High Conductivity Copper for Electrical Engineering (CDA Publication 122)

About this Publication

This publication describes the electrical and mechanical properties of high conductivity copper and copper alloys that are intended for use in electrical applications.

It is primarily aimed at electrical engineers rather than metallurgists, but gives the basic metallurgical detail needed to understand the processing requirements of alloys.

High conductivity copper is the best choice for bulk electrical conductors, such as cables, motor windings and busbars, but there are many electrical accessories, such as terminations, connectors, contactors and circuit breakers, where other material properties are equally or more important. For these applications, there is a very wide range of copper alloys available with, for example, enhanced strength, resistance to stress relaxation or creep, while retaining excellent conductivity.

Links to individual sections in the publication are available by clicking on each section below. The entire book can also be downloaded as a pdf.

Whilst this publication has been prepared with care, we can give no warranty regarding the contents and shall not be liable for any direct, incidental or consequential damage arising out of its use. For complete information on any material the appropriate standard should be consulted.


Section 1 Introduction
Section 2 High Conductivity Copper
2.1 Effect of Impurities and Minor Alloying Additions on Conductivity
2.1.1 Oxygen Content
2.2 Mechanical Properties
2.2.1 Cold Working
2.2.2 Annealing
2.2.3 Stress Relieving
2.2.4 Tensile Strength
2.2.5 Proof Strength
2.2.6 Hardness
2.2.7 Resistance to Softening
2.2.8 Creep Resistance
2.2.9 Fatigue Resistance
2.3 Physical Properties
2.4 Production of High Conductivity Copper
2.4.1 Cathode Copper
2.4.2 Refinery Shapes
2.5 Types of High Conductivity Copper
2.5.1 High Conductivity Copper Grades (Non-Alloyed)
2.5.2 Low-Alloyed High Conductivity Copper Alloys
Section 3 Copper Alloys
3.1 Types of Alloys
3.1.1 Non Heat-treatable Alloys
3.1.2 Heat-treatable Alloys
3.2 Common Non Heat-treatable Alloys
3.2.1 High Conductivity Copper Alloys
3.2.2 Free-machining Coppers
3.3 Common Heat-treatable Alloys
3.3.1 Copper-beryllium Alloys
3.3.2 Copper-chromium
3.3.3 Copper-chromium-zirconium
3.3.4 Copper-chromium-magnesium
3.3.5 Copper-zirconium
3.3.6 Copper-nickel Alloys
3.3.7 Copper-nickel-silicon
3.3.8 Copper-nickel-phosphorus
3.3.9 Copper-nickel-tin
Section 4 Appendix
4.1 Copper Alloys for Semiconductor Lead Frames
4.2 Oxidation and Corrosion
4.2.1 The Oxidation Laws
4.2.2 Galvanic CorrosionTables
Table 1  Properties of 100% IACS Copper at 20°C
Table 2  Implied Properties of 100% IACS Copper at 20°C
Table 3  Typical Hardness Values for a Range of Tempers
Table 4  Comparison of Creep Properties of High Conductivity Copper and Aluminium
Table 5  Comparison of Fatigue Properties of High Conductivity Copper and Aluminium
Table 6  Properties of Cu-ETP (CW004A)
Table 7  Unwrought and Wrought High Conductivity Coppers – Designations and Applications
Table 8  Unwrought and Wrought Coppers – Compositions and Properties
Table 9  Wrought Low Alloyed Copper Alloys – Composition and Typical Properties
Table 10  Copper Alloys for Semiconductor Lead FramesFigures
Figure 1  Effect of various elements (impurities or intentional additions) on the conductivity of copper
Figure 2  Effect of various elements (impurities or intentional additions) on the conductivity of oxygen-free copper (Cu-OF)
Figure 3  Effect of various elements (impurities or intentional additions) on the conductivity of ETP copper (Cu-ETP)
Figure 4  Effect of cold rolling on mechanical properties and hardness of high conductivity copper strips
Figure 5  Typical effect of the extent of previous cold work on the annealing behaviour of Cu-ETP
Figure 6  Typical effect of annealing temperature on annealing behaviour of Cu-ETP
Figure 7  Annealing behaviour of four high conductivity coppers
Figure 8  Relationship between time and reciprocal absolute annealing temperature to produce 50% softening of cold-worked Cu-ETP and CuAg0,08
Figure 9  Typical creep properties of commercially pure copper and aluminium
Figure 10  The oxidation rate laws
Figure 11  Effect of temperature on oxidation of copper
Figure 12  Corrosion susceptibility of metals