EXPERIMENTAL INVESTIGATION OF ELECTROMAGNETIC BEHAVIOR OF ALUMINA REINFORCED COPPER MATRIX COMPOSITES

Abstract

Copper is the third highest used metal in the industry because of its excellent electrical conductivity (100% IACS) with relatively high hardness at room temperature. However, the continuous degradation of mechanical performance of pure copper with increasing temperature eventually limits its use for electronic construction, especially for high temperature applications. Moreover, due to the conventional theoretical assumption of electromagnetic properties of metallic copper, scientists hardly made attempts to reveal the potential applicability of copper for next generation technology. In this research, attempts have been made to overcome the high temperature degradation of pure copper using trace addition of nano-crystalline Al2O3 particle as well as to evaluate the corresponding electromagnetic performance of copper. 99.99% pure copper was subjected to reinforcement using 0.5%, 1%, 2% and 5% white Al2O3 particles through conventional sand stir casting technique. The little percentage of Al2O3 made significant impact on the mechanical and electromagnetic properties of copper, especially when subjected to thermal treatments. The microhardness of Cu-Al2O3 composite increased with the increase of annealing temperature up to 6000C according to Hall Petch theory. The electrical conductivity was found to be very close to that of copper observed at room-temperature condition. The diamagnetic behavior of copper was transformed to paramagnetic behavior with the trace addition of Al2O3 particles, which was further influenced significantly by the thermal treatments. Dielectric behavior of pure copper was also investigated and the result of which were justified using Jonscher’s theory of colossal permittivity. The present investigation suggested that the proper selection of composition and appropriate post thermal treatment can improve the mechanical as well as electromagnetic property of Cu-Al2O3 composite, thereby revealing the potential applicability of copper for future high-temperature/power applications.