Brass Alloys - Wrought Alloys (C20500 to C29800)

Topics Covered

Introduction

Brass is an alloy mainly consisting of copper and zinc. Different brass alloys with distinct properties can be formed by varying the amount of zinc from 5 to 45%. Alpha brasses and alpha-beta/duplex alloys are the two major types of brasses. Brasses containing zinc of less than 35% and one solid solution are known as alpha brasses. These brasses are malleable at room temperature and suitable for cold working. Brasses containing more than 35% of zinc are known as alpha-beta/duplex alloys, which are best suited for hot working.

Brass alloys are easy to shape and available in various colors, and hence they are preferred for applications which require aesthetic appeal.

Special brasses are the series of zinc-copper-nickel alloys with 10-20% nickel. They are silver in color and have similar anti-corrosion properties as that of brasses. But the special alloys with high nickel content have excellent resistance to tarnishing and cracking due to stress corrosion. They are used in jewelry, ball point refills, fishing rods, bagpipes, test probes, model making, musical instruments such as flutes and decorative applications.

Properties

The following are the properties of brass alloys:

• Excellent machinability
• Medium strength
• Excellent corrosion resistance
• Good electrical and thermal conductivity
• Bacteriostatic function
• Recyclability of brass scrap

Composition

The composition of brass alloys is outlined in the following table.

¹Cu + sum of named elements, 99.8% min.
²Cu + sum of named elements, 99.7% min.
³Cu + sum of named elements, 99.5% min.
⁴Cu + sum of named elements, 99.3% min.
⁵Cu + sum of named elememts, 99.1% min.