading frequency has been widely studied for tin-lead (Sn-Pb) solders and is recognized as an important variable in the fatigue response of lead-free alloys (Ref 1-3). 

The Fe, Co, and Ni deposits are extremely fine grained at high current density and pH. Electroless nickel, cobalt, and nickel—cobalt alloy plating from fluoroborate-containing baths yields a deposit of superior corrosion resistance, low stress, and excellent hardenabiUty (114). Lead is plated alone or ia combination with tin, iadium, and antimony (115). Sound iasulators are made as lead—plastic laminates by electrolyticaHy coating Pb from a fluoroborate bath to 0.5 mm on a copper-coated nylon or polypropylene film (116) (see Insulation, acoustic). Steel plates can be simultaneously electrocoated with lead and poly(tetrafluoroethylene) (117). Solder is plated ia solutioas containing Pb(Bp4)2 and Sn(Bp4)2 thus the lustrous solder-plated object is coated with a Pb—Sn alloy (118). 

Low (2—5 wt %) antimony, low (2—5 wt %) tin lead alloys are used for automobde body solder. Special lead—antimony alloys containing 1—4 wt % antimony are used for wheel-balancing weights, battery cable clamps, collapsible tubes, and highly machined isotope pots. 

The low-melting-point (157 °C), silver metal is mainly used in alloys to decrease the melting point. Combined with tin, lead, and bismuth to produce soldering metal for wide temperature ranges. The element is highly valuable in the electronics age as its unique properties are ideal for solar cells, optoelectronics, and microwave equipment. The arsenide is used in lasers and is also suitable for transistors. ITO (indium tin oxide) is a transparent semiconductor with wide application in displays, touchscreens, etc. In the household, indium as an additive prevents the tarnishing of silverware. Some electronic wristwatches contain indium batteries. 

Corrosion by dealloying is common in brasses here the zinc component of the alloy is preferentially removed. Brasses with high proportions of the P phase are especially prone to this type of attack. The mechanism appears to be corrosion of both copper and zinc from the metal the zinc passes into solution but the copper is re-deposited with a porous structure of low strength. Aluminium bronzes also suffer dealloying of the aluminium component if incorrectly heat treated. Other metals which may be preferentially dissolved from their alloys are manganese from copper-manganese, nickel from copper-nickel, copper from either copper-silver or copper-gold, and tin from tin-lead (solders). It is evident from this list that it is the component which is anodic to the alloy which is removed. 

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