Alloys with zinc

For example,copper has relatively good corrosion resistance under non-oxidizing conditions. It can be alloyed with zinc to yield a stronger material (brass), but with lowered corrosion resistance. Flowever, by alloying copper with a passivating metal such as nickel, both mechanical and corrosion properties are improved. Another important alloy is steel, which is an alloy between iron (>50%) and other alloying elements such as carbon. 

Reactor-grade zirconium is essentially free of hafnium. Zircaloy(R) is an important alloy developed specifically for nuclear applications. Zirconium is exceptionally resistant to corrosion by many common acids and alkalis, by sea water, and by other agents. Alloyed with zinc, zirconium becomes magnetic at temperatures below 35oK. 

Copper and Copper Alloys. The coppers are divided into oxygen-bearing and oxygen-free coppers. Numerous copper alloys are of commercial importance, including those alloys with zinc (brasses), with tin (phosphor bronzes), and with aluminum (aluminum bronzes) all are weldable. 

Copper and nickel can be alloyed with zinc to form nickel silvers. Nickel silvers are ductile, easily formed and machined, have good corrosion resistance, can be worked to provide a range of mechanical properties, and have an attractive white color. These alloys are used for ornamental purposes, as sHverplated and uncoated tableware and flatware in the electrical iadustry as contacts, connections, and springs and as many formed and machined parts (see Electrical connectors). 

The outstanding properties of copper-base materials are high electrical and thermal conductivity, good durabihty in mildly corrosive chemical environments and excellent ductility for forming complex shapes. As a relatively weak material, copper is often alloyed with zinc (brasses), tin (bronzes), aluminum and nickel to improve its mechanical properties and corrosion resistance. 

The main alloys of copper are the brasses, alloyed with zinc, and the bronzes, alloyed with tin. Other, so-called bronzes are the aluminium bronzes and the silicon bronzes. 

Alloys with Zinc compounds Mercury compounds ... 

Copper is used in three basic forms pure, alloyed with zinc (brass), and alloyed with tin (bronze). Copper and copper alloys are difficult to bond satisfactorily, especially if high shear and peel strengths are desired. The primary reason for this difficulty is that the oxide that forms on copper develops rapidly (although not as fast as the rate of oxide development on aluminum). The copper oxide layer is weakly attached to the base metal under usual conditions. Thus, if clean, bare copper substrates were bonded, the initial strength of the joint would be relatively high, but on environmental exposure an oxide layer could develop which will reduce the durability of the joint. 

An alloy with zinc was also prepared by Deville and Debray, which yielded hexagonal prisms, and was combustible in air with feeble deflagration. Its composition was not determined. Ruthenium dissolves in lead, but yields no compound with it. On treatment with acid the lead dissolves, leaving the ruthenium as a crystalline residue.2... 

Platinum scrap is conveniently worked up into chlor-platinic acid by alloying with zinc under a layer of borax. The melt is treated with hydrochloric acid, which removes most of the zinc, and the finely divided platinum is dissolved in aqua regia. 

Figure 11.1. A. Changes in the intensity of the Cu NMR signal in annealed and cold-worked copper and in alloys with zinc and silver. The maximum NMR absorption is corrected for the number of copper nuclei in the sample and plotted as a function of the solute concentration C. Data points for zinc alloys denoted by crosses and by open circles for silver. From Bloembergen and Rowlands (1953) by permission of Elsevier Science. B. " Mg NMR spectrum of pure annealed magnesium (lower), magnesium work-hardened by filing (middle) and a Mg+ 6 % Al alloy (upper). The insets in the upper spectrum shows the satellite powder pattern features enlarged vertically. From Bastow and Smith (1995), by permission of the copyright owner.

Ternary compounds (not alloys) such as CdCr2Sc4 can be grown from a PbCl2-CdCl2 flux. These are magnetic semiconductors, but they have been eclipsed by the manganese- and iron-based alloys with zinc and cadmium chalcogenides, such as Cdi -,cMn,tTe. The pure compounds, usually made by direct reaction, are often used as... 

Bullets and shot are usually lead or lead-antimony alloys of between 0.5% and 3% antimony to harden the lead (in rare cases tin can be the hardener). Bullets can also be semijacketed, tipped, or fully jacketed, with copper and copper alloys with zinc and/or tin being the most common materials. Bullet jackets... 

Another metal, used in alloys with zinc was silver a Zn/Ag couple was successfully used in a modification of the Simmons-Smith reaction [57]. 

Where high purity concentrates are processed and only minor amounts of copper have to be removed, one method used at the Naoshima smelter in Japan is to add aluminium to form the intermetallic compound CUAI2. Aluminium is added as a 40 per cent alloy with zinc because of its low melting point at 560°C compared with aluminium at 660°C. Zinc is removed from the lead later either in the dezincing process or by caustic soda treatment. This method produces a dry powdery dross, which is easily handled and can reduce copper levels to less than one gram per tonne (Moriya, 1989). 

Brass is the most used alloy of copper metal. Normally brass is copper alloyed with zinc. There are two types of this alloy, a-brass and a/ 3-brass. At room temperature, copper can dissolve up to 38% zinc in solid solution. In physical metallurgy this phase is called the a-phase. An alloy with 37% zinc, the most common brass, thus consists entirely of the a-phase, and is also called a-brass. It is used as sheet metal and strip for all types of cold forming. For deep drawing, which is especially difficult for the material, the zinc content is decreased to 30%. 

The physical properties of many metals render them unsuitable for fabrication and engineering purposes. By combining two or more metals, or metals with non-metals, one can form alloys with enhanced properties such as strength, malleability, ductility, hardness or resistance to corrosion. For example, copper is alloyed with zinc (2-40% by weight) to produce different types of brasses which are stronger than copper but retain good fabrication properties. 

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