High conductivity copper is the best choice for bulk electrical conductors such as cables, motor windings and busbars. There are, however, many electrical accessories – including terminations, connectors, contactors and circuit breakers – where material properties beyond conductivity are equally, or more important. For these applications, a wide range of copper alloys are available, offering, for example, enhanced strength, or resistance to stress relaxation or creep, while retaining excellent conductivity.
The new publication from Copper Development Association gives an overview of high conductivity coppers, their properties and applications.
After a brief introduction, Section 2 covers the mechanical and physical properties of copper, and the effect of impurities and minor alloying additions on copper’s conductivity. It describes the various types of high conductivity copper in existence today, and looks at production methods, with chapters on cathode copper and refinery shapes.
Section 3 describes the wide variety of alloying elements that can expand copper’s inherent properties – adding higher tensile strength, increased softening temperature, lower creep, better wear resistance or easier machinability – to suit different applications. The copper alloys discussed are divided into heat-treatable and non-heat-treatable.
The development of more advanced microchips has required the production of copper alloys as lead frame materials, with properties that provide long, reliable life at elevated temperatures. This is the focus of Section 4. It describes copper alloys for semiconductor lead frames, and also discusses oxidation and corrosion.
‘We developed this publication after identifying a strong need for copper users to understand metallurgical properties and processing requirements of copper-based conductivity materials,’ says Angela Vessey, Copper Development Association’s Director. ‘It covers a wealth of information in a well-structured and easily readable format, and we hope it will evolve into a ‘go to’ reference book on this topic for electrical engineers.’
High Conductivity Copper for Electrical Engineering can be downloaded in full from Copper Development Association’s resource library: www.copperalliance.org.uk/hcc