Influence of a cold deformation process by drawing on the electrical properties of copper wires

Marcolino Fernandes Neto,Rafael Da Silva Bernardo

doi:10.1590/0370-44672015700201

Abstract

This article presents a study of the drawing, deformation, hardening and heat treatment of copper wire, in order to investigate the influence of combinations of operating variables (annealing factor, oil emulsion temperature and machine speed) during the drawing process on the electrical conductivity of copper wires. The results showed that when the metal is deformed, the value of electrical conductivity suffers a decrease due to the hardening phenomenon. Because of this, it is necessary to heat treat the material. So, it was observed that the annealing factor, which is associated with the thermal treatment temperature, showed a high degree of correlation with the electrical conductivity. This fact is explained by the annealing factor which is responsible for the intensity of the heat treatment. The speed at which the drawing occurs also showed a direct correlation with electric conductivity because the higher the value, the greater the heat treatment temperature and consequently, the greater the electrical conductivity of the material. On the other hand, it had not been possible to establish a conclusion about the correlation between the electrical conductivity and oil emulsion temperature during the drawing process.

Highlights

The prediction of copper wire electrical properties through plastic deformation resulting from the drawing process, represents a theme with great potential for the industries that operate in the field of electrical conductors
The annealing factor-AF has a direct connection with the electric current (A) and the voltage (V) of the oven. The higher these values, the greater the heat treatment applied to the wire
Dieter (1988) argues that the modifications that occur in metals during the cold deformation process for drawing, affect the mechanical and electrical properties of the material

Summary

Introduction

The prediction of copper wire electrical properties through plastic deformation resulting from the drawing process, represents a theme with great potential for the industries that operate in the field of electrical conductors. For an effective control of the electrical conductivity of copper wires, it is necessary to develop a study of the main process variables that affect this activity. In this sense, a research of the industrial process must include several factors, such as: drawing analysis with the oil emulsion temperature of the drawing machine at high and low temperatures; the effect of heat treatment temperature on the material; and the material response behavior during the drawing process, occurring at different speeds. The influence of cold deformation process for drawing was analyzed in this study with the objective of investigating the influence of combinations of operating variables (annealing factor – AF, Oil emulsion temperature - OET and machine speed - MS) during the drawing process on the electrical conductivity of copper wires

Methods

Results

Discussion

Conclusion