Copper alloys

On an upcaster, Lamifil produces a series of copper alloys that are mainly used in overhead electrification lines of railway tracks, from light rail up to high speed rail.
Other uses are in special fine wire for aerospace and electronics, where high strength and good conductivity have to be combined with excellent flexlife.

CuMg
Copper magnesium was developed as an environmental friendly alternative to copper cadmium. The wave on the contact wire caused by the pantograph needs to propagate at a higher speed than the speed of the train. Therefore the contact wire on high speed lines should be installed under sufficiently high tensions. CuMg can resist these tensions. As high speed lines are supplied by AC systems at higher voltages than conventional lines, the lower current carrying capacity is not a big issue. CuMg can be used for speeds well above 300km/h.

CuCd
For certain applications copper cadmiumis still required because of its superior characteristics. CuCd combines high strength with good conductivity. The alloy has unsurpassed flex life, it is therefore still used for certain, critical applications or where it can’t become a threat to the environment.

CuSn
Where the strength of CuMg is not required, copper tin may be an alternative. It can be used as an alternative to CuMg on high speed lines supplied by AC power. CuSn is relatively easy to install and has a good conductivity.

Cu - CuAg
On DC systems conductivity is of prime importance. Electrolytic copper and copper silver contact wires are widely used. CuAg has virtually the same electrical and mechanical characteristics as ETP copper. The benefit is a better thermal stability, which is due to the higher recrystalisation temperature. This allows higher overcurrents without increasing the wear on the contact wire.

Conductivity vs. Tensile strength
Depending on whether strength or electrical conductivity is the most important, the appropriate alloy will be chosen. This choice will reflect mechanical design parameters of the catenary system and the electrical power supply. It is up to the system designer to select the right alloy taking into account factors such as speed, traffic frequency, required lifetime, maintenance and power supply.

As you may expect from Lamifil, we continue to innovate and expand our product lines. That is why we are focusing our research both on new copper alloys and on optimisation of their characteristics.