Effect of Al_2O_3 Nano-Particles on Mechanical Properties of Al-5%Zn-3%Mg Alloy

摘要

Aluminium (Al) and its alloys possess wide range of properties and are generally used in engineering structures. Selecting the right alloy for a given application entails considerations of its tensile strength, density, ductility, formability, workability, weldability and corrosion resistance. Aluminium matrix composites with Al_2O_3 reinforcements give superior mechanical and physical properties. Their applications in several demanding fields like automobile, aerospace, defence, sports, electronics, bio-medical and other industrial purposes are becoming essential for the last several decades. Various alloying elements are added to Al to enhance their mechanical properties. Magnesium (Mg) is added to Al to increase its strength and hardness. The addition of Zn improves strength, fluidity and castability. The current work emphasises on the improvement of mechanical properties of Al-5%Zn-3%Mg alloy by heat treatment and by addition of non-aluminium oxide (Al_2O_3) particles. The heat treatment improved hardness, wear resistance and compressive strength of the alloy. Al_2O_3 nano-particles are prepared by co-precipitation method and these are added to the alloy by stir-casting method. SEM is used for determining the size and shape of the nano-particles. The addition of nano-particles showed better properties when compared to the base alloy and heat-treated alloy.