Cupal
Cupal is a composite material made of aluminum and copper to connect electrical cables made of copper and aluminum. Further applications are cost- and weight-saving parts with the appearance of copper. It is made by cold rolling .
Main application
Aluminum cables are often used to save cost and weight over copper. The electrical conductivity of aluminum in relation to volume is 35 percent lower than that of copper, but in relation to mass it is almost twice as high. In practice this means that a conductor track made of aluminum needs a cross-section approximately one and a half times larger than a conductor track made of copper in order to achieve the same current-carrying capacity. In return, this aluminum conductor track is considerably lighter and cheaper than the thinner copper conductor track.
A disadvantage of aluminum is that it cannot be soldered because of its passivating surface layer and that, for the same reason, a contact resistance arises in screw and clamp connections. A highly conductive connection element can be interposed here with clamps or sleeves made of cupal, whereby aluminum surfaces are pressed onto one another and the copper surface is further connected with the usual electrical connection techniques.
Brand name
The composite material was registered by HYDROSTATIC EXTRUSIONS LIMITED in 2008 under the brand name 'CUPONAL'. Hydrostatic Extrusions LTd. is a subsidiary of BRUKER ADVANCED SUPERCON INC (Bruker EST division).
literature
- A. Ernst, L. Neumann (Ed.), Hans Blücher: Information book for the chemical industry. 18th edition, Walter de Gruyter & Co, Berlin 1954.
- Eckhard Ignatowitz: Materials technology for metal construction professions. 5th edition, Nourney, Vollmer GmbH & Co. KG, Haan-Gruiten 2011, ISBN 978-3-8085-1545-7 .
- Herwarth von Renesse: Materials Guide. 3rd new edition, Verlag W. Girardet, 1943.
Web links
- Copper-aluminum alloys (accessed July 12, 2019)
- Material properties and product forms from CUPONAL (accessed August 2, 2019)