The Effect of Weight Fraction of Reinforcement Particles on Mechanical Properties of Al 6061-nano Al2O3 Composites prepared by Compo-casting

Aluminum and its alloys have an ever growing demand in many industries such as aerospace, automotive due to their high strength to weight ratio and corrosion resistance. In this research, in order to improve the wettability and distribution of nano-sized Al2O3particles within the matrix with low agglomeration and to achieve the good mechanical properties, injection of the milled nano- Al2O3/Al composite powder within the molten and mechanical stirring was used. Different mass fractions of nano alumina particles up to 0/3, 0/5, 0/7 and 0/9 wt% were injected into the melt under stirring. The microstructure and mechanical properties of the fabricated nanocomposites were studied. The density measurements showed that the porosity in the composites increased with increasing the mass fraction of Al2O3 Hardness, yield and ultimate tensile strengths of the composites increased with increasing Al2O3 particles up to 0/5 wt% The increase in mechanical properties can be explained by more uniform distribution of Al2O3 in the matrix, and grain refinement. The further addition of Al2O3 particles (>0/5%) particle agglomeration and porosity were the two important factors for decreasing strength and ductility.