ABSTRACT— Aluminum Matrix Composites (AMCs) have been used in several applications in the aerospace and automotive industries. Although several technical challenges exist with casting technology. Achieving a uniform distribution of reinforcement within the matrix is one such challenge, which affects directly the properties and quality of composite. Hence, this work aims to improve the mechanical and corrosive resistance of aluminum by reinforcing with yttrium oxide and nickel through stir casting using the vortex technique. Al-Ni Y2O3 composite with the percentage of Ni fixed at 20 % and Y2O3differed through 3-9% in increments of 3 wt.%. The hardness value of the aluminum matrix composite improved with increased percentages of Y2O3, and the maximum increase was obtained for 9% Y2O3 composite, viewing an increase of about 52%. Potentiostatic polarization test for the Al-20%Ni base alloy and the prepared composite was carried out in 3.5wt% NaCl solution as a corrosive medium. There was a noticeable improvement in the corrosion resistance of the aluminum composite compared to its purest form, owing to the presence of nickel. However, the increase in Y2O3 percentage decreased the corrosion rates. The extreme decrease in corrosion rates was obtained for 6% Y2O3 composite in 3% wt. NaCl solution reaches 5.51 in (mpy) unit for composite material which is lower than that of the base alloy 118.59 (mpy).
CONCLUSIONS Fabricated composites containing 20% Ni and 3, 6, & 9% of Y2O3 particle as reinforcements in the base matrix of pure aluminum using stir casting were optimized. The hardness of the Al 20% Ni matrix composites increased with an increasing percentage of Y2O3; a maximum increase was obtained for 9% Y2O3 composite with an increase of 73%. There was a noticeable decrease in the corrosion rate of the composites compared to pure Al due to the presence of Ni. Further, the increase in Y2O3 percentage decreased the corrosion rate in the 3.5wt%NaCl solution