Effect of deformation and annealing on elastic properties of copper wires

Abstract

The fundamental requirement of copper destined for enamelled wire production is a relatively low recrystallization temperature. It is well known that impurities raise the recrystallization temperature. Until recently, therefore, there was a tendency to produce purer and purer copper cathodes. The method of rod production and the final deformation of the wire are essential factors influencing its properties, being responsible for the texture of the as-drawn wire, as well as for the recrystallization texture. It was the aim of these studies to correlate the texture formation with the degree of deformation and the recrystallization temperature. Particular attention was given to the measurement of springiness by means of the spiral-elongation and spring-back tests. Based on these laboratory studies, an intermediate annealing method, using the box furnace or strand-resistivity annealing process, was introduced into wire production. It has been shown that through the introduction of the intermediate annealing process, the elastic properties of copper wires for enamelling can be changed.