Development of Aluminium-Nanoclay Composite by Using Powder Metallurgy and Hot Extrusion Process

Abstract

It is well-known that Al matrix nanocomposites are always more expensive compared to conventional materials. In this study, the Al matrix composite containing montmorillonite Nanoclay reinforcement has been synthesized, which is cheaper and more abundant than other reinforcements. Powder metallurgy and extrusion process were employed for the production of the nanocomposite samples containing 0%, 1%, 2%, 6%, and 10% Nanoclay. Microstructural evaluations were carried out by using optical and scanning electron microscopy. Phase investigation was done by using X-ray diffraction and energy-dispersive X-ray spectrometer methods. Mechanical evaluations including macro- and micro-hardness, density evaluation, tensile and compression tests were also conducted. It was revealed that aluminium-clay nanocomposite properties were higher than the monolithic type. According to the obtained results, the addition of montmorillonite Nanoclay caused improvement of the mechanical properties, due to the mechanisms like Orowan and thermal expansion mismatch between reinforcement and the matrix. Thus, the ultimate tensile strengths of 1%, 2%, 6%, and 10% Nanoclay samples were increased about 31%, 46%, 62%, and 95%, respectively, than 0% Nanoclay specimen. The sample containing 2% Nanoclay represented the optimum properties which were the increase in hardness, tensile and compressive strengths about 63%, 46% and 53%, respectively. The increase in the Nanoclay content of the Al matrix changed the complete ductile fracture mode to the shear ductile type.