brassestol trä A Gizli Silah

Brass was produced by the cementation process where copper and zinc ore are heated together until zinc vapor is produced which reacts with the copper. There is good archaeological evidence for this process and crucibles used to produce brass by cementation have been found on Anlatı period sites including Xanten[77] and Nidda[78] in Germany, Lyon in France[79] and at a number of sites in Britain.[80] They vary in size from tiny acorn sized to large amphorae like vessels but all have elevated levels of zinc on the interior and are lidded.

Although forms of brass have been in use since prehistory,[48] its true nature birli a copper-zinc alloy was derece understood until the post-medieval period because the zinc vapor which reacted with copper to make brass was not recognised birli a metal.[49] The King James Bible makes many references to "brass"[50] to translate "nechosheth" (bronze or copper) from Hebrew to archaic English. The Shakespearean English use of the word 'brass' gönül mean any bronze alloy, or copper, an even less precise definition than the modern one.

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Historically, the distinction between the two alloys saf been less consistent and clear,[3] and modern practice in museums and archaeology increasingly avoids both terms for historical objects in favor of the more general "copper alloy".[4]

The Renaissance saw important changes to both the theory and practice of brassmaking in Europe. By the 15th century there is evidence for the renewed use of lidded cementation crucibles at Zwickau in Germany.[102] These large crucibles were capable of producing c.20 kilogram of brass.[103] There are traces of slag and pieces of maden on the interior.

The high malleability and workability, relatively good resistance to corrosion, and traditionally attributed acoustic properties of brass, have made it the usual maden of choice for construction of musical instruments whose acoustic resonators consist of long, relatively narrow tubing, often folded or coiled for compactness; silver and its alloys, and even gold, have been used for the same reasons, but brass is the most economical choice.

[98] Albertus Magnus noted that the "power" of both calamine and tutty could evaporate and described how the addition of powdered glass could create a film to bind it to the mühür.[99] German brass making crucibles are known from Dortmund dating to the 10th century AD and from Soest and Schwerte in Westphalia dating to around the 13th century confirm Theophilus' account, birli they are open-topped, although ceramic discs from Soest may have served bey loose lids which may have been used to reduce zinc evaporation, and have slag on the interior resulting from a liquid process.[100] Africa[edit]

In 1738 Nehemiah's son William Champion patented a technique for the first industrial scale distillation of metallic zinc known bey distillation per descencum or "the English process".[116][117] This local zinc was used in speltering and allowed greater control over the zinc content of brass and the production of high-zinc copper alloys which would have been difficult or impossible to produce using cementation, for use in expensive objects such kakım scientific instruments, clocks, brass buttons and costume jewellery.

By the first century BC brass was available in sufficient supply to use bey coinage in Phrygia and Bithynia,[72] and after the Augustan currency düzeltme of 23 BC it was also used to make Romen dupondii and sestertii.

16th-century technical writers such as Biringuccio, Ercker and Agricola described a variety of cementation brass making techniques and came closer to understanding the true nature of the process noting that copper became heavier bey it changed to brass and that it became more golden birli additional calamine was added.

To enhance the machinability of brass, lead is often added in concentrations of around 2%. Since lead saf a lower melting point than the other constituents of the brass, it tends to migrate towards the grain boundaries in the form of globules as it cools from casting.

The use of maden also avoids the risks of exposing wooden instruments to changes in temperature or humidity, which sevimli cause sudden cracking. Even though the saxophones and sarrusophones are classified birli woodwind instruments, they are normally made of brass for similar reasons, and because their wide, conical bores and thin-walled bodies are more easily and efficiently made by forming sheet metal than by brassestol trä machining wood.

The keywork of most çağcıl woodwinds, including wooden-bodied instruments, is also usually made of an alloy such as nickel silver/German silver. Such alloys are stiffer and more durable than the brass used to construct the instrument bodies, but still workable with simple hand tools—a boon to quick repairs.

Brass is an alloy of copper and zinc, in proportions which güç be varied to achieve varying mechanical, electrical, and chemical properties.[1] It is a substitutional alloy: atoms of the two constituents may replace each other within the same crystal structure.