Some of the most common copper alloys used in forging applications are oxygen free electronic (OFE), naval brass, aluminum bronze, chromium copper, copper nickel and chromium zirconium copper. Forged copper provides an economical alternative to cast, welded and fabricated copper as well as offering a superior density and freedom from flaws.
In addition, copper forgings have non-magnetic properties and non-sparking characteristics that are beneficial to industries such as electronics, automotive, mining, construction, aerospace, defense, material processing, architectural and industrial. Copper forgings offer high strength at low densities.
Copper forgings can be made through different forging processes, depending on the type of copper alloy. The different copper alloys are typically divided into five categories: brass, a copper and zinc alloy; phosphor bronze, an alloy of copper with 3.5 to 10% of tin; aluminum bronze, with aluminum as the main alloying metal added to copper; silicon bronze, usually containing about 96 percent copper; and copper nickel and nickel silvers, with compositions from 10% nickel to 45% nickel.
Copper alloys can be forged using closed die forging. Closed die forging involves the movement of metal blanks through a set of dies shaped in the required part design. Copper alloys can also be forged using open die forging. Open die forging creates parts by the hammering or pressing of the copper alloy by the die into the required shape.
Copper alloys can be cold forged, warm forged or hot forged, depending on the composition of the specific alloy. In cold forging the copper alloy is not directly heated, but formed using high pressure. In hot forging the copper alloy is heated to high temperatures then formed. In warm forging the copper alloy is heated to a range that is above room temperature but below the metal’s re-crystallization temperature.