Development and Characterization of Carbon Nanotube Reinforced Aluminium-6061 Metal Matrix Composites

Abstract

An emerging class of new materials is being developed with carbon nanotubes as reinforcements for Al6061 matrix material resulting in CNT-MMC composite materials. To maximize tensile strength and electrical conductivity properties of CNT materials and for the MMCs to possess optimal properties, some synthetic techniques are developed. Care is taken to ensure that these techniques are economical in production, provide uniform reinforcement dispersion in the matrix and also realize strong coherence adhesion of the CNT reinforcements and Al-6061 matrix material. Aluminum reinforced with CNT via powder metallurgy (PM) technique can provide a very distinct advantage. The primary drive and distinct advantage in adopting aluminum is lightweight in comparison to metal and wood composites. Besides weight savings, non-corrosive, flexible, resistance to dent, low on maintenance cost and design flexibility are the highlights of aluminum. Aluminum has wide range of application in industries because of their low density, good workability and relatively low yield strength; whereas reinforcement adds rigidity and impedes crack propagation to a great extent. Thin fibers are used as reinforcement since they possess very high strength with improved overall properties, whereas CNT has a number of invaluable and unique properties in comparison to other fibers used as reinforcement. Due to the reinforcement of CNT in aluminum, the resultant composite possesses high strength to weight ratio. In this work, the CNTs used as reinforcement with varying weight % of 1, 1.5, 2 and Al6061 alloy as a matrix material. The composites were fabricated through powder metallurgy route. Ball milling was done to get homogeneous dispersion of CNT’s. Samples were prepared as per ASTM standards for various compositions and investigated for microstructure using scanning Electron microscopy (SEM). The mechanical properties like hardness were evaluated by Micro Vickers hardness tester and compression strength by Universal Testing Machine. The expected improvements in micro hardness and compressive strength of the MMC s were achieved.