Brass electrical conductivity

A 99.5% Cu—0.5% Te alloy has been on the market for many years (78). The most widely used is alloy No. CA145 (number given by Copper Development Association, New York), nominally containing 0.5% tellurium and 0.008% phosphorous. The electrical conductivity of this alloy, in the aimealed state, is 90—98%, and the thermal conductivity 91.5—94.5% that of the tough-pitch grade of copper. The machinahility rating, 80—90, compares with 100 for free-cutting brass and 20 for pure copper. 

This computation is also referred to as calculating the zinc equivalent of the alloy. The increase in strength in this alloy series is caused by increased amounts of beta phase in the stmcture. The silicon brasses show similar hardening effects accompanying a second phase. Typical mechanical properties and electrical conductivity for various cast alloys are shown in Table 2. 

Chlorides have probably received the most study in relation to their effect on corrosion. Like other ions, they increase the electrical conductivity of the water so that the flow of corrosion currents will be facilitated. They also reduce the effectiveness of natural protective films, which may be permeable to small ions the effect of chloride on stainless steel is an extreme example but a similar effect is noted to a lesser degree with other metals. Turner" has observed that the meringue dezincification of duplex brasses is affected by the chloride/bicarbonate hardness ratio. 

Copper and Alloys Copper and its alloys are widely used in chemical processing, particularly when heat and electrical conductivity are important factors. The thermal conductivity of copper is twice that of aluminum and 90 percent that of silver. A large number of copper alloys are available, including brasses (Cu-Zn), bronzes (Cu-Sn), cupronickels (Cu-Ni), and age-hardenable alloys such as copper beryllium (Cu-Be) and copper nickel tin (Cu-Ni-Sn). 

The reddish metal was already known in prehistoric times. It occasionally occurs as a native metal, but mostly in conspicuous green ores, from which it is extracted relatively easily. It is convenient to work, but not very hard. Not very optimal as a tool ("Otzi the Iceman" had a copper axe with him). Only through the addition of tin is the more useful bronze obtained. Its zinc alloy is the versatile and widely used brass. Copper is one of the coinage metals. Water pipes are commonly made of copper. Its very good thermal and electrical conductivity is commonly exploited (cable ), as well as its durability (roofs, gutters), as the verdigris (basic copper carbonate) protects the metal. Cu phthalocyanines are the most beautiful blue pigments. Seems to be essential to all life as a trace element. In some molluscs, Cu replaces Fe in the heme complex. A 70-kg human contains 72 mg. 

Metallic Pigments. These pigments are metal flakes of various sizes made up of aluminum, copper, zinc, and/or their alloys. The aluminum flakes develop the silver metallic colors, whereas the copper, zinc, and aluminum alloys produce the gold, copper, brass, and bronze colors. The metal effect is modified, not only by shape and size, but also by perticle size distribution within a given product. Since aluminum, in particular, as a fine dry powder, can form explosive mixtures with air, most of these materials are commercially available in paste or liquid concentrates. In addition, surface treatments of these materials enhance their appearance and performance. Flakes of other metals, such as stainless steel, are used for surface protection purposes such as corrosion resistance and electrical conductivity. 

Copper is a tough, soft, and ductile reddish metal, second only to Ag in its high thermal and electrical conductivities. It is used in alloys such as brasses and is completely miscible with Au. It is only superficially oxidized in air, sometimes acquiring a green coating of hydroxo carbonate and hydroxo sulfate. 

Tellurium is even less abundant (2 X 10 % of the earth s crust) than selenium. It occurs mainly in sulfide ores, especially with copper sulfide, and as the tellurides of gold and silver. It, too, is obtained from the anode mud from refining of copper. The element forms brass-colored, shiny, hexagonal crystals having low electrical conductivity. It is added to some metals, particularly lead, to increase electrical resistance and improve resistance to heat, corrosion, mechanical shock, and wear. 

When sparks are used for the ablation of electrically conducting solids, less changes with variations in the matrix composition than in the case of arc ablation occur. This is due to the fact that thermal volatilization plays less of a role. However, in the case of brass, it is seen from x-ray analyses of the ablated material on a Nudepore filter, for samples of the crater wall and the burning crater, that zinc volatilizes more than copper (Table 5), which makes the method difficult to apply to these samples. 

Migration of Zn + ions is a function of the electrical conductivity of the brass coating. Addition of Co " " or Ni " " ions will reduce this conductivity. 

Silicon is a nonmetallic chemical element that is used quite extensively in the manufacturing of transistors and various electronic and computer chips. Pure silicon is not found in nature it is found in the form of silicon dioxide in sands and rocks or found combined with other elements such as aluminum or calcium or sodium or magnesium in the form that is commonly referred to as silicates. Silicon, because of its atomic structure, is an excellent semiconductor, a material whose electrical conductivity properties can be chai d to act either as a conductor of electricity or as an insulator (preventor of electricity flow). Silicon is also used as an alloying element with other elements such as iron and copper to give steel and brass cert desired characteristics. 

Differences in efficiencies between cobalt adhesion promoters is due to the ease with which Co + ions can be formed. For example, zinc or brass reacts more easily with cobalt boron decanoate complexes tihan with cobalt naph-thenate or stearate. The Co + and Co + ions are incorporated into the ZnO film before the sulfide film has been built up. Both di- and trivalent cobalt ions reduce the electrical conductivity of the ZnO lattice, thereby reducing the diffusion of Zn + ions through the semiconducting film. 

---