Development of nanoclay reinforced aluminium metal matrix composites for enhanced mechanical and tribological properties

Abstract

Nano-metal-matrix composites (NMCs) are novel composite materials in which nano-phase such as nano-particles, nano-rods, nano-structured materials are reinforced with metals or alloys to improve the physical, mechanical, wear and other properties. The nano reinforcements phases like nano-SiC, nano-alumina, nano-TiC, etc. are well known for present day reinforcement. The results of previous works have shown that the addition of nanoclay reinforcement to aluminium alloys has improved the hardness, tensile strength and Young s modulus, and also the nanoclay gave positive results when used as reinforcement for polymer composites. Hence, the present work is focused on development and characterisation of nanoclay reinforced NMCs. In the present research work, Al6061 alloy has been chosen and used as the matrix material and nanoclay as the reinforcement. Evaluating the effect of the reinforcement on the various important physical properties (such as coefficient of thermal expansion and damping properties), mechanical properties, wear properties, corrosion properties, ageing characteristics and machinability studies were carried out. All the properties have been evaluated and compared with the matrix alloy. Four different weight percentage of nanoclay particulate viz 5, 10, 15 and 20 % and three different sizes (30nm, 50nm and 70nm) have been tried. The composites were fabricated by liquid melt metallurgical technique. newlineMathematical modelling on the elastic modulus of the NMCs were predicted using Eshelby s model using two reinforcement phases such as spherical and cylindrical newlinevi newlineshapes models. The experimental result of this study lies between these two phases which indicated that reinforced particles are of irregular shape but within the range. The Young s modulus enhancement is associated with the particles content. As nanoclay particle content was increased from 0 to 20 % in steps of 5% by weight, an improvement in Young s modulus of 20 % was observed. Comparing the steady-state values with the predications of the Esh