Improving the strength to weight ratio is a target aimed by many researchers. Metal Matrix Nano Composites (MMNC) have recently emerged as a new generation of composites, where the addition of nano-sized particles leads to an increase in the strength not according to conventional Metal Matrix Composites rules. Aluminium matrix composites reinforced with nano-sized Al2O3particles are widely used for high performance applications such as automotive, aerospace and electricity industries. In thiswork a numberof cast specimens made from hypoeutectic aluminium silicon alloy (A356) were cast with and without alumina (Al2O3) nanoparticles at different pouring temperatures with stirring during the addition of nano-reinforcement. The microstructure of the new castings was studied using optical microscopy and scanning electron microscopic techniques. Also, the tensile strength, hardness and ductility were evaluated. The significant factors for the tensile strength were analysed usingL4 orthogonal array and Analysis of Variance (ANOVA) techniques then building a model by Response Surface Methodology(RSM). The results obtained in this work show that adding alumina nanoparticles and pouring at different temperatures lead to an increase in the tensile strength and the hardness with less change in ductility
Key words: Nano-dispersion; MMNC; hypoeutectic; alumina; ANOVA; L4; RSM
|
