Studies on the characterization of hybrid composites containing two different reinforcements are gaining popularity in recent years due to their improved properties with respect to mechanical behavior and corrosion resistance. Many researchers have carried out the experiments with respect to mechanical behaviour. Where as research works on corrosion characterization of the hybrid metal matrix composite materials are very scarce. This book gives the details of the corrosion studies of the hybrid metal matrix composite materials made up of Alluminium 356 alloy reinforced with fly ash and silicon carbide particulates, Hybrid composite materials are subjected to weight loss, potentiodynamic polarization, stress corrosion test, electrochemical impedance and salt spray tests are conducted in different concentrated solutions of acid, base and salt solutions. Experiments were also conducted in solution mixture containing salt and base. Scanning electron microscopy has been adopted to find out the impact of the reinforcement and corrosion medium on the corrosion behaviour of Alluminium356 alloy.