3 Fundamentals of press design

454 Solid forming (Forging)
Table 6.3.3: Selection of copper materials for cold extrusion
Material group Abbreviation No. DIN US designation / UNS JIS
pure copper E-Cu F20 2.0060 1787 ETP 99,95 C0-0,04O / C11000 OFCu
SF-Cu 2.0090 1787 DHP Copper / C12200 DCu
copper alloys CuZn10 2.0230.10 17660 Commercial copper / C22000 BS( ), RBS ( )
CuZn28 2.0261.10 17660 Cartridge brass 70 % / C26000 RBS ( )
CuZn40 2.0360 17660 Muntz Metal / C28000 RBS ( )
CuNi2Si 2.0855 17666 Silicon bronze / C64700 CN ( ) 1
CuNi12Zn24 2.0730.10 17663 65Ni-12Ag / C75700
CuNi20Fe 2.0878.10 17664 Cu-20Ni / C71000
CuAl11Ni 2.0978 17665 Aluminium bronze / C63200
CuSn2 2.1010 17662 Phosphor bronze / C50500
als are age-hardenable through heat treatment. The most important copper
alloys are the brass family. The formability of the material improves
as the copper content increases and the Zn content decreases. With a Zn
content above 36%, the materials become brittle and their cold formability
decreases rapidly. As a result, hot forming methods should preferably
be used. Flow stress curves for copper alloys are given in the VDI
Guidelines 3134 and 3200.
Other materials such as lead, zinc, tin, titanium or zirconium and
their alloys can also be successfully formed. However, in terms of quantity
and economic significance, these play only a minor role.
6.3.2 Billet or slug preparation
The workpiece materials are specified by the user: Any modifications to
the material, to exploit the benefits offered by cold forming (hardening)
or to simplify the forming process, must be agreed upon with the
die maker and the production engineer. In addition to the workpiece
material itself, the nature of the semi-finished product, its separation to
prepare individual billets, and the heat and surface treatment are all
important points for consideration.
Semi-finished products
Wires, bars and tubes are used as semi-finished products for the production
of billets or slug. Wire is delivered in coil form and generally
Metal Forming Handbook / Schuler (c) Springer-Verlag Berlin Heidelberg 1998