Soft solder metals

Figure 4.12. The position in the Periodic Table of a few classes of commercially important metals. L Light metals, R Refractory metals, F Ferro alloy metals, P Precious metals, C Coinage metals and S Soft solder metals.

The metal is employed to form numerous alloys with other metals. Brass, nickel silver, typewriter metal, commercial bronze, spring bronze, German silver, soft solder, and aluminum solder are some of the more important alloys. 

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... 

Metal considered platinum, rhodium, silver aluminium bronzes, tin bronzes, gunmetals brasses, nickel silvers Nickel Lead, On and soft solders and cast iron... 

All soft solders are alloys composed mainly of lead and tin mixed in proportions that vary from as little as 30% lead (and 70% tin), to as much as 98% lead (and only 2% tin). The brazing metals are mostly alloys of copper or silver their composition, as well as that of other alloys used since antiquity for soldering, are listed in Table 48 (Zhadkevich 2004). 

The mechanical and electrical contact between two metals may be made by soldering them together. Unfortunately most soft solder become superconducting at low temperature (see Table 4.3). 

F. Lead. Lead (mp 328°C), is a soft metal which finds use in gaskets, soft solder, and radiation shields. While lead tank liners are used in some industrial processes, this metal is not attractive for laboratory containers. 

Low-temperature vapor-pressure apparatus. (Metal parts to be well tinned and soft soldered, except where otherwise indicated.)... 

Brass is basically a copper- zinc alloy bronze is a copper- tin alloy. In practice both often contain many other metals. Their high machinability, resistance to corrosion, and ease of soft soldering make them very useful in apparatus construction. Owing to the volatility of zinc, brass should not be used in vacuum components that must be baked out or operated hot. Certain bronzes such as phosphor bronze are useful for springs and diaphragms beryllium copper is also useful in these applications. 

Soft-soldering of copper, iron, steel, and brass objects of large size is usually accomplished by the use of a burner or hand torch, with an acid flux—frequently a concentrated aqueous solution of zinc chloride and ammonium chloride (2 1 ratio)—brushed onto the hot metal concurrently with the addition of solder. Initially, heat should be applied around the area to be soldered but not directly on the region to be soldered. If the region to be soldered is heated too much without the application of flux, an oxide coating will form that can make proper surface adhesion impossible. The surfaces to be joined should be pretinned if possible, and excess solder is shaken off or wiped off with a cloth. The two surfaces to be joined are then placed in contact and heated with the torch until the solder begins to flow more solder is then added as required, and the pieces are allowed to cool undisturbed. The finished work should be washed thoroughly with water to remove the flux. 

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). 

Lead has a low melting point (326°C). It is a soft, malleable metal, i.e., it can be easily formed into a variety of shapes. It can form alloys with many other metals. Other important industrial products containing Pb include pipes, paints, solders, glass, pottery glazes, rubber, plastics, and insecticides. 

Aqueous fluids are normally formulated with corrosion inhibitors. Because these fluids are ionic, improper selection of corrosion inhibitors can lead to severe corrosion. Glycols and brines are normally not recommended with galvanized steel and soft solder. Aluminum systems are not recommended above a certain temperature. Sodium and calcium chloride brines are very corrosive toward most of the metals even with the inhibitors. 

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