Synthesis and characterization of CNT-TiO2 reinforced copper matrix composites

Abstract

Copper matrix composites have become popular in the past few decades due to their excellent mechanical and thermo-physical properties. In this work, synthesis and characterization of Cu matrix based hybrid composites reinforced with carbon nano tube (CNT) and TiO2 is presented. CNT and TiO2 have been chosen as reinforcement phases due to their different natures as TiO2 is extremely hard and CNT has entirely different set of properties that it imparts to the composite. CNT has gained popularity due to its capability to impart extraordinary properties to the metal matrix composites (MMCs) as reinforcements like strength, endurance, thermal conductivity and wear resistance etc. CNTs have high electrical and thermal conductivity, high tensile strength, good flexibility, favourable aspect ratio and low coefficient of thermal expansion. The aim of this paper is to bring to the fore the effect of addition of CNT and TiO2 to the pure copper matrix. The characterization includes scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS), compression behaviour, hardness, thermal conductivity and specific heat. The compressive strength of the composite containing 4 wt% of both reinforcements was found to be nearly-seven times of that of pure copper. The hardness of pure copper was found to be 157 BHN while that of the composite specimen containing 4 wt% of both the reinforcements was found to be 563 BHN. Specific heat of the composite specimens is found to be marginally more than that of pure Cu. A reduction of 2.33% in the thermal conductivity of the composite specimen with lowest concentration of reinforcements was observed as compared to pure copper. It is expected that the material will be suitable for heat exchanger applications at lower concentration of reinforcements.