Brass is by alloying copper and zinc. The metal maintains the lustrous appearance of copper, but since zinc is much cheaper than copper, brass is only about one-third the price of copper. This gives the alloy a wide range of uses, most commonly as a decorative material for architecture. Brass sales allow large quantities of brass to be purchased at prices much less than pure copper.
Varied Appearance and Properties
Although a yellowish shiny metal is the standard appearance for brass, this appearance can be altered depending on the exact composition of copper and zinc used. A composition containing more copper will have a reddish color, for example. Most brass styles contain between 55 percent and 95 percent copper. As the amount of zinc in the alloy is increased, the properties of the metal change. Reddish brass made of mostly copper will have the highest grade of corrosion resistance but will be weaker than a more balanced alloy. Zinc primarily adds strength, so an alloy of 40 percent or higher zinc will be more suited to machine parts or load-bearing items.
Other Elements in the Mix
Certain types of brass may contain trace amounts of other materials besides copper and zinc. Lead may be added to improve weight and structure for machined parts. Iron may also be added to improve strength. Muntz metal is a common type of brass alloy composed of 60 percent copper and 40 percent zinc with trace iron. It is one of the most durable forms of brass, combining effective corrosion resistance with strength suitable for use on ships and as bolts in architecture. The inclusion of iron allows brass to be worked by forging. Arsenic may be added to brass alloys with more than 20 percent zinc to fortify the metal’s corrosion resistance.
Versatility Unmatched by Any Other Alloy
Brass can be worked into a variety of shapes such as tubes, square tubes, balls and sheets. The metal is light, durable and corrosion resistant. Different grades of brass can be shaped in different ways. Wrought brass is made by either hot rolling or forging the brass. Cast brass is made by pouring molten brass into molds. The chemical composition of the brass, usually determined by the ratio of copper to zinc and other metals, determines the best way to shape the brass.
Sources:
Brass, MadeHow.com
What is Muntz Metal?, WiseGeek.com
