Fabrication and characteristics of ADC-12 reinforced nano-SiC and nano-Al₂O₃ composites through stir casting route

Aluminum ADC-12 reinforced with nano-SiC and nano-Al₂O₃ have been successfully produced by stir casting method. The effect of addition nano SiC and Al₂O₃ into matrix has been studied with variation of 0.05, 0.10, 0.15, 0.20, 0.30 vf-% for each composites. The addition of Mg was introduced with 10 wt-% to promote wetting between molten Al and ceramic particle reinforcement. The OES result shows decreasing amount of excess Si and Mg in the composite compared to as-cast ADC-12. One of the main intermetallic phases present evenly in aluminum matrix is Mg₂Si which was confirmed by EDS and XRD. The highest tensile strength and hardness of composites were achieved by the addition of 0.15 and 0.30 %vf SiC and Al₂O₃, respectively, with the values of 111 and 115 MPa and 42 and 41 HRB. The increasing hardness generated significant improvement in wear resistance of composites. The higher the reinforcement content, the higher the porosity formed, due to the tendency of dewetting as well as nano particles agglomeration.