"All That Glitters Is Not Gold" (*)
Traveling from the Greek term oreikhalkon which literally means mountain of copper, to the Latin term aurichalcum which indicates the copper with the gold colour, brass has gone a long way to be considered as one of the most useful metallic alloys for manufacturing and decorating applications.
The natural alloys that combined copper with zinc have a history that takes us back in the 5th millennia BC, in China, where with no intention the metalworkers produced artefacts from zinc- rich copper ores. Calamine brass (smithsonite ore) made its first appearance in the Roman ages, as documents inform us, due to the use of the cementation process. A type of pure brass was produced, with 15 to 30 zinc concentration, which was eventually used in coinage throughout the Roman Empire. Localised production of brass continued in Europe until the 15th century, when the arrival of silver and gold from the New World turned brass to the use of church monuments and tombs. With the method of speltering, a process that directly alloys metallic zinc with copper, the growing demand of brass met the increasing production in Germany, Netherlands and Sweden. In 1738, William Champion was able to take out a patent for the production of zinc by distillation from calamine and charcoal, along with the improvements that were made to the purity of the alloy, production succeeded in the areas around Birmingham, Bristol, Swansea.
Pins for the wool industry, clocks, buttons, lamps, navigational tools, ammunition cartridges and rifles were some of the products that went into massive production once brass alloy’s unique properties were appreciated. With the invention of 60/40 brass by Muntz in 1832 it became possible to make cheaper workable brass plates.
Harrison’s invention of the marine chronometer in 1761 depended on the use of brass for the manufacture of an accurate timekeeper.
Entering the field of arts, sculptors, architects and interior designers have valued the aesthetic that derives from the use of brass, since there is an impressive range of colours that can be produced, from deep red to bright yellow, depending on the composition of each brass alloy and the proportion of other elements. The musicality of this copper alloy is mostly known through the “Brass Section” [where we took our blog’s name from], indicating the production of a category of instruments which are used in orchestras, concert bands and jazz ensembles, such as French horns, trumpets, tubas.
The Properties of Brass Metal
The exact properties of brass depend on the composition of the alloy, with first to examine the copper- zinc ratio. All brasses, however, are characterised of the ease with which the metal can be formed into the desirable shape, in the same time retaining high sustainability. Brass alloys are malleable, ductile, can be cold worked and welded and have good electrical conductivity, from 23% to 44%, which pure copper has.
• Alloy Type: Binary
• Melting Point: 900-940 °C
• Mohs Hardness: 3-4
• Copper-Zinc Percentage in common Brass: 63- 37 %
• Corrosion Resistant
• Non - Magnetic
(*) Most popular origin of the expression is a William Shakespeare’s line in the play The Merchant of Venice, in a secondary plot of the play where the Puzzle of Portia’s boxes takes place:
"All that glisters is not gold -
Often have you heard that told.
Many a man his life hath sold
But my outside to behold.
Gilded tombs do worms enfold.
Had you been as wise as bold,
Young in limbs, in judgment old,
Your answer had not been inscrolled
Fare you well. Your suit is cold—
Cold, indeed, and labour lost"