An experimental and micrographical investigation on aluminum nano metal matrix composites

In the present investigation, a comparative study using X-ray mapping analysis and Field emission gun scanning electron micrographs is performed to understand the distribution and the mechanical properties of aluminum nano metal matrix composites. Parameters considered for comparison have two different forms for adding nanoreinforcement into metal melt. One form is produced by the addition of mechanically alloyed powders with an increasing launching vehicle weight percentage (L-1, L-3 and L-5), and the other form is produced by pellets of mechanically alloyed powders (PL-1). Micrographs reveal uniform distribution of nanoreinforcements, while X-ray mapping observations show Iron (Fe) contamination due to the addition of pellets in some areas unlike the mechanically alloyed powders. L-5 is observed to attain the highest tensile strength of 202 MPa for the Al-Cu/1.5 wt. % Al2O3 composite. The results illustrate an increase in composites strength with increase in launching vehicle content but on the expense of nanoreinforcement particle rejection from the melt.