High temperature characteristics of Al2024/SiC metal matrix composite fabricated by friction stir processing

In the present study, friction stir processing (FSP) is used for the synthesis of an aluminum metal matrix composite (MMC) reinforced by SiC particles. MMC specimens with reinforced microstructures exhibited significant improvement in hardness (near 50%). Isothermal uniaxial tensile tests were employed for the as-received, friction stir processed and composite microstructures at ambient and high temperatures under strain rates ranging from 10(-2) to 10(-4) s(-1) to investigate the effect of deformation rate on the mechanical behavior. At ambient temperature, notable improvement of the yield strength was observed reaching about 240% of the as-received samples while the ductility was reduced near to 4%. Elevated temperature flow curves were perceptibly sensitive to strain rate, especially for FSPed and MMC samples. Fracture surface observations hinted at the distribution of second phase particles along with possible damage mechanisms.