Alloys of copper

Copper and tin phosphides are used as deoxidants in the production of the respective metals, to increase the tensile strength and corrosion resistance in phosphor bronze [12767-50-9] and as components of brazing solders (see Solders and brazing alloys). Phosphor bronze is an alloy of copper and 1.25—11 wt % tin. As tin may be completely oxidized in a copper alloy in the form of stannic oxide, 0.03—0.35 wt % phosphoms is added to deoxidize the alloy. Phosphor copper [12643-19-5] is prepared by the addition of phosphoms to molten copper. Phosphor tin [66579-64-4] 2.5—3 wt % P, is made for the deoxidation of bronzes and German silver. 

The output from brass mills in the United States is spHt nearly equally between copper and the alloys of copper. Copper and dilute copper alloy wrought products are melted and processed from electrically refined copper so as to maintain low impurity content. Copper alloys are commonly made from either refined copper plus elemental additions or from recycled alloy scrap. Copper alloys can be readily manufactured from remelted scrap while maintaining low levels of nonalloy impurities. A greater proportion of the copper alloys used as engineering materials are recycled than are other commercial materials. 

Give an approximate expression for the time t required for significant diffusion to take place over a distance x in terms of x, and the diffusion coefficient, D. A component is made from an alloy of copper with 18% by weight of zinc. The... 

The phase rule is a mathematical expression that describes the behavior of chemical systems in equilibrium. A chemical system is any combination of chemical substances. The substances exist as gas, liquid, or solid phases. The phase rule applies only to systems, called heterogeneous systems, in which two or more distinct phases are in equilibrium. A system cannot contain more than one gas phase, but can contain any number of liquid and solid phases. An alloy of copper and nickel, for example, contains two solid phases. The rule makes possible the simple correlation of very large quantities of physical data and limited prediction of the behavior of chemical systems. It is used particularly in alloy preparation, in chemical engineering, and in geology. 

Brasses Brasses are basically alloys of copper and zinc, containing between about 10 and 45 l o Zn, but many other additions are made and the resulting alloys are the most complicated of all the copper-base series. The singlephase (a) brasses, containing up to about 37 7o Zn in the binary alloys, may have additions of 1% Sn (Admiralty brass), 2 7o A1 (aluminium-brass), or... 

Gunmetals are alloys of copper, tin and zinc, with or without lead, used in the cast condition. Commonly used alloys are (a) 10Sn-2Zn, and b) 5Sn-5Zn-5Pb. 

Many of the alloys of copper are more resistant to corrosion than is copper itself, owing to the incorporation either of relatively corrosion-resistant metals such as nickel or tin, or of metals such as aluminium or beryllium that would be expected to assist in the formation of protective oxide films. Several of the copper alloys are liable to undergo a selective type of corrosion in certain circumstances, the most notable example being the dezincification of brasses. Some alloys again are liable to suffer stress corrosion by the combined effects of internal or applied stresses and the corrosive effects of certain specific environments. The most widely known example of this is the season cracking of brasses. In general brasses are the least corrosion-resistant of the commonly used copper-base alloys. 

Whether the rate of oxidation of an alloy of copper with a baser metal is less or more than that of copper will depend on the concentration of the alloying element and the relative diffusion velocities of metal atoms or ions in the oxide layers. There is extensive literature on the oxidation behaviour of copper alloys According to Wagner s theory the rate of oxida-... 

C04-0159. Bronze is an alloy of copper and zinc. When a 5.73-g sample of bronze was treated with excess aqueous HCl, 21.3 mg of H2 was produced. What was the percentage by mass composition of the bronze ... 

In former times, tin was used widely as a constituent of metal alloys, of which bronze, solder, and pewter are common examples. Bronze is an alloy of copper containing approximately 20% tin and smaller amounts of zinc. Pewter is another Cu-Sn alloy that contains tin as the major component ( 85%), with roughly equal portions of copper, bismuth, and antimony. Solder consists of 67% lead and 33% tin. 

Brass (alloy of copper and zinc) used for ship s propellers, screws, wind instruments. 

Bronze (alloy of copper and tin) used for coins, medals, statues, church bells. 

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. 

To keep the order, next in line would be the bronze medal. This is known to be an alloy of copper and tin and is thus not really part of this discussion. So let us stick to copper. With 114 hits in the bible, this element does, indeed, take third place, but much lower down the rank. That is also true today. Gold and silver wedding anniversaries are celebrated, but copper not. 

Relatively soon after ancient humans recognized the metals and their special properties, they also discovered ways to make alloys. Some alloys were produced in antiquity directly, by the smelting of ores that include two metals in their composition or mixtures of ores of different metals. Arsenical copper, bronze, and brass, for example, three alloys of copper... 

Under equal environmental conditions, the rate of corrosion of alloys is generally faster than that of their components. The tendency of bronze, an alloy of copper and tin, to corrode is greater than that of its separate (unalloyed) components, copper and tin. Moreover, once a corrosion process sets up in bronze, it also proceeds, under similar conditions, at a faster rate than in either copper or tin. 

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). 

As important as the transition metals are, the fact that they form many important alloys greatly extends the versatility of the metals. In this section, we will briefly describe some of the major factors that are relevant to the behavior of alloys. The study of alloys is a vast area of applied science, so in order to illustrate some of the principles in an efficient way, we will deal primarily with the behavior of alloys of copper and iron. Alloys of some of the nontransition metals (lead, antimony, tin, etc.) will be described in subsequent chapters. Many of the principles that apply in the behavior of a specific metal are involved in the behavior of others. 

Alloys of copper and zinc can be obtained by combining the molten metals. However, zinc is soluble in copper up to only about 40% (of the total). When the content of a copper/zinc alloy contains less than 40% zinc, cooling the liquid mixture results in the formation of a solid solution in which Zn and Cu atoms are uniformly distributed in an fee lattice. When the mixture contains more than 40% zinc, cooling the liquid mixture results in the formation of a compound having the composition CuZn. The solid alloy consists of two phases, one of which is the compound CuZn and the other is a solid solution that contains Cu with approximately 40% Zn dissolved in it. This type of alloy is known as a two-phase alloy, but many alloys contain more than three phases (multiple-phase alloys). 

It must be borne in mind when reviewing the theories of the alchemists, that there were a number of phenomena known at the time, the superficial examination of which would naturally engender a belief that the transmutation of the metals was a common occurrence. For example, the deposition of copper on iron when immersed in a solution of a copper salt e.g., blue vitriol) was naturally concluded to be a transmutation of iron into copper, although, had the alchemists examined the residual liquid, they would have found that the two metals had merely exchanged places and the fact that white and yellow alloys of copper with arsenic and other substances could be produced, pointed to the possibility of transmuting copper into silver and gold. It was also known that if water (and this is tme of distilled water which does not contain solid matter in solution) was boiled for some time in a glass flask, some solid, earthy matter was produced and if water could be transmuted into earth, surely one metal could be... 

Redox reactions are involved in some very important industrial processes, such as iron and steel production. However, the widespread use of metals has occupied a relatively small part of human history. In the Stone Age, humans relied on stone, wood, and bone to make tools and weapons. The Stone Age ended in many parts of the world with the start of the Bronze Age, which was marked by the use of copper and then bronze (an alloy of copper and tin). In the Iron Age, bronze was replaced by the use of iron. The dates of the Bronze Age and the Iron Age vary for different parts of the world. 

A cobalt alloy of copper and tungsten, called stellite, also maintains its hardness at high temperatures, making it an ideal alloy for high-speed drills and cutting tools. 

Many people are fooled when they buy Mexican or German silver jewelry, thinking they are purchasing a semiprecious metal. These forms of silver jewelry go under many names, including Mexican silver, German silver, Afghan silver, Austrian silver, Brazilian silver, Nevada silver, Sonara silver, Tyrol silver, Venetian silver, or just the name silver with quotes around it. None of these jewelry items, under these names or under any other names, contain any silver. These metals are alloys of copper, nickel, and zinc. 

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